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Sample records for hydrogen bromides

  1. Advanced hydrogen electrode for hydrogen-bromide battery

    NASA Technical Reports Server (NTRS)

    Kosek, Jack A.; Laconti, Anthony B.

    1987-01-01

    Binary platinum alloys are being developed as hydrogen electrocatalysts for use in a hydrogen bromide battery system. These alloys were varied in terms of alloy component mole ratio and heat treatment temperature. Electrocatalyst evaluation, performed in the absence and presence of bromide ion, includes floating half cell polarization studies, electrochemical surface area measurements, X ray diffraction analysis, scanning electron microscopy analysis and corrosion measurements. Results obtained to date indicate a platinum rich alloy has the best tolerance to bromide ion poisoning.

  2. Advanced hydrogen electrode for hydrogen-bromide battery

    NASA Astrophysics Data System (ADS)

    Kosek, Jack A.; Laconti, Anthony B.

    1987-09-01

    Binary platinum alloys are being developed as hydrogen electrocatalysts for use in a hydrogen bromide battery system. These alloys were varied in terms of alloy component mole ratio and heat treatment temperature. Electrocatalyst evaluation, performed in the absence and presence of bromide ion, includes floating half cell polarization studies, electrochemical surface area measurements, X ray diffraction analysis, scanning electron microscopy analysis and corrosion measurements. Results obtained to date indicate a platinum rich alloy has the best tolerance to bromide ion poisoning.

  3. Unveiling Residual Molecular Binding in Triply Charged Hydrogen Bromide

    SciTech Connect

    Penent, F.; Lablanquie, P.; Palaudoux, J.; Gamblin, G.; Carniato, S.; Andric, L.; Hikosaka, Y.; Ito, K.

    2011-03-11

    We present an experimental and theoretical study of triply charged hydrogen bromide ions formed by photoionization of the inner 3d shell of Br. The experimental results, obtained by detecting the 3d photoelectron in coincidence with the two subsequent Auger electrons, are analyzed using calculated potential energy curves of HBr{sup 3+}. The competition between the short-range chemical binding potential and the Coulomb repulsion in the dissociative process is shown. Two different mechanisms are observed for double Auger decay: one, a direct process with simultaneous ejection of two Auger electrons to final HBr{sup 3+} ionic states and the other, a cascade process involving double Auger decay characterized by the autoionization of Br*{sup +} ion subsequent to the HBr{sup 2+} fragmentation.

  4. Study on the purification of hydrogen bromide gas by fractional distillation technique and its effect on improvement of copper-hydrogen bromide laser performance

    NASA Astrophysics Data System (ADS)

    Biswal, Ramakanta; Agrawal, Praveen Kumar; Dixit, Sudhir K.; Nakhe, Shankar V.

    2012-11-01

    This paper presents a purification process of hydrogen bromide (HBr) gas by fractional distillation technique and its use for performance enhancement of copper-HBr laser (Cu-HBrL). The residual impurities in HBr were suppressed by a two-step distillation process at temperatures of -196°C and -20°C. The lowering of the impurities was confirmed by comparing the mass spectrograph of the HBr gas before and after distillation, using a quadrupole mass spectrometer. The effect of the purified HBr gas on the performance of Cu-HBrL average output power as well its electrical discharge characteristics were studied. More than 37% improvement in the laser average output power (40 to 55 W) was observed with the use of this distilled HBr gas compared to undistilled gas. The underlying mechanism of the enhancement was analyzed by comparing electrical discharge characteristics in the two cases. The improvement in Cu-HBrL performance with distilled HBr gas was attributed to lowering of bromine and hydrogen concentration, mainly manifested as increased average electrical energy coupling to the discharge. This resulted in increased laser gain as well as gain volume, which were reflected in increases in laser output power and beam diameter.

  5. Recovery of bromine from waste gas-phase hydrogen bromide streams using an electrolytic membrane

    SciTech Connect

    Wauters, C.N; Winnick, J.

    1996-09-01

    An electrochemical cell is used to demonstrate a significant improvement in the recovery of bromine (Br{sub 2}) from waste gas-phase hydrogen bromide (HBr) streams. The continuous process operates at 300 C and utilizes reticulated vitreous carbon gas-diffusion electrodes, a molten (Li{sub 0.575}K{sub 0.133}Cs{sub 0.292})Br electrolyte, and borosilicate glass fiber membrane. HBr is simultaneously electrolytically decomposed and separated into a hydrogen enriched waste stream and pure anhydrous Br{sub 2} product stream. Simulated industrial waste streams containing HBr, nitrogen, water vapor, and organic compounds have been tested. These results include removals of greater than 90% and current densities approaching 1.0 A/cm{sup 2}.

  6. Solubilities of bromide salts of aluminum, cobalt, lead, manganese, potassium, and sodium when sparged with hydrogen bromide

    SciTech Connect

    Noble, E.G.; Shanks, D.E.

    1988-01-01

    The effects of HBr concentration and temperature on the solubility and hydration state of AlBr/sub 3/, CoBr/sub 2/, PbBr/sub 2/, MnBr/sub 2/, KBr, and NaBr were investigated by the Bureau of Mines. Saturated aqueous solutions of the Al, Pb, K, and Na bromides were sparged with HBr gas at 20/sup 0/, 40/sup 0/, and 60/sup 0/C, and saturated solutions of Co and Mn bromides were sparged at 20/sup 0/C. Increased HBr concentration caused decreased salt solubility because of the common ion effect for all the investigated bromides except PbBr/sub 2/. Aqueous solubilities at 20/sup 0/C were, in percent, 51.7 for AlBr/sub 3/, 53.2 for CoBr/sub 2/, 1.1 for PbBr/sub 2/, 59.6 for MnBr/sub 2/, 39.5 for KBr, and 47.4 for Na Br. At 60/sup 0/C,the solubilities were, in percent, 53.3 for AlBr/sub 3/, 2.2 for PbBr/sub 2/, 46.0 for KBr, and 53.8 for NaBr. Solubilities in solutions sparged to HBr saturation at 20/sup 0/C were, in percent, 0.5 for AlBr/sub 3/, 42.0 for CoBr/sub 2/, 32.2 for Br/sub 2/, 21.0 for MnBr/sub 2/, 0.6 for KBr, and 0.3 for NaBr. At 60/sup 0/C, the solubilities at HBr saturation were, in percent, 1.8 for AlBr/sub 3/, 41.4 for PbBr/sub 2/, 1.3 for KBr, and 0.4 for NaBr. CoBr/sub 2/ precipitated out to a minimum solubility of 27.2 pct at 28.7-pct-HBr concentration. Further increases in HBr concentration increased CoBr/sub 2/ solubility because of the formation of bromide complexes. PbBr/sub 2/ increased in solubility as HBr concentration increased.

  7. Hydrogen bonding. Part 21. Infrared spectral study of the high-temperature phases of choline bromide and choline iodide

    NASA Astrophysics Data System (ADS)

    Harmon, Kenneth M.; Avci, Günself F.; Thiel, Anne C.

    1986-06-01

    Infrared spectra have been obtained for the high-temperature phase of choline bromide, and for the three high-temperature phases of choline iodide, and the results correlated with our previous studies on choline chloride. All eight known phases of the choline halides contain OH⋯X hydrogen bonds. β-Choline chloride, β-choline bromide, and δ- choline iodide appear to have identical environments; thus, when secondary interionic interactions are overcome by elevated temperatures, a face-centered cubic crystal habit is preferred for all three halides.

  8. Production of hydrogen bromide by bromine-methane reactions at elevated temperature.

    SciTech Connect

    Bradshaw, Robert W.; Larson, Richard S.

    2003-05-01

    Hydrogen bromide is a potentially useful intermediate for hydrogen production by electrolysis because it has a low cell potential and is extremely soluble in water. Processes have been proposed to exploit these properties, but among the important issues to be resolved is the efficiency of HBr production from hydrocarbon precursors. This investigation evaluated a fundamental facet of such a technology by studying the reaction of methane and bromine at elevated temperature to determine the yield and kinetics of HBr formation. Laboratory experimentation and computational chemistry were combined to provide a description of this reaction for possible application to reactor design at a larger scale. Experimental studies with a tubular flow reactor were used to survey a range of reactant ratios and reactor residence times at temperatures between 500 C and 800 C. At temperatures near 800 C with excess methane, conversions of bromine to HBr exceeded 90% and reaction products included solid carbon (soot) in stoichiometric amounts. At lower temperatures, HBr conversion was significantly reduced, the products included much less soot, and the formation of bromocarbon compounds was indicated qualitatively. Calculations of chemical equilibrium behavior and reaction kinetics for the experimental conditions were performed using the Sandia CHEMKIN package. An elementary multistep mechanism for the gas-phase chemistry was used together with a surface mechanism that assumed facile deposition of radical species at the reactor walls. Simulations with the laminar-flow boundary-layer code of the CHEMKIN package gave reasonable agreement with experimental data.

  9. Influence of chloride on modification of unsaturated phosphatidylcholines by the myeloperoxidase/hydrogen peroxide/bromide system.

    PubMed

    Panasenko, Oleg M; Vakhrusheva, Tatyana; Tretyakov, Vadim; Spalteholz, Holger; Arnhold, Juergen

    2007-01-01

    The leukocyte enzyme myeloperoxidase (MPO) is capable of catalyzing the oxidation of chloride and bromide ions, at physiological concentrations of these substrates, by hydrogen peroxide, generating hypochlorous acid (HOCl) and hypobromous acid (HOBr), respectively. Our previous results showed that the hypohalous acids formed react with double bonds in phosphatidylcholines (PCs) to produce chloro- and bromohydrins. Lysophosphatidylcholine (lyso-PC) is additionally formed in PCs with two or more double bonds. This study was conducted to determine the effect physiological chloride concentration (140 mM) has on the formation of bromohydrins and lyso-PC from unsaturated PC upon treatment with the myeloperoxidase/hydrogen peroxide/bromide (MPO/H2O2/Br-) system using physiological bromide concentrations (20-100 microM). The composition of reaction products was analyzed by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS). With monounsaturated PC, we demonstrated that the rate and extent of mono-bromohydrin formation were higher in the samples with 140 mM chloride compared to those with no added chloride. Moreover, mono-bromohydrin came to be the major product and no mono-chlorohydrin was observed already at 60 microM bromide. We attributed these effects to the involvement of HOBr arising from the reaction of MPO-derived HOCl with bromide rather than to the exchange of bromide with chlorine atoms of chlorohydrins or direct formation of HOBr by MPO. The presence of chloride shifted the pH optimum for mono-bromohydrin formation (pH 5.0) toward neutral values, and a significant yield of mono-bromohydrin was detected at physiological pH values (7.0-7.4). For polyunsaturated PC, chloride enhanced also lyso-PC production, the effect being pronounced at bromide concentrations below 40 microM. The results indicate that at physiological levels of chloride and bromide, chloride promotes MPO-mediated formation of bromohydrins and lyso

  10. Homogeneous catalysis on the gas-phase dehydration reaction of tertiary alcohols by hydrogen bromide. Density functional theory calculation

    NASA Astrophysics Data System (ADS)

    Maldonado, Alexis; Rosas, Felix; Mora, Jose R.; Brusco, Yannely; Córdova-Sintjago, Tania C.; Chuchani, Gabriel

    2015-02-01

    The gas-phase thermal dehydration mechanism of tert-butanol, 2-methyl-2-butanol, 2-methyl-2-pentanol and 2,3-dimethyl-2-butanol by homogeneous catalysis of hydrogen bromide was examined by density functional theory calculations with the hybrid functionals: M062X, CAMB3LYP and WB97XD. Reasonable agreements were found between theoretical and experimental enthalpy values at the WB97XD/6-311++G(d,p) level. The dehydration mechanism of tert-butanol with and without catalysis was evaluated in order to examine the catalyst effect on the mechanism. The elimination reaction without catalysis involves a four-membered transition state (TS), while the reaction with catalysis involves a six-membered TS. The mechanism without catalysis has enthalpy activation over 150 kJ mol-1 greater than the catalysed reaction. In all these reactions, the elongation of the C-O bond is significant in the TS. The un-catalysed reaction is controlled by breaking of C-O bond, and it was found to be more synchronous (Sy ≈ 0.91) than the hydrogen bromide catalysed reactions (Sy ≈ 0.75-0.78); the latter reactions are dominated by the three reaction coordinates associated with water formation. No significant effect on the enthalpies of activation was observed when the size of the alkyl chain was increased.

  11. Hydrogen bonding Part 53. Correlation of differential scanning calorimetric data with IR and dissociation vapor pressure studies of transitions of hexamethonium chloride and bromide dihydrates and hexamethonium bromide monohydrate

    NASA Astrophysics Data System (ADS)

    Snider, Barbara L.; Harmon, Kenneth M.

    1994-03-01

    Differential scanning calorimetry of hexamethonium chloride dihydrate shows an endothermic transition of 2.70 kcal mol -1 at 36.81°C. This correlates well with the temperatures observed by IR spectra (36°C) and equilibrium dissociation vapor pressure studies (37°C) for the transition between Type I planar cluster and Type II extended linear HOH⋯Cl - hydrogen bonding, and with the value of 2.77 kcal mol -1 for this transition derived by Hess' law treatment of dissociation vapor pressure data. Differential scanning calorimetry of hexamethonium bromide shows a rapid endothermic transition of 2.38 kcal mol -1 at 35.15°C and a very slow endothermic transition of about 12-13 kcal mol -1 centered near 50°C. This latter endotherm corresponds to the transition between Type I and Type II HOH⋯Br - hydrogen bonding observed by IR and vapor pressure studies at 49°C. The nature of the 35.15°C endotherm is not known. Hexamethonium bromide also shows a third endotherm at 142.91°C, which presumably results from melting of hydrate in the sealed DSC cell. Combined analysis of differential scanning calorimetry and dissociation vapor pressure data predicts a value of about -13 kcal mol -1 for an exothermic disproportionation at 52°C of two hexamethonium bromide monohydrate to Type II dihydrate and anhydrous bromide.

  12. {gamma}-Radiolysis of NaCl Brine in the Presence of UO{sub 2}(s): Effects of Hydrogen and Bromide

    SciTech Connect

    Metz, Volker; Bohnert, Elke; Kelm, Manfred; Schild, Dieter; Kienzler, Bernhard

    2007-07-01

    A concentrated NaCl solution was {gamma}-irradiated in autoclaves under a pressure of 25 MPa. A set of experiments were conducted in 6 mol (kg H{sub 2}O){sup -1} NaCl solution in the presence of UO{sub 2}(s) pellets; in a second set of experiments, {gamma}-radiolysis of the NaCl brine was studied without UO{sub 2}(s). Hydrogen, oxygen and chlorate were formed as long-lived radiolysis products. Due to the high external pressure, all radiolysis products remained dissolved. H{sub 2} and O{sub 2} reached steady state concentrations in the range of 5.10{sup -3} to 6.10{sup -2} mol (kg H{sub 2}O){sup -1} corresponding to a partial gas pressure of {approx}2 to {approx}20 MPa. Radiolytic formation of hydrogen and oxygen increased with the concentration of bromide added to solution. Both, in the presence of bromide, resulting in a relatively high radiolytic yield, and in the absence of bromide surfaces of the UO{sub 2}(s) samples were oxidized, and concentration of dissolved uranium reached the solubility limit of the schoepite / NaUO{sub 2}O(OH)(cr) transition. At the end of the experiments, the pellets were covered by a surface layer of a secondary solid phase having a composition close to Na{sub 2}U{sub 2}O{sub 7}. The experimental results demonstrate that bromide counteracts an H{sub 2} inhibition effect on radiolysis gas production, even at a concentration ratio of [H{sub 2}] / [Br{sup -}] > 100. The present observations are related to the competitive reactions of OH radicals with H{sub 2}, Br{sup -} and Cl{sup -}. A similar competition of hydrogen and bromide, controlling the yield of {gamma}-radiolysis products, is expected for solutions of lower Cl{sup -} concentration. (authors)

  13. Enhancement of mercury capture by the simultaneous addition of hydrogen bromide (HBr) and fly ashes in a slipstream facility.

    PubMed

    Cao, Yan; Wang, Quan-Hai; Li, Jun; Cheng, Jen-Chieh; Chan, Chia-Chun; Cohron, Marten; Pan, Wei-Ping

    2009-04-15

    Low halogen content in tested Powder River Basin (PRB) coals and low loss of ignition content (LOI) in PRB-derived fly ash were likely responsible for higher elemental mercury content (averaging about 75%) in the flue gas and also lower mercury capture efficiency by electrostatic precipitator (ESP) and wet-FGD. To develop a cost-effective approach to mercury capture in a full-scale coal-fired utility boiler burning PRB coal, experiments were conducted adding hydrogen bromide (HBr) or simultaneously adding HBr and selected fly ashes in a slipstream reactor (0.152 x 0.152 m) under real flue gas conditions. The residence time of the flue gas inside the reactorwas about 1.4 s. The average temperature of the slipstream reactor was controlled at about 155 degrees C. Tests were organized into two phases. In Phase 1, only HBr was added to the slipstream reactor, and in Phase 2, HBr and selected fly ash were added simultaneously. HBr injection was effective (>90%) for mercury oxidation at a low temperature (155 degrees C) with an HBr addition concentration of about 4 ppm in the flue gas. Additionally, injected HBr enhanced mercury capture by PRB fly ash in the low-temperature range. The mercury capture efficiency, attesting conditions of the slipstream reactor, reached about 50% at an HBr injection concentration of 4 ppm in the flue gas. Compared to only the addition of HBr, simultaneously adding bituminous-derived fly ash in a minimum amount (30 lb/MMacf), together with HBr injection at 4 ppm, could increase mercury capture efficiency by 30%. Injection of lignite-derived fly ash at 30 lb/MMacf could achieve even higher mercury removal efficiency (an additional 35% mercury capture efficiency compared to HBr addition alone).

  14. Enhancement of mercury capture by the simultaneous addition of hydrogen bromide (HBr) and fly ashes in a slipstream facility

    SciTech Connect

    Yan Cao; Quan-Hai Wang; Jun Li; Jen-Chieh Cheng; Chia-Chun Chan; Marten Cohron; Wei-Ping Pan

    2009-04-15

    Low halogen content in tested Powder River Basin (PRB) coals and low loss of ignition content (LOI) in PRB-derived fly ash were likely responsible for higher elemental mercury content (averaging about 75%) in the flue gas and also lower mercury capture efficiency by electrostatic precipitator (ESP) and wet-FGD. To develop a cost-effective approach to mercury capture in a full-scale coal-fired utility boiler burning PRB coal, experiments were conducted adding hydrogen bromide (HBr) or simultaneously adding HBr and selected fly ashes in a slipstream reactor (0.152 x 0.152 m) under real flue gas conditions. The residence time of the flue gas inside the reactor was about 1.4 s. The average temperature of the slipstream reactor was controlled at about 155{sup o}C. Tests were organized into two phases. In Phase 1, only HBr was added to the slipstream reactor, and in Phase 2, HBr and selected fly ash were added simultaneously. HBr injection was effective (>90%) for mercury oxidation at a low temperature (155{sup o}C) with an HBr addition concentration of about 4 ppm in the flue gas. Additionally, injected HBr enhanced mercury capture by PRB fly ash in the low-temperature range. The mercury capture efficiency, at testing conditions of the slipstream reactor, reached about 50% at an HBr injection concentration of 4 ppm in the flue gas. Compared to only the addition of HBr, simultaneously adding bituminous-derived fly ash in a minimum amount (30 lb/MMacf), together with HBr injection at 4 ppm, could increase mercury capture efficiency by 30%. Injection of lignite-derived fly ash at 30 lb/MMacf could achieve even higher mercury removal efficiency (an additional 35% mercury capture efficiency compared to HBR addition alone). 25 refs., 5 figs., 1 tab.

  15. Analysis of Te and TeO2 on CdZnTe Nuclear Detectors Treated with Hydrogen Bromide and Ammonium-Based Solutions

    DOE PAGES

    Drabo, Mebougna L.; Egarievwe, Stephen U.; Okwechime, Ifechukwude O.; ...

    2017-04-30

    Surface defects caused during cutting and polishing in the fabrication of cadmium zinc telluride (CdZnTe) nuclear detectors limit their spectral performance. Chemical treatments are often used to remove surface damages and defects. In this paper, we present the analysis of Te and TeO2 species on the surfaces of CdZnTe nuclear detectors treated with hydrogen bromide and ammonium-based solutions. The CdZnTe wafers were chemo-mechanically polished in a mixture of hydrogen bromide in hydrogen peroxide and ethylene glycol, followed by a chemical passivation in a mixture of ammonium fluoride and hydrogen peroxide solution. X-ray photoelectron spectroscopy showed significant conversion of Te tomore » TeO2, thus producing a more chemically stable surface. The resistivity of the CdZnTe samples is in the order of 1010 ohms-cm. The current for a given applied voltage increased following the passivation and decreased after a 3-hour period. Results from spectral response measurements showed that the 59.5-keV gamma-peak of Am-241 was stable under the same channel for the surface treatment processes.« less

  16. Alteration Behavior of High Burnup Spent Fuel in Salt Brine Under Hydrogen Overpressure and in Presence of Bromide

    SciTech Connect

    Loida, Andreas; Metz, Volker; Kienzler, Bernhard

    2007-07-01

    Recent studies have shown that in the presence of H2 overpressure, which forms due to the corrosion of the Fe based container, the dissolution rate of the spent fuel matrix is slowed down by a factor of about 10, associated with a distinct decrease of concentrations of important radionuclides. However, in a natural salt environment as well as in geological formations with chloride rich groundwater the presence of radiation chemically active impurities such as bromide must be taken in consideration. Bromide is known to react with {beta}/{gamma} radiolysis products, thus counteracting the protective H{sub 2} effect. In the present experiments using high burnup spent fuel, it is observed that during 212 days the matrix dissolution rate was enhanced by a factor of about 10 in the presence of up to 10{sup -3} M bromide and 3.2 bar H{sub 2} overpressure. However, concentrations of matrix bound actinides were found at the same level or below as found under identical conditions, but in the absence of bromide. In the long-term it is expected that the effect of bromide becomes less important, because the decrease of {beta}/{gamma}-activity results in a decrease of oxidative radicals, which react with bromide, while a-activity will dominate the radiation field. (authors)

  17. Degradation pathway and kinetics of 1-alkyl-3-methylimidazolium bromides oxidation in an ultrasonic nanoscale zero-valent iron/hydrogen peroxide system.

    PubMed

    Zhou, Haimei; Shen, Yuanyuan; Lv, Ping; Wang, Jianji; Li, Pu

    2015-03-02

    Fenton and Fenton-like oxidation has been already demonstrated to be efficient for the degradation of imidazolium ionic liquids (ILs), but little is known for their degradation pathway and kinetics in such systems. In this work, degradation pathway and kinetics of 1-alkyl-3-methylimidazolium bromides ([Cnmim]Br, n=2, 4, 6, 8, and 10) were investigated in an ultrasound nanoscale zero-valent iron/hydrogen peroxide (US-nZVI/H2O2) system. For this purpose, 1-butyl-3-methylimidazolium bromide ([C4mim]Br) was used as a representative ionic liquid to optimize pH value, nZVI dose, and H2O2 concentration for the degradation reaction. Then, the degradation kinetics of [Cnmim]Br was investigated under optimal conditions, and their degradation intermediates were monitored by gas chromatography-mass spectrometry (GC-MS). It was shown that the degradation of [Cnmim]Br in such a heterogeneous Fenton-like system could be described by a second order kinetic model, and a number of intermediate products were detected. Based on these intermediate products, detailed pathways were proposed for the degradation of [Cnmim]Br in the ultrasound-assisted nZVI/H2O2 system. These findings may be useful for the better understanding of degradation mechanism of the imidazolium ILs in aqueous solutions.

  18. Hydrogen bonding and molecular association in 2-(quinuclidinium)-butyric acid bromide hydrate studied by X-ray diffraction, DFT calculations, FTIR and NMR spectroscopy, and potentiometric titration

    NASA Astrophysics Data System (ADS)

    Dega-Szafran, Z.; Katrusiak, A.; Szafran, M.; Barczyński, P.

    2010-06-01

    The structure of 2-(quinuclidinium)-butyric acid bromide hydrate (QNBu·H 2O·HBr, 3) has been determined by X-ray diffraction, DFT calculations and characterized by FTIR and NMR spectroscopy. Crystals of 3 are monoclinic, space group P2 1. The water molecule interacts with the carboxylic group of 2-(quinuclidinium)-butyric acid and with the bromide anion by the COOH⋯OH 2 and HOH⋯Br hydrogen bonds of 2.575(3) and 3.293(2) Å, respectively. The structures of monomer ( 4) and dimeric cation ( 5) of the title complex have been optimized by the B3LYP/6-31G(d,p) approach, yielding conformations consistent with this in the crystal. The solid-state FTIR spectra of 3 and its deuterated analogue have been measured and compared with the theoretical spectrum of 4. The assignments of the observed and predicted bands have been proposed. The molecule of 3 has a chiral center at the C(9) atom, which is responsible for the non-magnetically equivalence of the α-ring and C(11)H 2 methylene protons in 1H NMR spectrum. The values of p Ka of quinuclidinium-acetate (quinuclidine betaine), 2-(quinuclidinium)-propionate and 2-(quinuclidinium)-butyrate have been determined by the potentiometric titration of their hydrohalides.

  19. Cyanogen bromide

    Integrated Risk Information System (IRIS)

    Cyanogen bromide ; CASRN 506 - 68 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  20. Vinyl bromide

    Integrated Risk Information System (IRIS)

    Vinyl bromide ; CASRN 593 - 60 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  1. Rapacuronium bromide.

    PubMed

    Stump, L

    2000-08-01

    Rapacuronium bromide (Raplon; Organon Inc, West Orange, NJ) is a new, fast-onset, short-duration surgical muscle relaxant. While anesthesia providers are learning how to use this new relaxant, PACU nurses must become aware of the potential problems associated with rapacuronium. This article compares and contrasts the effects of succinylcholine and rapacuronium.

  2. A new class of cuprous bromide cluster-based hybrid materials: direct observation of the stepwise replacement of hydrogen bonds by coordination bonds.

    PubMed

    Zhang, Xian-Ming; Hou, Juan-Juan; Guo, Cai-Hong; Li, Chun-Fang

    2015-01-20

    Although a variety of functional metal-organic frameworks (MOFs) have been synthesized, post-modified, and applied in various areas, there is little knowledge about how molecular cluster building units are stepwise evolved into MOFs via intermediates. Coordination bonds are generally stronger than hydrogen bonds, and thus equivalent replacement of X-H···Y hydrogen bonds by X-M-Y coordination bonds can transform hydrogen bond networks into MOFs. In this work, solvothermal in situ reduction reactions of CuBr2 and 1,4-diazoniabicyclo[2,2,2]octane (DABCO) generated a myriad of tunable photoluminescent cuprous body-centered cubic bromide cluster-based networks with the general formula [Cu4+xH4-xBr6(DABCO)4](HCO2)2·S (x = 0, 0.56, 0.81, 1.27, 1.39, 2.56, 2.78, and 4 for compounds 1-8, respectively). All of these compounds crystallize in the cubic space group with the largest volume difference being only 5.2%, but they belong to three remarkably different kinds of crystals. Complex 1 is a molecular crystal and consists of tetrahedral [Cu4Br6(HDABCO)4](2+) clusters with monodentate HDABCO groups that are supported via N-H···Br synthons in the hydrogen bond network. Compound 8 is a [Cu8Br6](2+) cube cluster-based MOF with bridged DABCO ligands. Complexes 2-7 are seemingly impossible Cu/H-substituted solid solutions of 1 and 8. The CuBr framework components in 1-8 are Cu4Br6, Cu4.56Br6, Cu4.81Br6, Cu5.27Br6, Cu5.39Br6, Cu6.56Br6, Cu6.78Br6, and Cu8Br6, respectively. Crystallization kinetics studies revealed that the [Cu4Br6(HDABCO)4](2+) cluster-based hydrogen bond network (1) was initially formed such that N-H···Br hydrogen bonds could be stepwise replaced by N-Cu-Br coordination bonds to form the [Cu8Br6](2+) cube cluster-based MOF (8) via solid solutions. These observations directly reveal the equivalence and transformation between the N-H···Br hydrogen bond and the N-Cu-Br coordination bond and the evolutionary mechanism of a molecular crystal to a MOF via

  3. Ipratropium bromide HFA.

    PubMed

    Wellington, Keri

    2005-01-01

    Ipratropium bromide is a nonselective antagonist of the muscarinic receptors located on airway smooth muscle, and is delivered via a metered-dose inhaler (MDI). Because of the requirement to phase out chlorofluorocarbon (CFC)-propelled MDIs, the ipratropium bromide inhalation aerosol MDI has been redesigned with a hydrofluoroalkane as the propellant (ipratropium bromide HFA). Ipratropium bromide HFA has recently been approved in the US for the maintenance treatment of bronchospasm associated with COPD. Ipratropium bromide HFA 42 microg four times daily (one dose [42 microg] is delivered via two puffs of the inhaler) demonstrated comparable efficacy to that of ipratropium bromide CFC 42 microg four times daily, as measured by spirometric testing, in a large, randomized, double-blind, placebo-controlled, 12-week trial in patients with stable COPD. Similarly, four-times-daily ipratropium bromide HFA 42 microg and ipratropium bromide CFC 42 microg provided a comparable degree of bronchodilation in patients with stable COPD during a 1-year, open-label study primarily designed to assess safety. In both studies, the tolerability profiles of ipratropium bromide HFA and ipratropium bromide CFC were comparable. The most common adverse events were related to respiratory system disorders. During the 1-year study, dry mouth was reported by 1.3% and 0.7% of patients in the ipratropium bromide HFA or ipratropium bromide CFC groups.

  4. How hydrogen bonds influence the mobility of imidazolium-based ionic liquids. A combined theoretical and experimental study of 1-n-butyl-3-methylimidazolium bromide.

    PubMed

    Kohagen, Miriam; Brehm, Martin; Lingscheid, Yves; Giernoth, Ralf; Sangoro, Joshua; Kremer, Friedrich; Naumov, Sergej; Iacob, Ciprian; Kärger, Jörg; Valiullin, Rustem; Kirchner, Barbara

    2011-12-29

    The virtual laboratory allows for computer experiments that are not accessible via real experiments. In this work, three previously obtained charge sets were employed to study the influence of hydrogen bonding on imidazolium-based ionic liquids in molecular dynamics simulations. One set provides diffusion coefficients in agreement with the experiment and is therefore a good model for real-world systems. Comparison with the other sets indicates hydrogen bonding to influence structure and dynamics differently. Furthermore, in one case the total charge was increased and in another decreased by 0.1 e. Both the most acidic proton as well as the corresponding carbon atom were artificially set to zero, sequentially and simultaneously. In the final setup a negative charge was placed on the proton in order to introduce a barrier for the anion to contact the cation via this most acidic hydrogen atom. The following observations were made: changing the hydrogen bonding ability strongly influences the structure while the dynamic properties, such as diffusion and viscosity, are only weakly changed. However, the introduction of larger alterations (stronger hydrogen bonding and antihydrogen bonding) also strongly influences the diffusion coefficients. The dynamics of the hydrogen bond, ion pairing, and the ion cage are all affected by the level of hydrogen bonding. A change in total charges predominantly influences transport properties rather than structure. For ion cage dynamics with respect to transport porperties, we find a good correlation and a weak or no correlation for the ion pair or the hydrogen bond dynamics, respectively. Nevertheless, the hydrogen bond does influence ion cage dynamics. Therefore, we confirm that ionic liquids rather consist of loosely interacting counterions than of discrete ion pairs. Hydrogen bonding affects the properties only in a secondary or indirect manner.

  5. Computational and vibrational spectroscopic studies of ipratropium bromide.

    PubMed

    Ali, H R H; Edwards, H G M; Kendrick, J; Scowen, I J

    2009-02-01

    In this study, ipratropium bromide is investigated using vibrational spectroscopy and quantum chemical calculations. The structure of ipratropium bromide was optimised using density functional theory calculations and the geometry optimisation has been carried out on two conformations with and without intramolecular hydrogen bonding. Infrared and Raman spectra were calculated from the optimised structures. Many modes in the calculated spectra could be matched with the experimental spectra and a description of the modes is given. By analysis of the theoretical vibrational modes, it is shown that ipratropium bromide specimens are likely to be a mixture of the two conformations with and without intramolecular hydrogen bonding. In addition, several spectral features and band intensities in the CH and OH stretching regions are explained. Quantum mechanical calculations allowed improved understanding of ipratropium bromide and its vibrational spectra.

  6. Mercury Bromide Laser Research.

    DTIC Science & Technology

    1981-05-04

    Discharge", Optics Lett., 2(3), (March 1978). 7. R. Burnham, "Discharge Pumped Mercuric Halide Dissociation Lasers", Appl. Phys. Lett., 33: 15 (July 1978...laser and fluorescence signals. Neutral density filters served to prevent saturation of the detector during the laser measurements. F. Laser Output as a...REFERENCES . E. J. Schimitschek and J. E. Celto, " Mercuric Bromide Dissociation Laser in an Electric Discharge," Optics Lett. 2(3), March 1978. This

  7. Rapacuronium bromide (Organon Teknika).

    PubMed

    Plowman, A N

    1999-07-01

    Organon Teknika's rapacuronium bromide (Org-9487), the 16-N-allyl, 17-beta-propionate analog of vecuronium bromide, is in phase III clinical trials in the US and Europe for potential use as an anesthetic. It is a steroidal neuromuscular blocking drug characterized by low potency, rapid rate of block development and short time course of neuromuscular blocking action as compared with other non-depolarizing compounds [170210,221422]. A multicenter, randomized, assessor-blind, placebo-controlled, dose-finding study in patients undergoing tracheal intubation showed that the drug produced a dose dependent neuromuscular block. Doses of 1.5 to 2 mg/kg allowed rapid intubation and short duration of action [273336]. Another study showed that the drug does not cause cardiovascular side-effects [273336]. A meeting was held in Europe on 8 February 1999 to brief company employees on the registration and release of rapacuronium [319211] for which the company anticipates a launch in late 1999 [320706]. Organon estimates that the market value of Org-9487 is between dollar 100 m and dollar 250 m a year, each for Europe and the US [221422].

  8. Neuropsychiatric manifestations of bromide ingestion

    PubMed Central

    Battin, David G. J.; Varkey, T. Antony

    1982-01-01

    Two cases of bromide intoxication are reported. Although the serum bromide levels were not particularly high, they were related to typical neurological and psychiatric features of bromism. The authors wish to suggest that the rare syndrome of bromism be considered in the differential diagnosis of obscure or refractory neuro-psychiatric symptomatology. PMID:7134096

  9. Managing Nematodes without Methyl Bromide

    USDA-ARS?s Scientific Manuscript database

    Methyl bromide is an effective pre-plant soil fumigant used to control nematodes in many high-input, high-value production systems including vegetables, nurseries, ornamentals, tree fruits, strawberries, and grapes. Because methyl bromide has provided a reliable return on investment for nematode c...

  10. Iron bromide vapor laser

    NASA Astrophysics Data System (ADS)

    Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

    2016-03-01

    We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

  11. Hydrogen

    PubMed Central

    Bockris, John O’M.

    2011-01-01

    The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan). Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs) by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech. PMID:28824125

  12. Hydrogen-Bromine Secondary Battery

    NASA Technical Reports Server (NTRS)

    England, C. (Inventor)

    1975-01-01

    A secondary battery is described utilizing hydrogen and halogen as primary reactants. It comprises inert anode and cathode initially contacting an aqueous solution of an acid and an alkali metal bromide. The hydrogen generated during charging of the cell is stored as gas, while the bromine becomes dissolved predominantly in the lower layers of the acid electrolyte. Preferred components are phosphoric acid and lithium bromide.

  13. 77 FR 35295 - Methyl Bromide; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... AGENCY 40 CFR Part 180 RIN 2070-ZA16 Methyl Bromide; Pesticide Tolerances AGENCY: Environmental... methyl bromide in or on cotton, undelinted seed under the Federal Food, Drug, and Cosmetic Act (FFDCA... to establish a tolerance for residues of methyl bromide, including metabolites and degradates in or...

  14. Bromide Adsorption by Reference Minerals and Soils

    USDA-ARS?s Scientific Manuscript database

    Bromide, Br-, adsorption behavior was investigated on amorphous Al and Fe oxide, montmorillonite, kaolinite, and temperate and tropical soils. Bromide adsorption decreased with increasing solution pH with minimal adsorption occurring above pH 7. Bromide adsorption was higher for amorphous oxides t...

  15. Spectral characteristics of the bentonite loaded with benzyldimethyloctadecylammonium chloride, hexadecyltrimethylammonium bromide and dimethyldioctadecylammonium bromide

    NASA Astrophysics Data System (ADS)

    Majdan, Marek; Maryuk, Oksana; Gładysz-Płaska, Agnieszka; Pikus, Stanisław; Kwiatkowski, Ryszard

    2008-02-01

    The spectral characterization, including the FTIR, DRIFT (diffusive reflectance), SWAXS (small and wide angle X-ray scattering) spectra comparison of the sodium bentonite modified by BDMODA-Cl (benzyldimethyloctadecylammonium chloride), HDTMA-Br (hexadecyltrimethylammonium bromide), DDA-Br (dimethyldioctadecylammonium bromide) is presented in the paper. The FTIR spectra show the shift of C-H stretching vibrations: νsym(CH2), νasym(CH2) of surfactants methylene chains toward lower frequencies (from 2855 to 2851 cm -1 for νsym(CH2) and from 2927 to 2918 cm -1 for νansym(CH2) with the surfactant concentration in bentonite phase. The bending vibrations δH-O-H in water molecules change their positions in the direction of higher frequencies (from 1634 to 1647 cm -1) with the surfactant concentration for bentonite-BDMODA and bentonite-DDA contrary to bentonite-HDTMA, where the constant position δH-O-H is explained as the consequence of the lower concentration of the hydrogen bonded water in bentonite-HDTMA phase when compared with the remaining forms of bentonite. The DRIFT spectra reveal dramatic shift of the νSi-O stretching vibration toward higher frequencies upon intercalation of the sodium bentonite with the surfactant cations. The SWAXS spectra and SEM images of the bentonite are the evidence of somewhat different sorption mechanism of DDA-Br when compared with the BDMODA-Cl and HDTMA-Br, including remarkable external surface sorption contribution in the overall sorption.

  16. Kinetics of manganese(III) acetate in acetic acid: Generation of Mn(III) with Co(III), Ce(IV), and dibromide radicals; reactions of Mn(III) with Mn(II), Co(II), hydrogen bromide, and alkali bromides

    SciTech Connect

    Jiao, X.D.; Espenson, J.H.

    2000-04-03

    The reaction of cobalt(III) acetate with excess manganese(II) acetate in acetic acid occurs in two stages, since the two forms Co(IIIc) and Co(IIIs) are not rapidly equilibrated and thus react independently. The rate constants at 24.5 C are {kappa}{sub c} = 37.1 {+-} 0.6 L mol{sup {minus}1} s{sup {minus}1} and {kappa}{sub s} = 6.8 {+-} 0.2 L mol{sup {minus}1} s{sup {minus}1} at 24.5 C in glacial acetic acid. The Mn(III) produced forms a dinuclear complex with the excess of Mn(II). This was studied independently and is characterized by the rate constant (3.43 {+-} 0.01) x 10{sup 2} L mol{sup {minus}1} s{sup {minus}1} at 24.5 C. A similar interaction between Mn(III) and Co(II) is substantially slower, with {kappa} = (3.73 {+-} 0.05) x 10{sup {minus}1} L mol{sup {minus}1} s{sup {minus}1} at 24.5 C. Mn(II) is also oxidized by Ce(IV), according to the rate law {minus}d[Ce(IV)]/dt = {kappa}[Mn(II)]{sup 2}[Ce(IV)], where {kappa} = (6.0 {+-} 0.2) x 10{sup 4} L{sup 2} mol{sup {minus}2} s{sup {minus}1}. The reaction between Mn(II) and HBr{sub 2}{sup {sm_bullet}}, believed to be involved in the mechanism by which Mn(III) oxidizes HBr, was studied by laser photolysis; the rate constant is (1.48 {+-} 0.04) x 10{sup 8} L mol{sup {minus}1} s{sup {minus}1} at {approximately}23 C in HOAc. Oxidation of Co(II) by HBr{sub 2}{sup {sm_bullet}} has the rate constant (3.0 {+-} 0.1) x 10{sup 7} L mol{sup {minus}1} s{sup {minus}1}. The oxidation of HBr by Mn(III) is second order with respect to [HBr]; {kappa} = (4.10 {+-} 0.08) x 10{sup 5} L{sup 2} mol{sup {minus}2} s{sup {minus}1} at 4.5 C in 10% aqueous HOAc. Similar reactions with alkali metal bromides were studied; their rate constants are 17--23 times smaller. This noncomplementary reaction is believed to follow that rate law so that HBr{sub 2}{sup {sm_bullet}} and not Br{sup {sm_bullet}} (higher in Gibbs energy by 0.3 V) can serve as the intermediate. The analysis of the reaction steps then requires that the oxidation of HBr{sub 2

  17. Hydrogen Embrittlement

    NASA Technical Reports Server (NTRS)

    Woods, Stephen; Lee, Jonathan A.

    2016-01-01

    Hydrogen embrittlement (HE) is a process resulting in a decrease in the fracture toughness or ductility of a metal due to the presence of atomic hydrogen. In addition to pure hydrogen gas as a direct source for the absorption of atomic hydrogen, the damaging effect can manifest itself from other hydrogen-containing gas species such as hydrogen sulfide (H2S), hydrogen chloride (HCl), and hydrogen bromide (HBr) environments. It has been known that H2S environment may result in a much more severe condition of embrittlement than pure hydrogen gas (H2) for certain types of alloys at similar conditions of stress and gas pressure. The reduction of fracture loads can occur at levels well below the yield strength of the material. Hydrogen embrittlement is usually manifest in terms of singular sharp cracks, in contrast to the extensive branching observed for stress corrosion cracking. The initial crack openings and the local deformation associated with crack propagation may be so small that they are difficult to detect except in special nondestructive examinations. Cracks due to HE can grow rapidly with little macroscopic evidence of mechanical deformation in materials that are normally quite ductile. This Technical Memorandum presents a comprehensive review of experimental data for the effects of gaseous Hydrogen Environment Embrittlement (HEE) for several types of metallic materials. Common material screening methods are used to rate the hydrogen degradation of mechanical properties that occur while the material is under an applied stress and exposed to gaseous hydrogen as compared to air or helium, under slow strain rates (SSR) testing. Due to the simplicity and accelerated nature of these tests, the results expressed in terms of HEE index are not intended to necessarily represent true hydrogen service environment for long-term exposure, but rather to provide a practical approach for material screening, which is a useful concept to qualitatively evaluate the severity of

  18. Lanthanum Bromide Detectors for Safeguards Measurements

    SciTech Connect

    Wright, J.

    2011-05-25

    Lanthanum bromide has advantages over other popular inorganic scintillator detectors. Lanthanum bromide offers superior resolution, and good efficiency when compared to sodium iodide and lanthanum chloride. It is a good alternative to high purity germanium detectors for some safeguards applications. This paper offers an initial look at lanthanum bromide detectors. Resolution of lanthanum bromide will be compared lanthanum chloride and sodium-iodide detectors through check source measurements. Relative efficiency and angular dependence will be looked at. Nuclear material spectra, to include plutonium and highly enriched uranium, will be compared between detector types.

  19. Surface and volume properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide I. Surface properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide.

    PubMed

    Harkot, Joanna; Jańczuk, Bronisław

    2009-03-15

    Surface tension measurements were carried out for aqueous solutions of two cationic surfactants: dodecylethyldimethylammonium bromide (C(12)(EDMAB)) and benzyldimethyldodecylammonium bromide (BDDAB). Isotherms and thermodynamic adsorption parameters were determined from the surface tension data. Firstly, the surface excess concentration in the adsorbed monolayer and the total concentration of the surfactants were determined, then the standard free energy of adsorption was calculated by different methods. In the calculations, different orientations of the surfactants at the adsorbed monolayer were also taken into account. From the experimental and calculated data it results that the difference in the structure of the two cationic surfactants by changing the methyl group for aryl one in their heads causes an increase of the efficiency and a decrease of the effectiveness of adsorption at water-air interface, and that the standard free energy of adsorption can be predicted from the surface tension of the surfactants assuming the aryl group to be equivalent to 3.5 methylene groups. The experimentally obtained difference between the standard free energy of adsorption of the C(12)(EDMAB) and BDDAB was in good agreement with that theoretically accounted, corresponding to the standard free energy of adsorption of the aryl group. However, the best correlation between the values was obtained when a parallel orientation of the surfactant molecules at the adsorbed monolayer was taken into account.

  20. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be...) Bromoacetone, methyl bromide, chloropicrin and methyl bromide mixtures, chloropicrin and methyl...

  1. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be... Group I performance level. (b) Bromoacetone, methyl bromide, chloropicrin and methyl bromide...

  2. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be...) Bromoacetone, methyl bromide, chloropicrin and methyl bromide mixtures, chloropicrin and methyl...

  3. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be... Group I performance level. (b) Bromoacetone, methyl bromide, chloropicrin and methyl bromide...

  4. Pharmacological studies on otilonium bromide.

    PubMed

    Giachetti, A

    1991-11-01

    Otilonium bromide (OB) is a quaternary ammonium compound characterized by a long aliphatic chain. Its chemical properties are responsible for both a poor penetration in CNS and a prolonged binding to cell membranes. OB is a spasmolytic agent which acts by modifying Ca++ fluxes from extra and intracellular sites. It has been documented that iv administration (10 mg/kg) of OB causes a marked reduction of colonic motility lasting from 2 to 3 hours, whereas an inhibition of upper GI motor activity is present only at higher dosages. In conclusion, OB seems to exert its activity mainly on distal GI tract, and its spasmolytic effect may be due to its ability to inhibit Ca++ fluxes and to a direct action of the drug on the contractile proteins of the smooth muscle.

  5. N-(2-Bromo-benz-yl)cinchoninium bromide.

    PubMed

    Skórska-Stania, Agnieszka; Jezierska-Zięba, Magdalena; Kąkol, Barbara; Fedoryński, Michał; Oleksyn, Barbara J

    2012-09-01

    The title compound {systematic name: 1-(2-bromo-benz-yl)-5-ethenyl-2-[hy-droxy(quinolin-4-yl)meth-yl]-1-aza-bicyclo-[2.2.2]octan-1-ium bromide}, C(26)H(28)BrN(2)O(+)·Br(-), is a chiral quater-nary ammonium salt of one of the Cinchona alkaloids. The planes of the quinoline and of the bromo-benzyl substituent are inclined to one another by 9.11 (9)°. A weak intra-molecular C-H⋯O hydrogen bond occurs. The crystal structure features strong O-H⋯Br hydrogen bonds and weak C-H⋯Br inter-actions.

  6. N-(2-Bromo­benz­yl)cinchoninium bromide

    PubMed Central

    Skórska-Stania, Agnieszka; Jezierska-Zięba, Magdalena; Kąkol, Barbara; Fedoryński, Michał; Oleksyn, Barbara J.

    2012-01-01

    The title compound {systematic name: 1-(2-bromo­benz­yl)-5-ethenyl-2-[hy­droxy(quinolin-4-yl)meth­yl]-1-aza­bicyclo­[2.2.2]octan-1-ium bromide}, C26H28BrN2O+·Br−, is a chiral quater­nary ammonium salt of one of the Cinchona alkaloids. The planes of the quinoline and of the bromo­benzyl substituent are inclined to one another by 9.11 (9)°. A weak intra­molecular C—H⋯O hydrogen bond occurs. The crystal structure features strong O—H⋯Br hydrogen bonds and weak C—H⋯Br inter­actions. PMID:22969676

  7. Bromidotetra-kis-(2-ethyl-1H-imidazole-κN (3))copper(II) bromide.

    PubMed

    Godlewska, Sylwia; Kelm, Harald; Krüger, Hans-Jörg; Dołęga, Anna

    2012-12-01

    The Cu(II) ion in the title mol-ecular salt, [CuBr(C5H8N2)4]Br, is coordinated in a square-pyramidal geometry by four N atoms of imidazole ligands and one bromide anion in the apical position. In the crystal, the ions are linked by N-H⋯Br hydrogen bonds involving both the coordinating and the free bromide species as acceptors. A C-H⋯Br inter-action is also observed. Overall, a three-dimensional network results.

  8. Neurological manifestation of methyl bromide intoxication.

    PubMed

    Suwanlaong, Kanokrat; Phanthumchinda, Kammant

    2008-03-01

    Methyl bromide is a highly toxic gas with poor olfactory warning properties. It is widely used as insecticidal fumigant for dry foodstuffs and can be toxic to central and peripheral nervous systems. Most neurological manifestations of methyl bromide intoxication occur from inhalation. Acute toxicity characterized by headache, dizziness, abdominal pain, nausea, vomiting and visual disturbances. Tremor, convulsion, unconsciousness and permanent brain damage may occur in severe poisoning. Chronic exposure can cause neuropathy, pyramidal and cerebellar dysfunction, as well as neuropsychiatric disturbances. The first case of methyl bromide intoxication in Thailand has been described. The patient was a 24-year-old man who worked in a warehouse of imported vegetables fumigated with methyl bromide. He presented with unstable gait, vertigo and paresthesia of both feet, for two weeks. He had a history of chronic exposure to methyl bromide for three years. His fourteen co-workers also developed the same symptoms but less in severity. Neurological examination revealed ataxic gait, decreased pain and vibratory sense on both feet, impaired cerebellar signs and hyperactive reflex in all extremities. The serum concentration of methyl bromide was 8.18 mg/dl. Electrophysilogical study was normal. Magnetic resonance imaging of the brain (MRI) revealed bilateral symmetrical lesion of abnormal hypersignal intensity on T2 and fluid-attenuation inversion recovery (FLAIR) sequences at bilateral dentate nuclei of cerebellum and periventricular area of the fourth ventricle. This incident stresses the need for improvement of worker education and safety precautions during all stages of methyl bromide fumigation.

  9. Surface and volume properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide: II. Volumetric properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide.

    PubMed

    Harkot, Joanna; Jańczuk, Bronisław

    2009-02-15

    Density measurements were carried out for aqueous solutions of two cationic surfactants: dodecylethyldimethylammonium bromide (C(12)(EDMAB)) and benzyldimethyldodecylammonium bromide (BDDAB). On the basis of the obtained results of the measurements the CMC and partial molar volumes of the surfactants studied were also determined. The obtained CMC values were also analyzed with those accounted on the basis of the surface tension data from the previous paper [J. Harkot, B. Jańczuk, J. Colloid Interface Sci. (2008), submitted for publication]. The values of CMC determined from the surface tension and density measurements for C(12)(EDMAB) are equal to 9.9x10(-3) and 1.5x10(-2) M and for BDDAB to 5.25x10(-3) and 5.3x10(-3) M, respectively. These obtained values are very similar. However, in the literature it is difficult to find the CMC values for C(12)(EDMAB) and BDDAB determined by these two methods used by us-especially from the density measurements for BDDAB and surface tension measurements for C(12)(EDMAB). In the case of the apparent molar volumes of C(12)(EDMAB) there is a good agreement between the values obtained by us and those found in the literature. The CMC values for C(12)(EDMAB) and BDDAB were also determined on the basis of their surface tension and free energy of electrostatic interactions between the polar heads of these surfactants and compared with those obtained from the surface tension and density measurements. It was found that the theoretically obtained CMC values were close to those determined from the density and surface tension data for the C(12)(EDMAB) and that the ratios of the CMC values of the surfactants to their concentration at which the water surface tension decreased by about 20 mN/m proved that the presence of the aryl group in the BDDAB head instead of the methyl group caused that its micellization process was more inhibited in relation to its adsorption at air-water interface than that of C(12)(EDMAB).

  10. Growth and characterization of lead bromide crystals

    NASA Technical Reports Server (NTRS)

    Singh, N. B.; Gottlieb, M.; Henningsen, T.; Hopkins, R. H.; Mazelsky, R.; Glicksman, M. E.; Coriell, S. R.; Santoro, G. J.; Duval, W. M. B.

    1992-01-01

    Lead(II) bromide was purified by a combination of directional freezing and zone-refining methods. Differential thermal analysis of the lead bromide showed that a destructive phase transformation occurs below the melting temperature. This transformation causes extensive cracking, making it very difficult to grow a large single crystal. Energy of phase transformation for pure lead bromide was determined to be 24.67 cal/g. To circumvent this limitation, crystals were doped by silver bromide which decreased the energy of phase transformation. The addition of silver helped in achieving the size, but enhanced the inhomogeneity in the crystal. The acoustic attenuation constant was almost identical for the pure and doped (below 3000 ppm) crystals.

  11. Emission of methyl bromide from biomass burning

    SciTech Connect

    Manoe, S.; Andreae, M.O. )

    1994-03-04

    Bromine is, per atom, far more efficient than chlorine in destroying stratospheric ozone, and methyl bromide is the single largest source of stratospheric bromine. The two main previously known sources of this compound are emissions from the ocean and from the compound's use as an agricultural pesticide. Laboratory biomass combustion experiments showed that methyl bromide was emitted in the smoke from various fuels tested. Methyl bromide was also found in smoke plumes from wildfires in savannas, chaparral, and boreal forest. Global emissions of methyl bromide from biomass burning are estimated to be in the range of 10 to 50 gigagrams per year, which is comparable to the amount produced by ocean emission and pesticide use and represents a major contribution ([approximately]30 percent) to the stratospheric bromine budget.

  12. Growth and characterization of lead bromide crystals

    NASA Technical Reports Server (NTRS)

    Singh, N. B.; Gottlieb, M.; Henningsen, T.; Hopkins, R. H.; Mazelsky, R.; Glicksman, M. E.; Coriell, S. R.; Santoro, G. J.; Duval, W. M. B.

    1992-01-01

    Lead(II) bromide was purified by a combination of directional freezing and zone-refining methods. Differential thermal analysis of the lead bromide showed that a destructive phase transformation occurs below the melting temperature. This transformation causes extensive cracking, making it very difficult to grow a large single crystal. Energy of phase transformation for pure lead bromide was determined to be 24.67 cal/g. To circumvent this limitation, crystals were doped by silver bromide which decreased the energy of phase transformation. The addition of silver helped in achieving the size, but enhanced the inhomogeneity in the crystal. The acoustic attenuation constant was almost identical for the pure and doped (below 3000 ppm) crystals.

  13. Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS

    NASA Astrophysics Data System (ADS)

    Liao, J.; Huey, L. G.; Scheuer, E.; Dibb, J. E.; Stickel, R. E.; Tanner, D. J.; Neuman, J. A.; Nowak, J. B.; Choi, S.; Wang, Y.; Salawitch, R. J.; Canty, T.; Chance, K.; Kurosu, T.; Suleiman, R.; Weinheimer, A. J.; Shetter, R. E.; Fried, A.; Brune, W.; Anderson, B.; Zhang, X.; Chen, G.; Crawford, J.; Hecobian, A.; Ingall, E. D.

    2012-02-01

    A focus of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was examination of bromine photochemistry in the spring time high latitude troposphere based on aircraft and satellite measurements of bromine oxide (BrO) and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometer (CIMS) to measure BrO and a mist chamber (MC) to measure soluble bromide. We have determined that the MC detection efficiency to molecular bromine (Br2), hypobromous acid (HOBr), bromine oxide (BrO), and hydrogen bromide (HBr) as soluble bromide (Br-) was 0.9±0.1, 1.06+0.30/-0.35, 0.4±0.1, and 0.95±0.1, respectively. These efficiency factors were used to estimate soluble bromide levels along the DC-8 flight track of 17 April 2008 from photochemical calculations constrained to in situ BrO measured by CIMS. During this flight, the highest levels of soluble bromide and BrO were observed and atmospheric conditions were ideal for the space-borne observation of BrO. The good agreement (R2 = 0.76; slope = 0.95; intercept = -3.4 pmol mol-1) between modeled and observed soluble bromide, when BrO was above detection limit (>2 pmol mol-1) under unpolluted conditions (NO<10 pmol mol-1), indicates that the CIMS BrO measurements were consistent with the MC soluble bromide and that a well characterized MC can be used to derive mixing ratios of some reactive bromine compounds. Tropospheric BrO vertical column densities (BrOVCD) derived from CIMS BrO observations compare well with BrOTROPVCD from OMI on 17 April 2008.

  14. Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS

    NASA Astrophysics Data System (ADS)

    Liao, J.; Huey, L. G.; Scheuer, E.; Dibb, J. E.; Stickel, R. E.; Tanner, D. J.; Neuman, J. A.; Nowak, J. B.; Choi, S.; Wang, Y.; Salawitch, R. J.; Canty, T.; Chance, K.; Kurosu, T.; Suleiman, R.; Weinheimer, A. J.; Shetter, R. E.; Fried, A.; Brune, W.; Anderson, B.; Zhang, X.; Chen, G.; Crawford, J.; Hecobian, A.; Ingall, E. D.

    2011-09-01

    A focus of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was examination of bromine photochemistry in the spring time, high latitude troposphere based on aircraft and satellite measurements of BrO and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometry (CIMS) instrument to measure BrO and a mist chamber (MC) to measure soluble bromide. We have determined that the MC detection efficiency to molecular bromine (Br2), hypobromous acid (HOBr), bromine oxide (BrO), and hydrogen bromide (HBr) as soluble bromide (Br-) was 0.9±0.1, 1.06±0.30, 0.4±0.1, and 0.95±0.1, respectively. These efficiency factors were used to estimate soluble bromide levels along the DC-8 flight track of 17 April 2008 from photochemical calculations constrained to in situ BrO measured by CIMS. During this flight, the highest levels of soluble bromide and BrO were observed and atmospheric conditions were ideal for the space-borne observation of BrO. The good agreement (R2 = 0.76; slope = 0.98; intercept = -3.5 pptv) between modeled and observed soluble bromide, when BrO was above detection limit (>2 pptv) under unpolluted conditions (NO < 100 pptv), indicates that the CIMS BrO measurements were consistent with the MC soluble bromide. Tropospheric BrO vertical column densities (BROTROPVCD) derived from CIMS BrO observations compare well with BROTROPVCD from OMI on 17 April 2008.

  15. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be...

  16. Palladium-catalyzed cross-coupling of cyclopropylmagnesium bromide with aryl bromides mediated by zinc halide additives.

    PubMed

    Shu, Chutian; Sidhu, Kanwar; Zhang, Li; Wang, Xiao-Jun; Krishnamurthy, Dhileepkumar; Senanayake, Chris H

    2010-10-01

    The key Pd-catalyzed cross-coupling of aryl bromides or triflates and cyclopropylmagnesium bromide in the presence of substoichiometric amounts of zinc bromide produces cyclopropyl arenes in good to excellent yields. The cross-coupling of other alkyl, cycloalkyl, and aryl Grignard reagents with aryl bromides under the same conditions gives the corresponding substituted arenes in good yields.

  17. Bromidotetra-kis-(2-isopropyl-1H-imidazole-κN)copper(II) bromide.

    PubMed

    Godlewska, Sylwia; Socha, Joanna; Baranowska, Katarzyna; Dołęga, Anna

    2011-10-01

    The Cu(II) atom in the title salt, [CuBr(C(6)H(10)N(2))(4)]Br, is coordinated in a square-pyramidal geometry by four imidazole N atoms and one bromide anion that is located at the apex of the pyramid. The cations and the anions form a two-dimensional network parallel to (001) through N-H⋯Br hydrogen bonds.

  18. [The clinical pharmacological profile of pinaverium bromide].

    PubMed

    Guslandi, M

    1994-04-01

    Pinaverium bromide is a locally acting spasmolytic agent of the digestive tract. Its mechanism of action relies upon inhibition of calcium ion entrance into smooth muscle cells (calcium-antagonist effect). In humans pinaverium facilitates gastric emptying and decreases intestinal transit time in patients with constipation. Pinaverium is very effective in improving symptoms of irritable bowel syndrome (abdominal pain, gas, diarrhea or constipation). In this respect the drug proved to be significantly superior to placebo, at least as effective as trimebutine and on the whole more active than otilonium and prifinium bromide, being always extremely well tolerated.

  19. Methyl Bromide Investigation Expands to Puerto Rico

    EPA Pesticide Factsheets

    (New York, N.Y.) The U.S. Environmental Protection Agency, working with the Virgin Islands government, is investigating the March 2015 incident involving the use of a pesticide containing methyl bromide to fumigate a residence at the Sirenusa apartments on

  20. Cherry angiomas associated with exposure to bromides.

    PubMed

    Cohen, A D; Cagnano, E; Vardy, D A

    2001-01-01

    Cherry angiomas are the most common vascular proliferation; however, little is known about the pathogenesis and etiology of these lesions. We present two laboratory technicians who were exposed to brominated compounds for prolonged periods and who developed multiple cherry angiomas on the trunk and extremities. We suggest that the association between exposure to bromides and cherry angiomas should be investigated by a controlled study.

  1. METHYL BROMIDE ALTERNATIVES FOR CALIFORNIA STRAWBERRY NURSERIES

    USDA-ARS?s Scientific Manuscript database

    The effects of methyl bromide (MB) alternative fumigants on soil pests, plant productivity in nursery and fruiting fields, as well as production costs, were evaluated in California strawberry nurseries by an interdisciplinary team. Our trials followed nursery stock through low and high elevation ph...

  2. Methyl bromide emissions from tarped fields

    SciTech Connect

    Cicerone, R.J.; Williams, J.; Wang, N.Y.

    1995-12-31

    Once in the stratosphere, bromine atoms can destroy ozone effectively. Because of this potential effect, certain organobromine compounds including methyl bromide (MeBr) are being controlled or eliminated by national and international regulations. It would be valuable to determine the fraction of MeBr used in soil fumigations that subsequently enters the atmosphere to better assess the need for, and value of, strong regulations. We have designed and conducted several experiments accompanying field fumigations with MeBr/chloropicrin mixtures. In each of three field-fumigation experiments new Irvine, CA in which the fumigated field was covered immediately with plastic tarping, we have deployed static flux chambers on top of the tarping and measured escape fluxes of MeBr. After tarp removal, the same chambers were replaced on the bare soil to continue the measurements. We have also measured soil bromide contents before and after the fumigation. One experiment yielded an escape fraction of 80 to 87% (with 19% remaining as bromide) while the other two experiments yielded escape fractions of 30 to 35% (with about 70% remaining as bromide). This paper will summarize stratospheric bromine chemistry, describe the field experiments and discuss factors that influence emissions, including soil pH, moisture and organic content and injection technique. We acknowledge TriCal, Inc. for many helpful discussions and for professional field applications of MeBr.

  3. A comparison of the action of otilonium bromide and pinaverium bromide: study conducted under clinical control.

    PubMed

    Defrance, P; Casini, A

    1991-11-01

    We studied 40 patients with irritable bowel syndrome (IBS) which received in a simple-blind fashion otilonium and pinaverium bromide (15 days each drug). During each 15-day period we evaluated: number of pain episodes, intensity of pain, number of bowel movements, side effects. Otilonium bromide, (OB), compared with pinaverium bromide was able to significantly (p less than 0.05) reduce the number of pain attacks, whereas no significant differences were found between the 2 groups as regards the other parameters. The occurrence of side effects was similar in the two treatment courses. We can conclude that the two types of treatment were similarly useful in IBS, although OB seems more effective than pinaverium bromide.

  4. Kinetics and mechanism of the oxidation of bromide by periodate in aqueous acidic solution.

    PubMed

    Szél, Viktor; Csekő, György; Horváth, Attila K

    2014-11-13

    The periodate–bromide reaction has been studied spectrophotometrically mainly in excess of bromide ion, monitoring the formation of the total amount of bromine at 450 nm at acidic buffered conditions and at a constant ionic strength in the presence of a phosphoric acid/dihydrogen phosphate buffer. The stoichiometry of the reaction was established to be strictly IO4(–) + 2Br(–) + 2H(+) → Br2 + IO3(–) + H2O. The formal kinetic order of the reactants was found to be perfectly one and two in the cases of periodate and bromide, respectively, but that of the hydrogen ion lies between one and two. We have also provided experimental evidence that dihydrogen phosphate accelerates the formation of bromine, suggesting the appearance of strong buffer assistance. On the basis of the experiments, a simple two-step kinetic model is proposed involving BrIO3 as a key intermediate that perfectly explains all of the experimental findings. Furthermore, we have also shown that in huge excess of bromide, the apparent rate coefficient obtained from the individual curve fitting method of the absorbance–time series is necessarily independent of the initial periodate concentration that may falsely be interpreted as the rate of bromine formation is also independent of the concentration of periodate.

  5. 77 FR 20752 - Methyl Bromide; Proposed Pesticide Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-06

    ... feeding items resulting from fumigation of cottonseed with methyl bromide are covered by existing... produced from cottonseed fumigated with methyl bromide would not contain residues of methyl bromide... pest within the United States. As a feed commodity, imported cottonseed that has been fumigated with...

  6. 21 CFR 522.275 - N-Butylscopolammonium bromide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false N-Butylscopolammonium bromide. 522.275 Section 522....275 N-Butylscopolammonium bromide. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) N-butylscopolammonium bromide. (b) Sponsor. See No. 000010 in § 510.600(c) of this chapter...

  7. Flow injection determination of bromide ion in a developer using bromide ion-selective electrode detector.

    PubMed

    Masadome, T; Asano, Y; Nakamura, T

    1999-10-01

    A potentiometric flow injection determination method for bromide ion in a developer was proposed, by utilizing a flow-through type bromide ion-selective electrode detector. The sensing membrane of the electrode was Ag(2)S-AgBr membrane. The response of the electrode detector as a peak-shape signal was obtained for injected bromide ion in a developer. A linear relationship was found to exist between peak height and the concentration of the bromide ion in a developer in a concentration range from 1.0x10(-3) to 1.0x10(-2) mol l(-1). The relative standard deviation for 10 injections of a 6x10(-3) mol l(-1) bromide ion in a developer was 1.3% and the sampling rate was ca 17-20 samples h(-1). The present method was free from the interference of an organic reducing reagent, an organic substance in a developer sample solution for the determination of bromide ion in a developer.

  8. Bromidotetra­kis­(2-ethyl-1H-imidazole-κN 3)copper(II) bromide

    PubMed Central

    Godlewska, Sylwia; Kelm, Harald; Krüger, Hans-Jörg; Dołęga, Anna

    2012-01-01

    The CuII ion in the title mol­ecular salt, [CuBr(C5H8N2)4]Br, is coordinated in a square-pyramidal geometry by four N atoms of imidazole ligands and one bromide anion in the apical position. In the crystal, the ions are linked by N—H⋯Br hydrogen bonds involving both the coordinating and the free bromide species as acceptors. A C—H⋯Br inter­action is also observed. Overall, a three-dimensional network results. PMID:23468738

  9. Hydrogen bonding. Part 25. The nature of the hydrogen bond in hydroxytropenylium chloride (tropone hydrochloride)

    NASA Astrophysics Data System (ADS)

    Harmon, Kenneth M.; Cross, Joan E.; Toccalino, Patricia L.

    1988-08-01

    Hydroxytropenylium iodide and bromide contain normal electrostatic OH⋯X - hydrogen bonds. Hydroxytropenylium chloride, however, contains a hydrogen bond intermediate between the normal electrostatic type and the very strong covalent type, similar to the hydrogen bonds found in choline fluoride or the Type I C∞v hydrogen dihalide ions. Infrared comparisons with compounds previously studied demonstrate that the hydroxytropenylium ion is a stronger hydrogen bond donor than either choline cation or protonated betaine cation, and suggest that hydroxytropenylium fluoride, if it can be prepared, should contain a three-center covalent hydrogen bond.

  10. A Systematic Study on the Mesomorphic Behavior of Asymmetrical 1-Alkyl-3-dodecylimidazolium Bromides

    SciTech Connect

    Yang, Mei; Mallick, Bert; Mudring, Anja-Verena

    2014-04-02

    To determine the essential parameters for mesophase formation in imidazolium-based ionic liquids (ILs), a library of 1-alkyl-3-dodecylimidazolium bromides was synthesized, abbreviated as CnC12, where 0 ≤ n ≤ 13, as the general notion is that a dodecyl side chain would guarantee the formation of an ionic liquid crystal (ILC). All salts were fully characterized by NMR spectroscopy and mass spectrometry. Their thermal properties were recorded, and mesophase formation was assessed. An odd–even effect is observed for 5 ≤ n ≤ 10 in the temperatures of melting transitions. While the majority of this series, as expected, formed mesophases, surprisingly compounds C2C12 and C6C12 could not be classified as ILCs, the latter being a room temperature IL, while C2C12 is a crystalline solid with melting point at 37 °C. The single crystal structure of compound 1-ethyl-3-dodecylimidazolium bromide (C2C12) was successfully obtained. Remarkably, the arrangement of imidazolium cores in the structure is very complicated due to multiple nonclassical hydrogen bonds between bromide anions and imidazolium head groups. In this arrangement, neighboring imidazolium rings are forced by hydrogen bonds to form a “face-to-face” conformation. This seems to be responsible for the elimination of a mesophase. To conclude, the general view of a dodecyl chain being a functional group to generate a mesophase is not entirely valid.

  11. [Research advances in methyl bromide in the ocean].

    PubMed

    Du, Hui-na; Xie, Wen-xia; Cui, Yu-qian; Chen, Jian-lei; Ye, Si-yuan

    2014-12-01

    Methyl bromide is an important atmospheric trace gas, which plays significant roles in the global warming and atmospheric chemistry. The ocean plays important and complex roles in the global biogeochemical cycles of methyl bromide, not only the source of atmospheric methyl bromide, but also the sink. Therefore, developing the chemical research of the soluble methyl bromide in the ocean, will not only have a certain guiding significance to the atmospheric ozone layer protection, but also provide a theoretical basis for estimating methyl bromide's contribution to the global environmental change on global scale. This paper reviewed the research advances on methyl bromide in the ocean, from the aspects of the biogeochemical cycle of methyl bromide in the ocean, the analysis and determination method, the concentration distribution, the sea-to-air flux and its sources and sinks in the atmosphere. Some deficiencies in the current studies were put forward, and the directions of the future studies were prospected.

  12. Thallium bromide iodide crystal acoustic anisotropy examination.

    PubMed

    Mantsevich, S N

    2017-03-01

    Thallium bromide iodide crystal also known as KRS-5 is the well known material used in far infrared radiation applications for optical windows and lenses fabrication. The main advantage of this material is the transparency in wide band of wavelengths from 0.53 to 50μm. Despite such advantages as transparency and large acousto-optic figure of merit values, KRS-5 is rarely used in acousto-optics. Nevertheless this material seems to be promising for far infrared acousto-optic applications. The acoustic and acousto-optic properties of KRS-5 needed for the full use in optoelectronics are not well understood to date. In this paper the detailed examination of thallium bromide iodide crystal acoustic properties is presented.

  13. Measurements of atmospheric methyl bromide and bromoform

    SciTech Connect

    Cicerone, R.J.; Heidt, L.E.; Pollock, W.H.

    1988-04-20

    We have measured gaseous methyl bromide (CH/sub 3/Br) and bromoform (CHBr/sub 3/) in air samples that were gathered approximately weekly from five ground-level sites: Point Barrow, Alaska; Mauna Loa Observatory and Cape Kumukahi, Hawaii; Matatula, Samoa; and Kaitorete Spit, New Zealand. Approximately 750 samples have been analyzed for CH/sub 3/Br between January 1985 and October 1987 and 990 samples have been analyzed for CHBr/sub 3/ between early 1984 and September 1987, all by gas chromatography/mass spectroscopy. Methyl bromide concentrations are typically 10--11 parts per trillion (ppt) by volume; there are no clear indications of temporal increases. Bromoform concentrations are typically 2--3 ppt, but large seasonal variations are seen at Point Barrow. copyright American Geophysical Union 1988

  14. Data for methyl bromide decon testing

    EPA Pesticide Factsheets

    Spreadsheets containing data for recovery of spores from different materials. Data on the fumigation parameters are also included.This dataset is associated with the following publication:Wood , J., M. Wendling, W. Richter, A. Lastivka, and L. Mickelsen. Evaluation of the Efficacy of Methyl Bromide in the Decontamination of Building and Interior Materials Contaminated with Bacillus anthracis Spores. APPLIED AND ENVIRONMENTAL MICROBIOLOGY. American Society for Microbiology, Washington, DC, USA, 1-28, (2016).

  15. Ipratropium bromide in children with asthma.

    PubMed Central

    Mann, N P; Hiller, E J

    1982-01-01

    Eighteen children between 6 and 14 years of age with perennial asthma were studied over two four-week treatment periods. Ipratropium bromide, given in addition to their current treatment, was compared with placebo using a double-blind crossover technique. The period of treatment with ipratropium was associated with a significant reduction in symptoms during both day and night and significantly higher morning peak expiratory flow rates. PMID:6461943

  16. Nitroethylation of Vinyl Triflates and Bromides

    PubMed Central

    Padilla–Salinas, Rosaura; Walvoord, Ryan R.; Tcyrulnikov, Sergei

    2013-01-01

    A two-carbon homologation of vinyl triflates and bromides for the synthesis of homoallylic nitro products is described. This palladium-catalyzed double coupling of nitromethane exploits the anion stabilizing and leaving group properties of nitromethane, generating the homo allyl nitro products via a tandem cross-coupling/π-allylation sequence. The resultant process provides a mild and convenient entry of nitroethylated products, which are versatile precursors to β,γ-unsaturated carbonyls, homoallylic amines, and nitrile oxides. PMID:23885976

  17. Nitroethylation of vinyl triflates and bromides.

    PubMed

    Padilla-Salinas, Rosaura; Walvoord, Ryan R; Tcyrulnikov, Sergei; Kozlowski, Marisa C

    2013-08-02

    A two-carbon homologation of vinyl triflates and bromides for the synthesis of homoallylic nitro products is described. This palladium-catalyzed double coupling of nitromethane exploits the anion stabilizing and leaving group properties of nitromethane, generating the homo allyl nitro products via a tandem cross-coupling/π-allylation sequence. The resultant process provides a mild and convenient entry to nitroethylated products, which are versatile precursors to β,γ-unsaturated carbonyls, homoallylic amines, and nitrile oxides.

  18. Methyl bromide users search for science

    SciTech Connect

    Winegar, E.D.

    1995-01-01

    Workers, neighbors and the ozone are protected by regulation from this chemical, but those needing it complain that a solid foundation is lacking for the rules. Although not yet featured on {open_quotes}60 Minutes,{close_quotes} the pesticide methyl bromide is gaining widespread attention because of its central position in debates about worker health and safety, environmental toxics exposure and global ozone depletion.

  19. Methyl bromide fate in fumigated soils

    SciTech Connect

    Anderson, T.A.; Rice, P.J.; Cink, J.H.

    1995-12-31

    Although widespread use of methyl bromide (MeBr) as a sail and structure fumigant has previously been recognized as a potential significant source of atmospheric MeBr, losses have not been well quantified. Our research indicates that, in laboratory studies, MeBr is volatilized rapidly from fumigated soils and that volatility increases with temperature (35{degrees}C > 25{degrees}C and 15{degrees}C) and moisture (0.03 bar and 0.3 bar > 1 bar > 3 bar). Degradation of MeBr in soil, as indicated by production of bromide ion, was also directly related to temperature and moisture. Most of the soil degradation of MeBr in these studies appears to be abiotic based on the observation of toxicity (reduced microbial respiration) in fumigated soils. We also determined the transformation and movement of MeBr in undisturbed soil columns. These studies also indicated that MeBT volatilizes rapidly (> 50% in 48 h) from soil. In addition, MeBr was not detected in the leachate from the soil columns, however, bromide ion was detected at levels above background 48 h after fumigation and peaked at 5 weeks.

  20. The neurological effects of methyl bromide intoxication.

    PubMed

    de Souza, Aaron; Narvencar, Kedareshwar P S; Sindhoora, K V

    2013-12-15

    Used primarily as a fumigant or as a substrate in chemical processes, methyl bromide is a highly toxic gas. The gas is usually absorbed by inhalation and effects on the lungs, gastrointestinal tract, skin, and brain are seen. Numerous instances of acute and chronic neurologic injury have been reported: acute poisoning results in seizures, myoclonus, ataxia or cerebral oedema beginning as early as 30 min after exposure while subacute or chronic intoxication presents with diverse slowly progressive neurological and neurobehavioral symptoms. Serum bromide levels may be elevated, but often return rapidly to normal. Electroencephalography may show frontally-predominant slow waves or polyspikes with following slow wave, and MRI reveals characteristic involvement in the dentate nucleus of the cerebellum, the brainstem, and the splenium of the corpus callosum. Symmetric and selective lesions in characteristic sites are observed on imaging and on histopathological examination. These are likely produced by methylation of intracellular lipids, protein and glutathione; production of toxic metabolites; defective neurotransmitter function; and abnormal oxidative phosphorylation. This article reviews the toxic effects of this gas, the pathophysiology and symptoms of its effects on the nervous system, and characteristic findings on MRI; and presents an illustrative case of methyl bromide intoxication due to exposure at a factory producing the compound commercially.

  1. Methyl bromide volatility measurements from treated fields

    SciTech Connect

    Majewski, M.S.; Woodrow, J.E.; Seiber, J.N. |

    1995-12-31

    Methyl bromide is used as an agricultural soil fumigant and concern is growing over the role it may play in the depletion of stratospheric ozone. Methyl bromide is applied using various techniques and little is known about how much of the applied fumigant volatilizes into the atmosphere after application. The post-application volatilization losses of methyl bromide from two fields using different application practices were measured using an aerodynamic-gradient technique. One field was covered with a high-barrier plastic film tarp during application and the other was left uncovered, but the furrows made by the injection shanks were bedded over. The cumulative volatilization losses from the tarped field were 22% of the nominal application within the first 5 days of the experiment and about 32% of the nominal application within 9 days including the one day after the tarp was removed on day 8. The nontarped field lost 89%of the nominal application by volatilization in 5 days. The error associated, with each flux measurement, as well as variations in daily flux losses with differing sampling period lengths show the degree of variability inherent in this type of study.

  2. Reductive cross-coupling of nonaromatic, heterocyclic bromides with aryl and heteroaryl bromides.

    PubMed

    Molander, Gary A; Traister, Kaitlin M; O'Neill, Brian T

    2014-06-20

    Reductive cross-coupling allows the direct C-C bond formation between two organic halides without the need for preformation of an organometallic reagent. A method has been developed for the reductive cross-coupling of nonaromatic, heterocyclic bromides with aryl or heteroaryl bromides. The developed conditions use an air-stable Ni(II) source in the presence of a diamine ligand and a metal reductant to allow late-stage incorporation of saturated heterocyclic rings onto aryl halides in a functional-group tolerant manner.

  3. IBS and the role of otilonium bromide.

    PubMed

    Boeckxstaens, Guy; Corazziari, Enrico S; Mearin, Fermín; Tack, Jan

    2013-03-01

    Awareness of the seriousness of irritable bowel disorder (IBS) remains low among clinicians. In this review, we summarize the current knowledge of IBS and highlight the major personal, economic, and social burden of the disease, and the importance of adequate treatment of what is still often viewed as a trivial disorder. In fact, IBS is a major reason for referral. It is crucial that the varied pathophysiologies of this complex heterogeneous disease are understood in order to be able to treat both the presenting symptoms (pain, bloating, flatulence, abnormal defecation, diarrhea, constipation) and the underlying disorder effectively. Low-grade inflammatory and immune activation has been observed, but the precise triggers and mechanisms, and the relevance to symptom generation, remain to be established. IBS patients require different treatment strategies according to the pattern, severity, frequency, and symptoms. While initial therapy traditionally targets the most bothersome symptom, long-term therapy aims at maintaining symptom control and preventing recurrence. In addition to dietary/lifestyle interventions and psychosocial strategies, a wide range of pharmacologic therapies are approved for use in IBS depending on the symptoms reported. Musculotropic spasmolytics, which act directly on intestinal smooth muscle contractility, such as otilonium bromide, are effective, particularly in the relief of abdominal pain and bloating, and are well tolerated in IBS. THE OBIS TRIAL: The recent large placebo-controlled Otilonium Bromide in Irritable Bowel Syndrome study demonstrated the superiority of otilonium bromide versus placebo not only in the reduction of pain and bloating, but also in protection from relapse due to the long-lasting effect.

  4. Europium-doped barium bromide iodide

    SciTech Connect

    Gundiah, Gautam; Hanrahan, Stephen M.; Hollander, Fredrick J.; Bourret-Courchesne, Edith D.

    2009-10-21

    Single crystals of Ba0.96Eu0.04BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl2 structure [Braekken (1932). Z. Kristallogr. 83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = +-0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement.

  5. Bromide oxidation by ferrate(VI): The formation of active bromine and bromate.

    PubMed

    Jiang, Yanjun; Goodwill, Joseph E; Tobiason, John E; Reckhow, David A

    2016-06-01

    Ferrate (VI) (abbreviated as Fe(VI)) has long been considered as a green oxidant that does not produce any known hazardous byproducts. However, this work shows that Fe(VI) can slowly oxidize bromide forming active bromine (HOBr/OBr(-)) and bromate, and in natural waters total organic bromine (TOBr) can also be detected. Results showed that the highest levels of active bromine and bromate were formed at lower pHs and in the absence of phosphate. Hydrogen peroxide, which forms from the reaction of Fe(VI) and water, plays an essential role in suppressing bromate formation by reducing active bromine back to bromide. Fe(VI) decomposition products (assumed to be particulate phase Fe(III)) can catalyze the decomposition of hydrogen peroxide by Fe(VI). Phosphate had a substantial inhibiting effect on the formation of active bromine, but less so on bromate formation. The presence of the raw water matrix in natural water suppressed bromate formation. For a natural water spiked with 0.1 mg/L of bromide, the bromate and TOBr concentrations after Fe(VI) oxidation were below 3.0 and 15 μg/L, respectively. No consistent trend regarding the effect of pH or buffer ions on TOBr formation was observed due to the competition between Fe(VI), hydrogen peroxide, and natural organic matter (NOM) for reaction with active bromine. Under environmentally relevant conditions, the formation of bromate and TOBr would not be a problem for Fe(VI) application as their concentration levels are quite low.

  6. [Spectrophotometer detection of benzalkonium bromide concentration in seawater].

    PubMed

    Pan, Jianyu; Yin, Pinghe; Zhao, Ling; Qi, Yuzao; Xie, Longchu

    2003-07-01

    Benzalkonium bromide is a high-efficiency algaecide. Its concentration in seawater was measured by the method of spectrophotometer. The results indicated that the deposition appeared if the concentration of benzalkonium bromide in seawater was more than 50 mg.L-1, and affected the detection of benzalkonium bromide. But, there was a good linear relationship between concentration and absorbance when the concentration was lower than 50 mg.L-1 (R2 = 0.9996). Therefore, spectrophotometer could be used to detect benzalkonium bromide in seawater.

  7. Copper bromide vapour laser with an output pulse duration of up to 320 ns

    SciTech Connect

    Gubarev, F A; Fedorov, K V; Evtushenko, G S; Fedorov, V F; Shiyanov, D V

    2016-01-31

    We report the development of a copper bromide vapour laser with an output pulse duration of up to 320 ns. To lengthen the pulse, the discharge current was limited using a compound switch comprising a pulsed hydrogen thyratron and a tacitron. This technique permits limiting the excitation of the working levels at the initial stage of the discharge development to lengthen the inversion lifetime. The longest duration of a laser pulse was reached in tubes 25 and 50 mm in diameter for a pulse repetition rate of 2 – 4 kHz. (lasers and laser beams)

  8. Corrosion inhibition in lithium bromide absorption fluid for advanced and current absorption cycle machines

    SciTech Connect

    Verma, S.K.; Mekhjian, M.S.; Sandor, G.R.; Nakada, N.

    1999-07-01

    This paper presents the results of a novel corrosion inhibitor that exhibits improved protection of carbon steel over the inhibitors currently in practice. This inhibitor, formulated in 65 wt% lithium bromide solution, offers excellent corrosion protection to carbon steel. Corrosion rates were determined using autoclave coupon testing. The corrosion rate in the 300 F to 450 F range was found to be low (1 to 4 mils per year), and the product also showed very low hydrogen generation (0.03 mg/in.{sup 2} of carbon steel per week). The metal was protected with a stable and adherent film.

  9. 1,3-Bis[(6-methyl-2-pyrid-yl)meth-yl]imidazolium bromide.

    PubMed

    Kim, Ga Young; Park, Sang-Kyu; Lee, Dong-Heon; Park, Gyungse

    2009-02-28

    The title compound, C(17)H(19)N(4) (+)·Br(-), is built up from 1,3-bis-[(6-methyl-2-pyridin-yl)meth-yl]imidazolium cations and bromide anions. Each of two 6-methyl-2-pyridyl rings is rotated out of the imidazole plane, making dihedral angles of 79.90 (9) and 86.40 (9)°. The packing is consolidated by aromatic π-π inter-actions between the pyridine rings of neighbouring mol-ecules [centroid-centroid distance = 3.554 (2) Å] and by weak C-H⋯N and C-H⋯Br hydrogen bonds.

  10. A new oxo-vanadium complex employing an imidazole-rich tripodal ligand: a bioinspired bromide and hydrocarbon oxidation catalyst.

    PubMed

    Fernández, Tatiana L; Souza, Elizabeth T; Visentin, Lorenzo C; Santos, Jeniffer V; Mangrich, Antonio S; Faria, Roberto B; Antunes, O A C; Scarpellini, Marciela

    2009-04-01

    A vanadyl complex with the ligand (bis(1-methylimidazol-2-yl)methyl)(2-(pyridyl-2-yl)ethyl)amine was synthesized and fully characterized by X-ray crystallography, elemental analyses, cyclic voltammetry and infrared, electronic and electron paramagnetic resonance spectroscopies. This compound was designed under the so called hybrid concept. It shows to be able to promiscuously use hydrogen peroxide to oxidize bromide and to catalyze the oxidation of benzene and cyclohexane with very good selectivities.

  11. Bromidotetra­kis­(2-isopropyl-1H-imidazole-κN 3)copper(II) bromide

    PubMed Central

    Godlewska, Sylwia; Socha, Joanna; Baranowska, Katarzyna; Dołęga, Anna

    2011-01-01

    The CuII atom in the title salt, [CuBr(C6H10N2)4]Br, is coordinated in a square-pyramidal geometry by four imidazole N atoms and one bromide anion that is located at the apex of the pyramid. The cations and the anions form a two-dimensional network parallel to (001) through N—H⋯Br hydrogen bonds. PMID:22064905

  12. Effect of alkyl chain asymmetry on catanionic mixtures of hydrogenated and fluorinated surfactants.

    PubMed

    Blanco, Elena; Rodriguez-Abreu, Carlos; Schulz, Pablo; Ruso, Juan M

    2010-01-15

    In this work we studied and compared the physicochemical properties of the catanionic mixtures cetyltrimethyl-ammonium bromide-sodium dodecanoate, cetyltrimethyl-ammonium bromide-sodium perfluorodacanoate, octyltrimethylammonium bromide-sodium perfluorodacanoate and cetyltrimethyl-ammonium bromide-sodium octanoate by a combination of rheological, transmission electron microscopy (TEM) and polarized optical microscopy measurements. The binary mixtures of the surfactants have been analyzed at different mixed ratios and total concentration of the mixture. Mixtures containing a perfluorinated surfactant are able to form lamellar liquid crystals and stable spontaneous vesicles. Meanwhile, system containing just hydrogenated surfactants form hexagonal phases or they are arranged in elongated aggregates.

  13. An Ill Wind: Methyl Bromide Use Near California Schools, 1998.

    ERIC Educational Resources Information Center

    Ross, Zev; Walker, Bill

    A California study investigates the use of the toxic pesticide methyl bromide near the state's public schools, explains why proposed safety rules have failed to protect children and others from exposure, and examines regions at particular exposure risk. Study results show an increasing exposure to methyl bromide near schools already at risk while…

  14. 40 CFR 721.10393 - Sodium bromide MDA complex (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sodium bromide MDA complex (generic... Specific Chemical Substances § 721.10393 Sodium bromide MDA complex (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as sodium...

  15. Indirect spectrophotometric determination of traces of bromide in water

    USGS Publications Warehouse

    Fishman, M. J.; Skougstad, M.W.

    1963-01-01

    A rapid, accurate, and sensitive indirect spectrophotometric method for the determination of bromide in natural waters is based on the catalytic effect of bromide on the oxidation of iodine to iodate by potassium permanganate in sulfuric acid solution. The method is applicable to concentrations ranging from 1 to 100 ??g. of bromide per liter, but may be modified to extend the concentration range. Most ions commonly occurring in water do not interfere. The standard deviation is 2.9 at bromide concentrations of 100 ??g. per liter and less at lower concentrations. The determination of bromide in samples containing known added amounts gave values ranging from 99 to 105% of the concentration calculated to be present.

  16. Sir Charles Locock and potassium bromide.

    PubMed

    Eadie, M J

    2012-01-01

    On 12 May 1857, Edward Sieveking read a paper on epilepsy to the Royal Medical and Chirurgical Society in London. During the discussion that followed Sir Charles Locock, obstetrician to Queen Victoria, was reported to have commented that during the past 14 months he had used potassium bromide to successfully stop epileptic seizures in all but one of 14 or 15 women with 'hysterical' or catamenial epilepsy. This report of Locock's comment has generally given him credit for introducing the first reasonably effective antiepileptic drug into medical practice. However examination of the original reports raises questions as to how soundly based the accounts of Locock's comments were. Subsequently, others using the drug to treat epilepsy failed to obtain the degree of benefit that the reports of Locock's comments would have led them to expect. The drug might not have come into more widespread use as a result, had not Samuel Wilks provided good, independent evidence for the drug's antiepileptic efficacy in 1861.

  17. Irritable bowel syndrome: focus on otilonium bromide.

    PubMed

    Boeckxstaens, Guy; Clavé, Pere; Corazziari, Enrico S; Tack, Jan

    2014-02-01

    Irritable bowel syndrome is a prevalent and chronic disorder, characterized by recurrent abdominal pain/discomfort, bloating and altered bowel habits. This condition affects an estimated 10-15% of the population worldwide and impacts heavily on a patient's daily life and ability to work, as well as healthcare resource utilization. Drug therapy aimed at correcting the primary symptoms of diarrhea/constipation/bloating may have little effect on abdominal pain, which results from visceral hypersensitivity. Smooth muscle relaxants or antispasmodics decrease the tone and contractility of intestinal smooth muscle, effectively managing abdominal pain. Otilonium bromide has been widely used worldwide and has been found to be safe and well tolerated, and superior to placebo for the reduction of symptoms and the prevention of symptom relapse in patients with irritable bowel syndrome.

  18. Receptor binding profile of Otilonium bromide.

    PubMed

    Evangelista, S; Giachetti, A; Chapelain, B; Neliat, G; Maggi, C A

    1998-08-01

    The interaction of Otilonium bromide (OB) with binding sites for 63 different receptors and ion channels in appropriate preparations has been investigated. Experiments were also performed in rat colon, the preferred tissue for OB 'in vivo' uptake after oral administration. Among the receptors investigated OB binds with sub microM affinity to muscarinic M1, M2, M4, M5 and PAF receptors and with microM affinity to the diltiazem binding site on L type Ca2+ channels. In the rat colon OB shows competitive interaction with the verapamil binding site on L type Ca2+ channels and with muscarinic M2 receptors with IC50 of 1020 and 1220 nM, respectively. These findings provide a molecular rationale to explain the spasmolytic action exerted by OB on intestinal smooth muscle. In particular, a combination of antimuscarinic and Ca2+ channel blocker properties seems to best account for the action of this compound.

  19. Single ion dynamics in molten sodium bromide

    SciTech Connect

    Alcaraz, O.; Trullas, J.; Demmel, F.

    2014-12-28

    We present a study on the single ion dynamics in the molten alkali halide NaBr. Quasielastic neutron scattering was employed to extract the self-diffusion coefficient of the sodium ions at three temperatures. Molecular dynamics simulations using rigid and polarizable ion models have been performed in parallel to extract the sodium and bromide single dynamics and ionic conductivities. Two methods have been employed to derive the ion diffusion, calculating the mean squared displacements and the velocity autocorrelation functions, as well as analysing the increase of the line widths of the self-dynamic structure factors. The sodium diffusion coefficients show a remarkable good agreement between experiment and simulation utilising the polarisable potential.

  20. Degradation of methyl bromide in anaerobic sediments

    USGS Publications Warehouse

    Oremland, R.S.; Miller, L.G.; Strohmaler, F.E.

    1994-01-01

    Methyl bromide (MeBr) was anaerobically degraded in saltmarsh sediments after reaction with sulfide. The product of this nucleophilic substitution reaction was methanethiol, which underwent further chemical and bacterial reactions to form dimethyl sulfide. These two gases appeared transiently during sediment incubations because they were metabolized by methanogenic and sulfate-reducing bacteria. A second, less significant reaction of MeBr was the exchange with chloride, forming methyl chloride, which was also susceptible to attack by sulfide. Incubation of 14C-labeled methyl iodide as an analogue of MeBr resulted in the formation of 14CH4 and 14CO2 and also indicated that sulfate-reducing bacteria as well as methanogens metabolized the methylated sulfur intermediates. These results suggest that exposed sediments with abundant free sulfide, such as coastal salt-marshes, may constitute a sink for atmospheric MeBr.

  1. Florida Hydrogen Initiative

    SciTech Connect

    Block, David L

    2013-06-30

    at any facility engaged in transport, handling and use of hydrogen. Development of High Efficiency Low Cost Electrocatalysts for Hydrogen Production and PEM Fuel Cell Applications ? M. Rodgers, Florida Solar Energy Center The objective of this project was to decrease platinum usage in fuel cells by conducting experiments to improve catalyst activity while lowering platinum loading through pulse electrodeposition. Optimum values of several variables during electrodeposition were selected to achieve the highest electrode performance, which was related to catalyst morphology. Understanding Mechanical and Chemical Durability of Fuel Cell Membrane Electrode Assemblies ? D. Slattery, Florida Solar Energy Center The objective of this project was to increase the knowledge base of the degradation mechanisms for membranes used in proton exchange membrane fuel cells. The results show the addition of ceria (cerium oxide) has given durability improvements by reducing fluoride emissions by an order of magnitude during an accelerated durability test. Production of Low-Cost Hydrogen from Biowaste (HyBrTec?) ? R. Parker, SRT Group, Inc., Miami, FL This project developed a hydrogen bromide (HyBrTec?) process which produces hydrogen bromide from wet-cellulosic waste and co-produces carbon dioxide. Eelectrolysis dissociates hydrogen bromide producing recyclable bromine and hydrogen. A demonstration reactor and electrolysis vessel was designed, built and operated. Development of a Low-Cost and High-Efficiency 500 W Portable PEMFC System ? J. Zheng, Florida State University, H. Chen, Bing Energy, Inc. The objectives of this project were to develop a new catalyst structures comprised of highly conductive buckypaper and Pt catalyst nanoparticles coated on its surface and to demonstrate fuel cell efficiency improvement and durability and cell cost reductions in the buckypaper based electrodes. Development of an Interdisciplinary Hydrogen and Fuel Cell Technology Academic Program ? J

  2. Control of the misuse of bromide in horses.

    PubMed

    Ho, Emmie N M; Wan, Terence S M; Wong, April S Y; Lam, Kenneth K H; Schiff, Peter J; Stewart, Brian D

    2010-07-01

    Bromide is a sedative hypnotic. Due to its potential use as a sedative or calmative agent in competition horses, a method to control bromide is needed. Colorimetric method had been employed in the authors' laboratory from 2003 for the semi-quantification of bromide in equine plasma samples. However, the method was found to be highly susceptible to matrix interference, and was replaced in 2008 with a more reliable inductively coupled plasma-mass spectrometry (ICP/MS) method. Equine plasma was protein-precipitated using trichloroacetic acid, diluted with nitric acid, and then submitted directly to ICP/MS analysis. Since bromide is naturally occurring in equine plasma, a threshold is necessary to control its misuse in horses. Based on population studies (n = 325), a threshold of 90 µg/mL was proposed (with a risk factor of less than 1 in 10 000). Using the ICP/MS screening method, equine plasma samples with bromide greater than 85 µg/mL would be further quantified using the more accurate ICP/MS standard addition method. Confirmation of bromide was achieved by gas chromatography-mass spectrometry (GC-MS), with the bromide detected as its pentafluorobenzyl derivative. A sample is considered positive if its plasma bromide concentration exceeds the threshold (90 µg/mL) plus the measurement uncertainty of the quantification method (8 µg/mL at 99% 1-tailed confidence level) and its presence is confirmed using the GC-MS method. Following oral administration of potassium bromide (60 g each) to two geldings, plasma bromide levels peaked after approximately 2 hours at about 300 µg/mL, and then remained above the threshold for 8 and 13 days respectively. Copyright 2010 John Wiley & Sons, Ltd.

  3. Crystal structure of 2-carboxy- N,N,N- trimethylethanaminium bromide monohydrate

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Ming; Mak, Thomas C. W.

    1991-05-01

    A new betaine derivative, 2-carboxy- N,N,N-trimethylethanaminium bromide monohydrate, (Me 3NCH 2CH 2COOH)Br·H 2O, I, has been synthesized and characterized by X-ray crystallography. Compound I crystallizes in space group Pnma (no. 62), with a=10.452(2), b=6.855(2), c=13.737(2)Å, and Z=4. The structure ( RF=0.047 for 881 observed (⋎ FO⋎&>;6⋎ FO⋎) Mo Kα data) features a hydrogen-bonded (BR -·H 2O) ∞zigzag chain running parallel to the a axis. The quaternary ammonium ions, each attaining Cs molecular symmetry, are laterally attached by donor hydrogen bonds to the exposed water molecules of the zigzag chain. The crystal structure consists of layers each having a zipper-like arrangement of the quaternary ammonium "side-chains".

  4. Selective oxidation of bromide in wastewater brines from hydraulic fracturing.

    PubMed

    Sun, Mei; Lowry, Gregory V; Gregory, Kelvin B

    2013-07-01

    Brines generated from oil and natural gas production, including flowback water and produced water from hydraulic fracturing of shale gas, may contain elevated concentrations of bromide (~1 g/L). Bromide is a broad concern due to the potential for forming brominated disinfection byproducts (DBPs) during drinking water treatment. Conventional treatment processes for bromide removal is costly and not specific. Selective bromide removal is technically challenging due to the presence of other ions in the brine, especially chloride as high as 30-200 g/L. This study evaluates the ability of solid graphite electrodes to selectively oxidize bromide to bromine in flowback water and produced water from a shale gas operation in Southwestern PA. The bromine can then be outgassed from the solution and recovered, as a process well understood in the bromine industry. This study revealed that bromide may be selectively and rapidly removed from oil and gas brines (~10 h(-1) m(-2) for produced water and ~60 h(-1) m(-2) for flowback water). The electrolysis occurs with a current efficiency between 60 and 90%, and the estimated energy cost is ~6 kJ/g Br. These data are similar to those for the chlor-alkali process that is commonly used for chlorine gas and sodium hydroxide production. The results demonstrate that bromide may be selectively removed from oil and gas brines to create an opportunity for environmental protection and resource recovery.

  5. Pyridostigmine bromide protection against acetylcholinesterase inhibition by pesticides.

    PubMed

    Henderson, John D; Glucksman, Gabriela; Leong, Bryan; Tigyi, Andras; Ankirskaia, Anna; Siddique, Imteaz; Lam, Helen; DePeters, Ed; Wilson, Barry W

    2012-01-01

    Pyridostigmine bromide (PB) has been used to protect soldiers from the toxic effects of soman, a chemical warfare agent. Recent research shows that pyridostigmine bromide protects a significant percentage of acetylcholinesterase in isolated human intercostal muscle. Findings presented here indicate that red blood cell acetylcholinesterase is similarly protected by pyridostigmine bromide from the action of diisopropyl fluorophosphate and several organophosphate pesticides including chlorpyrifos-oxon, diazinon-oxon, and paraoxon, but not malaoxon, using the bovine red blood cell as a subject. These findings suggest that pretreatment with PB may protect growers, farmworkers, first responders, and the public, in general, from the effects of selected pesticides. Copyright © 2011 Wiley Periodicals, Inc.

  6. Dual-frequency oscillations induced by bromide ion

    NASA Astrophysics Data System (ADS)

    Li, Hexing; Huang, Xiaojun

    1996-06-01

    The experimental behavior of the ferroin-catalyzed Belousov-Zhabotinskii (BZ)-type reaction with 3,4-dihydroxybenzoic acid as organic substrate has been investigated. It was found that the system displays two types of temporal oscillations depending on the initial concentration of bromide. When [Br -] is very high, damped high-frequency oscillations appear. When [Br -] is very low, low-frequency oscillations of the normal type are obtained. At moderate concentrations of bromide, both high-frequency and low-frequency oscillations can be monitored with a bromide ion selective electrode. The mechanism of the dual-frequency oscillation is discussed.

  7. Hydrogen production

    NASA Technical Reports Server (NTRS)

    England, C.; Chirivella, J. E.; Fujita, T.; Jeffe, R. E.; Lawson, D.; Manvi, R.

    1975-01-01

    The state of hydrogen production technology is evaluated. Specific areas discussed include: hydrogen production fossil fuels; coal gasification processes; electrolysis of water; thermochemical production of hydrogen; production of hydrogen by solar energy; and biological production of hydrogen. Supply options are considered along with costs of hydrogen production.

  8. Hydrogen production

    NASA Technical Reports Server (NTRS)

    England, C.; Chirivella, J. E.; Fujita, T.; Jeffe, R. E.; Lawson, D.; Manvi, R.

    1975-01-01

    The state of hydrogen production technology is evaluated. Specific areas discussed include: hydrogen production fossil fuels; coal gasification processes; electrolysis of water; thermochemical production of hydrogen; production of hydrogen by solar energy; and biological production of hydrogen. Supply options are considered along with costs of hydrogen production.

  9. Chloride, bromide and iodide scintillators with europium

    DOEpatents

    Zhuravleva, Mariya; Yang, Kan

    2016-09-27

    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.

  10. Minimizing methyl bromide emissions from soil fumigation

    NASA Astrophysics Data System (ADS)

    Yates, S. R.; Wang, D.; Gan, J.; Ernst, F. F.; Jury, W. A.

    There is great controversy concerning the need to phase out methyl bromide (MeBr) to protect stratospheric ozone. Unlike chlorinated hydrocarbons, MeBr occurs naturally in the atmosphere making it difficult to differentiate the threat to stratospheric ozone depletion from anthropogenic use of MeBr compared to natural sources. New technology has been developed which could nearly eliminate MeBr emissions from soil fumigation, bringing into question the need for a phase out. A field experiment demonstrated that virtually impermeable films (VIF) reduced MeBr emissions to near-zero levels. When compared to soil fumigation using conventional high-density polyethylene film (HDPE), the total global MeBr emission could be reduced from 32 Gg/yr to less than 1 Gg/yr, if VIF were required. In addition, reduced application rates are possible since using VIF reduces wasteful leakage and increases pest-control efficiency. With such low emission rates, and considering the large uncertainty in global estimates of MeBr, it seems that the phase-out of MeBr as a soil fumigant is unjustified.

  11. Intrapulmonary perfluorooctyl bromide instillation in fetal rabbits.

    PubMed

    Muensterer, Oliver J; Klis, Verena J; Till, Holger; Bergmann, Florian; Metzger, Roman; Simbruner, Georg

    2005-07-01

    Instilling perfluorooctyl bromide (PFOB) into the fetal lung may lead to alveolar distension. The aim of the study was to evaluate the safety of PFOB instillation into fetal lungs and to determine the radiographic distribution and tissue concentration of PFOB in New Zealand white rabbits. Sibling fetuses of pregnant (day 27) New Zealand white rabbits were randomized to intratracheal instillation of 1 mL PFOB with tracheal ligation, instillation without ligation, and unmanipulated controls. The maternal animals were killed directly after instillation, at 3 or 6 hours (n = 10 each). For each study cohort, we determined fetal lung/body weight (FLBW) ratios, the radiographic distribution of PFOB, as well as pulmonary PFOB and water content by tissue distillation. PFOB concentrations in maternal and fetal tissues were assessed by gas chromatography. The relative amount of fetal lung PFOB recovered by fractional distillation was highest in ligated (25%) and lower in unligated lungs (9%). Extrapulmonary PFOB was found in the fetal brain (2.0 +/- 0.7 ppm), but not in any other fetal or maternal tissues. Mean FLBW ratios were highest in ligated fetuses, followed by unligated fetuses and controls. PFOB partially displaced fetal lung water. PFOB was visible in the lungs of all treated fetuses. Fetal survival between manipulated and unmanipulated fetuses did not differ. After prenatal intrapulmonary instillation, some PFOB remains in the lung, even if the trachea is not ligated, and may exert distending pressure on the alveoli.

  12. Selective oxidation of alcohols with alkali metal bromides as bromide catalysts: experimental study of the reaction mechanism.

    PubMed

    Moriyama, Katsuhiko; Takemura, Misato; Togo, Hideo

    2014-07-03

    A bromide-catalyzed oxidation of alcohols was developed which proceeded in the presence of an alkali metal bromide and an oxidant under mild conditions. The reaction involved an organic-molecule-free oxidation using KBr and Oxone and a Brønsted acid assisted oxidation using KBr and aqueous H2O2 solution to provide a broad range of carbonyl compounds in high yields. Moreover, the bromide-catalyzed oxidation of primary alcohols enabled the divergent synthesis of carboxylic acids and aldehydes under both reaction conditions in the presence of TEMPO. A possible catalytic mechanism was suggested on the basis of various mechanistic studies.

  13. Methyl Bromide Commodity Fumigation Buffer Zone Lookup Tables

    EPA Pesticide Factsheets

    Product labels for methyl bromide used in commodity and structural fumigation include requirements for buffer zones around treated areas. The information on this page will allow you to find the appropriate buffer zone for your planned application.

  14. 7 CFR 305.6 - Methyl bromide fumigation treatment schedules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., fumigation with methyl bromide for sapote fruit fly. Regulated citrus fruits originating inside an area quarantined for sapote fruit fly that are to be moved outside the quarantined area may be treated with...

  15. Pd-catalyzed nucleophilic fluorination of aryl bromides.

    PubMed

    Lee, Hong Geun; Milner, Phillip J; Buchwald, Stephen L

    2014-03-12

    On the basis of mechanism-driven reaction design, a Pd-catalyzed nucleophilic fluorination of aryl bromides and iodides has been developed. The method exhibits a broad substrate scope, especially with respect to nitrogen-containing heteroaryl bromides, and proceeds with minimal formation of the corresponding reduction products. A facilitated ligand modification process was shown to be critical to the success of the reaction.

  16. Pd-Catalyzed Nucleophilic Fluorination of Aryl Bromides

    PubMed Central

    2015-01-01

    On the basis of mechanism-driven reaction design, a Pd-catalyzed nucleophilic fluorination of aryl bromides and iodides has been developed. The method exhibits a broad substrate scope, especially with respect to nitrogen-containing heteroaryl bromides, and proceeds with minimal formation of the corresponding reduction products. A facilitated ligand modification process was shown to be critical to the success of the reaction. PMID:24559304

  17. Disinfection byproduct regulatory compliance surrogates and bromide-associated risk.

    PubMed

    Kolb, Chelsea; Francis, Royce A; VanBriesen, Jeanne M

    2017-08-01

    Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health. However, DBPs are regulated based on the mass sum of DBPs within a given class (e.g., trihalomethanes and haloacetic acids), not based on species-specific risk or extent of bromine incorporation. The regulated surrogate measures are intended to protect against not only the species they directly represent, but also against unregulated DBPs that are not routinely measured. Surrogates that do not incorporate effects of increasing bromide may not adequately capture human health risk associated with drinking water when source water bromide is elevated. The present study analyzes trihalomethanes (THMs), measured as TTHM, with varying source water bromide concentrations, and assesses its correlation with brominated THM, TTHM risk and species-specific THM concentrations and associated risk. Alternative potential surrogates are evaluated to assess their ability to capture THM risk under different source water bromide concentration conditions. The results of the present study indicate that TTHM does not adequately capture risk of the regulated species when source water bromide concentrations are elevated, and thus would also likely be an inadequate surrogate for many unregulated brominated species. Alternative surrogate measures, including THM3 and the bromodichloromethane concentration, are more robust surrogates for species-specific THM risk at varying source water bromide concentrations. Copyright © 2017. Published by Elsevier B.V.

  18. Hydrogen systems

    SciTech Connect

    Veziroglu, T.N.; Zhu, Y.; Bao, D.

    1985-01-01

    This book presents the papers given at a symposium on hydrogen fuels. Topics considered at the symposium included hydrogen from fossil fuels, electrolysis, photolytic hydrogen generation, thermochemical and photochemical methods of hydrogen production, catalysts, hydrogen biosynthesis, novel and hybrid methods of hydrogen production, storage and handling, metal hydrides and their characteristics, utilization, hydrogen fueled internal combustion engines, hydrogen gas turbines, hydrogen flow and heat transfer, fuel cells, synthetic hydrocarbon fuels, thermal energy transfer, hydrogen purification, research programs, economics, primary energy sources, environmental impacts, and safety.

  19. Synthesis, self-aggregation and biological properties of alkylphosphocholine and alkylphosphohomocholine derivatives of cetyltrimethylammonium bromide, cetylpyridinium bromide, benzalkonium bromide (C16) and benzethonium chloride.

    PubMed

    Lukáč, Miloš; Mrva, Martin; Garajová, Mária; Mojžišová, Gabriela; Varinská, Lenka; Mojžiš, Ján; Sabol, Marián; Kubincová, Janka; Haragová, Hana; Ondriska, František; Devínsky, Ferdinand

    2013-08-01

    A series of alkylphosphocholine and alkylphosphohomocholine derivatives of cetyltrimethylammonium bromide, cetylpyridinium bromide, benzalkonium bromide (C16) and benzethonium chloride have been synthesized. Their physicochemical properties were also investigated. The critical micelle concentration (cmc), the surface tension value at the cmc (γcmc), and the surface area at the surface saturation per head group (Acmc) were determined by means of surface tension measurements. The prepared compounds exhibit significant cytotoxic, antifungal and antiprotozoal activities. Alkylphosphocholines and alkylphosphohomocholines possess higher antifungal activity against Candida albicans in comparison with quaternary ammonium compounds in general. However, quaternary ammonium compounds exhibit significantly higher activity against human tumor cells and pathogenic free-living amoebae Acanthamoeba lugdunensis and Acanthamoeba quina compared to alkylphosphocholines. The relationship between structure, physicochemical properties and biological activity of the tested compounds is discussed.

  20. 77 FR 29341 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-17

    .... Structures and Facilities (Flour Mills, Rice Mills, Pet Food) Applicants must address potential economic... methyl bromide over the last three years; the rate, volume, and target CT of methyl bromide at each... methyl bromide over the last three years; the rate, volume, and target CT of methyl bromide at each...

  1. (Furfuryl-amino)-triphenyl-phospho-nium bromide.

    PubMed

    Martínez de León, Carla; Tlahuext, Hugo; Flores-Parra, Angelina; Duarte-Hernández, Angélica María; Grévy, Jean-Michel

    2013-01-01

    In the title salt, C23H21NOP(+)·Br(-), the dihedral angles between the phenyl rings are 70.41 (18), 73.6 (2) and 80.85 (19)°. In the crystal, neighboring mol-ecules are linked through an N-H⋯Br hydrogen bond and four weak C-H⋯Br contacts, forming a three-dimensional network.

  2. Re-manufacture of cobalt-manganese-bromide as a liquid catalyst from spent catalyst containing cobalt generated from petrochemical processes via hydrometallurgy.

    PubMed

    Joo, Sung-Ho; Shin, Dong Ju; Oh, Chang Hyun; Wang, Jei-Pil; Shin, Shun Myung

    2016-11-15

    Cobalt and manganese have been the subject of individual separation studies because their fields of application are different. However, this study shows that high-value products can be manufactured in the form of a cobalt-manganese-bromide (CMB) liquid catalyst by simultaneously recovering cobalt and manganese. Na-bis-(2,4,4-tri-methyl-pentyl)phosphinic acid was employed in order to manufacture the CMB liquid catalyst from the spent catalyst generated from petroleum chemistry processes. The pH-isotherm, degree of saponification of solvent and separation factor values were investigated. ΔpH50 and separation factor values show that Co and Mn can be separated from impurities such as Mg and Ca. Further, the extraction stages and organic/aqueous ratio isotherms were investigated using counter-current simulation extraction batch tests. To prepare CMB from a loaded organic phase obtained in a stripping study using hydrogen bromide, the Co and Mn were completely stripped and concentrated by a factor of 6 using a 2M hydrogen bromide solution. When compared with manufactured and commercial CMB, the CMB liquid catalyst could be produced by supplying a shortage of Mn in the form of manganese bromide. Finally, the method of manufacture of CMB was subjected to a real pilot plant test. Copyright © 2016. Published by Elsevier B.V.

  3. Effects of xenon insertion into hydrogen bromide. Comparison of the electronic structure of the HBr···CO2 and HXeBr···CO2 complexes using quantum chemical topology methods: electron localization function, atoms in molecules and symmetry adapted perturbation theory.

    PubMed

    Makarewicz, Emilia; Gordon, Agnieszka J; Mierzwicki, Krzysztof; Latajka, Zdzislaw; Berski, Slawomir

    2014-06-05

    Quantum chemistry methods have been applied to study the influence of the Xe atom inserted into the hydrogen-bromine bond (HBr → HXeBr), particularly on the nature of atomic interactions in the HBr···CO2 and HXeBr···CO2 complexes. Detailed analysis of the nature of chemical bonds has been carried out using topological analysis of the electron localization function, while topological analysis of electron density was used to gain insight into the nature of weak nonbonding interactions. Symmetry-adapted perturbation theory within the orbital approach was applied for greater understanding of the physical contributions to the total interaction energy.

  4. 4-Meth-oxy-benzamidinium bromide.

    PubMed

    Irrera, Simona; Portalone, Gustavo

    2013-01-01

    The title salt, C8H11N2O(+)·Br(-), was synthesized by the reaction between 4-meth-oxy-benzamidine (4-amidino-anisole) and hydro-bromic acid. In the cation, the amidinium group has two similar C-N bonds [1.304 (2) and 1.316 (2) Å], and its plane forms a dihedral angle of 31.08 (5)° with the benzene ring. The ions are associated in the crystal into a three-dimension hydrogen-bonded supra-molecular network featuring N-H(+)⋯Br(-) inter-actions.

  5. Intranasal ipratropium bromide for the common cold.

    PubMed

    AlBalawi, Zaina H; Othman, Sahar S; Alfaleh, Khalid

    2013-06-19

    The common cold is one of the most common illnesses in humans and constitutes an economic burden both in terms of productivity and expenditure for treatment. There is no proven cure for the common cold and symptomatic relief is the mainstay of treatment. The use of intranasal ipratropium bromide (IB) has been addressed in several studies and might prove an effective treatment for the common cold. To determine the effect of IB versus placebo or no treatment on severity of rhinorrhoea and nasal congestion in children and adults with the common cold. Subjective overall improvement was another primary outcome and side effects (for example, dry mucous membranes, epistaxis and systemic anticholinergic effects) were reported as a secondary outcome. In this updated review we searched CENTRAL 2013, Issue 3, MEDLINE (1950 to March week 4, 2013), MEDLINE in-process and other non-indexed citations (8 April 2013), EMBASE (1974 to April 2013), AMED (1985 to April 2013), Biosis (1974 to February 2011) and LILACS (1985 to April 2013). Randomised controlled trials (RCTs) comparing IB to placebo or no treatment in children and adults with the common cold. Two review authors independently extracted data and assessed trial quality. We used a standardised form to extract relevant data and we contacted trial authors for additional information. Seven trials with a total of 2144 participants were included. Four studies (1959 participants) addressed subjective change in severity of rhinorrhoea. All studies were consistent in reporting statistically significant changes in favour of IB. Nasal congestion was reported in four studies and was found to have no significant change between the two groups. Two studies found a positive response in the IB group for the global assessment of overall improvement. Side effects were more frequent in the IB group, odds ratio (OR) 2.09 (95% confidence interval (CI) 1.40 to 3.11). Commonly encountered side effects included nasal dryness, blood tinged mucus

  6. Intranasal ipratropium bromide for the common cold.

    PubMed

    Albalawi, Zaina H; Othman, Sahar S; Alfaleh, Khalid

    2011-07-06

    The common cold is one of the most common illnesses in humans and constitutes an economic burden both in terms of productivity and expenditure for treatment. There is no proven cure for the common cold and symptomatic relief is the mainstay of treatment. The use of intranasal ipratropium bromide (IB) has been addressed in several studies and might prove an effective treatment for the common cold. To determine the effect of IB versus placebo or no treatment on severity of rhinorrhoea and nasal congestion in children and adults with the common cold. Subjective overall improvement was another primary outcome and side effects were reported as a secondary outcome. We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2011, Issue 1) which contains the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1950 to January week 4, 2011), MEDLINE in-process and other non-indexed citations (February 2011), EMBASE (1974 to February 2011), AMED (1985 to February 2011), Biosis (1974 to February 2011) and LILACS (1985 to February 2011). Randomised controlled trials (RCTs) comparing IB to placebo or no treatment in children and adults with the common cold. Two review authors independently extracted data and assessed trial quality. We used a standardised form to extract relevant data and we contacted trial authors for additional information. Seven trials with a total of 2144 participants were included. Four studies (1959 participants) addressed subjective change in severity of rhinorrhoea. All studies were consistent in reporting statistically significant changes in favour of IB. Nasal congestion was reported in four studies and was found to have no significant change between the two groups. Two studies found a positive response in the IB group for the global assessment of overall improvement. Side effects were more frequent in the IB group, odds ratio (OR) 2.09 (95% confidence interval (CI) 1.40 to 3.11). Commonly encountered side effects included

  7. Zinc Bromide Combustion: Implications for the Consolidated Incinerator Facility

    SciTech Connect

    Oji, L.N.

    1998-12-16

    In the nuclear industry, zinc bromide (ZnBr2) is used for radiation shielding. At Savannah River Site (SRS) zinc bromide solution, in appropriate configurations and housings, was used mainly for shielding in viewing windows in nuclear reactor and separation areas. Waste stream feeds that will be incinerated at the CIF will occasionally include zinc bromide solution/gel matrices.The CIF air pollution systems control uses a water-quench and steam atomizer scrubber that collects salts, ash and trace metals in the liquid phase. Water is re-circulated in the quench unit until a predetermined amount of suspended solids or dissolved salts are present. After reaching the threshold limit, "dirty liquid", also called "blowdown", is pumped to a storage tank in preparation for treatment and disposal. The air pollution control system is coupled to a HEPA pre-filter/filter unit, which removes particulate matter from the flue gas stream (1).The objective of this report is to review existing literature data on the stability of zinc bromide (ZnBr2) at CIF operating temperatures (>870 degrees C (1600 degrees F) and determine what the combustion products are in the presence of excess air. The partitioning of the combustion products among the quencher/scrubber solution, bottom ash and stack will also be evaluated. In this report, side reactions between zinc bromide and its combustion products with fuel oil were not taken into consideration.

  8. Methyl bromide: effective pest management tool and environmental threat.

    PubMed

    Thomas, W B

    1996-12-01

    Methyl bromide is used extensively on a global basis as a pesticide against nematodes, weeds, insects, fungi, bacteria, and rodents. As a soil fumigant, it is used in significant quantities in the production of strawberry and tomato, as well as other agriculture commodities. Grain, fresh fruit, forestry products, and other materials are fumigated with methyl bromide to control pest infestations during transport and storage. Structures also are treated with this chemical to control wood-destroying insects and rodents. However, methyl bromide has been identified as a significant ozone-depleting substance, resulting in regulatory actions being taken by the U.S. Environmental Protection Agency and the United Nations Environment Program (Montreal Protocol). The science linking methyl bromide to ozone depletion is strong and was reinforced by the 1994 UNEP Montreal Protocol Science Assessment on Ozone Depletion, which states, "Methyl bromide continues to be viewed as a significant ozone-depleting compound." Identifying efficacious and viable alternatives in the near term is critical.

  9. Methyl Bromide: Effective Pest Management Tool and Environmental Threat

    PubMed Central

    Thomas, W. B.

    1996-01-01

    Methyl bromide is used extensively on a global basis as a pesticide against nematodes, weeds, insects, fungi, bacteria, and rodents. As a soil fumigant, it is used in significant quantities in the production of strawberry and tomato, as well as other agriculture commodities. Grain, fresh fruit, forestry products, and other materials are fumigated with methyl bromide to control pest infestations during transport and storage. Structures also are treated with this chemical to control wood-destroying insects and rodents. However, methyl bromide has been identified as a significant ozone-depleting substance, resulting in regulatory actions being taken by the U.S. Environmental Protection Agency and the United Nations Environment Program (Montreal Protocol). The science linking methyl bromide to ozone depletion is strong and was reinforced by the 1994 UNEP Montreal Protocol Science Assessment on Ozone Depletion, which states, "Methyl bromide continues to be viewed as a significant ozone-depleting compound." Identifying efficacious and viable alternatives in the near term is critical. PMID:19277178

  10. Cross-coupling of aromatic bromides with allylic silanolate salts.

    PubMed

    Denmark, Scott E; Werner, Nathan S

    2008-12-03

    The sodium salts of allyldimethylsilanol and 2-butenyldimethylsilanol undergo palladium-catalyzed cross-coupling with a wide variety of aryl bromides to afford allylated and crotylated arenes. The coupling of both silanolates required extensive optimization to deliver the expected products in high yields. The reaction of the allyldimethylsilanolate takes place at 85 degrees C in 1,2-dimethoxyethane with allylpalladium chloride dimer (2.5 mol %) to afford 73-95% yields of the allylation products. Both electron-rich and sterically hindered bromides reacted smoothly, whereas electron-poor bromides cross-coupled in poor yield because of a secondary isomerization to the 1-propenyl isomer (and subsequent polymerization). The 2-butenyldimethylsilanolate (E/Z, 80:20) required additional optimization to maximize the formation of the branched (gamma-substitution) product. A remarkable influence of added alkenes (dibenzylideneacetone and norbornadiene) led to good selectivities for electron-rich and electron-poor bromides in 40-83% yields. However, bromides containing coordinating groups (particularly in the ortho position) gave lower, and in one case even reversed, selectivity. Configurationally homogeneous (E)-silanolates gave slightly higher gamma-selectivity than the pure (Z)-silanolates. A unified mechanistic picture involving initial gamma-transmetalation followed by direct reductive elimination or sigma-pi isomerization can rationalize all of the observed trends.

  11. Effect of Bromide-Hypochlorite Bactericides on Microorganisms1

    PubMed Central

    Shere, Lewis; Kelley, Maurice J.; Richardson, J. Harold

    1962-01-01

    A new principle in compounding stable, granular bactericidal products led to unique combinations of a water-soluble inorganic bromide salt with a hypochlorite-type disinfectant of either inorganic or organic type. Microbiological results are shown for an inorganic bactericide composed of chlorinated trisodium phosphate containing 3.1% “available chlorine” and 2% potassium bromide, and for an organic bactericide formulated from sodium dichloroisocyanurate so as to contain 13.4% “available chlorine” and 8% potassium bromide. Comparison of these products with their nonbromide counterparts are reported for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus lactis, Aerobacter aerogenes, and Proteus vulgaris. Test methods employed were the Chambers test, the A.O.A.C. Germicidal and Detergent Sanitizer-Official test, and the Available Chlorine Germicidal Equivalent Concentration test. The minimal killing concentrations for the bromide-hypochlorite bactericides against this variety of organisms were reduced by a factor 2 to 24 times those required for similar hypochlorite-type disinfectants not containing the bromide. PMID:13977149

  12. Crystal structure of 3-amino-1-propyl­pyridinium bromide

    PubMed Central

    Venkatesan, P.; Rajakannan, V.; Thamotharan, S.

    2014-01-01

    The title mol­ecular salt, C8H13N2 +·Br−, crystallizes with two independent 3-amino­pyridinium cations and two bromide anions in the asymmetric unit (Z′ = 2). In the pyridine ring, the N atom is alkyl­ated by a propyl group. The dihedral angle between the mean planes of the pyridinium ring and the propyl group is 84.84 (2)° in cation A, whereas the corresponding angle is 89.23 (2)° in cation B. In the crystal, the anions and cations are linked via N—H⋯Br and C—H⋯Br hydrogen bonds, forming chains propagating along [100]. PMID:25552997

  13. Bromidotetra-kis-(1H-2-ethyl-5-methyl-imidazole-κN)copper(II) bromide.

    PubMed

    Godlewska, Sylwia; Baranowska, Katarzyna; Socha, Joanna; Dołęga, Anna

    2011-12-01

    The Cu(II) ion in the title compound, [CuBr(C(6)H(10)N(2))(4)]Br, is coordinated in a square-based-pyramidal geometry by the N atoms of four imidazole ligands and a bromide anion in the apical site. Both the Cu(II) and Br(-) atoms lie on a crystallographic fourfold axis. In the crystal, the [CuBr(C(6)H(10)N(2))(4)](+) complex cations are linked to the uncoordinated Br(-) anions (site symmetry [Formula: see text]) by N-H⋯Br hydrogen bonds, generating a three-dimensional network. The ethyl group of the imidazole ligand was modelled as disordered over two orientations with occupancies of 0.620 (8) and 0.380 (8).

  14. Tetrabutylammonium bromide (TBABr)-based deep eutectic solvents (DESs) and their physical properties.

    PubMed

    Yusof, Rizana; Abdulmalek, Emilia; Sirat, Kamaliah; Rahman, Mohd Basyaruddin Abdul

    2014-06-13

    Density, viscosity and ionic conductivity data sets of deep eutectic solvents (DESs) formed by tetrabutylammonium bromide (TBABr) paired with ethlyene glycol, 1,3-propanediol, 1,5-pentanediol and glycerol hydrogen bond donors (HBDs) are reported. The properties of DES were measured at temperatures between 303 K and 333 K for HBD percentages of 66.7% to 90%. The effects of HBDs under different temperature and percentages are systematically analyzed. As expected, the measured density and viscosity of the studied DESs decreased with an increase in temperature, while ionic conductivity increases with temperature. In general, DESs made of TBABr and glycerol showed the highest density and viscosity and the lowest ionic conductivity when compared to other DESs. The presence of an extra hydroxyl group on glycerol in a DES affected the properties of the DES.

  15. Hydrogen sensor

    DOEpatents

    Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

    2010-11-23

    A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

  16. Reaction of myeloperoxidase compound I with chloride, bromide, iodide, and thiocyanate.

    PubMed

    Furtmüller, P G; Burner, U; Obinger, C

    1998-12-22

    Myeloperoxidase plays a fundamental role in oxidant production by neutrophils. The enzyme uses hydrogen peroxide to oxidize chloride (Cl-), bromide (Br-), iodide (I-), and the pseudohalide thiocyanate (SCN-) to their respective hypohalous acids. This study for the first time presents transient kinetic measurements of the oxidation of these halides and thiocyanate by the myeloperoxidase intermediate compound I, using the sequential mixing stopped-flow technique. At pH 7 and 15 degrees C, the two-electron reduction of compound I to the native enzyme by Cl- has a second-order rate constant of (2.5 +/- 0.3) x 10(4) M(-1) s(-1), whereas reduction of compound I by SCN- has a second-order rate constant of (9.6 +/- 0.5) x 10(6) M(-1) s(-1). Iodide [(7.2 +/- 0.7) x 10(6) M(-1) s(-1)] is shown to be a better electron donor for compound I than Br- [(1.1 +/- 0.1) x 10(6) M(-1) s(-1)]. The pH dependence studies suggest that compound I reduction by (pseudo-)halides is controlled by a residue with a pKa of about 4.6. The protonation of this group is necessary for optimum (pseudo-)halide anion oxidation. These transient kinetic results are underlined by steady-state spectral and kinetic investigations. SCN- is shown to be most effective in shifting the system myeloperoxidase/hydrogen peroxide from the peroxidatic cycle to the halogenation cycle, whereas iodide is shown to be more effective than bromide which in turn is much more effective than chloride. Decreasing pH increases the rate of this transition. Our results show that thiocyanate is an important substrate of myeloperoxidase in most environments and that hypothiocyanate is likely to contribute to leukocyte antimicrobial activity.

  17. Hydrogenation apparatus

    DOEpatents

    Friedman, Joseph [Encino, CA; Oberg, Carl L [Canoga Park, CA; Russell, Larry H [Agoura, CA

    1981-01-01

    Hydrogenation reaction apparatus comprising a housing having walls which define a reaction zone and conduits for introducing streams of hydrogen and oxygen into the reaction zone, the oxygen being introduced into a central portion of the hydrogen stream to maintain a boundary layer of hydrogen along the walls of the reaction zone. A portion of the hydrogen and all of the oxygen react to produce a heated gas stream having a temperature within the range of from 1100.degree. to 1900.degree. C., while the boundary layer of hydrogen maintains the wall temperature at a substantially lower temperature. The heated gas stream is introduced into a hydrogenation reaction zone and provides the source of heat and hydrogen for a hydrogenation reaction. There also is provided means for quenching the products of the hydrogenation reaction. The present invention is particularly suitable for the hydrogenation of low-value solid carbonaceous materials to provide high yields of more valuable liquid and gaseous products.

  18. Cetyltrimethyl ammonium bromide assisted hydrothermal growth of hematite hollow cubes

    SciTech Connect

    Wang, Wei-Wei; Yao, Jia-Liang

    2010-11-15

    Hematite hollow cubes have been prepared by forced hydrolysis of ferric chloride solutions under hydrothermal conditions. The effects of reaction time, reaction temperature and cetyltrimethyl ammonium bromide on the transformation process from akageneite to hematite were investigated in detail. The products were characterized by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. It is found that cetyltrimethyl ammonium bromide was a critical factor influencing the phase transformation process of akageneite and the final morphology of the as-prepared products. With cetyltrimethyl ammonium bromide, hematite hollow cubes and porous spheres were obtained. Otherwise only dense cubes were observed even prolonging reaction time or increasing reaction temperature. The mechanism was proposed.

  19. [Tiotropium bromide for treating chronic obstructive pulmonary disease].

    PubMed

    Uteshev, D B; Buniatian, N D; Kovaleva, V L

    2010-11-01

    Five different types of muscarine-sensitive receptors were identified until now. In routine practice, the nonselective antagonist of cholinoreceptors are replaced by ipratropium bromide that is selectively blocking M1, M2, and M3 subtypes with the same affinity to each of them. However, the blockage of M2 subtype leads to bronchoconstriction and is accompanied by inhibition of M3 receptors in bronchial smooth muscles. The new drug tiotropium bromide selectively inhibits only the M1 and M3 types of receptors and does not affect the M2 subtype. This drug is administered only once a day, which is very important in clinical practice. Thus tiotropium bromide is the drug of choice for basic therapy of COPD.

  20. Growth and characterization of a new NLO material: L-Glutamic acid hydro bromide [L-GluHBr

    SciTech Connect

    Sathyalakshmi, R.; Bhagavannarayana, G.; Ramasamy, P.

    2009-05-06

    L-(+)-Glutamic acid hydro bromide, an isomorphic salt of L-glutamic acid hydrochloride, was synthesized and the synthesis was confirmed using Fourier transform infrared analysis. Solubility of the material in water was determined. L-Glutamic acid hydro bromide crystals were grown by low temperature solution growth using the solvent evaporation technique. Single crystal X-ray diffraction studies were carried out and the cell parameters, atomic co-ordinates, bond lengths and bond angles were reported. High-resolution X-ray diffraction studies were carried out and good crystallinity for the grown crystal was observed from the diffraction curve. The grown crystals were subjected to dielectric studies. Ultraviolet-visible-near infrared spectral analysis shows good optical transmission in the visible and infrared region of the grown crystals. The second harmonic generation efficiency of L-glutamic acid hydro bromide crystal was determined using the Kurtz powder test and it was found that it had efficiency comparable with that of the potassium di-hydrogen phosphate crystal.

  1. Photochemistry of alkyl bromides trapped in water ice films

    NASA Astrophysics Data System (ADS)

    Schrems, O.; Okaikwei, B.; Bluszcz, Th.

    2012-04-01

    Photochemical reactions of atmospheric trace gases taking place at the surface of atmospheric ice particles and in bulk ice are important in stratospheric and tropospheric chemistry but also in polar and alpine snowpack chemistry. Consequently, the understanding of the uptake und incorporation of atmospheric trace gases in water ice as well as their interactions with water molecules is very important for the understanding of processes which occur in ice particles and at the air/ice interface. Reactive atmospheric trace gases trapped in ice are subject of photochemical reactions when irradiated with solar UV radiation. Among such compounds bromine species are highly interesting due to their potential of depleting ozone both in the stratosphere and troposphere. Organic bromine gases can carry bromine to the stratosphere. Methyl bromide (CH3Br) is the largest bromine carrier to the stratosphere. It has both natural and anthropogenic sources. In this contribution we will present the results of our laboratory studies of alkyl bromides (methyl, bromide (CH3Br), dimethyl bromide (CH2Br2), n-propyl bromide (C3H7Br), 1,2-dibromoethane C2H4Br2)), trapped in water ice. We have simulated the UV photochemistry of these brominated alkanes isolated in ice films kept at 16 K and for comparison in solid argon matrices. The photoproducts formed in the ice have been identified by means of FTIR spectroscopy. Reflection absorption infrared spectroscopy (RAIRS) is especially useful to study nascent ice surfaces, kinetics of adsorption/decomposition, and heterogeneous catalysis. Among the observed photoproducts we could identify carbon monoxide and carbon dioxide for each alkyl bromide studied. The photoproduct HBr is dissociated in the bulk ice. Based on the experimental observations possible reaction mechanisms will be discussed.

  2. Sodium cromoglycate and ipratropium bromide in exercise-induced asthma.

    PubMed Central

    Thomson, N C; Patel, K R; Kerr, J W

    1978-01-01

    In thirteen patients with extrinsic asthma the effects of placebo, sodium cromoglycate, ipratropium bromide, and ipratropium bromide plus sodium cromoglycate were studied in a random double-blind fashion to assess their inhibitory action in exercise-induced asthma (EIA). Exercise testing consisted of steady state running on an inclined treadmill for up to eight minutes. In eight of the 13 patients studied the baseline ratio of expiratory flow at 50% vital capacity (VC) breathing helium-oxygen (V50He) to V50air was over 1.20 and they were called responders; the remaining five patients were called non-responders. There was a significantly lower baseline maximum mid-expiratory flow rate (MMEF) in non-responders (P less than 0.02) as compared to responders but no difference in forced expiratory volume in one second (FEV1) or forced vital capacity (FVC). Sodium cromoglycate (P less than 0.02), ipratropium bromide (P less than 0.01), and ipratropium bromide plus spdium cromoglycate (P less than 0.01) all significantly inhibited the percentage fall in FEV1 after exercise in the responders. Ipratropium bromide had no preventive action on non-responders, unlike sodium cromoglycate (P less than 0.05) and ipratropium bromide plus sodium cromoglycate (P less than 0.02). It is postulated that mediator release is an important factor in development of EIA in most extrinsic asthmatics, whereas cholinergic mechanisms are relevant only in those patients in whom the main site of airflow obstruction is in the large central airways. PMID:154747

  3. Methyl Bromide Fumigation of Pratylenchus brachyurus in Peanut Shells

    PubMed Central

    Minton, N. A.; Gillenwater, H. B.

    1973-01-01

    Five dosages of methyl bromide were used to fumigate peanut (Arachis hypogaea L.) shells and whole pods of peanuts in 1-liter flasks for 24 hr at 25 C. Methyl bromide dosages as low as 24.5 mg/liter killed all Pratylenchus brachyurus (Godfrey) Filip. &Sch. Stech. in peanut shells. Dosages of 44.6 and 50.9 mg/liter killed all but one or two nematodes in shells of whole pods. A 15% reduction in seed germination occurred at the 50.9-mg/liter dosage. PMID:19319321

  4. Reactive films for mitigating methyl bromide emissions from fumigated soil

    USDA-ARS?s Scientific Manuscript database

    Emissions of methyl bromide (MeBr) from agricultural fumigation can lead to depletion of the stratospheric ozone layer, and so its use is being phased out. However, as MeBr is still widely used under Critical Use Exemptions, strategies are still required to control such emissions. In this work, nove...

  5. Actual hazard of methyl bromide fumigation in soil disinfection.

    PubMed Central

    Van Den Oever, R U; Roosels, D; Lahaye, D

    1982-01-01

    Methyl bromide, a highly toxic and ready penetrating fumigant, is widely used against rodents, insects, mites, and a range of pathogenic organisms in soil, compost, and timber. To disinfect soil in greenhouses, methyl bromide is brought under pressure from outside by a vaporiser and blown on to ground under a polyethylene cover. The gas being three times heavier than air easily penetrates the ground. Depending on the local ventilation, a considerable amount of gas evaporates into the surrounding atmosphere, this emission being especially serious during the fumigation procedure and at the removal of the plastic cover. Previously, mechanical injection of methyl bromide on to the ground within closed areas was prohibited, since this technique exposed at least four disinfection workers at a time, who were provided with only a canister respirator, to gas concentrations of over 1000 ppm CH3Br. The present study established that fumigation with methyl bromide also carries risks for the well-protected worker inside, as well as for the one controlling the vaporiser. The concentration during application varies from 30 to 3000 ppm. Concentration in the air declines with time to 4 ppm CH3Br five days after application. Discarding the plastic sheet involves exposure to peak values as high as 200 ppm for a few seconds. On the ninth day after application, milling the soil can expose workers to up to 15 ppm; on the eleventh day no CH3Br concentration in the air could be found. PMID:7066229

  6. Evaluation of the Efficacy of Methyl Bromide in the ...

    EPA Pesticide Factsheets

    Journal Article The objective of this article is to determine the required conditions for the effective inactivation of Bacillus anthracis (B.a.) spores on materials using methyl bromide (MeBr) and to obtain comparative efficacy data with three avirulent microorganisms, to assess their potential as surrogates for B.a. Ames.

  7. Direct acylation of aryl bromides with aldehydes by palladium catalysis.

    PubMed

    Ruan, Jiwu; Saidi, Ourida; Iggo, Jonathan A; Xiao, Jianliang

    2008-08-13

    A new protocol for the direct acylation of aryl bromides with aldehydes is established. It appears to involve palladium-amine cooperative catalysis, affording synthetically important alkyl aryl ketones in moderate to excellent yields in a straightforward manner, and broadening the scope of metal-catalyzed coupling reactions.

  8. 40 CFR 180.124 - Methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Methyl bromide; tolerances for residues. 180.124 Section 180.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...

  9. 40 CFR 180.124 - Methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Methyl bromide; tolerances for residues. 180.124 Section 180.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...

  10. 40 CFR 180.124 - Methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Methyl bromide; tolerances for residues. 180.124 Section 180.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...

  11. Chemical alternatives to methyl bromide for Florida ornamental production

    USDA-ARS?s Scientific Manuscript database

    This project is a cooperative effort among USDA, ARS and University of Florida researchers, Florida in-ground ornamental producers, and fumigant industry representatives. Funding is provided through the USDA-ARS Area-wide Pest Management Program for Alternatives to Methyl Bromide. The ornamental i...

  12. Bromide ion effect on N-nitrosodimethylamine formation by monochloramine.

    PubMed

    Luh, Jeanne; Mariñas, Benito J

    2012-05-01

    N-Nitrosodimethylamine (NDMA) formation experiments conducted in phosphate buffer demonstrated that in waters containing monochloramine, the presence of bromide ion enhanced NDMA formation at the relatively high pH values of 8 and 9 after 24 h of reaction time, which was consistent with literature results. However, at relatively low to neutral pH (6 to 7), the presence of bromide resulted in lower NDMA formation as compared to results obtained in the absence of bromide. The hypothesis that bromamines were the species directly responsible for enhanced NDMA formation at high pH was tested and was shown not to be valid. Additional active bromine species were also tested, including hypobromous acid, hypobromite ion, and tribromide ion, with no species showing an ability to directly enhance NDMA formation. Analysis of the UV spectral data corresponding to the NDMA experiments suggest that the mechanism by which bromide enhances NDMA formation lies in the formation of a haloamine compound, possibly the mixed dihaloamine bromochloramine.

  13. Ipratropium bromide spray as treatment for sialorrhea in Parkinson's disease.

    PubMed

    Thomsen, Teri R; Galpern, Wendy R; Asante, Abena; Arenovich, Tamara; Fox, Susan H

    2007-11-15

    Sialorrhea is a significant problem in advanced Parkinson's disease (PD). Current treatment options include systemic anticholinergics which frequently cause side effects. We hypothesized that sublingual application of ipratropium bromide spray, an anticholinergic agent that does not cross the blood brain barrier, may reduce drooling without systemic side effects. We performed a randomized, double blind, placebo-controlled, crossover study in 17 subjects with PD and bothersome drooling. Patients were randomized to receive ipratropium bromide or placebo (one to two sprays, maximum of four times per day) for 2 weeks followed by a 1 week washout and crossover for further 2 weeks of treatment. The primary outcome was an objective measure of weight of saliva production. Secondary outcomes were subjective rating of severity and frequency of sialorrhoea using home diaries, United Parkinson's Disease Rating Scale (UPDRS) part II salivation subscore, parkinsonian disability using UPDRS, and adverse events. Ipratropium bromide spray had no significant effect on weight of saliva produced. There was a mild effect of treatment on subjective measures of sialorrhea. There were no significant adverse events. Ipratropium bromide spray was well tolerated in subjects with PD. Although it did not affect objective measures of saliva production, further studies in parkinsonism may be warranted.

  14. Evaluation of the Efficacy of Methyl Bromide in the ...

    EPA Pesticide Factsheets

    Journal Article The objective of this article is to determine the required conditions for the effective inactivation of Bacillus anthracis (B.a.) spores on materials using methyl bromide (MeBr) and to obtain comparative efficacy data with three avirulent microorganisms, to assess their potential as surrogates for B.a. Ames.

  15. [Bioequivalence of pyridostigmine bromide dispersible tablets in rabbits].

    PubMed

    Wang, Hong; Wang, Hong; Tan, Qun-you; Zhang, Li; Cheng, Xun-guan; Zhang, Jing-qing

    2011-10-01

    To compare the pharmacokinetic parameters of pyridostigmine bromide dispersible tablets and common tablets in rabbits. Twelve rabbits were given an oral dose (60 mg) of pyridostigmine bromide dispersible tablets or common tablets in a randomized crossover study. The plasma concentration of pyridostigmine bromide was determined by reversed-phase ion pair chromatography. The pharmacokinetic parameters were calculated using DAS2.1.1 software. The pharmacokinetic parameters showed no significant differences in rabbit plasma between pyridostigmine bromide dispersible tablets and common tablets. The two tablets had a C(max) of 1.83∓0.08 mg·L(-1) and 1.68∓0.03 mg·L(-1), tmax of 2.33∓0.41 h and 2.58∓0.20 h, AUC(0-24) of 15.50∓0.62 mg·h·L(-1) and 15.14∓0.30 mg·h·L(-1), AUC(0-∞) of 15.82∓0.70 mg·h·L(-1) and 15.57∓0.32 mg·h·L(-1), respectively. The relative bioavailability F(0-24) was 102.38% and F(0-∞) was 101.61% for the dispersible tablets. The two tablets are bioequivalent in rabbits.

  16. Pyridostigmine bromide alters locomotion and thigmotaxis of rats: gender effects.

    PubMed

    Hoy, J B; Cody, B A; Karlix, J L; Schmidt, C J; Tebbett, I R; Toffollo, S; Van Haaren, F; Wielbo, D

    1999-07-01

    Male rats and female rats in the proestrous and metestrous stages of estrus were tested to determine the effects of pyridostigmine bromide on locomotion rate and thigmotactic response using doses of 3.0, 10.0, and 30.0 mg/kg. Thirty minutes after administration of the pyridostigmine bromide the rats were videorecorded for 2 h in a 1 m2 open-field arena. The rats' activities were analyzed for the drug's effect on speed throughout the 2 h and during six 20-min segments. Also, the times that the rats were observed moving through the central 50% of the arena were determined. Locomotion rates decreased significantly, and thigmotaxses increased significantly in all groups of rats as a dose response to pyridostigmine bromide. Habituation occurred over 2 h for both responses, primarily during the first 40 min. Female rats were more affected than males, but metestrous and proestrous females did not differ significantly in their responses. At the 30 mg/kg the effect was persistent throughout the test period. Proestrous females dosed at 30 mg/kg had much higher pyridostigmine bromide serum levels than metestrous females and males.

  17. Depleting methyl bromide residues in soil by reaction with bases

    USDA-ARS?s Scientific Manuscript database

    Despite generally being considered the most effective soil fumigant, methyl bromide (MeBr) use is being phased out because its emissions from soil can lead to stratospheric ozone depletion. However, a large amount is still currently used due to Critical Use Exemptions. As strategies for reducing the...

  18. The Fate of Alternative Soil Funigants to Methyl Bromide

    USDA-ARS?s Scientific Manuscript database

    Soil fumigation is an important agricultural practice for the control of soil-borne pests. Since the phase–out of methyl bromide, due to its role in the depletion of stratospheric ozone, several alternatives such as 1,3-dichloropropene (1,3-D), chloropicrin (CP), and dimethyl disulfide (DMDS) are b...

  19. EFFECT OF BROMIDE ION ON FORMATION OF HAAS DURING CHLORINATION

    EPA Science Inventory

    loacetic acids (HAAs) during chlorination and he effects of independent variables, including pH, reaction time, and chlorine dosage. Almost all of the indpendent loaetic acids (HAAs) during chlorin...designed to statistically evaluate the influence of bromide ion on the formatio...

  20. EFFECT OF BROMIDE ION ON FORMATION OF HAAS DURING CHLORINATION

    EPA Science Inventory

    loacetic acids (HAAs) during chlorination and he effects of independent variables, including pH, reaction time, and chlorine dosage. Almost all of the indpendent loaetic acids (HAAs) during chlorin...designed to statistically evaluate the influence of bromide ion on the formatio...

  1. Bromine in blood, EEG and transaminases in methyl bromide workers.

    PubMed Central

    Verberk, M M; Rooyakkers-Beemster, T; de Vlieger, M; van Vliet, A G

    1979-01-01

    In 33 methyl bromide users, slight electroencephalographic changes (in 10 subjects) and a small increase in serum transaminases were found which could be related to bromine concentration in blood. No relationship was found with subjective symptoms, general neurological examination or the results of serum protein electrophoresis. PMID:444442

  2. Capacitive-discharge-pumped copper bromide vapour laser

    SciTech Connect

    Sukhanov, V B; Fedorov, V F; Troitskii, V O; Gubarev, F A; Evtushenko, Gennadii S

    2007-07-31

    A copper bromide vapour laser pumped by a high-frequency capacitive discharge is developed. It is shown that, by using of a capacitive discharge, it is possible to built a sealed off metal halide vapour laser of a simple design allowing the addition of active impurities into the working medium. (letters)

  3. Status of Alternatives for Methyl Bromide in the United States

    USDA-ARS?s Scientific Manuscript database

    Methyl bromide is a fumigant used for disinfestation of soils, commodities and structures. Listed as an ozone-depleting chemical international environmental protocols and the U.S. Clean Air Act require that its use be severely restricted. Although use of this fumigant has fallen considerably, the U....

  4. REVIEW OF CONTROL OPTIONS FOR METHYL BROMIDE IN COMMODITY TREATMENT

    EPA Science Inventory

    The report describes recent developments in the control of methyl bromide (MeBr) and discusses technical considerations and requirements for and economic feasibility of recovery. (NOTE: MeBr, fumigant for agricultural commodities, is an ozone depleting chemical. The U.S. EPA has ...

  5. On the existence of ‘L-alanine cadmium bromide'

    NASA Astrophysics Data System (ADS)

    Srinivasan, Bikshandarkoil R.

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  6. On the existence of 'L-alanine cadmium bromide'.

    PubMed

    Srinivasan, Bikshandarkoil R

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  7. REVIEW OF CONTROL OPTIONS FOR METHYL BROMIDE IN COMMODITY TREATMENT

    EPA Science Inventory

    The report describes recent developments in the control of methyl bromide (MeBr) and discusses technical considerations and requirements for and economic feasibility of recovery. (NOTE: MeBr, fumigant for agricultural commodities, is an ozone depleting chemical. The U.S. EPA has ...

  8. 21 CFR 522.275 - N-Butylscopolammonium bromide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false N-Butylscopolammonium bromide. 522.275 Section 522.275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  9. 21 CFR 522.275 - N-Butylscopolammonium bromide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false N-Butylscopolammonium bromide. 522.275 Section 522.275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  10. 21 CFR 522.275 - N-Butylscopolammonium bromide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false N-Butylscopolammonium bromide. 522.275 Section 522.275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  11. 75 FR 5582 - Methyl Bromide; Amendments to Terminate Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... or on alfalfa hay and cottonseed for these product registrations. These are the last products containing the pesticide methyl bromide registered for use on alfalfa hay and cotton seed in the United... post-harvest alfalfa hay and post-harvest cottonseed uses is prohibited after October 31, 2009,...

  12. Methyl bromide phase out could affect future reforestation efforts

    USDA-ARS?s Scientific Manuscript database

    Methyl bromide has long been an integral component in producing healthy tree seedlings in forest nurseries of California, Idaho, Montana, Oregon and Washington. The fumigant was supposed to be completely phased out of use in the United States of America by 2005, but many forest nurseries continue to...

  13. Hydrogen halide cleaning of powder metallurgy nickel-20 chromium-3 thoria.

    NASA Technical Reports Server (NTRS)

    Herbell, T. P.

    1972-01-01

    The Cr2O3 content of powder metallurgy nickel-20 chromium-3 thoria was reduced with atmospheres consisting of hydrogen plus hydrogen chloride (HCl) or hydrogen bromide (HBr). The nonthoria oxygen content or 'oxygen excess' was reduced from an initial amount of greater than 50,000 ppm to less than 100 ppm. Low temperatures were effective, but lowest oxygen levels were achieved with the highest cleaning temperature of 1200 C.

  14. T-type Ca2+ channel modulation by otilonium bromide

    PubMed Central

    Strege, Peter R.; Sha, Lei; Beyder, Arthur; Bernard, Cheryl E.; Perez-Reyes, Edward; Evangelista, Stefano; Gibbons, Simon J.; Szurszewski, Joseph H.

    2010-01-01

    Antispasmodics are used clinically to treat a variety of gastrointestinal disorders by inhibition of smooth muscle contraction. The main pathway for smooth muscle Ca2+ entry is through L-type channels; however, there is increasing evidence that T-type Ca2+ channels also play a role in regulating contractility. Otilonium bromide, an antispasmodic, has previously been shown to inhibit L-type Ca2+ channels and colonic contractile activity. The objective of this study was to determine whether otilonium bromide also inhibits T-type Ca2+ channels. Whole cell currents were recorded by patch-clamp technique from HEK293 cells transfected with cDNAs encoding the T-type Ca2+ channels, CaV3.1 (α1G), CaV3.2 (α1H), or CaV3.3 (α1I) alpha subunits. Extracellular solution was exchanged with otilonium bromide (10−8 to 10−5 M). Otilonium bromide reversibly blocked all T-type Ca2+ channels with a significantly greater affinity for CaV3.3 than CaV3.1 or CaV3.2. Additionally, the drug slowed inactivation in CaV3.1 and CaV3.3. Inhibition of T-type Ca2+ channels may contribute to inhibition of contractility by otilonium bromide. This may represent a new mechanism of action for antispasmodics and may contribute to the observed increased clinical effectiveness of antispasmodics compared with selective L-type Ca2+ channel blockers. PMID:20203058

  15. T-type Ca(2+) channel modulation by otilonium bromide.

    PubMed

    Strege, Peter R; Sha, Lei; Beyder, Arthur; Bernard, Cheryl E; Perez-Reyes, Edward; Evangelista, Stefano; Gibbons, Simon J; Szurszewski, Joseph H; Farrugia, Gianrico

    2010-05-01

    Antispasmodics are used clinically to treat a variety of gastrointestinal disorders by inhibition of smooth muscle contraction. The main pathway for smooth muscle Ca(2+) entry is through L-type channels; however, there is increasing evidence that T-type Ca(2+) channels also play a role in regulating contractility. Otilonium bromide, an antispasmodic, has previously been shown to inhibit L-type Ca(2+) channels and colonic contractile activity. The objective of this study was to determine whether otilonium bromide also inhibits T-type Ca(2+) channels. Whole cell currents were recorded by patch-clamp technique from HEK293 cells transfected with cDNAs encoding the T-type Ca(2+) channels, Ca(V)3.1 (alpha1G), Ca(V)3.2 (alpha1H), or Ca(V)3.3 (alpha1I) alpha subunits. Extracellular solution was exchanged with otilonium bromide (10(-8) to 10(-5) M). Otilonium bromide reversibly blocked all T-type Ca(2+) channels with a significantly greater affinity for Ca(V)3.3 than Ca(V)3.1 or Ca(V)3.2. Additionally, the drug slowed inactivation in Ca(V)3.1 and Ca(V)3.3. Inhibition of T-type Ca(2+) channels may contribute to inhibition of contractility by otilonium bromide. This may represent a new mechanism of action for antispasmodics and may contribute to the observed increased clinical effectiveness of antispasmodics compared with selective L-type Ca(2+) channel blockers.

  16. 77 FR 31564 - Notice of Availability of a Treatment Evaluation Document; Methyl Bromide Fumigation of Cottonseed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-29

    ...; Methyl Bromide Fumigation of Cottonseed AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION... add to the Plant Protection and Quarantine Treatment Manual a treatment schedule for methyl bromide... EPA or by any other Federal entity. We have determined a new methyl bromide fumigation treatment...

  17. 77 FR 48153 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-13

    ... AGENCY Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications... Register requesting applications for the Critical Use Exemption from the phaseout of methyl bromide for 2015. On August 3, 2012, EPA received a letter from methyl bromide stakeholders requesting an extension...

  18. 78 FR 36507 - Notice of Availability of a Treatment Evaluation Document; Methyl Bromide Fumigation of Blueberries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ...; Methyl Bromide Fumigation of Blueberries AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION... schedule for methyl bromide fumigation of blueberries for Mediterranean fruit fly and South American fruit...-i-1-1) requires blueberries to be treated with methyl bromide at 70 F or above using 2 lbs...

  19. 78 FR 32646 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... using for their commodity. Structures and Facilities (flour mills, rice mills, pet food) Published data... the last three years; the rate, volume, and target CT of methyl bromide at each location; volume of... methyl bromide over the last three ] years; the rate, volume, and target CT of methyl bromide at each...

  20. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN P...

  1. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN P...

  2. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN P...

  3. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  4. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN P...

  5. Heat capacities of the water + lithium bromide + ethanolamine and water + lithium bromide + 1,3-propanediol systems

    SciTech Connect

    Kim, J.S.; Park, Y.; Lee, H.; Yu, S.I.

    1997-03-01

    Heat capacities of the water + lithium bromide + ethanolamine (LiBr/H{sub 2}N(CH{sub 2}){sub 2}OH mass ratio = 3.5) and water + lithium bromide + 1,3-propanediol (LiBr/HO(CH{sub 2}){sub 3}OH mass ratio = 3.5) systems were measured by using an isoperibol solution calorimeter at four temperatures (283.15, 298.15, 313.15, and 333.15 K) and absorbent (LiBr + H{sub 2}N(CH{sub 2}){sub 2}OH and LiBr + HO(CH{sub 2}){sub 3}OH) concentration ranges of (29.2 to 70.7)% and (30.7 to 68.3)%, respectively. The measured values were fitted with a simple equation by a least-squares method and the average absolute deviations between experimental and calculated values were 0.21% for the water + lithium bromide + ethanolamine system and 0.15% for the water + lithium bromide + 1,3-propanediol system, respectively.

  6. Uptake of ozone to mixed sodium bromide/ citric acid solutions

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Tao; Steimle, Emilie; Bartels-Rausch, Thorsten; Kato, Shunsuke; Lampimäki, Markus; Brown, Matthew; van Bokhoven, Jeroen; Nolting, Frithjof; Kleibert, Armin; Türler, Andreas; Ammann, Markus

    2013-04-01

    Sea-salt solution - air interfaces play an important role in the chemistry of the marine boundary layer. The reaction of ozone (O3) with bromide is of interest in the context of formation of photolabile halogens (Br2, BrCl) in the marine boundary layer. Recent experiments have suggested that the bromide oxidation rate is related to the surface concentration of bromide [1] and inversely related to the gas phase concentration of O3, an indication for a precursor mediated reaction at the surface [2]. So far, the effect of organics (such as those occurring at the ocean surface or in marine aerosols) on the reaction of O3 with bromide aerosols has not been studied yet. In our study we investigate the uptake kinetics of O3 to a mixed solution of sodium bromide (NaBr) and citric acid (CA), which represents highly oxidized organic compounds present in the environment, with a well-established coated wall flow tube technique, which leads to exposure of the film to O3 allowing the heterogeneous reactions to take place and the loss of O3 being measured. The results indicate that the uptake of O3 to the films with the higher bromide concentrations (0.34M and 4M) is independent of the gas phase concentration and roughly consistent with uptake limited by reaction in the bulk. For the lower bromide concentration (84mM), however, we observe a trend of the uptake coefficient to decrease with increasing O3 concentration, indicating an increasing importance of a surface reaction. In an attempt to constrain the kinetic data, we employed X-ray photoelectron spectroscopy (XPS) to get insight into the surface composition of the aqueous solution - air interface. Previous XPS studies have shown that halide ion concentrations are enhanced at the aqueous solution air interface [3-4], which likely promotes the surface reactions of bromide or iodide with O3. A first XPS study of ternary solutions of KI with butanol indicated the importance of specific interactions of the cation with the alcohol

  7. Hydrogen generator

    SciTech Connect

    Adlhart, O. J.

    1985-04-23

    This disclosure relates to a replaceable cartridge hydrogen generator of the type which relies at least partially on the process of anodic corrosion to produce hydrogen. A drum contains a plurality of the cartridges.

  8. Hydrogen Generator

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A unit for producing hydrogen on site is used by a New Jersey Electric Company. The hydrogen is used as a coolant for the station's large generator; on-site production eliminates the need for weekly hydrogen deliveries. High purity hydrogen is generated by water electrolysis. The electrolyte is solid plastic and the control system is electronic. The technology was originally developed for the Gemini spacecraft.

  9. Hydrogen Production

    SciTech Connect

    2014-09-01

    This 2-page fact sheet provides a brief introduction to hydrogen production technologies. Intended for a non-technical audience, it explains how different resources and processes can be used to produce hydrogen. It includes an overview of research goals as well as “quick facts” about hydrogen energy resources and production technologies.

  10. Hydrogen Storage

    SciTech Connect

    2008-11-01

    This 2-page fact sheet provides a brief introduction to hydrogen storage technologies. Intended for a non-technical audience, it explains the different ways in which hydrogen can be stored, as well as the technical challenges and research goals for storing hydrogen on board a vehicle.

  11. Multimetallic catalysed cross-coupling of aryl bromides with aryl triflates.

    PubMed

    Ackerman, Laura K G; Lovell, Matthew M; Weix, Daniel J

    2015-08-27

    The advent of transition-metal catalysed strategies for forming new carbon-carbon bonds has revolutionized the field of organic chemistry, enabling the efficient synthesis of ligands, materials, and biologically active molecules. In cases where a single metal fails to promote a selective or efficient transformation, the synergistic cooperation of two distinct catalysts--multimetallic catalysis--can be used instead. Many important reactions rely on multimetallic catalysis, such as the Wacker oxidation of olefins and the Sonogashira coupling of alkynes with aryl halides, but this approach has largely been limited to the use of metals with distinct reactivities, with only one metal catalyst undergoing oxidative addition. Here, we demonstrate that cooperativity between two group 10 metal catalysts--(bipyridine)nickel and (1,3-bis(diphenylphosphino)propane)palladium--enables a general cross-Ullmann reaction (the cross-coupling of two different aryl electrophiles). Our method couples aryl bromides with aryl triflates directly, eliminating the use of arylmetal reagents and avoiding the challenge of differentiating between multiple carbon-hydrogen bonds that is required for direct arylation methods. Selectivity can be achieved without an excess of either substrate and originates from the orthogonal reactivity of the two catalysts and the relative stability of the two arylmetal intermediates. While (1,3-bis(diphenylphosphino)propane)palladium reacts preferentially with aryl triflates to afford a persistent intermediate, (bipyridine)nickel reacts preferentially with aryl bromides to form a transient, reactive intermediate. Although each catalyst forms less than 5 per cent cross-coupled product in isolation, together they are able to achieve a yield of up to 94 per cent. Our results reveal a new method for the synthesis of biaryls, heteroaryls, and dienes, as well as a general mechanism for the selective transfer of ligands between two metal catalysts. We anticipate that this

  12. Multimetallic catalysed cross-coupling of aryl bromides with aryl triflates

    NASA Astrophysics Data System (ADS)

    Ackerman, Laura K. G.; Lovell, Matthew M.; Weix, Daniel J.

    2015-08-01

    The advent of transition-metal catalysed strategies for forming new carbon-carbon bonds has revolutionized the field of organic chemistry, enabling the efficient synthesis of ligands, materials, and biologically active molecules. In cases where a single metal fails to promote a selective or efficient transformation, the synergistic cooperation of two distinct catalysts--multimetallic catalysis--can be used instead. Many important reactions rely on multimetallic catalysis, such as the Wacker oxidation of olefins and the Sonogashira coupling of alkynes with aryl halides, but this approach has largely been limited to the use of metals with distinct reactivities, with only one metal catalyst undergoing oxidative addition. Here, we demonstrate that cooperativity between two group 10 metal catalysts--(bipyridine)nickel and (1,3-bis(diphenylphosphino)propane)palladium--enables a general cross-Ullmann reaction (the cross-coupling of two different aryl electrophiles). Our method couples aryl bromides with aryl triflates directly, eliminating the use of arylmetal reagents and avoiding the challenge of differentiating between multiple carbon-hydrogen bonds that is required for direct arylation methods. Selectivity can be achieved without an excess of either substrate and originates from the orthogonal reactivity of the two catalysts and the relative stability of the two arylmetal intermediates. While (1,3-bis(diphenylphosphino)propane)palladium reacts preferentially with aryl triflates to afford a persistent intermediate, (bipyridine)nickel reacts preferentially with aryl bromides to form a transient, reactive intermediate. Although each catalyst forms less than 5 per cent cross-coupled product in isolation, together they are able to achieve a yield of up to 94 per cent. Our results reveal a new method for the synthesis of biaryls, heteroaryls, and dienes, as well as a general mechanism for the selective transfer of ligands between two metal catalysts. We anticipate that this

  13. Hydrogen as a vector for central receiver solar utilities

    NASA Astrophysics Data System (ADS)

    Bilgen, E.; Bilgen, C.

    The production of hydrogen and hydrogen-rich fuels from water and raw petroleum and gas products by means of a central receiver solar utility plant is examined. The fuels produced would be employed for both industrial and domestic purposes. The latter is also considered as a market for the low-grade heat with small heliostat-central receiver configurations. The total system efficiencies for conversion of solar radiation to heat are calculated, as are the thermodynamic balances of water decomposition. Attention is given to the hybrid sulfuric acid, sulfuric acid-hydrogen bromide, and the sulfuric acid-hydrogen iodine cycles, noting that the last has an overall thermal efficiency of 50 percent. An initial outline of a solar hydrogen plant is provided, indicating annual hydrogen production costs of $18.2/GJ for a thermomechanical process and $20.7/GJ for a solar thermal electrolysis process in the 1990s.

  14. Aluminium Electroplating on Steel from a Fused Bromide Electrolyte

    SciTech Connect

    Prabhat Tripathy; Laura Wurth; Eric Dufek; Toni Y. Gutknecht; Natalie Gese; Paula Hahn; Steven Frank; Guy Fredrickson; J Stephen Herring

    2014-08-01

    A quaternary bromide bath (LiBr-KBr-CsBr-AlBr3) was used to electro-coat aluminium on steel substrates. The electrolyte was prepared by the addition of AlBr3 into the eutectic LiBr-KBr-CsBr melt. A smooth, thick, adherent and shiny aluminium coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminium coverage. Both salt immersion and open circuit potential measurement suggest that the coatings did display good corrosion-resistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminium coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminium coating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

  15. Thermal stability of octadecyltrimethylammonium bromide modified montmorillonite organoclay.

    PubMed

    Xi, Yunfei; Zhou, Qin; Frost, Ray L; He, Hongping

    2007-07-15

    Organoclays are significant for providing a mechanism for the adsorption of organic molecules from potable water. As such their thermal stability is important. A combination of thermogravimetric analysis and infrared emission spectroscopy was used to determine this stability. Infrared emission spectroscopy (IES) was used to investigate the changes in the structure and surface characteristics of water and surfactant molecules in montmorillonite, octadecyltrimethylammonium bromide and organoclays prepared with the surfactant octadecyltrimethylammonium bromide with different surfactant loadings. These spectra collected at different temperatures give support to the results obtained from the thermal analysis and also provide additional evidence for the dehydration which is difficult to obtain by normal thermoanalytical techniques. The spectra provide information on the conformation of the surfactant molecules in the clay layers and the thermal decomposition of the organoclays. Infrared emission spectroscopy proved to be a useful tool for the study of the thermal stability of the organoclays.

  16. Aluminum electroplating on steel from a fused bromide electrolyte

    SciTech Connect

    Prabhat K. Tripathy; Laura A. Wurth; Eric J. Dufek; Toni Y. Gutknecht; Natalie J. Gese; Paula Hahn; Steven M. Frank; Guy L. Frederickson; J. Stephen Herring

    2014-08-01

    A quaternary bromide bath (LiBr–KBr–CsBr–AlBr3) was used to electro-coat aluminum on steel substrates. The electrolytewas prepared by the addition of AlBr3 into the eutectic LiBr–KBr–CsBr melt. A smooth, thick, adherent and shiny aluminum coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminum coverage. Both salt immersion and open circuit potential measurement suggested that the coatings did display a good corrosionresistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminum coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminumcoating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

  17. Effect of bromide and nitrite on the degradation of monochloramine

    SciTech Connect

    Valentine, R.L.; Selleck, R.E.

    1981-10-01

    The results indicate that relatively small concentrations of nitrite can greatly accelerate the degradation of monochloramine in the presence of bromide. It does not appear that nitrite is being significantly consumed in a 1:1 stoichiometric oxidation by monochloramine. If the effect of nitrite is catalytic then these results suggest that the presence of nitrite may also accelerate other oxidation-reduction reactions. For example, nitrite may play an important role in oxidant decay in partially nitrified sewage effluents where both monochloramine and nitrite may be present. If not a complex oxidation-reduction possibly involving bromide as a catalyst is indicated. The results also suggest that the presence of other potentially oxidizable species may affect oxidant decay in a manner not attributable to a simple parallel oxidation.

  18. Experimental study of the micellar nematic phase of tetradecyltrimethylammonium bromide

    NASA Astrophysics Data System (ADS)

    Photinos, Panos; Xu, Shou Yi; Saupe, Alfred

    1990-07-01

    Measurements of the electric conductivity parallel and normal to the nematic director, of the reorientation time in magnetic fields, of the birefringence, and of the density are presented as functions of temperature and concentration, for the system tetradecyltrimethylammonium bromide-D2O. The density in the nematic and the isotropic phases decreases with temperature, almost linearly. The variation is described in terms of the expansion of the aqueous phase and the alkyl chains forming the micellar interior. The data also indicate denser packing at the transition to the isotropic phase. The conductivity anisotropy and the birefringence are rather low and show little variation with temperature; the reorientation times are very long, corresponding to rotational viscosities between 1000 and 3000 P. The high viscosity indicates that the micelles have total length much higher than the persistence length, and may show flow properties similar to polymer solutions.

  19. [The compatibility between packing material and ipratropium bromide aerosol].

    PubMed

    Yue, Zhi-hua; Shen, Dian-dian; Hu, Chang-qin

    2010-08-01

    With the establishment of HPLC and LC-MS methods to determine the related substances and the content of active pharmaceutical ingredient (API) in ipratropium bromide aerosol products, several packing material-related impurities were identified, including antioxygen BHT and antioxygen 2246. Results showed that these leachable additives from the packing materials may present at a relative high level in the drug solution, and the low content of API in the drug products is usually due to the adsorption of the packing material as well as the leaking of contents. The current available assay methods for the control of ipratropium bromide aerosol products are often lack of specificity and unable to assure the drug quality effectively. To meet the increasing attention on the regulations of drug packing materials, our research would be a pilot study, indicating that the inappropriate packing materials could cause the migration and adsorption of the active ingredients, and the importance to have compatibility studies between packing materials and drugs.

  20. [Preparation and quality control of pyridostigmine bromide orally disintegrating tablet].

    PubMed

    Zhang, Li; Tan, Qun-you; Cheng, Xun-guan; Wang, Hong; Hu, Ni-ni; Zhang, Jing-qing

    2012-05-01

    To prepare orally disintegrating tablets containing pyridostigmine bromide and optimize formulations. Solid dispersion was prepared using solvent evaporation-deposition method. The formulation was optimized by central composite design-response surface methodology (RSM plus CCD) with disintegration time as a reference parameter. The orally disintegrating tablets showed integrity and were smooth with desirable taste and feel in mouth. The disintegration time was less than 30 s. The cumulative drug dissolution was around 8.5% (around 2.5 mg which was less than bitterness threshold of pyridostigmine bromide of 3 mg) within 5 min in water while the cumulative drug dissolution was higher than 95% within 2 min in 0.1 N HCl. The orally disintegrating tablets are reasonable in formulation, feasible in technology and patient-friendly.

  1. Study of ferroelectric characteristics of diisopropylammonium bromide films

    NASA Astrophysics Data System (ADS)

    Thirmal, C.; Biswas, P. P.; Shin, Y. J.; Noh, T. W.; Giridharan, N. V.; Venimadhav, A.; Murugavel, P.

    2016-09-01

    Organic molecular ferroelectrics are highly desirable due to their numerous advantages. In the present work, a thick film of diisopropylammonium bromide organic molecular ferroelectric is fabricated on the ITO/glass substrate. The grown film shows preferential orientation along the c-axis with a ferroelectric transition at 419 K. The piezoresponse force microscopic measurements are done in a dual ac resonance tracking mode for its switching characteristics. The amplitude and phase images of the oppositely written domain patterns exhibit a clear contrast with 180° phase difference. The dynamical spectroscopic studies reveal a butterfly loop in amplitude and hysteretic character of the phase which are the expected characteristics features of ferroelectrics. In addition, the macroscopic polarization versus electric field hysteresis gives an additional proof for ferroelectric character of the film with the maximum polarization of 3.5 μC/cm2. Overall, we have successfully fabricated diisopropylammonium bromide organic films and demonstrated its room temperature ferroelectric characteristics.

  2. A novel and robust conditioning lesion induced by ethidium bromide

    PubMed Central

    Hollis, Edmund R; Ishiko, Nao; Tolentino, Kristine; Doherty, Ernest; Rodriguez, Maria J.; Calcutt, Nigel A.; Zou, Yimin

    2015-01-01

    Molecular and cellular mechanisms underlying the peripheral conditioning lesion remain unsolved. We show here that injection of a chemical demyelinating agent, ethidium bromide, into the sciatic nerve induces a similar set of regeneration-associated genes and promotes a 2.7-fold greater extent of sensory axon regeneration in the spinal cord than sciatic nerve crush. We found that more severe peripheral demyelination correlates with more severe functional and electrophysiological deficits, but more robust central regeneration. Ethidium bromide injection does not activate macrophages at the demyelinated sciatic nerve site, as observed after nerve crush, but briefly activates macrophages in the dorsal root ganglion. This study provides a new method for investigating the underlying mechanisms of the conditioning response and suggests that loss of the peripheral myelin may be a major signal to change the intrinsic growth state of adult sensory neurons and promote regeneration. PMID:25541322

  3. Hydrogenation apparatus

    DOEpatents

    Friedman, J.; Oberg, C. L.; Russell, L. H.

    1981-06-23

    Hydrogenation reaction apparatus is described comprising a housing having walls which define a reaction zone and conduits for introducing streams of hydrogen and oxygen into the reaction zone, the oxygen being introduced into a central portion of the hydrogen stream to maintain a boundary layer of hydrogen along the walls of the reaction zone. A portion of the hydrogen and all of the oxygen react to produce a heated gas stream having a temperature within the range of from 1,100 to 1,900 C, while the boundary layer of hydrogen maintains the wall temperature at a substantially lower temperature. The heated gas stream is introduced into a hydrogenation reaction zone and provides the source of heat and hydrogen for a hydrogenation reaction. There also is provided means for quenching the products of the hydrogenation reaction. The present invention is particularly suitable for the hydrogenation of low-value solid carbonaceous materials to provide high yields of more valuable liquid and gaseous products. 2 figs.

  4. Zinc Bromide Flow Battery Installation for Islanding and Backup Power

    DTIC Science & Technology

    2016-09-18

    This Environmental Security Technology Certification Program (ESTCP) effort demonstrates the energy security and cost benefits of implementing a Zinc...Bromide (Zn/Br) Flow Battery-based Energy Storage System (ESS) at the Marine Corps Air Station (MCAS) Miramar. The effort integrates an innovative Zn...Br Flow Battery and Intelligent Power and Energy Management (IPEM) technologies with the existing MCAS infrastructure, providing energy security and

  5. A Lithium Bromide Absorption Chiller with Cold Storage

    DTIC Science & Technology

    2011-01-15

    TO R A G E A LITHIUM BROMIDE ABSORPTION CHILLER WITH COLD STORAGE William Gerstler, et al, General Electric Global Research UNCLASSIFIED UNLIMITED...Research ABSTRACT A LiBr-based absorption chiller can use waste heat or solar energy to produce useful space cooling for small buildings...However, operating this absorption chiller at high ambient tem- peratures may result in performance degradation, crystallization in the absorber, and

  6. The Thz Absorption of Methyl Bromide (CH_3BR)

    NASA Astrophysics Data System (ADS)

    Ramos, Marlon; Drouin, Brian J.

    2011-06-01

    The possibility of monitoring Methyl Bromide is of interest for both environmental and health concerns. It has an ozone depletion potential of 0.2% and falls under regulations of the Clean Air Act. Neurological effects from long term exposure may result from its major use as a pesticide. Recent improvements in microwave limb sounding at mm & submm wavelengths have resulted in retrievals of Methyl Chloride from atmospheric spectra. It is conceivable that Methyl Bromide would also be measurable by this technique. In an effort to extend and improve the previous work, the THz spectrum of Methyl Bromide has been measured at JPL. We used an isotopically enriched 13CH_3Br (90%) sample and recorded spectra from 750 - 1200 GHz. Our assignment covers the CH_379Br, CH_381Br, 13CH_379Br and 13CH_381Br isotopologues with J< 66 and K< 17 for the ground vibrational state. We plan to assign vibrational satellites and investigate possible perturbations near K =12 in the ground state.

  7. Water-solubilization of alkyloxo(methoxo)porphyrinatoantimony bromides.

    PubMed

    Matsumoto, Jin; Tanimura, Shin-ichiro; Shiragami, Tsutomu; Yasuda, Masahide

    2009-11-14

    In order to develop water-soluble porphyrins, alkyloxo(methoxo)porphyrinatoantimony bromides (alkyl = hexyl (1a), decyl (1b), dodecyl (1c), tetradecyl (1d), octadecyl (1e)) were prepared. 1 had more than 1 mmol dm(-3) of solubility in water. From the dependence of the half-width of the bands in the absorption spectra and surface tension on the concentration of 1, it was estimated that 1b-d were present as aggregates in concentrations higher than 10 micromol dm(-3). From the NMR analysis in D(2)O, it was deduced that the alkyloxo ligands of 1 were arranged alternately in the aggregates. The diameter of the aggregates of 1 in water was determined to be around 100 nm by the dynamic light scattering method. Since the solubilities of di(methoxo)tetraphenylporphyrinatoantimony bromide and 5-(4'-decyloxyphenyl)-10,15,20-triphenylporphyrinato(dimethoxo)antimony(v) bromide were low, it was calculated that the long alkyl axial ligands were requisite for the high solubility in water.

  8. Structural, vibrational and theoretical studies of L-histidine bromide

    NASA Astrophysics Data System (ADS)

    Ahmed, A. Ben; Feki, H.; Abid, Y.; Boughzala, H.; Mlayah, A.

    2008-10-01

    This paper presents the results of our calculations of the geometric parameters, vibrational spectra and hyperpolarizability of a non linear optical material, L-histidine bromide. Due to the lack of sufficiently precise information on the geometric structure available in literature, theoretical calculations were preceded by re-determination of the crystal X-ray structure. Single crystals of L-histidine bromide have been grown by slow evaporation of an aqueous solution at room temperature. The compound crystallizes in the non-Centro symmetric space group P2 12 12 1 of the orthorhombic system. Raman spectra have been recorded in the range [200-3500 cm -1]. All observed vibrational bands have been discussed and assigned to normal mode or to combinations and overtones on the basis of our calculations. The optimized geometric bond lengths and bond angles obtained by using HF and DFT (B3LYP and BLYP) show good agreement with the experimental data. Comparison between the measured and the calculated vibrational frequencies indicate that B3LYP is superior to the scaled HF approach for molecular vibrational problems. To investigate microscopic second order non linear optical properties of L-histidine bromide, the electric dipole μ, the polarizability α and the hyperpolarizability β were computed using DFT//B3LYP/6-31G(d) method. According to our calculations, the title compound exhibits non-zero β value revealing microscopic second order NLO behaviour.

  9. Conservative tracer bromide inhibits pesticide mineralisation in soil.

    PubMed

    Bech, Tina B; Rosenbom, Annette E; Sørensen, Sebastian R; Jacobsen, Carsten S

    2017-03-01

    Bromide is a conservative tracer that is often applied with non-conservative solutes such as pesticides to estimate their retardation in the soil. It has been applied in concentrations of up to 250 g Br L(-1), levels at which the growth of single-celled organisms can be inhibited. Bromide applications may therefore affect the biodegradation of non-conservative solutes in soil. The present study investigated the effect of potassium bromide (KBr) on the mineralisation of three pesticides - glyphosate, MCPA and metribuzin - in four agricultural A-horizon soils. KBr was added to soil microcosms at concentrations of 0, 0.5, 2.5 and 5 g Br(-) L(-1) in the soil solution. The study concluded that KBr had a negative effect on pesticide mineralisation. The inhibitory effect varied depending on the KBr concentration, the type of pesticide and the type of soil. Furthermore, 16 S amplicon sequencing revealed that the KBr treatment generally reduced the abundance of bacteroidetes and proteobacteria on both an RNA and DNA level. Therefore, in order to reduce the effect of KBr on the soil bacterial community and consequently also on xenobiotic degradation, it is recommended that KBr be applied in a concentration that does not exceed 0.5 g Br(-) L(-1) in the soil water.

  10. Crystal structure of benz­yl(meth­yl)phen­yl[(piperidin-1-ium-1-yl)meth­yl]silane bromide

    PubMed Central

    Barth, Eva Rebecca; Golz, Christopher; Koller, Stephan G.; Strohmann, Carsten

    2015-01-01

    The title compound, C20H29NSi+·Br−, contains a chiral silicon atom but crystallizes as a racemate. The C—Si—C bond angles in the range of 103.64 (8)–111.59 (9)° are usual for tetra­hedral geometry. The piperidine ring shows a regular chair conformation with an equatorially positioned exocyclic N—C bond. In the crystal, there is a hydrogen bond between the ammonium cation and the bromide anion. The crystal packing shows the dominant inter­molecular inter­action to be the electrostatic attraction between the ammonium cation and the bromide anion. PMID:26594462

  11. Comparison of Heat and Bromide as Ground Water Tracers Near Streams

    USGS Publications Warehouse

    Constantz, J.; Cox, M.H.; Su, G.W.

    2003-01-01

    Heat and bromide were compared as tracers for examining stream/ground water exchanges along the middle reaches of the Santa Clara River, California, during a 10-hour surface water sodium bromide injection test. Three cross sections that comprise six shallow (<1 m) piezometers were installed at the upper, middle, and lower sections of a 17 km long study reach, to monitor temperatures and bromide concentrations in the shallow ground water beneath the stream. A heat and ground water transport simulation model and a closely related solute and ground water transport simulation model were matched up for comparison of simulated and observed temperatures and bromide concentrations in the streambed. Vertical, one-dimensional simulations of sediment temperature were fitted to observed temperature results, to yield apparent streambed hydraulic conductivities in each cross section. The temperature-based hydraulic conductivities were assigned to a solute and ground water transport model to predict sediment bromide concentrations, during the sodium bromide injection test. Vertical, one-dimensional simulations of bromide concentrations in the sediments yielded a good match to the observed bromide concentrations, without adjustment of any model parameters except solute dispersivities. This indicates that, for the spatial and temporal scales examined on the Santa Clara River, the use of heat and bromide as tracers provide comparable information with respect to apparent hydraulic conductivities and fluxes for sediments near streams. In other settings, caution should be used due to differences in the nature of conservative (bromide) versus nonconservative (heat) tracers, particularly when preferential flowpaths are present.

  12. Hydrogen Generator

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Another spinoff from spacecraft fuel cell technology is the portable hydrogen generator shown. Developed by General Electric Company, it is an aid to safer operation of systems that use hydrogen-for example, gas chromatographs, used in laboratory analysis of gases. or flame ionization detectors used as $ollution monitors. The generator eliminates the need for high-pressure hydrogen storage bottles, which can be a safety hazard, in laboratories, hospitals and industrial plants. The unit supplies high-purity hydrogen by means of an electrochemical process which separates the hydrogen and oxygen in distilled water. The oxygen is vented away and the hydrogen gas is stored within the unit for use as needed. GE's Aircraft Equipment Division is producing about 1,000 of the generators annually.

  13. Hydrogen energy progress 5678

    SciTech Connect

    Veziroglu, T.N. )

    1990-01-01

    This book covers the proceedings of the 8th World Hydrogen Energy Conference, and includes: international hydrogen energy programs; hydrogen production; storage of hydrogen; hydrogen transmission and distribution; combustion systems/hydrogen engines; fuel cells; and synfuel production.

  14. Synthesis, characterization and thermal properties of new aromatic quaternary ammonium bromides: precursors for ionic liquids and complexation studies

    NASA Astrophysics Data System (ADS)

    Busi, Sara; Lahtinen, Manu; Ropponen, Jarmo; Valkonen, Jussi; Rissanen, Kari

    2004-10-01

    Series of new aromatic R2R‧2N+Br- (R=benzyl, 4-methylbenzyl, 2-phenylethyl, 3-phenylpropyl; R‧=ethyl, methyl, isopropyl) or RR‧2NH+Br--type (R=benzyl, R‧=isopropyl) quaternary ammonium bromides were prepared by using novel synthetic route in which a formamide (N,N-diethylformamide, N,N-dimethylformamide, N,N-diisopropylformamide) is treated with aralkyl halide in presence of a weak base. The compounds were characterized by 1H-NMR and 13C-NMR spectroscopy and mass spectrometry. Structures of the crystalline compounds were determined by X-ray single crystal diffraction, and in addition the powder diffraction method was used to study the structural similarities between the single crystal and microcrystalline bulk material. Three of the compounds crystallized in monoclinic, two in orthorhombic and one in triclinic crystal system, showing ion pairs, which are interconnected by weak hydrogen bonds and weak π - π interactions between the phenyl rings. Three of the compounds appeared as viscous oil or waxes. Finally, TG/DTA and DSC methods were used to analyze thermal properties of the prepared compounds. The lowest melting points were obtained for diethyldi-(2-phenylethyl)ammonium bromide (122.2 °C) and for diethyldi-(3-phenylpropyl)-ammonium bromide (109.1 °C). In general, decomposition of the compounds started at 170-190 °C without identifiable cleavages, thus liquid ranges of 30-70 °C were observed for some of the compounds.

  15. Hydrogen generator

    SciTech Connect

    Hansen, J.R.

    1984-06-19

    A hydrogen generator decomposes water into hydrogen and oxygen, and includes an induction coil which is electrically heated to a temperature sufficient to decompose water passing therethrough. A generator coil is connected in communicating relation to the induction coil, and is positioned in a fire resistant crucible containing ferrous oxide pellets. Oxygen and hydrogen produced by decomposition of water pass through the ferrous oxide pellets where the oxygen reacts with the ferrous oxide and the hydrogen is burned to produce heat for heating a building, such as a conventional home.

  16. State-To Dynamics of Photoionization and Charge Transfer Reactions Involving Hydrogen Bromide.

    NASA Astrophysics Data System (ADS)

    Xie, Jinchun

    The selection rules for electric-dipole-allowed photoionization of diatomic molecule are derived. From a single rotational level of neutral molecules, the final rotational levels of the ions can be accessed only when their angular momentum, parity, spin, and other quantum numbers satisfy certain relations concerning photoelectron partial waves. Furthermore, under irreducible tensor treatment photoionization probability is simply expressed by three factors: the geometrical coefficient C^ {k}_{p} the rotational linestrength S^{k}_{p } and the square of the tensor moment < {bf T}^{k} _{p}>. This method makes photoionization and electron impact induced transitions as easy to interpret as the well known multiphoton transition. The photoionization HBr^*(nu,J) + hnu to HBr ^+(^2Pi_{i},nu ^+,J^+) + e^- has been studied experimentally. The HBr^*(nu,J) is prepared in three 5ppi Rydberg states: f ^3Delta_2, g ^3Sigma^-_0 ^+ and F ^1Delta _2 via 2-photon excitation, and the product HBr^+(^2Pi_{i} ,nu^+,J^+ ) is probed in a quantum state specific manner using laser induced fluorescence (LIF). Distributions of the HBr^+ product show very strong parity propensities for the type of transition (+/- )-(mp), and also rotational propensities: Delta J = +/-1.5, +/-0.5 for the type of transition (+/-)-( mp) and Delta J = +/-2.5, +/-1.5, +/-0.5 for (+/-)-( +/-). These results are able to be described by using selection rules and irreducible moment presentation. The charge-transfer reaction DBr^+( ^2Pi_{i},nu^+,J ^+) + HBr to HBr ^+(^2Pi_{i^{ '}},nu^{'+ },J^{'+}) + DBr is studied under thermal conditions in a flowing gas mixture of HBr and DBr. The DBr^+(^2Pi _{i},nu^+,J^+) reagent is prepared by using (2 + 1) resonance enhanced multiphoton ionization and the HBr^+(^2 Pi_{i^{'+} },nu^{'+},J^ {'+}) product is detected using LIF. From the measurements of the molecular density and the populations of both HBr^+ and DBr^+, the absolute rate constants k(i,nu^+to i^', nu^{'+}) are determined for this charge-transfer process. The rate constants for near-resonant charge-transfer are much faster than those for off-resonant charge-transfer. The rotational distribution of the HBr^+ product fits a temperature well in each case. For near-resonant charge-transfer the rotational temperature is slightly hotter than thermal whereas for non-resonant charge-transfer the rotational temperature is much hotter than thermal.

  17. Stabilization of Organic-Inorganic Perovskite Layers by Partial Substitution of Iodide by Bromide in Methylammonium Lead Iodide.

    PubMed

    Ruess, Raffael; Benfer, Felix; Böcher, Felix; Stumpp, Martina; Schlettwein, Derck

    2016-05-18

    Thin films of the methylammonium lead halides CH3 NH3 Pb(I1-x Brx )3 are prepared on fluorine-doped tin oxide substrates and exposed to humid air in the dark and under illumination. To characterize the stability of the materials, UV/Vis spectra are acquired at fixed intervals, accompanied by XRD, energy-dispersive X-ray spectroscopy, SEM, and confocal laser scanning microscopy. Different degradation mechanisms are observed depending on the environmental conditions. It is found that bromide can successfully suppress the transformation of the perovskite into the monohydrate, presumably owing to stronger hydrogen-bonding interactions with the organic cation. However, under illumination in humid air, rather rapid decomposition of the perovskites was still observed, which is due to phase segregation. The use of increased bromide content in methylammonium lead halide absorbers is discussed in terms of their application in perovskite solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Automated determination of bromide in waters by ion chromatography with an amperometric detector

    USGS Publications Warehouse

    Pyen, G.S.; Erdmann, D.E.

    1983-01-01

    An automated ion chromatograph, including a program controller, an automatic sampler, an integrator, and an amperometric detector, was used to develop a procedure for the determination of bromide in rain water and many ground waters. Approximately 10 min is required to obtain a chromatogram. The detection limit for bromide is 0.01 mg l-1 and the relative standard deivation is <5% for bromide concentrations between 0.05 and 0.5 mg l-1. Chloride interferes if the chloride-to-bromide ratio is greater than 1 000:1 for a range of 0.01-0.1 mg l-1 bromide; similarly, chloride interferes in the 0.1-1.0 mg l-1 range if the ratio is greater than 5 000:1. In the latter case, a maximum of 2 000 mg l-1 of chloride can be tolerated. Recoveries of known concentrations of bromide added to several samples, ranged from 97 to 110%. ?? 1983.

  19. Isotopic Composition of Marine-Derived Methyl Bromide

    NASA Astrophysics Data System (ADS)

    Cottrell, L. D.; Mak, J. E.

    2001-12-01

    Methyl bromide (CH3Br) is the largest source of atmospheric bromine, which catalytically destroys stratospheric ozone 50-60 times more efficiently than chlorine. Despite much attention that has been focused on CH3Br in recent years, it has proven difficult to constrain its global budget. It is of particular interest to compare the magnitude of the anthropogenic source with that of the largest naturally occurring source, which is believed to be marine-derived. One way to estimate the relative strengths of these sources is to use stable carbon isotopes as a tracer. The viability of this approach relies on the distinctiveness of the isotopic composition of each source and, in the case of marine-derived CH3Br, on the extent to which isotopic fracionation occurs during chemical degradation in the water column. Once produced in the water column, CH3Br undergoes ion exchange (CH3Br + Cl- \\rightarrow CH3Cl +Br-) and hydrolysis (CH3Br + H2O \\rightarrow CH3OH +HBr), which changes the isotopic composition of the remaining CH3Br. In this study we measured the fractionation factor (k12/k13) for both ion exchange and hydrolysis of CH3Br in sea water, and then used a simple air-sea exchange model to determine the extent of fractionation that occurs in the water column. Using a range of 20-30 per mil for the isotopic composition of marine biologically produced methyl bromide, the predicted isotopic composition of CH3Br emitted to the atmosphere is significantly enriched and further distinguished from the average anthropogenic signature of -54.4 per mil. An isotopic study may therefore prove to be a useful tool for constraining the methyl bromide budget.

  20. Freezing Hydrogen

    NASA Image and Video Library

    2009-11-17

    An engineer loads hydrogen gas into the Wide-Field Infrared Survey Explorer in a clean room at the Vandenberg Air Force Base, Calif. The hydrogen is cooled and frozen inside a Thermos-like bottle, called the cryostat, which keeps the science instrument

  1. Hydrogen Bibliography

    SciTech Connect

    Not Available

    1991-12-01

    The Hydrogen Bibliography is a compilation of research reports that are the result of research funded over the last fifteen years. In addition, other documents have been added. All cited reports are contained in the National Renewable Energy Laboratory (NREL) Hydrogen Program Library.

  2. Photodissociation of methyl chloride and methyl bromide in the atmosphere

    NASA Technical Reports Server (NTRS)

    Robbins, D. E.

    1976-01-01

    Methyl chloride (CH3Cl) and methyl bromide (CH3Br) have been suggested to be significant sources of the stratospheric halogens. The breakup of these compounds in the stratosphere by photodissociation or reaction with OH releases halogen atoms which catalytically destroy ozone. Experimental results are presented for ultraviolet photoabsorption cross sections of CH3Cl and CH3Br. Calculations are presented of loss rates for the methyl halides due to photodissociation and reaction with OH and of mixing ratios of these species in the stratosphere.

  3. Rhodium(NHC)-catalyzed O-arylation of aryl bromides.

    PubMed

    Kim, Hyun Jin; Kim, Min; Chang, Sukbok

    2011-05-06

    The first example of the rhodium-catalyzed O-arylation of aryl bromides is reported. While the right combination of rhodium species and N-heterocyclic carbene (NHC) offered an effective catalytic system enabling the arylation to proceed, the choice of NHC was determined to be most important. The developed O-arylation protocol has a wide range of substrate scope, high functional group tolerance, and flexibility allowing a complementary route to either N- or O-arylation depending on the choice of NHC.

  4. Tiotropium versus ipratropium bromide for chronic obstructive pulmonary disease.

    PubMed

    Cheyne, Leanne; Irvin-Sellers, Melanie J; White, John

    2015-09-22

    Tiotropium and ipratropium bromide are both recognised treatments in the management of people with stable chronic obstructive pulmonary disease (COPD). There are new studies which have compared tiotropium with ipratropium bromide, making an update necessary. To compare the relative effects of tiotropium to ipratropium bromide on markers of quality of life, exacerbations, symptoms, lung function and serious adverse events in patients with COPD using available randomised controlled trial (RCT) data. We identified RCTs from the Cochrane Airways Group Specialised Register of trials (CAGR) and ClinicalTrials.gov up to August 2015. We included parallel group RCTs of 12 weeks duration or longer comparing treatment with tiotropium with ipratropium bromide for patients with stable COPD. Two review authors independently assessed studies for inclusion and then extracted data on study quality and outcome results. We contacted trial sponsors for additional information. We analysed the data using Cochrane Review Manager. This review included two studies of good methodological quality that enrolled 1073 participants with COPD. The studies used a similar design and inclusion criteria and were of at least 12 weeks duration; the participants had a mean forced expiratory volume in one second (FEV1) of 40% predicted value at baseline. One study used tiotropium via the HandiHaler (18 µg) for 12 months and the other via the Respimat device (5 µg and 10 µg) for 12 weeks. In general, the treatment groups were well matched at baseline but not all outcomes were reported for both studies. Overall the risk of bias across the included RCTs was low.For primary outcomes this review found that at the three months trough (the lowest level measured before treatment) FEV1 significantly increased with tiotropium compared to ipratropium bromide (mean difference (MD) 109 mL; 95% confidence interval (CI) 81 to 137, moderate quality evidence, I(2) = 62%). There were fewer people experiencing one or

  5. Tiotropium versus ipratropium bromide for chronic obstructive pulmonary disease.

    PubMed

    Cheyne, Leanne; Irvin-Sellers, Melanie J; White, John

    2013-09-16

    Tiotropium and ipratropium bromide are both recognised treatments in the management of people with stable chronic obstructive pulmonary disease (COPD). There are new studies which have compared tiotropium with ipratropium bromide, making an update necessary. To compare the relative effects of tiotropium to ipratropium bromide on markers of quality of life, exacerbations, symptoms, lung function and serious adverse events in patients with COPD using available randomised controlled trial (RCT) data. We identified RCTs from the Cochrane Airways Group Specialised Register of trials (CAGR) and ClinicalTrials.gov up to November 2012. We included parallel group RCTs of 12 weeks duration or longer comparing treatment with tiotropium with ipratropium bromide for patients with stable COPD. Two review authors independently assessed studies for inclusion and then extracted data on study quality and outcome results. We contacted trial sponsors for additional information. We analysed the data using Cochrane Review Manager (RevMan 5.2). This review included two studies of good methodological quality that enrolled 1073 participants with COPD. The studies used a similar design and inclusion criteria and were of at least 12 weeks duration; the participants had a mean forced expiratory volume in one second (FEV1) of 40% predicted value at baseline. One study used tiotropium via the HandiHaler (18 µg) for 12 months and the other via the Respimat device (5 µg and 10 µg) for 12 weeks. In general, the treatment groups were well matched at baseline but not all outcomes were reported for both studies. Overall the risk of bias across the included RCTs was low.For primary outcomes this review found that at the three months trough (the lowest level measured before treatment) FEV1 significantly increased with tiotropium compared to ipratropium bromide (mean difference (MD) 109 mL; 95% confidence interval (CI) 81 to 137, moderate quality evidence, I(2) = 62%). There were fewer people

  6. Tiotropium Bromide in Chronic Obstructive Pulmonary Disease and Bronchial Asthma.

    PubMed

    Alvarado-Gonzalez, Alcibey; Arce, Isabel

    2015-11-01

    Inhaled bronchodilators are the mainstay of pharmacological treatment for stable chronic obstructive pulmonary disease (COPD), including β2-agonists and muscarinic antagonists. Tiotropium bromide, a long-acting antimuscarinic bronchodilator (LAMA), is a treatment choice for moderate-to-severe COPD; its efficacy and safety have been demonstrated in recent trials. Studies also point to a beneficial role of tiotropium in the treatment of difficult-to-control asthma and a potential function in the asthma-COPD overlap syndrome (ACOS). Combination of different bronchodilator molecules and addition of inhaled corticosteroids are viable therapeutic alternatives. A condensation of the latest trials and the rationale behind these therapies will be presented in this article.

  7. Mixed Iodide-Bromide Methylammonium Lead Perovskite-based Diodes for Light Emission and Photovoltaics.

    PubMed

    Gil-Escrig, Lidón; Miquel-Sempere, Araceli; Sessolo, Michele; Bolink, Henk J

    2015-09-17

    Vacuum deposition techniques are used to prepare mixed iodide-bromide methylammonium lead perovskite diodes via an intermediate double layer of the pure iodide and bromide perovskites. The diodes lead to bright electroluminescence, whose emission spectra maxima shift from the infrared toward the visible with increasing bromide content. When illuminated with AM1.5 simulated sunlight the devices function as efficient solar cells with power conversion efficiencies as high as 12.9%.

  8. Induced Adsorption of Chloride and Bromide by Submonolayer Amounts of Copper Underpotentially Deposited on Pt(111)

    DTIC Science & Technology

    1994-03-14

    S GD Induced Adsorption Of Chloride And Bromide By Submonolayer Amounts Of Copper Underpotentially Deposited On Pt(111). R. G6mez, J.M. Feliu, and...The underpotential deposition of submonolayer amounts of copper induces an enhanced adsorption of chloride and bromide on Pt(111) and is reflected in...nhinoItO _. •- Induced Adsorption of Chloride and Bromide by Submonolayer Amounts of Copper Underpotentially Deposited on Pt(1 11). R. G6mez1 , J.M

  9. Hydrogen carriers

    NASA Astrophysics Data System (ADS)

    He, Teng; Pachfule, Pradip; Wu, Hui; Xu, Qiang; Chen, Ping

    2016-12-01

    Hydrogen has the potential to be a major energy vector in a renewable and sustainable future energy mix. The efficient production, storage and delivery of hydrogen are key technical issues that require improvement before its potential can be realized. In this Review, we focus on recent advances in materials development for on-board hydrogen storage. We highlight the strategic design and optimization of hydrides of light-weight elements (for example, boron, nitrogen and carbon) and physisorbents (for example, metal-organic and covalent organic frameworks). Furthermore, hydrogen carriers (for example, NH3, CH3OH-H2O and cycloalkanes) for large-scale distribution and for on-site hydrogen generation are discussed with an emphasis on dehydrogenation catalysts.

  10. Spectroscopic study of tetradecyltrimethylammonium bromide Pt-C14TAB nanoparticles: Structure and Stability

    SciTech Connect

    Borodko, Y.; Jones, L.; Frei, H.; Somorjai, G.

    2009-01-09

    The vibrational spectra of platinum nanoparticles (12 nm) capped with tetradecyltrimethylammonium bromide, C{sub 14}TAB, were investigated by Fourier transform infrared (FTIR) spectroscopy. We have shown that the thermal decay of Pt-C{sub 14}TAB nanoparticles in N{sub 2}, H{sub 2} and O{sub 2} atmospheres leads to the release of hydrocarbon chain of surfactant and the formation of strongly bonded layer of ammonium cations on the platinum surface. The platinum atoms accessible to CO chemisorptions were not reducible by hydrogen in the temperature ranging from 30 C to 200 C. A FTIR spectrum of C{sub 14}TAB adsorbed on Pt nanoparticles dramatically perturbed as compared with pure C{sub 14}TAB. New intense and broad bands centered at 1450 cm{sup -1} and 760 cm{sup -1} are making their appearance in Pt-C{sub 14}TAB. It may be speculated, that new bands are result of coupling between conducting electrons of Pt and molecular vibrations of adsorbed C{sub 14}TAB and as a consequence specific vibrational modes of ammonium cation transformed into electron-vibrational modes.

  11. The clinical pharmacology of single doses of otilonium bromide in healthy volunteers.

    PubMed

    Sutton, J A; Kilminster, S G; Mould, G P

    1997-01-01

    Otilonium is a smooth muscle spasmolytic with greater affinity for receptors in the smooth muscle of distal than proximal gut in rats. This study was the first to compare distal and proximal GI transit effects in human subjects. Using an increasing dose design for the safe exploration of clinical and supraclinical single dose levels, two groups of eight volunteers received either 40, 120 and 200 mg or 80, 160 and 240 mg otilonium. Gastric emptying of 400 ml 10% glucose solution was assessed by epigastric impedance (EI), orocaecal transit time (OCTT) by the lactulose breath-hydrogen method and whole gut transit time (WGTT) by the method of Hinton et al. [1]. Potential anticholinergic effects were assessed via visual accommodation using the RAF rule and saliva flow in response to sucking a sweet. Median WGTT after 120 mg significantly increased by 4.1 h relative to placebo, but at higher doses median changes relative to placebo were not significant due to wide increases in group variance. The EI t50% was delayed by 1.4 min when results from the two highest doses were combined and compared with placebo; this small difference was statistically significant but seems unlikely to achieve physiological or clinical significance. OCTT, visual accommodation and saliva flow were unaltered. Otilonium bromide was well tolerated at all doses, due mainly to low systemic absorption.

  12. Power Plant Bromide Discharges and Downstream Drinking Water Systems in Pennsylvania.

    PubMed

    Good, Kelly D; VanBriesen, Jeanne M

    2017-10-04

    Coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems have been implicated in increasing bromide levels and subsequent increases in disinfection byproducts at downstream drinking water plants. Bromide was not included as a regulated constituent in the recent steam electric effluent limitations guidelines and standards (ELGs) since the U.S. EPA analysis suggested few drinking water facilities would be affected by bromide discharges from power plants. The present analysis uses a watershed approach to identify Pennsylvania drinking water intakes downstream of wet FGD discharges and to assess the potential for bromide discharge effects. Twenty-two (22) public drinking water systems serving 2.5 million people were identified as being downstream of at least one wet FGD discharge. During mean August conditions (generally low-flow, minimal dilution) in receiving rivers, the median predicted bromide concentrations contributed by wet FGD at Pennsylvania intake locations ranged from 5.2 to 62 μg/L for the Base scenario (including only natural bromide in coal) and from 16 to 190 μg/L for the Bromide Addition scenario (natural plus added bromide for mercury control); ranges depend on bromide loads and receiving stream dilution capacity.

  13. Comparison of Heat and Bromide as Tracers of Stream Exchanges With Shallow Ground Water

    NASA Astrophysics Data System (ADS)

    Constantz, J.; Cox, M. H.; Su, G. W.

    2002-12-01

    Heat and bromide were compared as tracers for examining stream/groundwater exchanges along the middle reaches of the Santa Clara River, CA, during a 10-hour surface-water sodium bromide injection. Three cross-sections comprised of 6 shallow (1 m) piezometers were installed at the upper, middle, and lower sections of a 17 km long study reach to monitor temperatures and bromide concentrations in the shallow ground water beneath the stream. The heat and ground-water transport simulation model, VS2DH, and a closely related solute and ground-water transport simulation model, VS2DT, were matched up for comparison of simulated and observed temperatures and bromide concentrations in the streambed. Simulated sediment temperature were fitted to observed temperature results to yield apparent streambed hydraulic conductivities in each cross-section. Saturated hydraulic conductivities ranged from 1.39 x 10-5 m/s in the upper reach to 5.56 x 10-4 m/s in the lower reach. The temperature-based hydraulic conductivities were inserted into VS2DT to predict sediment bromide concentrations during the sodium bromide injection. The predicted bromide concentration curves in the sediments yielded an excellent match to the observed bromide concentrations, without adjustment of any model parameters. This indicates that for the spatial and temporal scales examined on the Santa Clara River, the use of heat and bromide as tracers provide comparable information with respect to apparent hydraulic conductivities and water fluxes in near-stream environments.

  14. Transient neuromyopathy after bromide intoxication in a dog with idiopathic epilepsy

    PubMed Central

    2012-01-01

    A seven-year old Australian Shepherd, suffering from idiopathic epilepsy under treatment with phenobarbitone and potassium bromide, was presented with generalised lower motor neuron signs. Electrophysiology and muscle-nerve biopsies revealed a neuromyopathy. The serum bromide concentration was increased more than two-fold above the upper reference value. Clinical signs disappeared after applying diuretics and reducing the potassium bromide dose rate. This is the first case report describing electrophysiological and histopathological findings associated with bromide induced lower motor neuron dysfunction in a dog. PMID:23216950

  15. The occurrence of bromide in herbal drugs: is there a need for a Ph. Eur. limit?

    PubMed

    Albert, H; Busch, J; Klier, B; Klötzel, M; Kühn, M; Steinhoff, B

    2013-01-01

    This contribution provides an overview on the current legal requirements regarding limits for bromide and presents data on the actual bromide burden of commonly used herbal drugs. Evaluation of an extensive data base shows that results exceeding the limit of 50 mg/kg are found in specific plants which take up bromide to a high extent from the environment. Thus, positive findings of bromide in herbal drugs do not necessarily serve as a proof for methyl bromide treatment. Taking into account the ADI recommended by EMA and WHO, there are no toxicological concerns with regard to the intake of herbal teas, extracts or comminuted herbal drugs at therapeutic doses. Furthermore, the use of methyl bromide and other fumigants must be documented within the batch documentation. If stated in the batch documentation that no fumigation was carried out, it is not necessary to perform the test on bromide. In cases of a particular suspect and if toxicological concerns exist, additional testing can be performed in accordance with the limits set by Regulation (EC) No. 396/2005. For the above reasons, information obtained by performing the test on bromide is not significant for the assessment of quality. Therefore, it seems no longer necessary to maintain bromide in Ph. Eur. general chapter 2.8.13. Pesticide residues and it is recommended to delete it from Table 2.8.13.-1.

  16. Titrimetric determination of hydrogen peroxide in alkaline solution.

    PubMed

    McCurdy, W H; Bell, H F

    1966-07-01

    Direct titration of hydrogen peroxide in alkaline bromide media has been accomplished with sodium hypochlorite. The relative standard deviation is 0.2%. A photometric end-point is recommended for the determination of 0.10-1.0 mequiv of peroxide. Larger samples are evaluated by use of Bordeaux Red as visual indicator. The hypochlorite procedure compares favourably with iodometry and permanganate in the analysis of commercial peroxides.

  17. Equilibrium and kinetics studies of reactions of manganese acetate, cobalt acetate, and bromide salts in acetic acid solutions.

    PubMed

    Jiao, X D; Metelski, P D; Espenson, J H

    2001-06-18

    The oxidation of hydrogen bromide and alkali metal bromide salts to bromine in acetic acid by cobalt(III) acetate has been studied. The oxidation is inhibited by Mn(OAc)(2) and Co(OAc)(2), which lower the bromide concentration through complexation. Stability constants for Co(II)Br(n)() were redetermined in acetic acid containing 0.1% water as a function of temperature. This amount of water lowers the stability constant values as compared to glacial acetic acid. Mn(II)Br(n)() complexes were identified by UV-visible spectroscopy, and the stability constants for Mn(II)Br(n)() were determined by electrochemical methods. The kinetics of HBr oxidation shows that there is a new pathway in the presence of M(II)Br(n)(). Analysis of the concentration dependences shows that CoBr(2) and MnBr(2) are the principal and perhaps sole forms of the divalent metals that react with Co(III) and Mn(III). The interpretation of these data is in terms of this step (M, N = Mn or Co): M(OAc)(3) + N(II)Br(2) + HOAc --> M(OAc)(2) + N(III)Br(2)OAc. The second-order rate constants (L mol(-)(1) s(-)(1)) for different M, N pairs in glacial acetic acid are 4.8 (Co, Co at 40 degrees C), 0.96 (Mn, Co at 20 degrees C), 0.15 (Mn(III).Co(II), Co at 20 degrees C), and 0.07 (Mn, Mn at 20 degrees C). Following that, reductive elimination of the dibromide radical is proposed to occur: N(III)Br(2)OAc + HOAc --> N(OAc)(2) + HBr(2)(*). This finding implicates the dibromide radical as a key intermediate in this chemistry, and indeed in the cobalt-bromide catalyzed autoxidation of methylarenes, for which some form of zerovalent bromine has been identified. The selectivity for CoBr(2) and MnBr(2) is consistent with a pathway that forms this radical rather than bromine atoms which are at a considerably higher Gibbs energy. Mn(OAc)(3) oxidizes PhCH(2)Br, k = 1.3 L mol(-)(1) s(-)(1) at 50.0 degrees C in HOAc.

  18. IUPAC-NIST Solubility Data Series. 94. Rare Earth Metal Iodides and Bromides in Water and Aqueous Systems. Part 2. Bromides

    NASA Astrophysics Data System (ADS)

    Mioduski, Tomasz; Gumiński, Cezary; Zeng, Dewen; Voigt, Heidelore

    2013-03-01

    This work presents solubility data for rare earth metal bromides in water and in aqueous ternary systems. Compilations of all available experimental data are introduced for each rare earth metal bromide with a corresponding critical evaluation. Every such evaluation contains a collection of all solubility results in water, a selection of suggested solubility data and a brief discussion of the multicomponent systems. Because the ternary systems were almost never studied more than once, no critical evaluations of such data were possible. Only simple bromides (no complexes) are treated as the input substances in this work. The literature has been covered through the end of 2011.

  19. The in vitro and in vivo profile of aclidinium bromide in comparison with glycopyrronium bromide.

    PubMed

    Gavaldà, Amadeu; Ramos, Israel; Carcasona, Carla; Calama, Elena; Otal, Raquel; Montero, José Luis; Sentellas, Sonia; Aparici, Monica; Vilella, Dolors; Alberti, Joan; Beleta, Jorge; Miralpeix, Montserrat

    2014-08-01

    This study characterised the in vitro and in vivo profiles of two novel long-acting muscarinic antagonists, aclidinium bromide and glycopyrronium bromide, using tiotropium bromide and ipratropium bromide as comparators. All four antagonists had high affinity for the five muscarinic receptor sub-types (M1-M5); aclidinium had comparable affinity to tiotropium but higher affinity than glycopyrronium and ipratropium for all receptors. Glycopyrronium dissociated faster from recombinant M3 receptors than aclidinium and tiotropium but more slowly than ipratropium; all four compounds dissociated more rapidly from M2 receptors than from M3 receptors. In vitro, aclidinium, glycopyrronium and tiotropium had a long duration of action at native M3 receptors (>8 h versus 42 min for ipratropium). In vivo, all compounds were equi-potent at reversing acetylcholine-induced bronchoconstriction. Aclidinium, glycopyrronium and ipratropium had a faster onset of bronchodilator action than tiotropium. Aclidinium had a longer duration of action than glycopyronnium (time to 50% recovery of effect [t½ offset] = 29 h and 13 h, respectively); these compare with a t½ offset of 64 h and 8 h for tiotropium and ipratropium, respectively. Aclidinium was less potent than glycopyrronium and tiotropium at inhibiting salivation in conscious rats (dose required to produce half-maximal effect [ED50] = 38, 0.74 and 0.88 μg/kg, respectively) and was more rapidly hydrolysed in rat, guinea pig and human plasma compared with glycopyrronium or tiotropium. These results indicate that while aclidinium and glycopyrronium are both potent antagonists at muscarinic receptors with similar kinetic selectivity for M3 receptors versus M2, aclidinium has a longer dissociation half-life at M3 receptors and a longer duration of bronchodilator action in vivo than glycopyrronium. The rapid plasma hydrolysis of aclidinium, coupled to its kinetic selectivity, may confer a reduced propensity for systemic

  20. Metallic Hydrogen

    NASA Astrophysics Data System (ADS)

    Silvera, Isaac F.; Dias, Ranga; Noked, Ori; Salamat, Ashkan; Zaghoo, Mohamed

    2017-04-01

    One of the great challenges in condensed matter physics has been to produce metallic hydrogen (MH) in the laboratory. There are two approaches: solid molecular hydrogen can be compressed to high density at extreme pressures of order 5-6 megabars. The transition to MH should take place at low temperatures and is expected to occur as a structural first-order phase transition with dissociation of molecules into atoms, rather than the closing of a gap. A second approach is to produce dense molecular hydrogen at pressures of order 1-2 megabars and heat the sample. With increasing temperature, it was predicted that molecular hydrogen first melts and then dissociates to atomic metallic liquid hydrogen as a first-order phase transition. We have observed this liquid-liquid phase transition to metallic hydrogen, also called the plasma phase transition. In low-temperature studies, we have pressurized HD to over 3 megabars and observed two new phases. Molecular hydrogen has been pressurized to 4.2 megabars. A new phase transition has been observed at 3.55 megabars, but it is not yet metallic.

  1. Octahedral Rotation Preferences in Perovskite Iodides and Bromides.

    PubMed

    Young, Joshua; Rondinelli, James M

    2016-03-03

    Phase transitions in ABX3 perovskites are often accompanied by rigid rotations of the corner-connected BX6 octahedral network. Although the mechanisms for the preferred rotation patterns of perovskite oxides are fairly well recognized, the same cannot be said of halide variants (i.e., X = Cl, Br, or I), several of which undergo an unusual displacive transition to a tetragonal phase exhibiting in-phase rotations about one axis (a(0)a(0)c(+) in Glazer notation). To discern the chemical factors stabilizing this unique phase, we investigated a series of 12 perovskite bromides and iodides using density functional theory calculations and compared them with similar oxides. We find that in-phase tilting provides a better arrangement of the larger bromide and iodide anions, which minimizes the electrostatic interactions, improves the bond valence of the A-site cations, and enhances the covalency between the A-site metal and Br(-) or I(-) ions. The opposite effect is present in the oxides, with out-of-phase tilting maximizing these factors.

  2. Deswelling kinetics of polyacrylate gels in solutions of cetyltrimethylammonium bromide.

    PubMed

    Nilsson, Peter; Hansson, Per

    2007-08-23

    The deswelling kinetics of single sodium polyacrylate gel beads (radius 40-160 microm) in aqueous solutions of cetyltrimethylammonium bromide under conditions of forced convection are investigated using micromanipulator assisted light microscopy. The purpose of the study is to further evaluate a previously published model (J. Phys. Chem. B 2003, 107, 9203) using a higher homolog surfactant. For gels with expected fast deswelling (small gel size/low surfactant concentration) and/or in low electrolyte concentration, the model is found to correctly predict the deswelling characteristics of the gel beads. However, for some gels with expected slow deswelling, especially in high electrolyte concentration (10 mM NaBr), the model widely underestimates the required deswelling time. The reason for this is argued to be the longer time frame and high bromide concentration allowing the formation of a denser, more ordered structure in the surface phase, which resists the deformation and reorganization of material necessary for deswelling. Unexpectedly long lag times before the start of deswelling are also found for gels in low surfactant concentration, indicating that a relatively high surfactant concentration in the gel, greatly exceeding the critical aggregation concentration, is needed to start formation of a collapsed surface phase. This critical surfactant concentration is found to be dependent on initial gel radius, as small gels require a relatively higher concentration to initiate collapse.

  3. Bromoform formation in ozonated groundwater containing bromide and humic substances

    SciTech Connect

    Cooper, W.J.; Amy, G.L.; Moore, C.A.; Zika, R.G.

    1986-01-01

    The effect of bromide ion, organic carbon concentration (natural aquatic humic substances), pH, and solar irradiation on the formation of bromoform in ozonated groundwater has been studied. The studies were conducted on four unique samples of groundwater taken from different regions of the Biscayne Aquifer in southern Florida. All other conditions being equal, increases in bromide ion concentrations resulted in increases in CHBr/sub 3/ formation. In three of the four samples, CHBr/sub 3/ formation decreased as the pH level increased from 5 to 9. The fourth sample exhibited an opposite trend whereby the CHBr/sub 3/ concentration increased with increasing pH. Bromoform concentration increased with increased O/sub 3/ concentration over an ozone dosage range of 3.4 to 6.7 mg/L. Ozonated samples placed in sunlight immediately after ozone addition showed a decrease in the formation of CHBr/sub 3/ presumably due to the photodecomposition of HOBr/OBr.

  4. A drinking water utility's perspective on bromide, bromate, and ozonation.

    PubMed

    Bonacquisti, Thomas P

    2006-04-17

    Application of ozone in drinking water treatment plants in the US is growing because of ozone's multiple benefits. Ozone functions as a powerful oxidizing agent and disinfecting agent, it improves finished water quality by reducing turbidity, it reduces the formation of many halogenated disinfection by-products, and it is capable of treating chlorine resistant organisms like cryptosporidia. However, when bromide ion is present, e.g. from the geology, runoff, or sea water intrusion, ozone will convert some of the bromide to bromate depending upon the treatment reaction conditions. Bromate can also be introduced into drinking water as a contaminant in the chlorine used for disinfection. The current maximum contaminant level (MCL) in the USA is 0.010 mg/L, and the maximum contaminant level goal (MCLG) is zero, because of the possibility that bromate may function as a genotoxic carcinogen. The level of the MCL, especially if it is lowered, will significantly impact the ability of many water suppliers to utilize ozone in their water treatment processes and also raise the costs of those applications.

  5. Broad-spectrum antimicrobial photocatalysis mediated by titanium dioxide and UVA is potentiated by addition of bromide ion via formation of hypobromite.

    PubMed

    Wu, Ximing; Huang, Ying-Ying; Kushida, Yu; Bhayana, Brijesh; Hamblin, Michael R

    2016-06-01

    Antimicrobial photocatalysis involves the UVA excitation of titanium dioxide (TiO2) nanoparticles (particularly the anatase form) to produce reactive oxygen species (ROS) that kill microbial cells. For the first time we report that the addition of sodium bromide to photoactivated TiO2 (P25) potentiates the killing of Gram-positive, Gram-negative bacteria and fungi by up to three logs. The potentiation increased with increasing bromide concentration in the range of 0-10mM. The mechanism of potentiation is probably due to generation of both short and long-lived oxidized bromine species including hypobromite as shown by the following observations. There is some antimicrobial activity remaining in solution after switching off the light, that lasts for 30min but not 2h, and oxidizes 3,3',5,5'-tetramethylbenzidine. N-acetyl tyrosine ethyl ester was brominated in a light dose-dependent manner, however no bromine or tribromide ion could be detected by spectrophotometry or LC-MS. The mechanism appears to have elements in common with the antimicrobial system (myeloperoxidase+hydrogen peroxide+bromide).

  6. Validation of an automated fluorescein method for determining bromide in water

    USGS Publications Warehouse

    Fishman, M. J.; Schroder, L.J.; Friedman, L.C.

    1985-01-01

    Surface, atmospheric precipitation and deionized water samples were spiked with ??g l-1 concentrations of bromide, and the solutions stored in polyethylene and polytetrafluoroethylene bottles. Bromide was determined periodically for 30 days. Automated fluorescein and ion chromatography methods were used to determine bromide in these prepared samples. Analysis of the data by the paired t-test indicates that the two methods are not significantly different at a probability of 95% for samples containing from 0.015 to 0.5 mg l-1 of bromide. The correlation coefficient for the same sets of paired data is 0.9987. Recovery data, except for the surface water samples to which 0.005 mg l-1 of bromide was added, range from 89 to 112%. There appears to be no loss of bromide from solution in either type of container.Surface, atmospheric precipitation and deionized water samples were spiked with mu g l** minus **1 concentrations of bromide, and the solutions stored in polyethylene and polytetrafluoroethylene bottles. Bromide was determined periodically for 30 days. Automated fluorescein and ion chromatography methods were used to determine bromide in these prepared samples. Analysis of the data by the paired t-test indicates that the two methods are not significantly different at a probability of 95% for samples containing from 0. 015 to 0. 5 mg l** minus **1 of bromide. The correlation coefficient for the same sets of paired data is 0. 9987. Recovery data, except for the surface water samples to which 0. 005 mg l** minus **1 of bromide was added, range from 89 to 112%. Refs.

  7. The distribution of bromide in water in the Floridan aquifer system, Duval County, northeastern Florida

    USGS Publications Warehouse

    German, E.R.; Taylor, G.F.

    1995-01-01

    Although Duval County, Florida, has ample ground-water resources for public supply, the potential exists for a problem with excessive disinfectant by-products. These disinfectant by-products result from the treatment of raw water containing low concentrations of bromide and naturally occurring organic compounds. Because of this potential problem, the relation of bromide concentrations to aquifer tapped, well location and depth, and chemical characteristics of water in the Floridan aquifer system underlying Duval County were studied to determine if these relations could be applied to delineate water with low-bromide concentrations for future supplies. In 1992, water samples from 106 wells that tap the Floridan aquifer system were analyzed for bromide and major dissolved constituents. A comparison of bromide concentrations from the 1992 sampling with data from earlier studies (1979-80) indicates that higher bromide concentrations were detected during the earlier studies. The difference between the old and new data is probably because of a change in analytical methodology in the analysis of samples. Bromide concentrations exceeded the detection limit (0.10 milligrams per liter) in water from 28 of the 106 wells (26 percent) sampled in 1992. The maximum concentration was 0.56 milligrams per liter. There were no relations between bromide and major dissolved constituents, well depth, or aquifer tapped that would be useful for determining bromide concentrations. Areal patterns of bromide occurrence are not clearly defined, but areas with relatively high bromide concentrations tend to be located in a triangular area near the community of Sunbeam, Florida, and along the St. Johns River throughout Duval County.

  8. Optical and Rheological Properties of a Semi-Diluted Equimolar Solution of Cetyltrimethylammonium Bromide and Potassium Bromide

    NASA Astrophysics Data System (ADS)

    Decruppe, J. P.; Cappelaere, E.; Cressely, R.

    1997-02-01

    We report in this paper the results of rheological and optical experiments performed on a semi-diluted viscoelastic solution of cetyltrimethylammonium bromide (CTAB) in water with sodium bromide at a concentration of 0.3 M l^{-1} in surfactant and salt. This concentration in surfactant is much smaller than the concentration which gives a nematic phase at rest. The solution behaves like a Maxwell fluid with a single relaxation time. When submitted to a shear flow, this solution shows a behaviour typical of a system undergoing a phase transition. When observed between crossed polarizer and analyzer, the gap of the Couette cell appears divided in two bands the optical properties of which are different; in rheology, the curves σ(dot{γ}) are also characteristic of these systems where the shear stress presents a plateau extending between two critical values, dot{γ}_{1c}, and dot{γ}_{2c} of the shear rate. We finally compare the results with previous experiments performed on a concentrated solution of CTAB containing no salt.

  9. Budget of Methyl Bromide in the Atmosphere: Isotopic Constraints

    NASA Astrophysics Data System (ADS)

    Bill, M.; Miller, L. G.; Rhew, R. C.; Goldstein, A. H.

    2001-12-01

    Bromine radicals contribute significantly to stratospheric ozone loss through coupled reactions with ClO, HO2, and NO2 radicals. Bromine is approximately 40-100 times more effective, atom for atom, at destroying ozone than chlorine. For instance, Br coupled reactions are responsible for 30 to 50% of the total ozone loss in the polar vortex. The largest source of bromine to the stratosphere is methyl bromide (CH3Br). CH3Br has a concentration in the troposphere of about 10 pptv, a total estimated lifetime of 0.6 to 0.9 years, and has the highest concentration of any long lived organobromine. Unlike chlorofluorocarbons, which are produced entirely by humans, methyl bromide is produced by both anthropogenic and natural processes. We are developing the use of stable isotopes to constrain the budget of CH3Br through quantification of the source signatures and the isotopic fractionations associated with sinks. The largest natural sources appear to be biological production in oceans ( ~35%), biomass burning ( ~13%), and salt marshes ( ~10%). Thus far, the only natural emissions to be isotopically characterized is from salt marsh plants. Carbon isotopic ratios of CH3Br emitted from the salt marsh have a strong diurnal variation from -65\\permil during daytime when emission rates are highest to -12\\permil at night when emissions are ~13% of the daytime rates. The \\delta13C weighted mean of salt marsh emission is -43\\permil CH3Br. Anthropogenically produced CH3Br is used for fumigation of soils, harvested crops and structures, and represents approximately 30% of the total source flux. The fumigation of harvested crops and structures constitutes approximately one third of the anthropogenic source to the atmosphere and, because the release rate of applied CH3Br approaches 100%, it should have a mean isotopic composition equal to industrially manufactured CH3Br, -54.4\\permil. However during soil fumigation, some of the CH3Br is consumed insitu causing isotopic fractionation

  10. The first barium tin(II) bromide fluoride

    NASA Astrophysics Data System (ADS)

    Dénès, Georges; Merazig, Hocine; Muntasar, Abdualhafeed; Porterfield, Robyn

    2014-04-01

    In an effort to prepare barium tin(II) bromide fluorides for the first time, possibly similar to the chloride fluorides obtained earlier in our laboratory, precipitation reactions were carried out by mixing aqueous solutions of SnF2 and of BaBr2.2H2O. In contrast with the chloride fluoride system, a single powdered phase was obtained throughout the SnF2 - BaBr2 system, with the yield being maximum at X ≈ 0.25, where X is the molar fraction of barium bromide in the reaction mixture. Phase identification with the JCPDS database failed to produce a match, confirming that a new phase had been produced. The exact chemical composition of the new compound has not been obtained yet. Based on the X value for the maximum yield, the Sn/Ba ratio is likely to be 3/1 or 2/1. The Mössbauer spectrum at ambient conditions shows that bonding to tin(II) is covalent, therefore with the tin lone pair being stereoactive. The Mössbauer parameters ( δ = 3.68 mm/s, Δ = 0.99 mm/s) are similar to those of SnBrF and of Sn2BrF5, thereby showing that tin is bonded to both fluorine and bromine. The larger isomer shift and lower quadrupole splitting than in tin(II) fluorides show that the stereoactivity of the tin lone pair is lower than in the fluorides. The Mössbauer parameters fit well the linear correlation of the quadrupole splitting versus the isomer shift" that has been shown to be present in other series of tin(II) compounds. The linear decrease on this correlation shows that the contribution of non-spherical orbitals ( p and d) to the lone pair is a much larger contributor to the quadrupole splitting than lattice distortions. The structure is likely made of Ba2+ cations and tin(II) fluoride bromide polyatomic anions, with covalent bonding withinthe anions.

  11. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polybrominated ion-exchange resin (as a source of bromine) under the supervision of trained personnel. (2... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food...

  12. Destruction of methyl bromide sorbed to activated carbon by thiosulfate and electrolysis

    USDA-ARS?s Scientific Manuscript database

    Methyl bromide is widely used as a fumigant for post-harvest and quarantine uses at port facilities due to the low treatment times required, but it is vented to the atmosphere after its use. Due to the potential contributions of methyl bromide to stratospheric ozone depletion, technologies for the c...

  13. Surplus adsorption of bromide ion into π-conjugated carbon nanospaces assisted by proton coadsorption.

    PubMed

    Nishi, Masayasu; Ohkubo, Takahiro; Yamasaki, Masaru; Takagi, Hideyuki; Kuroda, Yasushige

    2017-12-15

    Nanoporous carbons can preferentially adsorb bromide ions from an aqueous solution of alkali metal bromides, even on π-conjugated surfaces. Our results show a new adsorption mechanism whereby coadsorption of protons enhances the adsorption of the anions onto the carbons. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Solid phase microextraction for active or passive sampling of methyl bromide during fumigations

    USDA-ARS?s Scientific Manuscript database

    The high diffusivity and volatility of methyl bromide make it an ideal compound for Solid Phase Micro Extraction (SPME)-based sampling of air prior to gas-chromatographic quantifications. SPME fibers can be used as active methyl bromide samplers, with high capacities and an equilibrium time of 1-2 m...

  15. Bromide's effect on DBP formation, speciation, and control; Part 1: Ozonation

    SciTech Connect

    Shukairy, H.M.; Summers, R.S. ); Miltner, R.J. . Drinking Water Research Div.)

    1994-06-01

    The effect of variable ozone dosage and bromide concentration on the formation of organic disinfection by-products (DBPs) and bromate were evaluated. Low ozone dosages resulted in oxidation of organic precursors, yielding decreases in the formation potential for total trihalomethanes (THMs), six haloacetic acids (HAAs), and total organic halide (TOX). Increasing the ozone dosage oxidized bromide to bromate, decreasing the bromide for incorporation into DBPs. Bromate concentrations were linearly correlated with ozone residuals. Changes in the bromine incorporation factors n and n[prime] reflected differences in the resulting speciation of THMs and HAAs, respectively. Because TOX measurements based on chloride equivalence may underestimate the halogenated DBP yield for high-bromide waters, a procedure is described whereby bromide and bromate concentrations were used to correct the TOX measurement.

  16. Nebulised ipratropium bromide and sodium cromoglycate in the first two years of life.

    PubMed Central

    Henry, R L; Hiller, E J; Milner, A D; Hodges, I G; Stokes, G M

    1984-01-01

    In a double blind crossover trial, we compared sodium cromoglycate, ipratropium bromide, and water in 23 asthmatic children less than 2 years old (mean age 11.8 months). Each child received nebulised solutions containing 20 mg of sodium cromoglycate, 250 micrograms of ipratropium bromide, or 2 ml water three times a day for three two month periods. Daily symptom scores did not show significant differences between the treatments but parental preferences indicated that both sodium cromoglycate and ipratropium bromide were superior to placebo. Sodium cromoglycate was prophylactic and was more likely to help the older patients. Ipratropium bromide produced an immediate clinical benefit and the response was not age dependent. We were unable to pick responders from non-responders on the basis of lung function tests performed on a routine outpatient basis. Both ipratropium bromide and sodium cromoglycate help some but not all asthmatic children aged less than 2 years. PMID:6230059

  17. X-Ray absorption spectroscopy investigation of 1-alkyl-3-methylimidazolium bromide salts

    SciTech Connect

    D'Angelo, Paola; Zitolo, Andrea; Migliorati, Valentina; Bodo, Enrico; Caminiti, Ruggero; Aquilanti, Giuliana; Hazemann, Jean Louis; Testemale, Denis; Mancini, Giordano

    2011-08-21

    X-ray absorption spectroscopy (XAS) has been used to unveil the bromide ion local coordination structure in 1-alkyl-3-methylimidazolium bromide [C{sub n}mim]Br ionic liquids (ILs) with different alkyl chains. The XAS spectrum of 1-ethyl-3-methylimidazolium bromide has been found to be different from those of the other members of the series, from the butyl to the decyl derivatives, that have all identical XAS spectra. This result indicates that starting from 1-buthyl-3-methylimidazolium bromide the local molecular arrangement around the bromide anion is the same independently from the length of the alkyl chain, and that the imidazolium head groups in the liquid ILs with long alkyl chains assume locally the same orientation as in the [C{sub 4}mim]Br crystal. With this study we show that the XAS technique is an effective direct tool for unveiling the local structural arrangements around selected atoms in ILs.

  18. Location of Bromide Ions in Tetragonal Lysozyme Crystals

    NASA Technical Reports Server (NTRS)

    Lim, Kap; Nadarajah, Arunan; Forsythe, Elizabeth L.; Pusey, Marc L.

    1998-01-01

    Anions have been shown to play a dominant role in the crystallization of chicken egg white lysozyme from salt solutions. Previous studies employing X-ray crystallography had found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. In this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from lysozyme crystal grown in bromide and chloride solutions. Five possible anion binding sites were found in this manner. Some of these sites were in pockets containing basic residues while others were near neutral, but polar, residues. The sole chloride ion binding site found in previous studies was confirmed, while four of these sites corresponded to four binding sites found for nitrate ions in monoclinic crystals. The study suggests that most of the anion binding sites in lysozyme remain unchanged, even when different anions and different crystal forms of lysozyme are employed.

  19. Location of Bromide Ions in Tetragonal Lysozyme Crystals

    NASA Technical Reports Server (NTRS)

    Lim, Kap; Nadarajah, Arunan; Forsythe, Elizabeth L.; Pusey, Marc L.

    1998-01-01

    Anions have been shown to play a dominant role in the crystallization of chicken egg white lysozyme from salt solutions. Previous studies employing X-ray crystallography had found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. In this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from lysozyme crystal grown in bromide and chloride solutions. Five possible anion binding sites were found in this manner. Some of these sites were in pockets containing basic residues while others were near neutral, but polar, residues. The sole chloride ion binding site found in previous studies was confirmed, while four of these sites corresponded to four binding sites found for nitrate ions in monoclinic crystals. The study suggests that most of the anion binding sites in lysozyme remain unchanged, even when different anions and different crystal forms of lysozyme are employed.

  20. Effects of pyridostigmine bromide on in-flight aircrew performance.

    PubMed

    Gawron, V J; Schiflett, S G; Miller, J C; Slater, T; Ball, J F

    1990-02-01

    The effects of a chemical defense pretreatment drug, pyridostigmine bromide (PB), on in-flight aircrew performance were assessed using the Total In-Flight Simulator (TIFS) aircraft. TIFS was used to supply appropriate control dynamics, handling characteristics, and cockpit instrumentation for a tactical transport airdrop simulation. Twenty-one C-130 pilots flew two familiarization and four data flights. During two data flights PB was given to both members of the aircrew using the dosage regimen of 30 mg/8 h prescribed by the U.S. Air Force surgeon general. The drug was administered using a double-blind technique. The results indicated that (1) aircrews successfully completed their assigned mission, (2) airdrop inaccuracies and navigation errors in time and distance were not specifically related to PB, (3) performance and crew coordination were not affected by PB, (4) PB and pilot/copilot not discriminate beyond chance between PB and placebo conditions.

  1. Error Evaluation of Methyl Bromide Aerodynamic Flux Measurements

    USGS Publications Warehouse

    Majewski, M.S.

    1997-01-01

    Methyl bromide volatilization fluxes were calculated for a tarped and a nontarped field using 2 and 4 hour sampling periods. These field measurements were averaged in 8, 12, and 24 hour increments to simulate longer sampling periods. The daily flux profiles were progressively smoothed and the cumulative volatility losses increased by 20 to 30% with each longer sampling period. Error associated with the original flux measurements was determined from linear regressions of measured wind speed and air concentration as a function of height, and averaged approximately 50%. The high errors resulted from long application times, which resulted in a nonuniform source strength; and variable tarp permeability, which is influenced by temperature, moisture, and thickness. The increase in cumulative volatilization losses that resulted from longer sampling periods were within the experimental error of the flux determination method.

  2. Protection of human muscle acetylcholinesterase from soman by pyridostigmine bromide.

    PubMed

    Maselli, Ricardo A; Henderson, John D; Ng, Jarae; Follette, David; Graves, Gregory; Wilson, Barry W

    2011-04-01

    Pretreatment with pyridostigmine bromide (PB) of human intercostal muscle fibers exposed to the irreversible acetylcholinesterase (AChE) inhibitor soman was investigated. Muscles were pretreated with 3 × 10(-6) M PB or saline for 20 minutes, then exposed to 10(-7) M soman for 10 minutes. AChE of muscles treated with soman alone was inhibited >95%. In contrast, PB pretreatment of soman-exposed bundles protected 20% of AChE activity. AChE of bundles exposed to PB alone recovered after 4 hours, but bundles exposed to both PB and soman did not. Soman-induced reduction of resting membrane potentials and increment of amplitudes and decay times of miniature endplate potentials (MEPPs) were partially corrected by PB pretreatment. In vitro pretreatment of human muscles with PB protected up to 20% of muscle AChE and ameliorated some deleterious effects on endplate physiology induced by soman. Copyright © 2011 Wiley Periodicals, Inc.

  3. Theoretical and experimental studies of silver bromide clusters

    NASA Astrophysics Data System (ADS)

    Zhang, Hongguang

    2000-11-01

    This work consists of three parts: Experimental synthesis of silver bromide clusters via the electroporation of unilamellar dioleoylphosphatidylcholine (DOPC) vesicles, theoretical study of the structure and electronic properties of (AgBr)n clusters, and characterization of silver bromide clusters grown and their interaction with the surface of DOPC vesicles. In the first part, we successfully synthesized AgBr quantum dots via the electroporation of vesicles. For the first time, we observed the entire blue-shift followed by red-shift of the absorption band (274nm --> 5h 269nm --> 6h 273nm) that is associated with the growth of the silver bromide clusters. The turn-around point is at 269 nm. In the second part, we have theoretically investigated the structures and UV absorption spectra of (AgBr)n clusters (n = 1-9) in both the gas phase and in a dielectric medium. The structures of clusters were determined at the B3P86/SB level with full geometry optimization. For clusters with n = 1-6, extensive searches of the potential energy surface yielded only one minimum, while larger clusters displayed two or more minima. UV absorption spectra were calculated by the configuration interaction singlet (CIS) method with a much larger basis set. Our computational results parallel the experimental trends, and show that the turn- around point occurs at the trimer according to HOMO-LUMO gap calculation and at the tetramer according to CIS calculation. The molecular origin of the blue/red shift associated with AgBr cluster growth can be readily explained by examining the orbital interactions which dominate the process and by the structure of the clusters. The detailed molecular orbital energy level correlation diagram for the dimerization, trimerization and tetramerization will be presented. In the third part, TEM characterization of the quantum dots show

  4. Reactions of buffers in cyanogen bromide-induced ligations.

    PubMed

    Vogel, Heike; Gerlach, Claudia; Richert, Clemens

    2013-01-01

    Rapid, template-directed ligation reactions between a phosphate-terminated oligonucleotide and an unphosphorylated reaction partner may be induced by cyanogen bromide (BrCN). Frequently, however, the reaction is low yielding, and even a large excess of the condensing agent can fail to induce quantitative conversions. In this study, we used BrCN to induce chemical primer extension reactions. Here, we report that buffers containing hydroxyl groups react with short oligodeoxynucleotides in the presence of BrCN. One stable adduct between HEPBS buffer and cytosine was characterized by mass spectrometry and NMR after HPLC purification, indicating that a side reaction occurred at this nucleobase. Further, a first example of a primer extension reaction between an unmodified oligodeoxynucleotide as primer and dGMP is reported. Together, our results shed light on the potency, as well as the drawbacks of BrCN as a highly reactive condensing reagent for the ligation of unmodified nucleic acids.

  5. Classifying the Basic Parameters of Ultraviolet Copper Bromide Laser

    NASA Astrophysics Data System (ADS)

    Gocheva-Ilieva, S. G.; Iliev, I. P.; Temelkov, K. A.; Vuchkov, N. K.; Sabotinov, N. V.

    2009-10-01

    The performance of deep ultraviolet copper bromide lasers is of great importance because of their applications in medicine, microbiology, high-precision processing of new materials, high-resolution laser lithography in microelectronics, high-density optical recording of information, laser-induced fluorescence in plasma and wide-gap semiconductors and more. In this paper we present a statistical study on the classification of 12 basic lasing parameters, by using different agglomerative methods of cluster analysis. The results are based on a big amount of experimental data for UV Cu+ Ne-CuBr laser with wavelengths 248.6 nm, 252.9 nm, 260.0 nm and 270.3 nm, obtained in Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences. The relevant influence of parameters on laser generation is also evaluated. The results are applicable in computer modeling and planning the experiments and further laser development with improved output characteristics.

  6. Accommodation coefficient of HOBr on deliquescent sodium bromide aerosol particles

    NASA Astrophysics Data System (ADS)

    Wachsmuth, M.; Gäggeler, H. W.; von Glasow, R.; Ammann, M.

    2002-06-01

    Uptake of HOBr on sea salt aerosol, sea salt brine or ice is believed to be a key process providing a source of photolabile bromine (Br2) and sustaining ozone depletion cycles in the Arctic troposphere. In the present study, uptake of HOBr on sodium bromide (NaBr) aerosol particles was investigated at an extremely low HOBr concentration of 300 cm-3 using the short-lived radioactive isotopes 83-86Br. Under these conditions, at maximum one HOBr molecule was taken up per particle. The rate of uptake was clearly limited by the mass accommodation coefficient, which was calculated to be 0.6 ± 0.2. This value is a factor of 10 larger than estimates used in earlier models. The atmospheric implications are discussed using the box model "MOCCA'', showing that the increase of the accommodation coefficient of HOBr by a factor of 10 only slightly affects net ozone loss, but significantly increases chlorine release.

  7. Tiotropium Bromide in Chronic Obstructive Pulmonary Disease and Bronchial Asthma

    PubMed Central

    Alvarado-Gonzalez, Alcibey; Arce, Isabel

    2015-01-01

    Inhaled bronchodilators are the mainstay of pharmacological treatment for stable chronic obstructive pulmonary disease (COPD), including β2-agonists and muscarinic antagonists. Tiotropium bromide, a long-acting antimuscarinic bronchodilator (LAMA), is a treatment choice for moderate-to-severe COPD; its efficacy and safety have been demonstrated in recent trials. Studies also point to a beneficial role of tiotropium in the treatment of difficult-to-control asthma and a potential function in the asthma-COPD overlap syndrome (ACOS). Combination of different bronchodilator molecules and addition of inhaled corticosteroids are viable therapeutic alternatives. A condensation of the latest trials and the rationale behind these therapies will be presented in this article. PMID:26491494

  8. Comparative mobility of sulfonamides and bromide tracer in three soils

    USGS Publications Warehouse

    Kurwadkar, S.T.; Adams, C.D.; Meyer, M.T.; Kolpin, D.W.

    2011-01-01

    In animal agriculture, sulfonamides are one of the routinely used groups of antimicrobials for therapeutic and sub-therapeutic purposes. It is observed that, the animals when administered the antimicrobials, often do not completely metabolize them; and excrete the partially metabolized forms into the environment. Due to the continued use of antimicrobials and disposal of untreated waste, widespread occurrence of partially metabolized antimicrobials in aquatic and terrestrial environments has been reported in various scientific journals. In this research, the mobility of two sulfonamides - sulfamethazine (SMN), sulfathiazole (STZ) and a conservative bromide tracer was investigated in three soils collected from regions in the United States with large number of concentrated animal-feed operations. Results of a series of column studies indicate that the mobility of these two sulfonamides was dependent on pH, soil charge density, and contact time. At low pH and high charge density, substantial retention of sulfonamides was observed in all three soils investigated, due to the increased fraction of cationic and neutral forms of the sulfonamides. Conversely, enhanced mobility was observed at high pH, where the sulfonamides are predominantly in the anionic form. The results indicate that when both SMN and STZ are predominantly in anionic forms, their mobility approximates the mobility of a conservative bromide tracer. This observation is consistent for the mobility of both SMN and STZ individually, and also in the presence of several other antimicrobials in all three soils investigated. Higher contact time indicates lower mobility due to increased interaction with soil material. ?? 2011.

  9. Electrochemical and spectroscopic study of octadecyltrimethylammonium bromide/DNA surfoplexes.

    PubMed

    Rodríguez-Pulido, Alberto; Aicart, Emilio; Junquera, Elena

    2009-04-21

    The use of cationic micelles consisting of octadecyltrimethylammonium bromide (C18TAB) to compact calf thymus DNA has been investigated in aqueous buffered solution at 310.15 K by means of conductometry, electrophoretic mobility, and several fluorescence spectroscopy methods. The results indicate that C18TAB micelles, consisting of 44 monomers on average, may compact DNA molecule by an electrostatic interaction that takes place at the cationic spherical micelle surface. The surfoplexes thus formed show a surface density charge that goes from negative to positive values at a Lmic/D mass ratio of around 1.0 (where Lmic and D are the masses of micellized cationic surfactant and DNA), called the isoneutrality ratio (Lmic/D)phi. Values of this characteristic parameter, determined in this work not only from the electrochemical experimental data but also from spectroscopic measurements, are in very good agreement with those ones calculated from molecular parameters and some other properties also obtained in this work. The electrostatic character of the DNA-micelle interaction has been confirmed by analyzing the decrease in fluorescence emission of the fluorophore ethidium bromide, EtBr, initially intercalated between DNA base pairs, as long as the surfoplexes are formed. Fluorescence anisotropy experiments have revealed that micelle packing becomes more rigid in the presence of DNA, but once the surfoplex is formed, the fluidity increases with the Lmic/D mass ratio, attaining its maximum when the isoneutrality ratio is exceeded. This fact, together with the net positive charge of the surfoplexes with the Lmic/D mass ratio over the isoneutrality ratio, makes this regimen of lipid and DNA content the optimum for efficiency in the transfection process.

  10. Oral bioavailability and enterohepatic recirculation of otilonium bromide in rats.

    PubMed

    Shin, Beom Soo; Kim, Jung Jun; Kim, John; Hu, Sul Ki; Kim, Hyoung Jun; Hong, Seok Hyun; Kim, Han Kyung; Lee, Hye Suk; Yoo, Sun Dong

    2008-01-01

    This study was conducted to examine the oral bioavailability and the possibility of enterohepatic recirculation of otilonium bromide in rats. A sensitive LC/MS/MS assay (LLOQ 0.5 ng/mL) was developed for the determination of otilonium and applied to i.v. and oral administration studies in bile duct cannulated (BDC) and non-BDC rats. After i.v. injection to BDC rats (1 mg/ kg as otilonium), average t(1/2), CL, Vz and AUC were 7.9 +/- 1.9 h, 8.7 +/- 3.1 mL/min/kg, 5.7 +/- 1.4 L/kg and 2,088 +/- 676 ng h/mL, respectively, and these values were comparable to those found in non-BDC rats. The percentages of i.v. dose excreted unchanged in bile and urine in BDC rats were 11.6 +/- 3.0 and 3.1 +/- 0.7%, respectively. Upon oral administration to non-BDC rats (20 mg/kg as otilonium), t(1/2), Cmax, Tmax and AUC were 6.4 +/- 1.3 h, 182.8 +/- 44.6 ng/mL, 1.9 +/- 1.6 h and 579 +/- 113 ng h/mL, respectively. The absolute oral bioavailability was low (1.1%), while the drug was preferentially distributed to gastrointestinal tissues. A secondary peak was observed in the serum concentration-time profiles in non-BDC rats following both i.v. and oral administration, indicating that otilonium bromide was subject to enterohepatic recirculation.

  11. Storing Hydrogen

    SciTech Connect

    Kim, Hyun Jeong; Karkamkar, Abhijeet J.; Autrey, Thomas; Chupas, Peter; Proffen, Thomas E.

    2010-05-31

    Researchers have been studying mesoporous materials for almost two decades with a view to using them as hosts for small molecules and scaffolds for molding organic compounds into new hybrid materials and nanoparticles. Their use as potential storage systems for large quantities of hydrogen has also been mooted. Such systems that might hold large quantities of hydrogen safely and in a very compact volume would have enormous potential for powering fuel cell vehicles, for instance. A sponge-like form of silicon dioxide, the stuff of sand particles and computer chips, can soak up and store other compounds including hydrogen. Studies carried out at the XOR/BESSRC 11-ID-B beamline at the APS have revealed that the nanoscopic properties of the hydrogenrich compound ammonia borane help it store hydrogen more efficiently than usual. The material may have potential for addressing the storage issues associated with a future hydrogen economy. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  12. Hydrogen program overview

    SciTech Connect

    Gronich, S.

    1997-12-31

    This paper consists of viewgraphs which summarize the following: Hydrogen program structure; Goals for hydrogen production research; Goals for hydrogen storage and utilization research; Technology validation; DOE technology validation activities supporting hydrogen pathways; Near-term opportunities for hydrogen; Market for hydrogen; and List of solicitation awards. It is concluded that a full transition toward a hydrogen economy can begin in the next decade.

  13. Hydrogen gas purification apparatus

    SciTech Connect

    Yanagihara, N.; Gamo, T.; Iwaki, T.; Moriwaki, Y.

    1984-04-24

    A hydrogen gas purification apparatus which includes at least one set of two hydrogen purification containers coupled to each other for heat exchanging therebetween, each of the hydrogen purification containers containing a hydrogen absorbing alloy. The hydrogen gas purification apparatus is so arranged as to cause hydrogen gas to be selectively desorbed from and absorbed into the hydrogen absorbing alloy by the amount of heat produced when the hydrogen gas is selectively absorbed into and desorbed from the hydrogen absorbing alloy.

  14. 78 FR 14508 - Notice of Affirmation of Addition of a Treatment Schedule for Methyl Bromide Fumigation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... Treatment Schedule for Methyl Bromide Fumigation of Cottonseed AGENCY: Animal and Plant Health Inspection... methyl bromide fumigation of cottonseed for the fungal plant pathogen Fusarium oxysporum f. sp... No. APHIS- 2012-0040), announcing our determination that a new methyl bromide fumigation treatment...

  15. Competition between silver ions and oxybromine species for bromide ions in the silver-perturbed Belousov-Zhabotinskii reaction

    SciTech Connect

    Roberts, J.; Stuk, L.; McCormick, W.D. )

    1991-04-18

    The authors investigated the relative rates of bromide consumption by silver ions and by the oxybromine species of the Belousov-Zhabotinskii reaction. Their results indicate that the consumption of bromide by silver is too slow to suppress bromide control of the oscillating reaction.

  16. Derivation of an occupational exposure limit (OEL) for n-propyl bromide using an improved methodology.

    PubMed

    Rozman, Karl K; Doull, John

    2002-10-01

    n-Propyl bromide is an industrial solvent with increasing production volume due to its use as a replacement for fluorohydrocarbons. Therefore, the number of occupationally exposed workers is growing accordingly. This manuscript presents a thorough evaluation of available animal and human data to derive an occupational exposure limit (OEL) for n-propyl bromide. In addition, structure activity relationship within the homologous series of methyl, ethyl, and n-propyl bromide and an identical spectrum of effects caused by similar doses of 2-propyl bromide are used to increase the confidence of the analysis. The structure activity relationship was entirely consistent for acute and subchronic (neurologic, reproductive, and hematopoietic) toxicities and for mutagenic potency in that CH3Br was more toxic than CH3CH2Br, which in turn was more toxic than CH3CH2CH2Br in every case in all species studied, including humans. Animals appeared to be similarly susceptible as, or slightly more susceptible than, humans to n-propyl bromide's toxicity. An OEL (60-90 ppm) was derived from a limited human study and supported by an across-the-toxic-spectrum comparison of animal and human data for both n-propyl and 2-propyl bromide. A carcinogenic classification was not deemed necessary at the recommended OEL based on very low mutagenic potency and the consistent structure activity relationship across the homologous series of these alkyl bromides.

  17. Hydrogen chloride

    Integrated Risk Information System (IRIS)

    Hydrogen chloride ; CASRN 7647 - 01 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  18. Hydrogen technologies

    SciTech Connect

    Not Available

    1992-05-01

    To the non-nonsense engineer, any talk of a hydrogen economy may seem like so much hot air. This paper reports that as legislative, safety and environmental issues continue to tighten, they're promoting hydrogen's chances as an energy source and, more immediately, its prospects as a chemical feedstock. Paradoxically, the environmental demands that are stimulating hydrogen demand are also inhibiting the gas's production. Previously, gasoline was made with benzene, which means that H{sub 2} was rejected. But now that the laws mandate lower aromatic and higher oxygenate levels in gasolines, there's less H{sub 2} available as byproduct. At the same time, H{sub 2} demand is rising in hydrodesulfurization units, since the same laws require refiners to cut sulfur levels in fuels. Supplementary sources for the gas are also shrinking. In the chlor-alkali industry, H{sub 2} output is dropping, as demand for its coproduct chlorine weakens. At the same time, H{sub 2} demand for the making of hydrogen peroxide is growing, as that environmentally safer bleach gains chlorine's market share.

  19. Hydrogen sulfide

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 03 / 005 www.epa.gov / iris TOXICOLOGICAL REVIEW OF HYDROGEN SULFIDE ( CAS No . 7783 - 06 - 4 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) June 2003 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been

  20. Destruction of methyl bromide sorbed to activated carbon by thiosulfate or electrolysis.

    PubMed

    Yang, Yu; Li, Yuanqing; Walse, Spencer S; Mitch, William A

    2015-04-07

    Methyl bromide (CH3Br) is widely used as a fumigant for postharvest and quarantine applications for agricultural products at port facilities due to the short treatment period required, but it is vented from fumigation chambers to the atmosphere after its use. Due to the potential contributions of CH3Br to stratospheric ozone depletion, technologies for the capture and degradation of the CH3Br are needed to enable its continued use. Although granular activated carbon (GAC) has been used for CH3Br capture and thiosulfate has been used for destruction of CH3Br in aqueous solution, this research explored techniques for direct destruction of CH3Br sorbed to GAC. Submerging the GAC in an aqueous thiosulfate solution achieved debromination of CH3Br while sorbed to the GAC, but it required molar concentrations of thiosulfate because of the high CH3Br loading and produced substantial concentrations of methyl thiosulfate. Submergence of the GAC in water and use of the GAC as the cathode of an electrolysis unit also debrominated sorbed CH3Br. The reaction appeared to involve a one-electron transfer, producing methyl radicals that incorporated into the GAC. Destruction rates increased with decreasing applied voltage down to ∼-1.2 V vs the standard hydrogen electrode. Cycling experiments conducted at -0.77 V indicated that >80% debromination of CH3Br was achieved over ∼ 30 h with ∼ 100% Coulombic efficiency. Sorptive capacity and degradation efficiency were maintained over at least 3 cycles. Capture of CH3Br fumes from fumigation chambers onto GAC, and electrolytic destruction of the sorbed CH3Br could mitigate the negative impacts of CH3Br usage pending the development of suitable replacement fumigants.

  1. Efficacy and safety of ipratropium bromide/albuterol delivered via Respimat inhaler versus MDI.

    PubMed

    Zuwallack, R; De Salvo, M C; Kaelin, T; Bateman, E D; Park, C S; Abrahams, R; Fakih, F; Sachs, P; Pudi, K; Zhao, Y; Wood, C C

    2010-08-01

    We compared the efficacy and safety of ipratropium bromide/albuterol delivered via Respimat inhaler, a novel propellant-free inhaler, versus chlorofluorocarbon (CFC)-metered dose inhaler (MDI) and ipratropium Respimat inhaler in patients with COPD. This was a multinational, randomized, double-blind, double-dummy, 12-week, parallel-group, active-controlled study. Patients with moderate to severe COPD were randomized to ipratropium bromide/albuterol (20/100mcg) Respimat inhaler, ipratropium bromide/albuterol MDI [36mcg/206mcg (Combivent Inhalation Aerosol MDI)], or ipratropium bromide (20mcg) Respimat inhaler. Each medication was administered four times daily. Serial spirometry was performed over 6h (0.15min, then hourly) on 4 test days. The primary efficacy variable was forced expiratory volume in 1s (FEV(1)) change from test day baseline at 12 weeks. A total of 1209 of 1480 randomized, treated patients completed the study; the majority were male (65%) with a mean age of 64 yrs and a mean screening pre-bronchodilator FEV(1) (percent predicted) of 41%. Ipratropium bromide/albuterol Respimat inhaler had comparable efficacy to ipratropium bromide/albuterol MDI for FEV(1) area under the curve at 0-6h (AUC(0-6)), superior efficacy to ipratropium Respimat inhaler for FEV(1) AUC(0-4) and comparable efficacy to ipratropium Respimat inhaler for FEV(1) AUC(4-6). All active treatments were well tolerated. This study demonstrates that ipratropium bromide/albuterol 20/100mcg inhaler administered four times daily for 12 weeks had equivalent bronchodilator efficacy and comparable safety to ipratropium bromide/albuterol 36mcg/206mcg MDI, and significantly improved lung function compared with the mono-component ipratropium bromide 20 mcg Respimat inhaler. [Clinical Trial Identifier Number: NCT00400153].

  2. The role of tiotropium bromide, a long-acting anticholinergic bronchodilator, in the management of COPD.

    PubMed

    Saberi, Farzad; O'Donnell, Denis E

    2005-01-01

    Bronchodilator therapy forms the mainstay of treatment for symptomatic patients with COPD. Long-acting bronchodilators, which maintain sustained airway patency over a 24-hour period, represent an advance in therapy. Tiotropium bromide is a new long-acting inhaled anticholinergic agent with superior pharmacodynamic properties compared with the short-acting anticholinergic, ipratropium bromide. Tiotropium bromide has been consistently shown to have a greater impact than ipratropium bromide on clinically important outcome measures such as health status. The mechanisms of clinical benefit with tiotropium bromide are multifactorial, but improved airway function, which enhances lung emptying and allows sustained deflation of over-inflated lungs, appears to explain improvements in dyspnea and exercise endurance in COPD. Inhaled tiotropium bromide therapy has also been associated with reduction in acute exacerbations of COPD as well as reduced hospitalizations. The safety profile of tiotropium bromide is impressive: dry mouth is the most common adverse event and rarely necessitates termination of the drug. No tachyphylaxis to tiotropium bromide has been demonstrated in clinical trials lasting up to 1 year. There is preliminary information that the combination of long-acting anticholinergics and long-acting beta2-adrenoceptor agonists provides additive physiological and clinical benefits. According to recent international guidelines, long-acting bronchodilators should be considered early in the management of symptomatic patients with COPD in order to achieve effective symptom alleviation and reduction in activity limitation. Tiotropium bromide, because of its once-daily administration and its established efficacy and tolerability profile, has emerged as an attractive therapeutic option for this condition.

  3. Metallic Hydrogen

    NASA Astrophysics Data System (ADS)

    Silvera, Isaac; Zaghoo, Mohamed; Salamat, Ashkan

    2015-03-01

    Hydrogen is the simplest and most abundant element in the Universe. At high pressure it is predicted to transform to a metal with remarkable properties: room temperature superconductivity, a metastable metal at ambient conditions, and a revolutionary rocket propellant. Both theory and experiment have been challenged for almost 80 years to determine its condensed matter phase diagram, in particular the insulator-metal transition. Hydrogen is predicted to dissociate to a liquid atomic metal at multi-megabar pressures and T =0 K, or at megabar pressures and very high temperatures. Thus, its predicted phase diagram has a broad field of liquid metallic hydrogen at high pressure, with temperatures ranging from thousands of degrees to zero Kelvin. In a bench top experiment using static compression in a diamond anvil cell and pulsed laser heating, we have conducted measurements on dense hydrogen in the region of 1.1-1.7 Mbar and up to 2200 K. We observe a first-order phase transition in the liquid phase, as well as sharp changes in optical transmission and reflectivity when this phase is entered. The optical signature is that of a metal. The mapping of the phase line of this transition is in excellent agreement with recent theoretical predictions for the long-sought plasma phase transition to metallic hydrogen. Research supported by the NSF, Grant DMR-1308641, the DOE Stockpile Stewardship Academic Alliance Program, Grant DE-FG52-10NA29656, and NASA Earth and Space Science Fellowship Program, Award NNX14AP17H.

  4. Bronchodilating effect of combined therapy with ipratropium bromide and ondansetron in patients with COPD.

    PubMed

    Pauwels, Romain; Joos, Guy F; Fogarty, Charles; Faiferman, Isidore; Hirschberg, Sandra; Vessey, Rupert; Wouters, Emiel F M

    2008-01-01

    The objectives of this study were to determine the effect of single and repeat dosing with oral ondansetron, a 5-HT3-specific receptor blocker, on the degree and duration of bronchodilation induced by inhaled ipratropium bromide in patients with COPD. Five clinics and university medical centers in four countries participated in the study; 47 patients with COPD were randomized to treatment; 44 completed all treatments. Patients had a baseline (pre-bronchodilator) FEV1>1L and post-bronchodilator (200 mcg salbutamol) FEV1<90% of predicted, with FEV1 reversibility (to 80 mcg inhaled ipratropium bromide and 400 mcg salbutamol) of at least 12% or 200 mL over baseline. The study was divided into two parts. In Part A, each patient received in a random order, four-way crossover manner, single doses of ondansetron placebo (oral) plus ipratropium bromide placebo (inhaled), ondansetron placebo plus ipratropium bromide 40 mcg inhaled via MDI, ondansetron 24 mg oral plus ipratropium bromide placebo and ondansetron 24 mg plus ipratropium bromide 40 mcg. In Part B, each patient received in a random order, two-way crossover manner, ipratropium bromide 40 mcg tid via MDI plus ondansetron 8 mg oral, qid, for 2 days; on day 3 patients received a single dose of ipratropium bromide 40 mcg plus 8 mg oral ondansetron. Alternatively, patients received ipratropium bromide via MDI and oral ondansetron placebo, as described above. Statistically significant differences in weighted mean FEV1 (0-6h), peak FEV1 and FEV1 determined 6h post-dose were noted comparing ipratropium bromide to placebo. Similar positive results were observed for sGaw and FVC. Addition of ondansetron to ipratropium bromide did not significantly modify values obtained with ipratropium alone. Ipratropium bromide induced a marked bronchodilation, compared to placebo. Addition of ondansetron (single or repeated doses) did not significantly increase the degree or duration of bronchodilation induced by ipratropium alone. s

  5. Rapid, easy cyanation of aryl bromides and chlorides using nickel salts in conjunction with microwave promotion.

    PubMed

    Arvela, Riina K; Leadbeater, Nicholas E

    2003-11-14

    We report here a fast, easy, and efficient method for the preparation of aryl nitriles from aryl bromides and chlorides. The methodology for aryl bromides involves the use of either Ni(CN)(2) or NaCN and NiBr(2). With aryl chlorides, a mix of NaCN and NiBr(2) is used and the reaction proceeds via the in situ formation of the corresponding aryl bromide. The reaction can be performed in air and is complete within 10 min.

  6. Bromination of aromatic compounds by residual bromide in sodium chloride matrix modifier salt during heated headspace GC/MS analysis.

    PubMed

    Fine, Dennis D; Ko, Saebom; Huling, Scott

    2013-12-15

    Analytical artifacts attributed to the bromination of toluene, xylenes, and trimethylbenzenes were found during the heated headspace gas chromatography/mass spectrometry (GC/MS) analysis of aqueous samples. The aqueous samples were produced from Fenton-like chemical oxidation reactions and contained aromatic compounds, hydrogen peroxide (H2O2), and ferric sulfate. Prior to GC/MS headspace analysis, the samples were acidified (pH<2), and sodium chloride was amended to the headspace vial as a matrix modifier. The brominated artifacts were generated during heated headspace analysis. Further, when samples were spiked with a mixture of volatile chlorinated and aromatic compounds (50 µg/L), poor spike recoveries of toluene and xylenes occurred, and in some cases complete loss of trimethylbenzenes and naphthalene resulted. Where poor recovery of aromatic spike compounds occurred, brominated aromatic compounds were found. The only significant source of bromine in the reaction scheme is the bromide typically present (<0.01% w/w) in the sodium chloride amended to the samples. Conversely, brominated artifacts were absent when a buffered salt mixture composed of sodium chloride and potassium phosphate dibasic/monobasic was used as a matrix modifier and raised the sample pH (pH~6). This indicated that the brominated artifacts resulted from the reaction of the aromatic compounds with BrCl, which was formed by the reaction of H2O2, chloride, and bromide under acidic conditions. An alternative matrix modifier salt is recommended that prevents the bromination reaction and avoids these deleterious effects on sample integrity during headspace analysis.

  7. Hydrogen peroxide poisoning

    MedlinePlus

    Hydrogen peroxide is used in these products: Hydrogen peroxide Hair bleach Some contact lens cleaners Note: Household hydrogen peroxide has a 3% concentration. That means it contains 97% water and 3% hydrogen peroxide. Hair ...

  8. Hydrogen forming reaction process

    SciTech Connect

    Marianowski, L.G.; Fleming, D.K.

    1989-03-07

    A hydrogen forming process is described, comprising: conducting in a hydrogen production zone a chemical reaction forming mixed gases comprising molecular hydrogen; contacting one side of a hydrogen ion porous and molecular gas nonporous metallic foil with the mixed gases in the hydrogen production zone; dissociating the molecular hydrogen to ionic hydrogen on the one side of the metallic foil; passing the ionic hydrogen through the metallic foil to its other side; and withdrawing hydrogen from the other side of the metallic foil, thereby removing hydrogen from the hydrogen production zone.

  9. Hydrogen environment embrittlement.

    NASA Technical Reports Server (NTRS)

    Gray, H. R.

    1972-01-01

    Hydrogen embrittlement is classified into three types: internal reversible hydrogen embrittlement, hydrogen reaction embrittlement, and hydrogen environment embrittlement. Characteristics of and materials embrittled by these types of hydrogen embrittlement are discussed. Hydrogen environment embrittlement is reviewed in detail. Factors involved in standardizing test methods for detecting the occurrence of and evaluating the severity of hydrogen environment embrittlement are considered. The effects of test technique, hydrogen pressure, purity, strain rate, stress concentration factor, and test temperature are discussed.

  10. PREPARATION OF ANHYDROUS CERIUM CHLORIDE, URANIUM BROMIDE OR PLUTONIUM FLUORIDE

    DOEpatents

    Marmon, K.M.; Wichers, E.

    1961-05-01

    A process is given for preparing anhydrous metal halides and converting metal oxalates to anhydrous metal halides which are free from oxyhalides. In accordance with one embodiment of the invention, cerous chloride is prepared by passing hydrogen chloride gas over hydrated cerous oxalate below lOO deg C until no more gas is absorbed and then continuing the treatmert at higher temperatures.

  11. [Treatment of cetyltrimethyl ammonium bromide wastewater by potassium ferrate].

    PubMed

    Yang, Wei-hua; Wang, Hong-hui; Zeng, Xiao-xu; Huang, Ting-ting

    2009-08-15

    A novel oxidant potassium ferrate (K2FeO4) was used to remove cetyltrimethyl ammonium bromide (CTAB) at room temperature. The effects of various conditions on the removal ratio, such as reaction time, dosing quantity of K2FeO4 and initial pH, were investigated. The experiments results show that the removal ratio reaches 79.4% when the reaction time is 30 min, the dosing quantity of K2FeO4 to CTAB is 1:1, the initial pH of the solution is 7. In the reaction progress, the oxidation of K2FeO4 and the flocculation of the reduction product have synergistic effect on the removal of CTAB. In addition, infrared spectra of CTAB before and after being treated with K2FeO4 were further studied. The results indicate that the degradation process involves the interruption of chain and the subsequent mineralization to inorganic molecules. Furthermore, the reaction of K2FeO4 and CTAB follows second order kinetics law.

  12. Chloride, bromide and iodide scintillators with europium doping

    DOEpatents

    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.

  13. Associated anisotropy decays of ethidium bromide interacting with DNA

    NASA Astrophysics Data System (ADS)

    Chib, Rahul; Raut, Sangram; Sabnis, Sarika; Singhal, Preeti; Gryczynski, Zygmunt; Gryczynski, Ignacy

    2014-03-01

    Ethidium Bromide (EB) is a commonly used dye in a deoxyribonucleic acid (DNA) study. Upon an intercalation, this dye significantly increases its brightness and fluorescence lifetime. In this report we have studied the time resolved fluorescence properties of EB existing simultaneously in free and DNA-bound forms in the solution. Fluorescence intensity decays were fitted globally to a double exponential model with lifetimes corresponding to free (1.6 ns) and bound (22 ns) forms, and molar fractions were determined for all used solutions. Anisotropy decays displayed characteristic time dependence with an initial rapid decline followed by recovery and slow decay. The short-lived fraction associated with free EB molecules decreases faster than long-lived fraction associated with EB bound to DNA. Consequently, contribution from fast rotation leads to initial rapid decay in anisotropy. On the other hand bound fraction, due to slow rotation helps recover anisotropy in time. This effect of associated anisotropy decays in systems such as EB free/EB-DNA is clearly visible in a wide range of concentrations, and should be taken into account in polarization assays and biomolecule dynamics studies.

  14. Vibrational spectroscopic and computational studies on diisopropylammonium bromide

    NASA Astrophysics Data System (ADS)

    Sahoo, Shradhanjali; Ravindran, T. R.; Chandra, Sharat; Sarguna, R. M.; Das, B. K.; Sairam, T. N.; Sivasubramanian, V.; Thirmal, C.; Murugavel, P.

    2017-09-01

    Diisopropylammonium bromide (DIPAB) can be crystallized either in an orthorhombic (P212121) or in a monoclinic (P21) structure at room temperature depending on synthesis conditions. The non-polar orthorhombic structure exhibits a subtle, irreversible transformation into the ferroelectric monoclinic-II (m-II) phase above 421 K. At a slightly higher temperature of 426 K this m-II (P21) phase reversibly transforms into a disordered, paraelectric monoclinic-I (P21/m) structure. We synthesized DIPAB in the orthorhombic structure, heated it to obtain the m-II phase and carried out a systematic study of their Raman and IR spectra. We obtained the phonon irreducible representations from factor group analysis of the orthorhombic and m-II structures based on the reported structural information. DIPAB is an organic molecular crystal, and the vibrational spectra in the intramolecular region (200-3500 cm- 1) of the two different phases are identical to each other, indicating weak inter-molecular interactions in both crystalline structures. In the low wavenumber region (10-150 cm- 1) the Raman spectra of the two phases are different due to their sensitivity to molecular environment. We also carried out first principles calculations using Gaussian 09 and CASTEP codes to analyze the vibrational frequencies. Mode assignments were facilitated by isolated molecule calculations that are also in good agreement with intramolecular vibrations, whereas CASTEP (solid state) results could explain the external modes.

  15. High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices

    PubMed Central

    Perumal, Ajay; Shendre, Sushant; Li, Mingjie; Tay, Yong Kang Eugene; Sharma, Vijay Kumar; Chen, Shi; Wei, Zhanhua; Liu, Qing; Gao, Yuan; Buenconsejo, Pio John S.; Tan, Swee Tiam; Gan, Chee Lip; Xiong, Qihua; Sum, Tze Chien; Demir, Hilmi Volkan

    2016-01-01

    Formamidinium lead halide (FAPbX3) has attracted greater attention and is more prominent recently in photovoltaic devices due to its broad absorption and higher thermal stability in comparison to more popular methylammonium lead halide MAPbX3. Herein, a simple and highly reproducible room temperature synthesis of device grade high quality formamidinium lead bromide CH(NH2)2PbBr3 (FAPbBr3) colloidal nanocrystals (NC) having high photoluminescence quantum efficiency (PLQE) of 55–65% is reported. In addition, we demonstrate high brightness perovskite light emitting device (Pe-LED) with these FAPbBr3 perovskite NC thin film using 2,2′,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) commonly known as TPBi and 4,6-Bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) as electron transport layers (ETL). The Pe-LED device with B3PYMPM as ETL has bright electroluminescence of up to 2714 cd/m2, while the Pe-LED device with TPBi as ETL has higher peak luminous efficiency of 6.4 cd/A and peak luminous power efficiency of 5.7 lm/W. To our knowledge this is the first report on high brightness light emitting device based on CH(NH2)2PbBr3 widely known as FAPbBr3 nanocrystals in literature. PMID:27827424

  16. Evaluation of alkali bromide salts for potential pyrochemical applications

    SciTech Connect

    Tripathy, P.K.; Gutknecht, T.Y.; Herrmann, S.D.; Fredrickson, G.L.; Lister, T.E.

    2013-07-01

    Transient techniques were employed to study the electrochemical behavior, reduction mechanism and transport properties of REBr{sub 3} (RE - La, Nd and Gd) in pure LiBr, LiBr-KBr (eutectic) and LiBr-KBr-CsBr (eutectic) melts. Gd(III) showed a reversible single step soluble-insoluble exchange phenomenon in LiBr melt at 973 K. Although La (III), Nd(III) and Gd(III) ions showed reversible behavior in eutectic LiBr-KBr melts, these ions showed a combination of temperature dependent reversible and pseudo-reversible behavior. While both La(III) and Gd(III) showed one step reduction, the reduction of Nd(III) was observed to be a two step process. La metal could be electrodeposited from the ternary electrolyte at a temperature of 673 K. Various electrochemical measurements suggest that both binary and ternary bromide melts can potentially be used to electro-deposit high purity RE metals at comparatively lower operating temperatures. (authors)

  17. High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices

    NASA Astrophysics Data System (ADS)

    Perumal, Ajay; Shendre, Sushant; Li, Mingjie; Tay, Yong Kang Eugene; Sharma, Vijay Kumar; Chen, Shi; Wei, Zhanhua; Liu, Qing; Gao, Yuan; Buenconsejo, Pio John S.; Tan, Swee Tiam; Gan, Chee Lip; Xiong, Qihua; Sum, Tze Chien; Demir, Hilmi Volkan

    2016-11-01

    Formamidinium lead halide (FAPbX3) has attracted greater attention and is more prominent recently in photovoltaic devices due to its broad absorption and higher thermal stability in comparison to more popular methylammonium lead halide MAPbX3. Herein, a simple and highly reproducible room temperature synthesis of device grade high quality formamidinium lead bromide CH(NH2)2PbBr3 (FAPbBr3) colloidal nanocrystals (NC) having high photoluminescence quantum efficiency (PLQE) of 55–65% is reported. In addition, we demonstrate high brightness perovskite light emitting device (Pe-LED) with these FAPbBr3 perovskite NC thin film using 2,2‧,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) commonly known as TPBi and 4,6-Bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) as electron transport layers (ETL). The Pe-LED device with B3PYMPM as ETL has bright electroluminescence of up to 2714 cd/m2, while the Pe-LED device with TPBi as ETL has higher peak luminous efficiency of 6.4 cd/A and peak luminous power efficiency of 5.7 lm/W. To our knowledge this is the first report on high brightness light emitting device based on CH(NH2)2PbBr3 widely known as FAPbBr3 nanocrystals in literature.

  18. Locations of Bromide Ions in Tetragonal Lysozyme Crystals

    NASA Technical Reports Server (NTRS)

    Lim, Kap; Nadarajah, Arunan; Forsythe, Elizabeth L.; Pusey, Marc L.

    1998-01-01

    Anions have been shown to play a dominant role in the crystallization of chicken egg-white lysozyme from salt solutions. Previous studies employing X-ray crystallography have found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. In this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from lysozyme crystals grown in bromide and chloride solutions. Five possible anion-binding sites were found in this manner. Some of these sites were in pockets containing basic residues while others were near neutral, but polar, residues. The sole chloride ion binding site found in previous studies was confirmed, while four further sites were found which corresponded to the four binding sites found for nitrate ions in monoclinic crystals. The study suggests that most of the anion-binding sites in lysozyme remain unchanged even when different anions and different crystal forms of lysozyme are employed.

  19. Bacterial oxidation of methyl bromide in Mono Lake, California

    USGS Publications Warehouse

    Connell, T.L.; Joye, S.B.; Miller, L.G.; Oremland, R.S.

    1997-01-01

    The oxidation of methyl bromide (MeBr) in the water column of Mono Lake, CA, was studied by measuring the formation of H14CO3 from [14C]MeBr. Potential oxidation was detected throughout the water column, with highest rates occurring in the epilimnion (5-12 m depth). The oxidation of MeBr was eliminated by filter-sterilization, thereby demonstrating the involvement of bacteria. Vertical profiles of MeBr activity differed from those obtained for nitrification and methane oxidation, indicating that MeBr oxidation is not simply a co-oxidation process by either nitrifiers or methanotrophs. Furthermore, specific inhibitors of methane oxidation and/or nitrification (e.g., methyl fluoride, acetylene, allyl sulfide) had no effect upon the rate of MeBr oxidation in live samples. Of a variety of potential electron donors added to Mono Lake water, only trimethylamine resulted in the stimulation of MeBr oxidation. Cumulatively, these results suggest that the oxidation of MeBr in Mono Lake waters is attributable to trimethylamine-degrading methylotrophs. Neither methyl chloride nor methanol inhibited the oxidation of [14C]MeBr in live samples, indicating that these bacteria directly oxidized MeBr rather than the products of MeBr nucleophilic substitution reactions.

  20. Determination of pyridostigmine bromide and its metabolites in biological samples.

    PubMed

    Zhao, Bin; Moochhala, Shabbir M; Lu, Jia; Tan, Donna; Lai, Mui Hoon

    2006-01-01

    Pyridostigmine bromide (PB) is a quartenary ammonium compound that inhibits the hydrolysis of acetylcholine by competitive reversible binding to acetylcholinesterase. PB is used for the symptomatic treatment of myasthenia gravis and has been applied as a prophylaxis against nerve agents. Many studies on PB have involved the reliance on techniques that extract and quantify PB in biological samples. This article presents an overview of the currently applied methodologies for the determination of PB and its metabolites in various biological samples. Articles published from January 1975 to the July 2005 were taken into consideration for the discussion of the metabolism and analytical method of PB. HPLC and GC methods have been used and discussed in most of the references cited in this review. Other methods such as RIA and CE that have been recently reported are also mentioned in this article. Basic information about the type of sample used for analysis, sample preparation, chromatographic column, mobile phase, detection mode and validation data are summarized in a table.

  1. Preparation and in vitro evaluation of pyridostigmine bromide microparticles.

    PubMed

    Hegazy, Nahed; Demirel, Müzeyyen; Yazan, Yasemin

    2002-08-21

    Pyridostigmine bromide (PB) is an anticholinesterase agent whose aqueous solubility is high and which has a short elimination half-life. Its dosage rate in the treatment of myastenia gravis is frequent due to the short half-life and it exhibits side effects. Microparticles designed to deliver a pharmaceutical active ingredient efficiently at the minimum dose and also to enhance stability, reduce side effects and modify drug release were prepared in this study using an acrylic polymer (Eudragit) as the vehicle by the spray-drying technique. The drug was either dissolved or dispersed in the polymeric solution and following the preparation of microparticles using different ratios of ingredients, characterization studies including the determination of shape, particle size distribution, amount loaded, release and stability of PB were performed. The results obtained were compared to those of pure PB. Drug release from microparticles could be modified and was found to depend on the shapes of the microparticles. In vitro evaluation results indicate that the frequent dosage and side effects of pure PB may be reduced with the formulation of microparticles.

  2. Structural and electronic properties of Diisopropylammonium bromide molecular ferroelectric crystal

    NASA Astrophysics Data System (ADS)

    Alsaad, A.; Qattan, I. A.; Ahmad, A. A.; Al-Aqtash, N.; Sabirianov, R. F.

    2015-10-01

    We report the results of ab-initio calculations based on Generalized Gradient Approximation (GGA) and hybrid functional (HSE06) of electronic band structure, density of states and partial density of states to get a deep insight into structural and electronic properties of P21 ferroelectric phase of Diisopropylammonium Bromide molecular crystal (DIPAB). We found that the optical band gap of the polar phase of DIPAB is ∼ 5 eV confirming it as a good dielectric. Examination of the density of states and partial density of states reveal that the valence band maximum is mainly composed of bromine 4p orbitals and the conduction band minimum is dominated by carbon 2p, carbon 2s, and nitrogen 2s orbitals. A unique aspect of P21 ferroelectric phase is the permanent dipole within the material. We found that P21 DIPAB has a spontaneous polarization of 22.64 consistent with recent findings which make it good candidate for the creation of ferroelectric tunneling junctions (FTJs) which have the potential to be used as memory devices.

  3. Evaluation of Alkali Bromide Salts for Potential Pyrochemical Applications

    SciTech Connect

    Prabhat K. Tripathy; Steven D. Herrmann; Guy L. Fredrickson; Tedd E. Lister; Toni Y. Gutknecht

    2013-10-01

    Transient techniques were employed to study the electrochemical behavior, reduction mechanism and transport properties of REBr3 (RE - La, Nd and Gd) in pure LiBr, LiBr-KBr (eutectic) and LiBr-KBr-CsBr (eutectic) melts. Gd(III) showed a reversible single step soluble-insoluble exchange phenomenon in LiBr melt at 973K. Although La (III), Nd(III) and Gd(III) ions showed reversible behavior in eutectic LiBr-KBr melts, these ions showed a combination of temperature dependent reversible and pseudo-reversible behavior. While both La(III) and Gd(III) showed one step reduction, the reduction of Nd(III) was observed to be a two step process. La metal could be electrodeposited from the ternary electrolyte at a temperature of 673K. Various electrochemical measurements suggest that both binary and ternary bromide melts can potentially be used to electrodeposit high purity RE metals at comparatively lower operating temperatures.

  4. Factors affecting a cyanogen bromide-based assay of thiamin.

    PubMed

    Wyatt, D T; Lee, M; Hillman, R E

    1989-11-01

    We analyzed extensively a modified thiochrome method for thiamin analysis. Acid phosphatase (EC 3.1.3.2) from potato was superior to either alpha-amylase or acid phosphatase from wheat germ as a dephosphorylating agent. Timing of cyanogen bromide exposure was important, but the assay had good precision and accuracy. The standard curve was linear from 10 to 3000 nmol/L. The within-run and between-run coefficients of variation for total thiamin in whole blood were 3.6% and 7.4%, respectively. Analytical recoveries for low, intermediate, and high additions of thiamin to whole blood were 93-109%. Sample yield was increased by 41% (+/- 29% SD) with pre-assay freezing. Samples were stable for two days at room temperature, for seven days when refrigerated, and for two years when frozen. Previously unreported interference was seen with penicillin derivatives, and with several commonly used diuretic and antiepileptic medications. This assay may be suitable for population screening; 200 samples could be analyzed weekly at a cost of +0.20 per sample.

  5. Bioreactors for removing methyl bromide following contained fumigations

    USGS Publications Warehouse

    Miller, L.G.; Baesman, S.M.; Oremland, R.S.

    2003-01-01

    Use of methyl bromide (MeBr) as a quarantine, commodity, or structural fumigant is under scrutiny because its release to the atmosphere contributes to the depletion of stratospheric ozone. A closed-system bioreactor consisting of 0.5 L of a growing culture of a previously described bacterium, strain IMB-1, removed MeBr (> 110 ??mol L-1) from recirculating air. Strain IMB-1 grew slowly to high cell densities in the bioreactor using MeBr as its sole carbon and energy source. Bacterial oxidation of MeBr produced CO2 and hydrobromic acid (HBr), which required continuous neutralization with NaOH for the system to operate effectively. Strain IMB-1 was capable of sustained oxidation of large amounts of MeBr (170 mmol in 46 d). In an open-system bioreactor (10-L fermenter), strain IMB-1 oxidized a continuous supply of MeBr (220 ??mol L-1 in air). Growth was continuous, and 0.5 mol of MeBr was removed from the air supply in 14 d. The specific rate of MeBr oxidation was 7 ?? 10-16 mol cell-1 h-1. Bioreactors such as these can therefore be used to remove large quantities of contaminant MeBr, which opens the possibility of biodegradation as a practical means for its disposal.

  6. Micellization of cetyltrimethylammonium bromide: effect of small chain Bola electrolytes.

    PubMed

    Pan, Animesh; Sil, Pallabi; Dutta, Sounak; Das, Prasanta Kumar; Bhattacharya, Subhash Chandra; Rakshit, Animesh Kumar; Aswal, Vinod Kumar; Moulik, Satya Priya

    2014-03-20

    Sodium dicarboxylates (or Bola salts) with methylene spacers 0, 2, 4, 6, 8, and 10 were studied in aqueous solution to investigate their influence on the micellization of cetyltrimethylammonium bromide (CTAB). Since bolas with spacer length ≤12 are known not to micellize in general, the herein used sodium dicarboxylates were treated as 2:1 amphiphilic electrolytes which reduced surface tension of water (except sodium oxalate with zero spacer) without self-association. Their concentration dependent conductance was also linear without breaks. The bolas affected the micellization of CTAB but acted like salts to decrease its CMC. Their combinations did not form bilayer aggregates as found in vesicles. Nevertheless, they synergistically interacted with CTAB at the air/water interface as revealed from Rosen's thermodynamic model. Hydrodynamic radius (Rh), Zeta-potential (ζ), and electrical double layer behavior of bola interacted CTAB micelles were assessed. From SANS measurements, micelle shape, shape parameters, aggregation number (Nagg), surface charge of the bola influenced CTAB micelles were also determined. NMR study as well supported the non-mixing of bolas with the CTAB micelles. They interacted in solution like "amphiphilic electrolytes" to influence the surface and micelle forming properties of CTAB.

  7. Are other fluorescent tags used instead of ethidium bromide safer?

    PubMed Central

    2013-01-01

    Ethidium bromide (EtBr) is a well-known fluorescent tag usually applied in molecular biological techniques like agarose gel electrophoresis. The mechanism of action for such compounds is known, in which these compounds are able to bind to the kinetoplastid DNA and to alter their conformation to Z-DNA molecules that stop replication of kinetoplastid DNA leading to Trypanosoma death. Although the usual amounts used in laboratories are considered as below the level required to cause toxicity (LD50 in oral administration in rat is 1.5 g/Kg), the mentioned concentrations are high enough to involve in replication of mitochondrial DNA in some human cell lines. Regarding the points that EtBr is very stable in the environment and if degraded especially by use of bleaches that result in formation of mutagenic compounds, there is a big concern about its use. Although application of EtBr is going to be restricted and replaced with other tags such as SYBR® products, the safety of the new substituted compounds are still in doubt and except a few data, there is no essential evidence available to confirm that they are safer than EtBr. Further investigations are recommended to compare their relative biosafety hazards. PMID:24355254

  8. High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices.

    PubMed

    Perumal, Ajay; Shendre, Sushant; Li, Mingjie; Tay, Yong Kang Eugene; Sharma, Vijay Kumar; Chen, Shi; Wei, Zhanhua; Liu, Qing; Gao, Yuan; Buenconsejo, Pio John S; Tan, Swee Tiam; Gan, Chee Lip; Xiong, Qihua; Sum, Tze Chien; Demir, Hilmi Volkan

    2016-11-09

    Formamidinium lead halide (FAPbX3) has attracted greater attention and is more prominent recently in photovoltaic devices due to its broad absorption and higher thermal stability in comparison to more popular methylammonium lead halide MAPbX3. Herein, a simple and highly reproducible room temperature synthesis of device grade high quality formamidinium lead bromide CH(NH2)2PbBr3 (FAPbBr3) colloidal nanocrystals (NC) having high photoluminescence quantum efficiency (PLQE) of 55-65% is reported. In addition, we demonstrate high brightness perovskite light emitting device (Pe-LED) with these FAPbBr3 perovskite NC thin film using 2,2',2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) commonly known as TPBi and 4,6-Bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) as electron transport layers (ETL). The Pe-LED device with B3PYMPM as ETL has bright electroluminescence of up to 2714 cd/m(2), while the Pe-LED device with TPBi as ETL has higher peak luminous efficiency of 6.4 cd/A and peak luminous power efficiency of 5.7 lm/W. To our knowledge this is the first report on high brightness light emitting device based on CH(NH2)2PbBr3 widely known as FAPbBr3 nanocrystals in literature.

  9. Otilonium bromide: a selective spasmolytic for the gastrointestinal tract.

    PubMed

    Evangelista, S

    1999-01-01

    Experimental studies have shown that otilonium bromide (OB) inhibits both baseline and chemically or physically stimulated gastrointestinal motility. The spasmolytic activity of OB in the gastrointestinal tract occurs at doses that do not affect gastric secretion or produce typical atropine-like side-effects. The mechanism of action is composite: interference with calcium ion movement from intra- and extracellular sites; blockade of calcium channels; and binding to muscarinic receptors and tachykinin neurokinin-2 receptors. Pharmacokinetic studies have shown that OB accumulates in the lower intestine and has poor systemic absorption. Clinical studies have confirmed OB as a potent spasmolytic drug with a good tolerability profile. Studies in patients with irritable bowel syndrome demonstrated OB to be superior to placebo and reference drugs in parameters such as pain, abdominal distension and motility. The composite and local mechanism of OB action reduces hypermotility and modulates visceral sensation: factors thought to be responsible for pain improvement recorded in clinical trials. The compound is marketed worldwide and no serious adverse events have been reported as yet, confirming its excellent tolerability.

  10. Polarization effects in thallium bromide x-ray detectors

    SciTech Connect

    Kozorezov, A.; Wigmore, J. K.; Gostilo, V.; Shorohov, M.; Owens, A.; Quarati, F.; Webb, M. A.

    2010-09-15

    We present the results of a detailed experimental study of polarization effects in thallium bromide planar x-ray detectors. Measurements were carried out in the range 10-100 keV by scanning a highly focused x-ray beam, 50 {mu}m in diameter, from a synchrotron source across the detector. Above a certain radiation threshold the detector response showed a systematic degradation of its spectroscopic characteristics, peak channel position, peak height, and energy resolution. Using a pump-and-probe technique, we studied the dynamics of spectral degradation, the spatial extent and relaxation of the polarized region, and the dependence of the detector response on bias voltage and temperature. For comparison, we modeled polarization effects induced by the charging of traps by both electrons and holes using a model based on recent theoretical work of Bale and Szeles. We calculated the charge collection efficiency and spectral line shapes as functions of exposure time, beam position, count rate, and photon energy, and obtained credible agreement with experimental results.

  11. Hydrogen scavengers

    SciTech Connect

    Carroll, David W.; Salazar, Kenneth V.; Trkula, Mitchell; Sandoval, Cynthia W.

    2002-01-01

    There has been invented a codeposition process for fabricating hydrogen scavengers. First, a .pi.-bonded allylic organometallic complex is prepared by reacting an allylic transition metal halide with an organic ligand complexed with an alkali metal; and then, in a second step, a vapor of the .pi.-bonded allylic organometallic complex is combined with the vapor of an acetylenic compound, irradiated with UV light, and codeposited on a substrate.

  12. Effect of Methyl Bromide on Mycorrhizae and Growth of Sweetgum Seedlings

    Treesearch

    T. H. Filer; E. R. Toole

    1968-01-01

    Fumigation of nursery beds with methyl bromide improved sweetgum, growth by reducing the population of soil-inhabiting pathogens . Although mycorrhizal fungi were reduced, sufficient inoculum survived for rapid mycorrhizal development

  13. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... checks of residual bromine using a bromine test kit. To assure safe use of the additives, the label and... bromide ion levels. (b) Section 18 emergency exemptions. (c) Tolerances with regional registrations....

  14. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... checks of residual bromine using a bromine test kit. To assure safe use of the additives, the label and... bromide ion levels. (b) Section 18 emergency exemptions. (c) Tolerances with regional registrations....

  15. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... checks of residual bromine using a bromine test kit. To assure safe use of the additives, the label and... bromide ion levels. (b) Section 18 emergency exemptions. (c) Tolerances with regional registrations....

  16. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... checks of residual bromine using a bromine test kit. To assure safe use of the additives, the label and... bromide ion levels. (b) Section 18 emergency exemptions. (c) Tolerances with regional registrations....

  17. CHLORPYRIFOS TRANSFORMATION BY AQUEOUS CHLORINE IN THE PRESENCE OF BROMIDE AND NATURAL ORGANIC MATTER

    EPA Science Inventory

    The aqueous chlorination of chlorpyrifos (CP) was investigated in the presence of bromide and natural organic matter (NOM), which were identified as naturally occurring aqueous constituents that could impact CP transformation rates to the toxic product chlorpyrifos oxon (CPO). Br...

  18. BROMIDE'S EFFECT ON DBP FORMATION, SPECIATION, AND CONTROL: PART 1, OZONATION

    EPA Science Inventory

    The effect of variable ozone dosage and bromide concentration on the formation of organic disinfection byproducts (DBPs) and bromate were evaluated. Low ozone dosages resulted in oxidation of organic precursors, yielding decreases in the formation potential for total trihalometha...

  19. BROMIDE'S EFFECT ON DBP FORMATION, SPECIATION, AND CONTROL: PART 1, OZONATION

    EPA Science Inventory

    The effect of variable ozone dosage and bromide concentration on the formation of organic disinfection byproducts (DBPs) and bromate were evaluated. Low ozone dosages resulted in oxidation of organic precursors, yielding decreases in the formation potential for total trihalometha...

  20. Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Treatment Longer than 8 Hours

    EPA Pesticide Factsheets

    This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

  1. Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Treatment 8 Hours or Less

    EPA Pesticide Factsheets

    This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

  2. CHLORPYRIFOS TRANSFORMATION BY AQUEOUS CHLORINE IN THE PRESENCE OF BROMIDE AND NATURAL ORGANIC MATTER

    EPA Science Inventory

    The aqueous chlorination of chlorpyrifos (CP) was investigated in the presence of bromide and natural organic matter (NOM), which were identified as naturally occurring aqueous constituents that could impact CP transformation rates to the toxic product chlorpyrifos oxon (CPO). Br...

  3. Novel method for the synthesis of enamines by palladium catalyzed amination of alkenyl bromides.

    PubMed

    Barluenga, José; Fernández, M Alejandro; Aznar, Fernando; Valdés, Carlos

    2002-10-21

    The intermolecular palladium catalyzed cross-coupling reaction between secondary amines and alkenyl bromides is described for the first time, giving rise to enamines with very high yields and regioselectivity.

  4. Stabilized thallium bromide radiation detectors and methods of making the same

    SciTech Connect

    Leao, Cedric Rocha; Lordi, Vincenzo

    2015-11-24

    According to one embodiment, a crystal includes thallium bromide (TlBr), one or more positively charged dopants, and one or more negatively charged dopants. According to another embodiment, a system includes a monolithic crystal including thallium bromide (TlBr), one or more positively charged dopants, and one or more negatively charged dopants; and a detector configured to detect a signal response of the crystal.

  5. Influence of bromide on the performance of the amphipod Hyalella azteca in reconstituted waters

    USGS Publications Warehouse

    Ivey, Chris D.; Ingersoll, Christopher G.

    2016-01-01

    Poor performance of the amphipod Hyalella azteca has been observed in exposures using reconstituted waters. Previous studies have reported success in H. azteca water-only exposures with the addition of relatively high concentrations of bromide. The present study evaluated the influence of lower environmentally representative concentrations of bromide on the response ofH. azteca in 42-d water-only exposures. Improved performance of H. azteca was observed in reconstituted waters with >0.02 mg Br/L.

  6. [Spectrophotometric analysis of tetracycline hydrochloride in the presence of thiamine bromide and riboflavin].

    PubMed

    Efimovskikh, S V; Anokhina, T A

    1991-08-01

    Spectrophotometric determination of tetracycline hydrochloride concentrations in the presence of thiamine bromide and riboflavin at a light absorption wave length of 300 nm was shown possible. When the ratio of tetracycline hydrochloride and the total of thiamine bromide and riboflavin (w/w) was at least 10:1 the error of the method was less than 2 per cent. The procedure is useful in quality control of the dosage forms.

  7. Small airways ventilation heterogeneity and hyperinflation in COPD: response to tiotropium bromide.

    PubMed

    Verbanck, Sylvia; Schuermans, Daniël; Vincken, Walter

    2007-01-01

    In chronic obstructive pulmonary disease (COPD) patients tiotropium bromide has been shown to improve forced expiratory volume in one second (FEV1) and inspiratory capacity (IC). We investigated whether the mechanism leading to these improvements is related to small airways ventilation heterogeneity, assessed by multiple breath washout tests. Forty stable tiotropium-free COPD patients (FEV1: 27%-78% predicted) were studied before and 90 min after administration of tiotropium bromide on visit0, and following 3 and 6 weeks of tiotropium bromide treatment (visit3wks, visit6wks). After study completion, COPD patients were classified into two subgroups according to degree of hyperinflation at visit0 (Hyp-, Hyp+). The Hyp+ group showed significant increases in trough (ie, pre-dose) FEV1 and IC after 3 and 6 weeks of tiotropium bromide, and the 90 min tiotropium bromide responses of FEV1 and IC were significant at visit0 (p < or = 0.001 for both) but not during subsequent visits. The Hyp- group showed significant FEV1 increases 90 min after tiotropium bromide on all three visits (all p < 0.005) but no sustained increase in trough values. In both COPD subgroups, the grossly abnormal ventilation heterogeneity barely showed any significant improvements with tiotropium bromide in the conductive airways (without changes in trough value) and no changes at all in the acinar airways. We conclude that the sustained improvements in trough IC and FEV1 with tiotropium bromide predominantly observed in COPD patients with considerable hyperinflation, are unrelated to small airways ventilation heterogeneity.

  8. [Otilonium bromide-diazepam in the treatment of the irritable colon. A controlled study versus otilonium bromide].

    PubMed

    Mollica, G; Manno, G

    1992-08-01

    Octylonium bromide (OB) is a drug with spasmolytic properties acting selectively on the smooth muscle of the gastrointestinal tract by interfering with calcium mobilization from extra- and intra-cellular deposits. The etiopathogenetic implications of a psychosomatic nature of the irritable bowel syndrome amply justify the use of a spasmolytic (OB) with a benzodiazepine. In our study, we compared the combination OB + DZ (20 mg + 2 mg) T.I.D. versus OB alone (20 mg) in 30 patients suffering from irritable bowel syndrome. The double-blind study lasting 3 weeks was aimed at evaluating gastrointestinal symptoms (bowel motions, aspect of faeces, abdominal pain, pre-evacuation pain, bloating) during the three days preceding the study and during the last five days of treatment, as well as the anxiogenic situation as assessed by the STAI scale (State Tract Anxiety Inventory) before and at the end of the treatment period. The results obtained showed that both treatments considerably reduced gastrointestinal symptoms even though OB alone did not appear to be equally effective and the anxiety component was significantly reduced only by treatment with the combination. The absence of side effects and the perfect tolerability of both treatments showed the OB + D combination T.I.D. to be the treatment of choice for patients suffering from irritable bowel syndrome.

  9. Flow Boiling Heat Transfer to Lithium Bromide Aqueous Solution in Subcooled Region

    NASA Astrophysics Data System (ADS)

    Furukawa, Masahiro; Kaji, Masao; Nishizumi, Takeharu; Ozaki, Shinji; Sekoguchi, Kotohiko

    To improve the thermal performance of high temperature generator of absorption chiller/heater, heat transfer characteristics of flow boiling of lithium bromide aqueous solution in the subcooled region were experimentally investigated. Experiments were made for water and lithium bromide aqueous solution flowing in a rectangular channel (5 mm × 20 mm cross section) with one side wall heated. Boiling onset quality of lithium bromide aqueous solution is greater than that of water. The heat transfer coefficient of lithium bromide aqueous solution is about a half of that of water under the same experimental conditions of inlet velocity and heat flux. The experimental data of heat transfer coefficient for water are compared with the empirical correlation of Thom et al.11) and a fairly good agreement is obtained. The predictive calculations by the method of Sekoguchi et al.12) are compared with the data for water and lithium bromide aqueous solution. Agreement between them is good for water, while the results for lithium bromide aqueous solution are not satisfactory.

  10. Otilonium bromide in irritable bowel syndrome: a double-blind, placebo-controlled, 15-week study.

    PubMed

    Battaglia, G; Morselli-Labate, A M; Camarri, E; Francavilla, A; De Marco, F; Mastropaolo, G; Naccarato, R

    1998-10-01

    To evaluate the efficacy of otilonium bromide, a spasmolytic agent, in the treatment of irritable bowel syndrome using modern and validated diagnostic criteria. Three hundred and seventy-eight patients with irritable bowel syndrome were enrolled in the study. At entry, endoscopy/barium enema, clinical examination and laboratory tests were used to rule out organic diseases. After a 2-week placebo run-in, 325 patients were randomly assigned to receive either otilonium bromide 40 mg t.d.s. or placebo for 15 weeks. Abdominal pain, abdominal distension and disturbed defecation were scored at the beginning of the study and every 5 weeks. A global determination of well-being by visual analogue scale and the tenderness of the sigmoid colon were also scored. The reduction in the number of abdominal pain episodes was significantly higher (P < 0.01) in otilonium bromide patients (55.3%) than in those taking placebo (39.9%) as was the severity of abdominal distension (42.0%, vs. 30.2%; P < 0.05). Bowel disturbance improved in both groups. but without any statistically significant difference. The visual analogue scale of well-being revealed a significant improvement (P < 0.05) in patients taking otilonium bromide. The investigators' global positive assessment was in favour of otilonium bromide (65.2%) compared with placebo (49.6%) (P < 0.01). Otilonium bromide may represent an effective treatment for irritable bowel syndrome because it reduces its predominant symptom (abdominal pain/ discomfort) more than placebo does.

  11. Preferential bromide and pesticide movement to tile drains under different cropping practices.

    PubMed

    Fortin, J; Gagnon-Bertrand, E; Vézina, L; Rompré, M

    2002-01-01

    Subsurface drainage systems are useful tools to study chemical leaching in soils. Our objective was to compare the breakthrough behavior of bromide, atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamid] to tile drains under two fall tillage practices (conventional tillage [CT] with a moldboard plow, and reduced tillage [RT] with a chisel plow) in field plots cultivated with corn (Zea mays L.). Leachate volume were greater in RT than in CT, with no statistical differences. Soil analysis showed that bromide migrated deeper in the soil profile than both herbicides, with little tillage effect. All chemicals were detected in drainage water at the same time and followed an event-driven behavior. Tillage had no effect on atrazine and metolachlor found in drainage water, while bromide concentration peaks were higher in RT than in CT in 1999. Concentration peaks were recorded earlier for atrazine and metolachlor than for bromide. Plots of cumulative relative chemical mass (cumulative mass divided by total mass measured in drainage) as a function of cumulative drainage were mostly linear for bromide, while they were S-shaped for both herbicides. Drainage that corresponded to 50% of relative cumulative mass ranged from 40 to 55% for bromide and from 5 to 28% for both herbicides. Rapid chemical movement to tile drains suggested that preferential flow was important in both CT and RT, and that these tillage practices had little influence on this phenomena.

  12. Drip application of methyl bromide alternative chemicals for control of soilborne pathogens and weeds.

    PubMed

    Gerik, James S; Hanson, Bradley D

    2011-09-01

    Producers of several high-value crops in California have traditionally used preplant soil fumigation with methyl bromide/chloropicrin combinations. Although methyl bromide has been phased out since 2005, several crop industries, including cut flower producers, have continued methyl bromide use under Critical Use Exemptions, a provision of the Montreal Protocol. This research was conducted to evaluate newer, emerging methyl bromide alternative chemicals. Two field trials were conducted to test several emerging chemicals in combination with metam sodium as replacements for methyl bromide. Emerging chemicals included 2-bromoethanol, dimethyl disulfide, furfural, propylene oxide and sodium azide. Weed and pathogen populations were measured after chemical application, and seed viability was assessed from weed seed previously buried in the plots. In the first trial, the emerging chemicals did not improve pest control compared with metam sodium alone. However, in the second trial, several of these chemicals did improve the pest control performance of metam sodium. The emerging alternative chemicals have the potential to provide better control of soilborne pathogens and weeds when used with metam sodium than metam sodium alone. Registration of these materials could provide California growers with a broader choice of tools compared with the limited methyl bromide alternatives now available. This article is a US Government work and is in the public domain in the USA. Published 2011 by John Wiley & Sons, Ltd.

  13. Hydrogen environment embrittlement

    NASA Technical Reports Server (NTRS)

    Gray, H. R.

    1972-01-01

    Hydrogen embrittlement is classified into three types: internal reversible hydrogen embrittlement, hydrogen reaction embrittlement, and hydrogen environment embrittlement. Characteristics of and materials embrittled by these types of hydrogen embrittlement are discussed. Hydrogen environment embrittlement is reviewed in detail. Factors involved in standardizing test methods for detecting the occurrence of and evaluating the severity of hydrogen environment embrittlement are considered. The effect of test technique, hydrogen pressure, purity, strain rate, stress concentration factor, and test temperature are discussed. Additional research is required to determine whether hydrogen environment embrittlement and internal reversible hydrogen embrittlement are similar or distinct types of embrittlement.

  14. Bacterial oxidation of methyl bromide in fumigated agricultural soils

    USGS Publications Warehouse

    Miller, L.G.; Connell, T.L.; Guidetti, J.R.; Oremland, R.S.

    1997-01-01

    The oxidation of [14C]methyl bromide ([14C]MeBr) to 14CO2 was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCI3NO2). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [14C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to 14CO2 and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy.

  15. Dicationic alkylammonium bromide gemini surfactants. Membrane perturbation and skin irritation.

    PubMed

    Almeida, João A S; Faneca, Henrique; Carvalho, Rui A; Marques, Eduardo F; Pais, Alberto A C C

    2011-01-01

    Dicationic alkylammonium bromide gemini surfactants represent a class of amphiphiles potentially effective as skin permeation enhancers. However, only a limited number of studies has been dedicated to the evaluation of the respective cytotoxicity, and none directed to skin irritation endpoints. Supported on a cell viability study, the cytotoxicity of gemini surfactants of variable tail and spacer length was assessed. For this purpose, keratinocyte cells from human skin (NCTC 2544 cell line), frequently used as a model for skin irritation, were employed. The impact of the different gemini surfactants on the permeability and morphology of model vesicles was additionally investigated by measuring the leakage of calcein fluorescent dye and analyzing the NMR spectra of ³¹P, respectively. Detail on the interaction of gemini molecules with model membranes was also provided by a systematic differential scanning calorimetry (DSC) and molecular dynamics (MD) simulation. An irreversible impact on the viability of the NCTC 2544 cell line was observed for gemini concentrations higher than 25 mM, while no cytotoxicity was found for any of the surfactants in a concentration range up to 10 mM. A higher cytotoxicity was also found for gemini surfactants presenting longer spacer and shorter tails. The same trend was obtained in the calorimetric and permeability studies, with the gemini of longest spacer promoting the highest degree of membrane destabilization. Additional structural and dynamical characterization of the various systems, obtained by ³¹P NMR and MD, provide some insight on the relationship between the architecture of gemini surfactants and the respective perturbation mechanism.

  16. Dicationic Alkylammonium Bromide Gemini Surfactants. Membrane Perturbation and Skin Irritation

    PubMed Central

    Almeida, João A. S.; Faneca, Henrique; Carvalho, Rui A.; Marques, Eduardo F.; Pais, Alberto A. C. C.

    2011-01-01

    Dicationic alkylammonium bromide gemini surfactants represent a class of amphiphiles potentially effective as skin permeation enhancers. However, only a limited number of studies has been dedicated to the evaluation of the respective cytotoxicity, and none directed to skin irritation endpoints. Supported on a cell viability study, the cytotoxicity of gemini surfactants of variable tail and spacer length was assessed. For this purpose, keratinocyte cells from human skin (NCTC 2544 cell line), frequently used as a model for skin irritation, were employed. The impact of the different gemini surfactants on the permeability and morphology of model vesicles was additionally investigated by measuring the leakage of calcein fluorescent dye and analyzing the NMR spectra of 31P, respectively. Detail on the interaction of gemini molecules with model membranes was also provided by a systematic differential scanning calorimetry (DSC) and molecular dynamics (MD) simulation. An irreversible impact on the viability of the NCTC 2544 cell line was observed for gemini concentrations higher than 25 mM, while no cytotoxicity was found for any of the surfactants in a concentration range up to 10 mM. A higher cytotoxicity was also found for gemini surfactants presenting longer spacer and shorter tails. The same trend was obtained in the calorimetric and permeability studies, with the gemini of longest spacer promoting the highest degree of membrane destabilization. Additional structural and dynamical characterization of the various systems, obtained by 31P NMR and MD, provide some insight on the relationship between the architecture of gemini surfactants and the respective perturbation mechanism. PMID:22102870

  17. Carbon isotope fractionation of methyl bromide during agricultural soil fumigations

    USGS Publications Warehouse

    Bill, M.; Miller, L.G.; Goldstein, Allen H.

    2002-01-01

    The isotopic composition of methyl bromide (CH3Br) has been suggested to be a potentially useful tracer for constraining the global CH3Br budget. In order to determine the carbon isotopic composition of CH3Br emitted from the most significant anthropogenic application (pre-plant fumigation) we directly measured the ??13C of CH3Br released during commercial fumigation. We also measured the isotopic fractionation associated with degradation in agricultural soil under typical field fumigation conditions. The isotopic composition of CH3Br collected in soil several hours after injection of the fumigant was -44.5??? and this value increased to -20.7??? over the following three days. The mean kinetic isotope effect (KIE) associated with degradation of CH3Br in agricultural soil (12???) was smaller than the reported value for methylotrophic bacterial strain IMB-1, isolated from previously fumigated agricultural soil, but was similar to methylotrophic bacterial strain CC495, isolated from a pristine forest litter zone. Using this fractionation associated with the degradation of CH3Br in agricultural soil and the mean ??13C of the industrially manufactured CH3Br (-54.4???), we calculate that the agricultural soil fumigation source has a carbon isotope signature that ranges from -52.8??? to -42.0???. Roughly 65% of industrially manufactured CH3Br is used for field fumigations. The remaining 35% is used for structural and post-harvest fumigations with a minor amount used during industrial chemical manufacturing. Assuming that the structural and post-harvest fumigation sources of CH3Br are emitted without substantial fractionation, we calculate that the ??13C of anthropogenically emitted CH3Br ranges from -53.2??? to -47.5???.

  18. Eudragit RS PO nanoparticles for sustained release of pyridostigmine bromide

    NASA Astrophysics Data System (ADS)

    Hoobakht, Fatemeh; Ganji, Fariba; Vasheghani-Farahani, Ebrahim; Mousavi, Seyyed Mohammad

    2013-09-01

    Pyridostigmine bromide (PB) is an inhibitor of cholinesterase, which is used in the treatment of myasthenia gravis and administered for protection against exposure to toxic nerve agents. Tests were done to investigate prolonging the half-life of PB and improving its release behavior. PB was loaded in nanoparticles (NPs) of Eudragit RS PO (Eu-RS) prepared using the technique of quasi emulsion solvent diffusion. Variables of output power of the sonicator, bath temperature and mixing time, were chosen as the optimization factors to obtain the minimum sized NPs. In addition, emulsions were tested at different ratios of drug-to-polymer by dynamic light scattering to determine size and zeta potential of NPs. UV-spectroscopy was used to determine PB content of the NPs. Drug-loaded NPs were characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectra. Results determined that mixing time had a significant impact on the size of Eu-RS NPs, but power output of sonicator and bath temperature had no significant effect. The particle size obtained at the optimum condition (power output of 70 W, bath temperature of 33 °C, and mixing time of 7 min) was less than 200 nm (optimum sizes were 138.9 and 179.5 nm for Eu-RS and PB-loaded Eu-RS NPs, respectively). The optimum PB-loaded Eu-RS NPs at the PB to Eu-RS weight ratio of 1-4 and 20 % of loaded PB released from the nanocarriers within 100 h.

  19. Inhalable Ipratropium Bromide Particle Engineering with Multicriteria Optimization.

    PubMed

    Vinjamuri, Bhavani Prasad; Haware, Rahul V; Stagner, William C

    2016-11-21

    Spray-dried ipratropium bromide (IPB) microspheres for oral inhalation were engineered using Quality by Design. The interrogation of material properties, process parameters, and critical product quality attributes interplay enabled rational product design. A 2(7-3) screening design exhibited the Maillard reaction between L-leucine (LL) and lactose at studied outlet temperatures (OT) >130°C. A response surface custom design was used in conjunction with multicriteria optimization to determine the operating design space to achieve inhalable microparticles. Statistically significant predictive models were developed for volume median diameter (p = 0.0001, adjusted R (2)  = 0.9938), span (p = 0.0278, adjusted R (2)  = 0.7912), yield (p = 0.0020, adjusted R (2)  = 0.9320), and OT (p = 0.0082, adjusted R (2)  = 0.8768). An independent verification batch confirmed the model's predictive capability. The prediction and actual values were in good agreement. Particle size and span were 3.32 ± 0.09 μm and 1.71 ± 0.18, which were 4.7 and 5.3% higher than the predicted values. The process yield was 50.3%, compared to the predicted value of 65.3%. The OT was 100°C versus the predicted value of 105°C. The label strength of IPB microparticles was 99.0 to 105.9% w/w suggesting that enrichment occurred during the spray-drying process. The present study can be utilized to initiate the design of the first commercial IPB dry powder inhaler.

  20. Clinical potential of aclidinium bromide in chronic obstructive pulmonary disease

    PubMed Central

    Jones, Paul W

    2015-01-01

    Three long-acting muscarinic antagonists (LAMAs) are now available in Europe, providing clinicians and patients with a choice of interventions, which is important in COPD, which is clinically a heterogeneous disease. The first LAMA, tiotropium, has been widely used over the last decade as a once-daily maintenance therapy in stable COPD to improve patients’ health-related quality of life and to reduce the risk of exacerbations. Administered via the HandiHaler® device, it is safe and well tolerated. Another new once-daily LAMA, glycopyrronium, has also been shown to improve health status and reduce exacerbations, and is well tolerated. The subject of this review is a third LAMA, aclidinium bromide, which was approved as a twice-daily maintenance bronchodilator treatment. In the pivotal Phase III clinical trials, patients receiving aclidinium achieved significantly greater improvements in lung function, reductions in breathlessness, and improvements in health status compared with placebo, for up to 24 weeks. In continuation studies, these improvements were sustained for up to 52 weeks. Pooled data showed exacerbation frequency was significantly reduced with aclidinium versus placebo. Preclinical and pharmacological studies demonstrating low systemic bioavailability and a low propensity to induce cardiac arrhythmias were translated into a favorable tolerability profile in the clinical trial program – the adverse event profile of aclidinium was similar to placebo, with a low incidence of anticholinergic and cardiac adverse events. While additional studies are needed to evaluate its full clinical potential, aclidinium is an important part of this recent expansion of LAMA therapeutic options, providing clinicians and patients with an effective and well-tolerated COPD treatment. PMID:25848244

  1. Membrane electrodes for the determination of pyridostigmine bromide.

    PubMed

    El-Kosasy, Amira M; Salem, Maissa Y; El-Bardicy, Mohamed G; Abd El-Rahman, Mohamed K

    2009-01-01

    Two pyridostigmine bromide (PB) selective electrodes were investigated with 2-nitrophenyl octyl ether as a plasticizer in a polymeric matrix of carboxylated polyvinyl chloride (PVC-COOH), based on the interaction between the drug solution and the dissociated COOH groups in the PVC-COOH. One of the sensors was fabricated by using PVC-COOH only as anionic site without incorporation of an ionophore (sensor 1). The second sensor was constructed by using 2-hydroxy propyl beta-cyclodextrin as an ionophore (sensor 2). Linear responses of PB within a concentration range of 10(-3)-10(-2) and 10(-5)-10(-2) M, with slopes of 51.9 +/- 0.31 and 56.7 +/- 0.40 mV/decade over pH range of 5-10 were obtained using sensors 2 and 1, respectively. The proposed method displayed useful analytical characteristics for determination of PB in tablets with average recoveries of 100.22 +/- 0.62, and 100.15 +/- 0.72, and in plasma with average recoveries of 99.14 +/- 1.19 and 99.79 +/- 0.72, for sensors 2 and 1, respectively. The utility of 2-hydroxy propyl beta-cyclodextrin as an ionophore has a significant influence on increasing both membrane sensitivity and selectivity of sensor 2 in comparison with sensor 1. The methods were also used to determine the intact drug in the presence of its degradate, and thus could be used as stability-indicating methods. The results obtained by the proposed procedures were statistically analyzed and compared with those obtained by the U.S. Pharmacopeia method. No significant difference for either accuracy or precision was observed.

  2. Predicting bromide incorporation in a chlorinated indoor swimming pool.

    PubMed

    Chowdhury, Shakhawat; Mazumder, Abu Jafar; Husain, Tahir

    2016-06-01

    The water in and air above swimming pools often contain high levels of disinfection byproducts (DBPs) due to chemical reactions between chlorine- or bromine-based disinfectants and organic/inorganic matter in the source water and released from swimmers. Exposure to these DBPs, though inevitable, can pose health threats to humans. In this study, DBPs in tap water (S1), and water from a chlorinated indoor swimming pool before (S2) and after swimming (S3) were measured. The brominated species constituted the majority of DBPs formed in S1, S2, and S3. Trihalomethanes (THMs) in S3 was 6.9 (range 2.9-11.1) and 1.4 (range 0.52-2.9) times those in S1 and S2, respectively; and the haloacetic acids (HAAs) in S3 was 4.2 (range 2.5-7.5) and 1.2 (range 0.6-2.6) times those in S1 and S2, respectively. The mean THMs in air above the swimming pool before (S2-A) and after swimming (S3-A) were 72.2 and 93.0 μg/m(3), respectively, and their ranges were 36.3-105.8 and 44.1-133.6 μg/m(3), respectively. The average percentages of bromide incorporation (BI) into THMs in S1, S2, and S3 were 3.0, 9.3, and 10.6 %, respectively; and the BI into HAAs in S1, S2, and S3 were 6.6, 12.0, and 12.2 %, respectively. Several models were trained for predicting the BI into THMs and HAAs. The results indicate that additional information is required to develop predictive models for BI in swimming pools.

  3. The Killing of African Trypanosomes by Ethidium Bromide

    PubMed Central

    Roy Chowdhury, Arnab; Bakshi, Rahul; Wang, Jianyang; Yildirir, Gokben; Liu, Beiyu; Pappas-Brown, Valeria; Tolun, Gökhan; Griffith, Jack D.; Shapiro, Theresa A.; Jensen, Robert E.; Englund, Paul T.

    2010-01-01

    Introduced in the 1950s, ethidium bromide (EB) is still used as an anti-trypanosomal drug for African cattle although its mechanism of killing has been unclear and controversial. EB has long been known to cause loss of the mitochondrial genome, named kinetoplast DNA (kDNA), a giant network of interlocked minicircles and maxicircles. However, the existence of viable parasites lacking kDNA (dyskinetoplastic) led many to think that kDNA loss could not be the mechanism of killing. When recent studies indicated that kDNA is indeed essential in bloodstream trypanosomes and that dyskinetoplastic cells survive only if they have a compensating mutation in the nuclear genome, we investigated the effect of EB on kDNA and its replication. We here report some remarkable effects of EB. Using EM and other techniques, we found that binding of EB to network minicircles is low, probably because of their association with proteins that prevent helix unwinding. In contrast, covalently-closed minicircles that had been released from the network for replication bind EB extensively, causing them, after isolation, to become highly supertwisted and to develop regions of left-handed Z-DNA (without EB, these circles are fully relaxed). In vivo, EB causes helix distortion of free minicircles, preventing replication initiation and resulting in kDNA loss and cell death. Unexpectedly, EB also kills dyskinetoplastic trypanosomes, lacking kDNA, by inhibiting nuclear replication. Since the effect on kDNA occurs at a >10-fold lower EB concentration than that on nuclear DNA, we conclude that minicircle replication initiation is likely EB's most vulnerable target, but the effect on nuclear replication may also contribute to cell killing. PMID:21187912

  4. The fate of alternative soil fumigants to methyl bromide

    NASA Astrophysics Data System (ADS)

    Qin, R.; Gao, S.

    2011-12-01

    Soil fumigation is an important agricultural practice for the control of soil-borne pests. Since the phase-out of methyl bromide, due to its role in the depletion of stratospheric ozone, several alternatives such as 1,3-dichloropropene (1,3-D), chloropicrin (CP), and dimethyl disulfide (DMDS) are being increasingly used. The major processes and factors affecting the fate of these chemicals are evaluated. The high volatility of fumigants leads to high emission loss when no proper containment is used. Recent tarping technology using low permeability films can significantly reduce emissions. Fumigant degradation rate becomes critical to the determination of fumigation rate that affects efficacy and residence time in soil. A series of laboratory incubation experiments were carried out to determine degradation rate of 1,3-D isomers, CP and DMDS in five different soils collected from California and Florida. Fumigant degradation rates depend highly on the amounts of fumigants in soil, chemical characteristics, and soil conditions. Fumigant degradation rate were found to increase for all fumigants as the fumigant amounts in soil decreased. The changes were smaller for 1,3-D isomers compared to CP and DMDS. In soils with the lowest application rate, the degradation rate of fumigants is in the order of CP > DMDS > cis-1,3-D > trans-1,3-D. Soil and environmental factors also affect fumigant degradation rate. These findings suggest that a proper application rate should be determined for specific fumigants in a soil when using low permeability tarp in order to achieve sufficient fumigation efficacy during a certain period of time while minimizing potential surge of emissions after tarp removal and/or long residence time in soil that may cause phytotoxicity or leaching.

  5. Otilonium bromide as spasmolytic during endoscopic retrograde cholangiopancreatography.

    PubMed

    Karahan, Ömer; Sevinç, Barış; Okuş, Ahmet; Ay, Serden; Aksoy, Nergis

    2015-08-01

    Endoscopic retrograde cholangiopancreatography (ERCP) is commonly used in both the diagnosis and the treatment of biliary and pancreatic disorders. The aim of this study is to evaluate the effects of OB usage during ERCP on duodenal motility, the tolerability of the procedure (by patients) and the difficulty of the procedure (by the endoscopist). The study was conducted in Konya Training and Research Hospital General Surgery Endoscopy Unit in randomized prospective pattern. The patients were divided into the two groups as spasmolytic and control groups. The procedure was performed under topical anesthesia and sedation. There were 100 cases included into the study (50 cases in each group). The mean duodenal motility score was found to be 1.9 ± 0.5 in the study group and 3 ± 0.6 in the control group. In the study group, the tolerability of the procedure score by the endoscopist was moderate in 16 % and well/very well in 78 % of the cases. On the other hand, in the control group, the scores were poor in 21 %, moderate in 71 %, and well/very well in 24 % of the cases. In terms of patient satisfaction, in study group 42 % of the cases reported the procedure as moderate and 58 % reported as well/very well. However, in the control group 16 % of the cases reported the procedure as poor, 58 % moderate, and 26 % as well/very well. Otilonium bromide is a safe agent with low side effects. It can be used before the ERCP procedure to decrease the duodenal motility. It eases the procedure, moreover, it increases the patients' satisfaction.

  6. Silica nanoparticles separation from water: aggregation by cetyltrimethylammonium bromide (CTAB).

    PubMed

    Liu, Y; Tourbin, M; Lachaize, S; Guiraud, P

    2013-07-01

    Nanoparticles will inevitably be found in industrial and domestic wastes in the near future and as a consequence soon in water resources. Due to their ultra-small size, nanoparticles may not only have new hazards for environment and human health, but also cause low separation efficiency by classical water treatments processes. Thus, it would be an important challenge to develop a specific treatment with suitable additives for recovery of nanoparticles from waters. For this propose, this paper presents aggregation of silica nanoparticles (Klebosol 30R50 (75nm) and 30R25 (30nm)) by cationic surfactant cetyltrimethylammonium bromide (CTAB). Different mechanisms such as charge neutralization, "depletion flocculation" or "volume-restriction", and "hydrophobic effect" between hydrocarbon tails of CTAB have been proposed to explicate aggregation results. One important finding is that for different volume concentrations between 0.05% and 0.51% of 30R50 suspensions, the same critical coagulation concentration was observed at CTAB=0.1mM, suggesting the optimized quantity of CTAB during the separation process for nanoparticles of about 75nm. Furthermore, very small quantities of CTAB (0.01mM) can make 30R25 nanosilica aggregated due to the "hydrophobic effect". It is then possible to minimize the sludge and allow the separation process as "greener" as possible by studying this case. It has also shown that aggregation mechanisms can be different for very small particles so that a special attention has to be paid to the treatment of nanoparticles contained in water and wastewaters.

  7. Depleting methyl bromide residues in soil by reaction with bases.

    PubMed

    Xuan, Richeng; Ashworth, Daniel J; Luo, Lifang; Wang, Haizhen; Yates, Scott R

    2010-12-01

    Despite generally being considered the most effective soil fumigant, methyl bromide (MeBr) use is being phased out because its emissions from soil can lead to stratospheric ozone depletion. However, a large amount is still currently used due to Critical Use Exemptions. As strategies for reducing the postfumigation emissions of MeBr from soil, Ca(OH)(2), K(2)CO(3), and NH(3) were assessed as means of promoting MeBr degradation. Ammonia aqueous solution (NH(4)OH) was the most effective, because MeBr can be degraded by both hydrolysis and ammonolysis. At 20 °C, the half-lives (t(1/2)) of MeBr were 18.0, 2.5, and 1.3 h in 0.1, 1.0, and 2.0 M NH(4)OH, respectively. In 1.0 M NH(4)OH, increasing the solution temperature to 40 °C reduced the half-life of MeBr to 0.23 h. Ammonia amendment to moist soil also promoted MeBr transformation, and the MeBr degradation rate increased with increasing soil temperature. NH(4)OH (30%, 16 M) very effectively reacted with MeBr that was contained under plastic film. Under Hytibar (a virtually impermeable film, VIF), over 99.5% of the MeBr could be destroyed by 30% NH(4)OH in 8 h at 20 °C. On the basis of these results, good management practices (i.e., VIF plus NH(4)OH) could be developed for continued use of MeBr as a soil fumigant under Critical Use Exemptions, without significant emissions.

  8. Aclidinium bromide for stable chronic obstructive pulmonary disease.

    PubMed

    Ni, Han; Soe, Zay; Moe, Soe

    2014-09-19

    Bronchodilators are the mainstay for symptom relief in the management of stable chronic obstructive pulmonary disease (COPD). Aclidinium bromide is a new long-acting muscarinic antagonist (LAMA) that differs from tiotropium by its higher selectivity for M3 muscarinic receptors with a faster onset of action. However, the duration of action of aclidinium is shorter than for tiotropium. It has been approved as maintenance therapy for stable, moderate to severe COPD, but its efficacy and safety in the management of COPD is uncertain compared to other bronchodilators. To assess the efficacy and safety of aclidinium bromide in stable COPD. We identified randomised controlled trials (RCT) from the Cochrane Airways Group Specialised Register of trials (CAGR), as well as www.clinicaltrials.gov, World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), US Food and Drug Administration (FDA) website and Almirall Clinical Trials Registry and Results. We contacted Forest Laboratories for any unpublished trials and checked the reference lists of identified articles for additional information. The last search was performed on 7 April 2014 for CAGR and 11 April 2014 for other sources. Parallel-group RCTs of aclidinium bromide compared with placebo, long-acting beta2-agonists (LABA) or LAMA in adults with stable COPD. Two review authors independently selected studies, assessed the risk of bias, and extracted data. We sought missing data from the trial authors as well as manufacturers of aclidinium. We used odds ratios (OR) for dichotomous data and mean difference (MD) for continuous data, and reported both with their 95% confidence intervals (CI). We used standard methodological procedures expected by The Cochrane Collaboration. We applied the GRADE approach to summarise results and to assess the overall quality of evidence. This review included 12 multicentre RCTs randomly assigning 9547 participants with stable COPD. All the studies were industry

  9. Hydrogen storage and ionic mobility in amide-halide systems.

    PubMed

    Anderson, Paul A; Chater, Philip A; Hewett, David R; Slater, Peter R

    2011-01-01

    We report the results of a systematic study of the effect of halides on hydrogen release and uptake in lithium amide and lithium imide, respectively. The reaction of lithium amide and lithium imide with lithium or magnesium chloride, bromide and iodide resulted in a series of amide-halide and imide-halide phases, only two of which have been reported previously. On heating with LiH or MgH2, the amide-halides synthesised all released hydrogen more rapidly than lithium amide itself, accompanied by much reduced, or in some cases undetectable, release of ammonia by-product. The imide-halides produced were found to hydrogenate more rapidly than lithium imide, reforming related amide-halide phases. The work was initiated to test the hypothesis that the incorporation of halide anions might improve the lithium ion conductivity of lithium amide and help maintain high lithium ion mobility at all stages of the de/rehydrogenation process, enhancing the bulk hydrogen storage properties of the system. Preliminary ionic conductivity measurements indicated that the most conducting amide- and imide-halide phases were also the quickest to release hydrogen on heating and to hydrogenate. We conclude that ionic conductivity may be an important parameter in optimising the materials properties of this and other hydrogen storage systems.

  10. Effect of halide and acid additives on the direct synthesis of hydrogen peroxide using supported gold-palladium catalysts.

    PubMed

    Ntainjua N, Edwin; Piccinini, Marco; Pritchard, James C; Edwards, Jennifer K; Carley, Albert F; Moulijn, Jacob A; Hutchings, Graham J

    2009-01-01

    The effect of halide and acid addition on the direct synthesis of hydrogen peroxide is studied for magnesium oxide- and carbon-supported bimetallic gold-palladium catalysts. The addition of acids decreases the hydrogenation/decomposition of hydrogen peroxide, and the effect is particularly pronounced for the magnesium oxide-supported catalysts whilst for carbon-supported catalysts the pH requires close control to optimize hydrogen peroxide synthesis. The addition of bromide leads to a marked decrease in the hydrogenation/decomposition of hydrogen peroxide with either catalyst. These effects are discussed in terms of the structure of the gold-palladium alloy nanoparticles and the isoelectric point of the support. We conclude that with the highly active carbon-supported gold-palladium catalysts these additives are not required and that therefore this system presents the potential for the direct synthesis of hydrogen peroxide to be operated using green process technology.

  11. Hydrogen detector

    DOEpatents

    Kanegae, Naomichi; Ikemoto, Ichiro

    1980-01-01

    A hydrogen detector of the type in which the interior of the detector is partitioned by a metal membrane into a fluid section and a vacuum section. Two units of the metal membrane are provided and vacuum pipes are provided independently in connection to the respective units of the metal membrane. One of the vacuum pipes is connected to a vacuum gauge for static equilibrium operation while the other vacuum pipe is connected to an ion pump or a set of an ion pump and a vacuum gauge both designed for dynamic equilibrium operation.

  12. Tiotropium bromide inhalation powder: a review of its use in the management of chronic obstructive pulmonary disease.

    PubMed

    Keating, Gillian M

    2012-01-22

    The anticholinergic agent tiotropium bromide (Spiriva®) is a long-acting bronchodilator that is indicated for the treatment of chronic obstructive pulmonary disease (COPD). This article reviews the clinical efficacy and tolerability of tiotropium bromide inhalation powder, administered using the HandiHaler® device, in patients with COPD, as well as reviewing its pharmacological properties and the results of pharmacoeconomic analyses. Shorter-term placebo-controlled trials in patients with COPD demonstrated significantly higher trough forced expiratory volume in 1 second (FEV(1)) responses with tiotropium bromide than with placebo, confirming it has a duration of action of ≥24 hours and is suitable for once-daily administration. Lung function improved to a greater extent with tiotropium bromide than with ipratropium bromide or, in most instances, salmeterol. Indacaterol was shown to be noninferior to tiotropium bromide in terms of the trough FEV(1) response. The large, 4-year UPLIFT® trial did not show a significant reduction in the annual rate of decline in FEV(1) with tiotropium bromide versus placebo in patients with COPD, although subgroup analyses demonstrated a significantly lower rate of decline with tiotropium bromide than with placebo in some patient groups (e.g. patients with moderate COPD, patients aged ≥50 years, patients not receiving maintenance therapy at baseline). Tiotropium bromide prevented exacerbations in patients with COPD, with a significantly lower exacerbation rate and a significantly longer time to first exacerbation seen with tiotropium bromide than with placebo or salmeterol. Exacerbation rates did not significantly differ between patients receiving tiotropium bromide and those receiving salmeterol/fluticasone propionate. Tiotropium bromide also had beneficial effects on health-related quality of life (HR-QOL) and other endpoints, such as dyspnoea and rescue medication use. Combination therapy with tiotropium bromide plus

  13. Graphane and hydrogenated graphene.

    PubMed

    Pumera, Martin; Wong, Colin Hong An

    2013-07-21

    Graphane, the fully hydrogenated analogue of graphene, and its partially hydrogenated counterparts are attracting increasing attention. We review here its structure and predicted material properties, as well as the current methods of preparation. Graphane and hydrogenated graphenes are far more complex materials than graphene, expected to have a tuneable band gap via the extent of hydrogenation, as well as exhibit ferromagnetism. The methods for hydrogenated graphene characterization are discussed. We show that hydrogenation methods based on low or high pressure gas hydrogenation lead to less hydrogen saturation than wet chemistry methods based on variations of Birch reduction. The special cases of patterning of hydrogenated graphene strips in a graphene lattice are discussed.

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

    PubMed

    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 (<63 μm) gave a 3.7 mg kg(-1) limit of detection for bromine which, in most cases, was suitable for monitoring total bromine content in soils (Br content range in soils = 5-40 mg kg(-1)). Information about bromide determination in soils is also possible by analyzing the Br content in 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.

  15. Residential Proximity to Methyl Bromide Use and Birth Outcomes in an Agricultural Population in California

    PubMed Central

    Gemmill, Alison; Gunier, Robert B.; Bradman, Asa; Eskenazi, Brenda

    2013-01-01

    Background: Methyl bromide, a fungicide often used in strawberry cultivation, is of concern for residents who live near agricultural applications because of its toxicity and potential for drift. Little is known about the effects of methyl bromide exposure during pregnancy. Objective: We investigated the relationship between residential proximity to methyl bromide use and birth outcomes. Methods: Participants were from the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study (n = 442), a longitudinal cohort study examining the health effects of environmental exposures on pregnant women and their children in an agricultural community in northern California. Using data from the California Pesticide Use Reporting system, we employed a geographic information system to estimate the amount of methyl bromide applied within 5 km of a woman’s residence during pregnancy. Multiple linear regression models were used to estimate associations between trimester-specific proximity to use and birth weight, length, head circumference, and gestational age. Results: High methyl bromide use (vs. no use) within 5 km of the home during the second trimester was negatively associated with birth weight (β = –113.1 g; CI: –218.1, –8.1), birth length (β = –0.85 cm; CI: –1.44, –0.27), and head circumference (β = –0.33 cm; CI: –0.67, 0.01). These outcomes were also associated with moderate methyl bromide use during the second trimester. Negative associations with fetal growth parameters were stronger when larger (5 km and 8 km) versus smaller (1 km and 3 km) buffer zones were used to estimate exposure. Conclusions: Residential proximity to methyl bromide use during the second trimester was associated with markers of restricted fetal growth in our study. PMID:23603811

  16. Mechanochemical hydrogenation of coal

    DOEpatents

    Yang, Ralph T.; Smol, Robert; Farber, Gerald; Naphtali, Leonard M.

    1981-01-01

    Hydrogenation of coal is improved through the use of a mechanical force to reduce the size of the particulate coal simultaneously with the introduction of gaseous hydrogen, or other hydrogen donor composition. Such hydrogen in the presence of elemental tin during this one-step size reduction-hydrogenation further improves the yield of the liquid hydrocarbon product.

  17. A strong Nsbnd H…Br vibrational behaviour studied through X-ray, vibrational spectra and quantum chemical studies in an isomorphous crystal: 2-Nitroanilinium bromide

    NASA Astrophysics Data System (ADS)

    Anitha, R.; Athimoolam, S.; Gunasekaran, M.

    2015-03-01

    A needle shaped transparent light brown crystals of 2-nitroanilinium bromide were successfully synthesized and crystallized from an aqueous mixture by slow evaporation technique. Single crystal XRD studies confirm the crystalline phase of this isomorphous compound which contains a positively charge 2-nitroanilinium cation and a negatively charged bromide anion. The solid phase FT-IR and FT-Raman spectra of the compound have been recorded in the range of 4000-400 cm-1. The observed modes are correlated by the factor group theory analysis and different IR and Raman active species were identified. Geometrical optimisations were carried out and harmonic vibrational wave numbers were computed for the minimum energy molecular structure at RHF level invoking 6-311++G(d,p) and SDD basis sets. Optimised molecular geometry was compared with the crystallographic data. The calculated wavenumbers were compared with the experimental values. The Nsbnd H vibrational bands are shifted from its normal range and the shifting is associated with the influence of the intermolecular hydrogen bonds in the crystal. A strong intensity peak in theoretical and corresponding band in experimental confirms the presence of Nsbnd H…Br interaction as predicted in crystalline state.

  18. Chlorine-36, bromide, and the origin of spring water

    USGS Publications Warehouse

    Davis, S.N.; Cecil, L.D.; Zreda, M.; Moysey, S.

    2001-01-01

    Natural ratios of chlorine-36 (36Cl) to stable chlorine (i.e., 36Cl/Cl ?? 10-15) vary in shallow groundwater of the United States from about 50 in coastal areas to about 1400 in the northern Rocky Mountains. Ratios lower than these indicate the presence of chloride (Cl-) that has been isolated from the atmosphere for hundreds of thousands of years, if not longer. Higher ratios, which can exceed 5000, usually originate from fallout from testing thermonuclear devices in the western Pacific in the 1950s. Natural mass ratios of chloride to bromide (Cl-/Br-) in precipitation vary in the United States from about 250 in coastal areas to about 50 in the north-central states. Lower ratios may suggest contamination from human sources. Higher ratios, which may exceed 2000, commonly reflect the dissolution of halite. Seawater has a Cl-/Br- ratio of 290. Both 36Cl and Cl-/Br- ratios have been measured in 21 samples of spring water collected from springs in 10 different states. Brackish water from Saratoga Springs area in New York has low values for both 36Cl and Cl-/Br- ratios. This indicates that a large component of the water has a very deep origin. Brackish water from Alexander Springs in Florida has a low 36Cl ratio but a high Cl-/Br- ratio similar to seawater. This suggests the addition of ancient seawater that may be trapped in the aquifer. Big Spring in Iowa discharges water with a very high Cl-/Br- ratio but a moderate 36Cl ratio. The high ratio of Cl-/Br- may be produced by dissolution of road salt or agricultural chemicals. Of the 21 springs sampled, only 10 appeared to have potable water not significantly affected by human activity. Chlorine-36 from testing of nuclear devices is still being flushed out of four of the spring systems that were sampled. Thus, more than 45 years have passed since 36Cl was introduced into the aquifers feeding the springs and the systems, as yet, have not been purged. Published by Elsevier Science B.V.

  19. The ocean in near equilibrium with atmospheric methyl bromide

    NASA Astrophysics Data System (ADS)

    Hu, Lei; Yvon-Lewis, Shari; Liu, Yina; Bianchi, Thomas S.

    2012-09-01

    Saturation-anomaly measurements of methyl bromide (CH3Br) were made in the eastern Pacific (3/30-4/27, 2010) and the eastern Atlantic (10/25-11/26, 2010) to assess the oceanic saturation state as the phaseout of fumigation - non-Quarantine and Pre-Shipment (non-QPS) uses of CH3Br nears completion and atmospheric concentrations continue to decline. These cruises occurred 16 years after the Bromine Latitudinal Air-Sea Transect (BLAST) cruises, which were conducted in the same regions and first established a global oceanic net sink of -12.6 Gg yr-1 for atmospheric CH3Br in 1994. Results from this study suggest saturation anomalies of CH3Br in the surface ocean have become less negative than those observed 16 years ago as the atmospheric burden has declined over the past decade. The global net sea-to-air flux was estimated at 0 to 3 Gg yr-1 in 2010, suggesting that the ocean may become a net small source to atmospheric CH3Br. There are no significant differences between this study and previous studies for measured biological loss rate constants and calculated annual production rates, suggesting that annual production rates and biological degradation rate constants for CH3Br in the surface ocean have likely remained relatively constant over the past 16 years. When including the biological loss rate constants from this study and all previous studies, the mean global biological loss rate constant is constrained to 0.05 ± 0.01 d-1 (at a 95% confidence level). Combining chemical and eddy degradation rate constants, and using an updated gas transfer velocity, we estimate the CH3Br partial atmospheric lifetime with respect to oceanic loss to be 3.1 (2.3 to 5.0) years. Although the new partial atmospheric lifetime is about 1.3 years longer than the best prior estimate, it does not change the overall atmospheric lifetime of CH3Br, 0.8 (0.7-0.9) years.

  20. Bacterial Oxidation of Methyl Bromide in Fumigated Agricultural Soils

    PubMed Central

    Miller, L. G.; Connell, T. L.; Guidetti, J. R.; Oremland, R. S.

    1997-01-01

    The oxidation of [(sup14)C]methyl bromide ([(sup14)C]MeBr) to (sup14)CO(inf2) was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCl(inf3)NO(inf2)). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [(sup14)C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to (sup14)CO(inf2) and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy. PMID:16535728

  1. Functionalization of Hydrogenated Chemical Vapour Deposition-Grown Graphene by On-Surface Chemical Reactions.

    PubMed

    Drogowska, Karolina; Kovaříček, Petr; Kalbáč, Martin

    2017-03-23

    The reactivity of hydrogenated graphene when treated with oxidising agents, KMnO4 and KIO4 , as well as alkylated with benzyl bromide (BnBr) was studied. The probed reactions are strictly limited to the partly hydrogenated form of graphene in which most of the hydrogen atoms are located in activated benzylic/allylic positions. This, in turn, clearly demonstrates the presence of hydrogen attached to the graphene lattice. Attachment of the benzyl group was also unequivocally demonstrated by characteristic vibrations recorded in the surface-enhanced Raman spectra, and all reactions were shown to proceed solely on hydrogenated graphene as evidenced by the comparison with pristine chemical vapour deposition-grown graphene.

  2. Comparison of Methyl Bromide and Other Nematicides for Control of Nematodes in Peanut

    PubMed Central

    Rodríguez-Kábana, R.; Robertson, D. G.; King, P. S.

    1987-01-01

    The efficacy of methyl bromide for control ofMeloidogyne arenaria and to increase yields of 'Florunner' peanut (Arachis hypogaea) was studied in a field at the Wiregrass Substation near Headland, Alabama. Methyl bromide was applied in the row at a depth of 35 cm using a subsoiler-bedder 2 weeks before planting at rates of 0, 34, 50, 67, 101, and 118 kg a.i./ha. Methyl bromide treatments of 67 kg a.i./ha or higher resulted in significant (P = 0.05) yield increases similar to those obtained in the same experiment with at-plant applications of aldicarb (2.2 kg a.i./ha), EDB (1.55 ml a.i./m row), or 1,3-D (5.10 ml a.i./m row). The relation between yield (Y) and methyl bromide rate (x) was described (R² = 0.97**) by the exponential function: Y = 2,302.963eb, where b = (- 1.901 - ln x)²/169.482. M. arenaria juvenile populations in soil in mid-August were too low to permit establishment of a relation between application rate of methyl bromide and size of the population. PMID:19290276

  3. Utility of bromide and heat tracers for aquifer characterization affected by highly transient flow conditions

    NASA Astrophysics Data System (ADS)

    Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew

    2012-08-01

    A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained "noise" caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.

  4. A novel explicit approach to model bromide and pesticide transport in soils containing macropores

    NASA Astrophysics Data System (ADS)

    Klaus, J.; Zehe, E.

    2011-01-01

    The present study tests whether an explicit treatment of worm burrows is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in the spatially highly resolved model domain. A recent Monte Carlo study (Klaus and Zehe, 2010) revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide and Isoproturon (IPU) for the 13 spatial model setups, which performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of IPU, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

  5. [Successful lobectomy in 3 lung cancer cases with severe COPD after treatment with tiotropium bromide].

    PubMed

    Matsuyama, Wataru; Suetsugu, Takayuki; Kawabata, Takashi; Kubota, Shingo; Iwakawa, Jun; Higashimoto, Ikkou; Osame, Mitsuhiro; Arimura, Kimiyoshi

    2007-02-01

    It is well known that lung cancer patients with severe chronic obstructive pulmonary disease (COPD) have a higher risk of postoperative complications than patients without COPD. However, the information regarding preoperative treatment to improve pulmonary function of the lung cancer patients with severe COPD is limited. Here, we report 3 lung cancer cases with severe COPD. Although all patients received medication without tiotropium bromide in combination with pulmonary rehabilitation for 1 or 2 months, their pulmonary function did not improve and the predicted postoperative FEV1/predicted FEV1 was below 40% in all cases. After the approval in Japan for use of tiotropium bromide in the treatment of COPD, all patients were treated with tiotropium bromide. The pulmonary function in all patients improved 2-4 weeks after the start of tiotropium bromide, and we performed lobectomy safely. Currently all patients maintain good pulmonary function without recurrence of lung cancer. We propose that treatment of tiotropium bromide might be one of the effective preoperative methods to improve pulmonary function of lung cancer patients with severe COPD.

  6. Mepenzolate bromide promotes diabetic wound healing by modulating inflammation and oxidative stress

    PubMed Central

    Zheng, Yongjun; Wang, Xingtong; Ji, Shizhao; Tian, Song; Wu, Haibin; Luo, Pengfei; Fang, He; Wang, Li; Wu, Guosheng; Xiao, Shichu; Xia, Zhaofan

    2016-01-01

    Diabetic wounds are characterized by persistent inflammation and the excessive production of reactive oxygen species, thus resulting in impaired wound healing. Mepenzolate bromide, which was originally used to treat gastrointestinal disorders in clinical settings, has recently been shown to display beneficial effects in chronic obstructive pulmonary disease and pulmonary fibrosis of a mouse model by inhibiting inflammatory responses and reducing oxidative stress. However,the role of mepenzolate bromide in diabetic wound healing is still unclear. In this study, full-thickness excisional skin wounds were created on the backs of db/db mice, and mepenzolate bromide was topically applied to the wound bed. We found that mepenzolate bromide significantly promoted diabetic wound healing by measuring wound closure rate and histomorphometric analyses. Further studies showed that inflammation was inhibited by assessing the number of macrophages and levels of pro-inflammatory cytokines and pro-healing cytokines in the wounds. Furthermore, oxidative stress was reduced by monitoring the levels of MDA and H2O2 and the activities of glutathione peroxidase and catalase in the wounds. These results demonstrated the potential application of mepenzolate bromide for treating diabetic ulcers and other chronic wounds in clinics. PMID:27398156

  7. Allyl triphenyl phosphonium bromide based DES-functionalized carbon nanotubes for the removal of mercury from water.

    PubMed

    AlOmar, Mohamed Khalid; Alsaadi, Mohammed Abdulhakim; Hayyan, Maan; Akib, Shatirah; Ibrahim, Muhammad; Hashim, Mohd Ali

    2017-01-01

    Recently, deep eutectic solvents (DESs) have shown their new and interesting ability for chemistry through their involvement in variety of applications. This study introduces carbon nanotubes (CNTs) functionalized with DES as a novel adsorbent for Hg(2+) from water. Allyl triphenyl phosphonium bromide (ATPB) was combined with glycerol as the hydrogen bond donor (HBD) to form DES, which can act as a novel CNTs functionalization agent. The novel adsorbent was characterized using Raman, FTIR, XRD, FESEM, EDX, BET surface area, TGA, TEM and Zeta potential. Response surface methodology was used to optimize the removal conditions for Hg(2+). The optimum removal conditions were found to be pH 5.5, contact time 28 min, and an adsorbent dosage of 5 mg. Freundlich isotherm model described the adsorption isotherm of the novel adsorbent, and the maximum adsorption capacity obtained from the experimental data was 186.97 mg g(-1). Pseudo-second order kinetics describes the adsorption rate order.

  8. 1H NMR study of the hetero-association of flavin-mononucleotide with mutagenic dyes: ethidium bromide and proflavine

    NASA Astrophysics Data System (ADS)

    Evstigneev, M. P.; Mukhina, Yu. V.; Davies, D. B.

    The hetero-association of the vitamin B2 derivative, flavin-mononucleotide (FMN), with a mutagenic dye, ethidium bromide (EB) or proflavine (PF), has been studied by 1D and 2D 500 MHz 1H NMR spectroscopy. The variations of proton chemical shifts of both the vitamin and dye as a function of concentration and temperature were analysed in terms of the structural and thermodynamical properties of the FMN-EB and FMN-PF complexes in solution. The structures of the complexes were also investigated by observed intermolecular ROE contacts and molecular mechanics calculations. The results show that the 1 : 1 hetero-association complexes in solution are more stable than the self-association complexes, which is consistent with formation of an intermolecular hydrogen-bond in the hetero-complexes of FMN-EB and FMN-PF. Hence it is possible that the toxicity of aromatic molecules such as EB and PF may be reduced in vitro by the presence of FMN, partly because of the known antimutagenic action of FMN and partly because it has been shown in this work that there is an effective intermolecular association between the mutagens and the vitamin.

  9. Evaluation of the effect of tetraethylammonium bromide and chloride on the growth and development of terrestrial plants.

    PubMed

    Pawłowska, Barbara; Biczak, Robert

    2016-04-01

    Quaternary ammonium salts (QAS), which also include ionic liquids, constitute a vast group of chemical compounds that are increasingly common in the commercial use. This situation may lead to the contamination of the natural environment and may constitute a potential threat to all its elements, including terrestrial higher plants. This paper presents the effect of tetraethylammonium chloride [TEA][Cl] and tetraethylammonium bromide [TEA][Br] on the growth and development of spring barley and common radish. The applied QAS were characterized with phytotoxicity dependent on the concentration of compound and characteristics of the study plants. Spring barley turned out to be highly susceptible plant to the analyzed compounds, which was confirmed by % inhibition of length of plants, root length and fresh weight of plants and by calculated values for EC50, NOEC as well as LOEC. On the contrary, a common radish revealed the resistance to QAS used in the study; although, phytotoxic symptoms were still observed when high concentrations of dry weight of soil were applied (1000, 3000 and 5000 mg/kg). The applied QAS caused oxidative stress symptoms, mainly in spring barley seedlings, which were manifested by decreased assimilation of pigments content, increased hydrogen peroxide (H2O2) and malondialdehyde (MDA) content in plant cells and with a changed activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Rocuronium Bromide Inhibits Inflammation and Pain by Suppressing Nitric Oxide Production and Enhancing Prostaglandin E2 Synthesis in Endothelial Cells

    PubMed Central

    2016-01-01

    Purpose Rocuronium bromide is a nondepolarizing neuromuscular blocking drug and has been used as an adjunct for relaxation or paralysis of the skeletal muscles, facilitation of endotracheal intubation, and improving surgical conditions during general anesthesia. However, intravenous injection of rocuronium bromide induces injection pain or withdrawal movement. The exact mechanism of rocuronium bromide-induced injection pain or withdrawal movement is not yet understood. We investigated whether rocuronium bromide treatment is involved in the induction of inflammation and pain in vascular endothelial cells. Methods For this study, calf pulmonary artery endothelial (CPAE) cells were used, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, nitric oxide detection, and prostaglandin E2 immunoassay were conducted. Results Rocuronium bromide treatment inhibited endothelial nitric oxide synthase and suppressed nitric oxide production in CPAE cells. Rocuronium bromide activated cyclooxygenase-2, inducible nitric oxide synthase and increased prostaglandin E2 synthesis in CPAE cells. Conclusions Rocuronium bromide induced inflammation and pain in CPAE cells. Suppressing nitric oxide production and enhancing prostaglandin E2 synthesis might be associated with rocuronium bromide-induced injection pain or withdrawal movement. PMID:28043117

  11. Hydrogen heat treatment of hydrogen absorbing materials

    NASA Astrophysics Data System (ADS)

    Park, Choong-Nyeon

    2000-12-01

    This study introduces the hydrogen heat treatment of hydrogen absorbing materials and its applicability for practical use. This treatment is somewhat different from normal heat treatment because of the interaction between metal atoms and hydrogen. Since hydrogen can be removed very fast by pumping it out the hydrogen-induced new lattice phase which can not be obtained without hydrogen can be preserved in a meta-stable state. A thermodynamic interpretation of the hydrogen heat treatment established previously was reformulated for graphical and analytical methods and applied to Pd-Pt-H and Pd-Ag-H alloy systems and a fair correlation between the calculation and experimental results was shown. The feasibility of applying the thermodynamic interpretation to intermetallic compounds-hydrogen systems was also discussed.

  12. Total synthesis of virgatolide B via exploitation of intramolecular hydrogen bonding.

    PubMed

    Hume, Paul A; Furkert, Daniel P; Brimble, Margaret A

    2014-06-06

    A full account of the enantioselective total synthesis of virgatolide B is reported. Key features of the synthesis include an sp(3)-sp(2) Suzuki-Miyaura cross-coupling of a β-trifluoroboratoamide with an aryl bromide, regioselective intramolecular carboalkoxylation, and a 1,3-anti-selective Mukaiyama aldol reaction. Intramolecular hydrogen bonding governed the regioselectivity of the key spiroketalization step, affording the natural product as a single regioisomer.

  13. Intramolecular charge delocalization and nonlinear optical properties of push-pull chromophore 1-(4-N,N-dimethylaminopyridinium) acetic acid bromide monohydrate from vibrational spectra.

    PubMed

    John, C Jesintha; Amalanathan, M; Sajan, D; Lakshmi, K Udaya; Joe, I Hubert

    2011-01-01

    FT-Raman and FT-IR spectra of the nonlinear optical crystal 1-(4-N,N-dimethylaminopyridinium) acetic acid bromide monohydrate have been recorded and analyzed. The equilibrium geometry, vibrational wavenumbers and the first order hyperpolarizability of the crystal have been calculated with the help of density functional theory computations. The assignments of the vibrational spectra have been carried out with the help of Scaled Quantum Mechanic force field theory. Optimized geometry gives the charge transfer interaction of the pyridine ring and the amino group in the electron-donor side of the nonlinear optic chromophore. Electron-phonon coupling and O-H⋯O interactions in making the molecule nonlinear optical active have been analyzed based on the vibrational spectral features. The Natural Bond Orbital analysis confirms the occurrence of strong intermolecular O-H⋯O hydrogen bonding. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Bromidotetra­kis­(1H-2-ethyl-5-methyl­imidazole-κN 3)copper(II) bromide

    PubMed Central

    Godlewska, Sylwia; Baranowska, Katarzyna; Socha, Joanna; Dołęga, Anna

    2011-01-01

    The CuII ion in the title compound, [CuBr(C6H10N2)4]Br, is coordinated in a square-based-pyramidal geometry by the N atoms of four imidazole ligands and a bromide anion in the apical site. Both the CuII and Br− atoms lie on a crystallographic fourfold axis. In the crystal, the [CuBr(C6H10N2)4]+ complex cations are linked to the uncoordinated Br− anions (site symmetry ) by N—H⋯Br hydrogen bonds, generating a three-dimensional network. The ethyl group of the imidazole ligand was modelled as disordered over two orientations with occupancies of 0.620 (8) and 0.380 (8). PMID:22199662

  15. Current and Potential Future Bromide Loads from Coal-Fired Power Plants in the Allegheny River Basin and Their Effects on Downstream Concentrations.

    PubMed

    Good, Kelly D; VanBriesen, Jeanne M

    2016-09-06

    The presence of bromide in rivers does not affect ecosystems or present a human health risk; however, elevated concentrations of bromide in drinking water sources can lead to difficulty meeting drinking water disinfection byproduct (DBP) regulations. Recent attention has focused on oil and gas wastewater and coal-fired power plant wet flue gas desulfurization (FGD) wastewater bromide discharges. Bromide can be added to coal to enhance mercury removal, and increased use of bromide at some power plants is expected. Evaluation of potential increases in bromide concentrations from bromide addition for mercury control is lacking. The present work utilizes bromide monitoring data in the Allegheny River and a mass-balance approach to elucidate bromide contributions from anthropogenic and natural sources under current and future scenarios. For the Allegheny River, the current bromide is associated approximately 49% with oil- and gas-produced water discharges and 33% with coal-fired power plants operating wet FGD, with 18% derived from natural sources during mean flow conditions in August. Median wet FGD bromide loads could increase 3-fold from 610 to 1900 kg/day if all plants implement bromide addition for mercury control. Median bromide concentrations in the lower Allegheny River in August would rise to 410, 200, and 180 μg/L under low-, mean-, and high-flow conditions, respectively, for the bromide-addition scenario.

  16. Hydrogen Permeation Barrier Coatings

    SciTech Connect

    Henager, Charles H.

    2008-01-01

    Gaseous hydrogen, H2, has many physical properties that allow it to move rapidly into and through materials, which causes problems in keeping hydrogen from materials that are sensitive to hydrogen-induced degradation. Hydrogen molecules are the smallest diatomic molecules, with a molecular radius of about 37 x 10-12 m and the hydrogen atom is smaller still. Since it is small and light it is easily transported within materials by diffusion processes. The process of hydrogen entering and transporting through a materials is generally known as permeation and this section reviews the development of hydrogen permeation barriers and barrier coatings for the upcoming hydrogen economy.

  17. Balance of Plant Requirements for a Nuclear Hydrogen Plant

    SciTech Connect

    Bradley Ward

    2006-04-01

    This document describes the requirements for the components and systems that support the hydrogen production portion of a 600 megawatt thermal (MWt) Next Generation Nuclear Plant (NGNP). These systems, defined as the "balance-of-plant" (BOP), are essential to operate an effective hydrogen production plant. Examples of BOP items are: heat recovery and heat rejection equipment, process material transport systems (pumps, valves, piping, etc.), control systems, safety systems, waste collection and disposal systems, maintenance and repair equipment, heating, ventilation, and air conditioning (HVAC), electrical supply and distribution, and others. The requirements in this document are applicable to the two hydrogen production processes currently under consideration in the DOE Nuclear Hydrogen Initiative. These processes are the sulfur iodide (S-I) process and the high temperature electrolysis (HTE) process. At present, the other two hydrogen production process - the hybrid sulfur-iodide electrolytic process (SE) and the calcium-bromide process (Ca-Br) -are under flow sheet development and not included in this report. While some features of the balance-of-plant requirements are common to all hydrogen production processes, some details will apply only to the specific needs of individual processes.

  18. Hydrogen embrittlement in nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Gross, Sidney

    1989-01-01

    It was long known that many strong metals can become weakened and brittle as the result of the accumulation of hydrogen within the metal. When the metal is stretched, it does not show normal ductile properties, but fractures prematurely. This problem can occur as the result of a hydrogen evolution reaction such as corrosion or electroplating, or due to hydrogen in the environment at the metal surface. High strength alloys such as steels are especially susceptible to hydrogen embrittlement. Nickel-hydrogen cells commonly use Inconel 718 alloy for the pressure container, and this also is susceptible to hydrogen embrittlement. Metals differ in their susceptibility to embrittlement. Hydrogen embrittlement in nickel-hydrogen cells is analyzed and the reasons why it may or may not occur are discussed. Although Inconel 718 can display hydrogen embrittlement, experience has not identified any problem with nickel-hydrogen cells. No hydrogen embrittlement problem is expected with the 718 alloy pressure container used in nickel-hydrogen cells.

  19. Hydrogen-bonding motifs and thermotropic polymorphism in redetermined halide salts of hexamethylenediamine.

    PubMed

    van Blerk, Charmaine; Kruger, Gert J

    2008-10-01

    The redetermined crystal structures of hexane-1,6-diammonium dichloride, C(6)H(18)N(2)(2+) x 2 Cl(-), (I), hexane-1,6-diammonium dibromide, C(6)H(18)N(2)(2+) x 2 Br(-), (II), and hexane-1,6-diammonium diiodide, C(6)H(18)N(2)(2+) x 2 I(-), (III), are described, focusing on their hydrogen-bonding motifs. The chloride and bromide salts are isomorphous, with both demonstrating a small deviation from planarity [173.89 (10) and 173.0 (2) degrees, respectively] in the central C-C-C-C torsion angle of the hydrocarbon backbone. The chloride and bromide salts also show marked similarities in their hydrogen-bonding interactions, with subtle differences evident in the hydrogen-bond lengths reported. Bifurcated interactions are exhibited between the N-donor atoms and the halide acceptors in the chloride and bromide salts. The iodide salt is very different in molecular structure, packing and intermolecular interactions. The hydrocarbon chain of the iodide straddles an inversion centre and the ammonium groups on the diammonium cation of the iodide salt are offset from the planar hydrocarbon backbone by a torsion angle of 69.6 (4) degrees. All three salts exhibit thermotropic polymorphism, as is evident from differential scanning calorimetry analysis and variable-temperature powder X-ray diffraction studies.

  20. Characterization of micelle formation of dodecyldimethyl-N-2-phenoxyethylammonium bromide in aqueous solution.

    PubMed

    Khatua, Dibyendu; Gupta, Abhisek; Dey, Joykrishna

    2006-06-01

    Aggregation behavior of dodecyldimethyl-N-2-phenoxyethylammonium bromide commonly called domiphen bromide (DB) was studied in aqueous solution. The Krafft temperature of the surfactant was measured. The surfactant has been shown to form micellar structures in a wide concentration range. The critical micelle concentration was determined by surface tension, conductivity, and fluorescence methods. The conductivity data were also employed to determine the degree of surfactant counterion dissociation. The changes in Gibb's free energy, enthalpy, and entropy of the micellization process were determined at different temperature. The steady-state fluorescence quenching measurements with pyrene and N-phenyl-1-naphthylamine as fluorescence probes were performed to obtain micellar aggregation number. The results were compared with those of dodecyltrimethylammonium bromide (DTAB) surfactant. The micelle formation is energetically more favored in DB compared to that in DTAB. The 1H-NMR spectra were used to show that the 2-phenoxyethyl group, which folds back onto the micellar surface facilitates aggregate formation in DB.

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

    PubMed Central

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

    1969-01-01

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

  2. [Extraction-spectrophotometric determination of carbethopendecinium-bromide in drug preparations].

    PubMed

    Lasková, M; Blesová, M

    2003-09-01

    The paper elaborated the conditions for the determination of carbethopendecinium bromide with bromthymol blue and methyl orange (concentration of the drug and the colouring agent, pH of the aqueous phase, period of extraction with chloroform). Within a carbethopendecinium bromide concentration range of 1.10(-5) to 6.10(-5) mol/l, the linear dependence of absorbance of the ion-associate with the colouring agent on concentration was confirmed. At pH 3 and pH 10, the above-described procedure was used to determine the content of carbethopendecinium bromide in medicinal preparations (eye and nasal drops) using the calibration curve and comparison with one standard. The results were reproducible and the found deviations from the declared content ranged within a tolerance of +/- 10%.

  3. Kinetics adsorption study of the ethidium bromide by graphene oxide as adsorbent from aqueous matrices

    NASA Astrophysics Data System (ADS)

    Rajabi, M.; Moradi, O.; Zare, K.

    2017-01-01

    In this study of ethidium bromide, adsorption from aqueous matrices by graphene oxide as adsorbent was investigated. Influencing parameters in the adsorption study included contact time, temperature, and pH. The optimum time was selected 17 min, and the best value of pH was determined at 8. All adsorption experiments were performed at 298 K temperature. The maximum wavelength of ethidium bromide was 475 nm. The Elovich, four types of the pseudo-second-order, the pseudo-first-order, and intra-particle diffusion kinetic adsorption models were used for kinetic study, and the results show that adsorption of ethidium bromide on graphene oxide surface best complied with type (I) of the pseudo-second-order kinetic model.

  4. Seeded Growth of Monodisperse Gold Nanorods Using Bromide-Free Surfactant Mixtures

    SciTech Connect

    Ye, XC; Gao, YZ; Chen, J; Reifsnyder, DC; Zheng, C; Murray, CB

    2013-05-01

    We demonstrate for the first time that monodisperse gold nanorods (NRs) with broadly tunable dimensions and longitudinal surface plasmon resonances can be synthesized using a bromide-free surfactant mixture composed of alkyltrimethylammonium chloride and sodium oleate. It is found that uniform gold NRs can be obtained even with an iodide concentration approaching 100 mu M in the growth solution. In contrast to conventional wisdom, our results provide conclusive evidence that neither bromide as the surfactant counterion nor a high concentration of bromide ions in the growth solution is essential for gold NR formation. Correlated electron microscopy study of three-dimensional structures of gold NRs reveals a previously unprecedented octagonal prismatic structure enclosed predominantly by high index {310} crystal planes. These findings should have profound implications for a comprehensive mechanistic understanding of seeded growth of anisotropic metal nanocrystals.

  5. Salty glycerol versus salty water surface organization: bromide and iodide surface propensities.

    PubMed

    Huang, Zishuai; Hua, Wei; Verreault, Dominique; Allen, Heather C

    2013-07-25

    Salty NaBr and NaI glycerol solution interfaces are examined in the OH stretching region using broadband vibrational sum frequency generation (VSFG) spectroscopy. Raman and infrared (IR) spectroscopy are used to further understand the VSFG spectroscopic signature. The VSFG spectra of salty glycerol solutions reveal that bromide and iodide anions perturb the interfacial glycerol organization in a manner similar as that found in aqueous halide salt solutions, thus confirming the presence of bromide and iodide anions at the glycerol surface. Surface tension measurements are consistent with the surface propensity suggested by the VSFG data and also show that the surface excess increases with increasing salt concentration, similar to that of water. In addition, iodide is shown to have more surface prevalence than bromide, as has also been determined from aqueous solutions. These results suggest that glycerol behaves similarly to water with respect to surface activity and solvation of halide anions at its air/liquid interface.

  6. [Use of spasmolytic agent otilonium bromide (spasmomen) in digestive endoscopy: a prospective study in 63 patients].

    PubMed

    Gómez, N A; León, C J; Gutiérrez, J

    1997-01-01

    Otilonium bromide is a calcium antagonist with a direct myolytic effect, that is indicated in spastic conditions and functional dyskinesias of the gastroenteric apparatus (irritable bowel syndrome) and as a premedication for gastrointestinal endoscopic procedures. The present study assessed otilonium bromide 40 mg PO the night before and 40 mg PO the morning in 49 upper and 14 lower flexible endoscopies in 63 patients, to determine the presence or absence of peristalsis and relaxation of the pylorus. No side effects were observed due to the medication. In 46 (93.8%) upper endoscopies marked relaxation of the gastrointestinal tract and also pylorus relaxation were observed. In 13 (92.8%) lower endoscopies, marked relaxation of the colonic tract was also seen. All patients tolerated well the endoscopies. Otilonium bromide was useful as premedication in order to enable upper and lower endoscopic explorations, because of its spasmolytic effect.

  7. Efficient Planar Heterojunction Perovskite Solar Cells Based on Formamidinium Lead Bromide.

    PubMed

    Hanusch, Fabian C; Wiesenmayer, Erwin; Mankel, Eric; Binek, Andreas; Angloher, Philipp; Fraunhofer, Christina; Giesbrecht, Nadja; Feckl, Johann M; Jaegermann, Wolfram; Johrendt, Dirk; Bein, Thomas; Docampo, Pablo

    2014-08-21

    The development of medium-bandgap solar cell absorber materials is of interest for the design of devices such as tandem solar cells and building-integrated photovoltaics. The recently developed perovskite solar cells can be suitable candidates for these applications. At present, wide bandgap alkylammonium lead bromide perovskite absorbers require a high-temperature sintered mesoporous TiO2 photoanode in order to function efficiently, which makes them unsuitable for some of the above applications. Here, we present for the first time highly efficient wide bandgap planar heterojunction solar cells based on the structurally related formamidinium lead bromide. We show that this material exhibits much longer diffusion lengths of the photoexcited species than its methylammonium counterpart. This results in planar heterojunction solar cells exhibiting power conversion efficiencies approaching 7%. Hence, formamidinium lead bromide is a strong candidate as a wide bandgap absorber in perovskite solar cells.

  8. Reaction kinetics of the CN radical with methyl bromide

    NASA Astrophysics Data System (ADS)

    Hodny, Michael; Hershberger, John F.

    2016-02-01

    The kinetics of the CN + CH3Br reaction were studied using transient infrared laser absorption spectroscopy to detect CN reactants and HCN products. This reaction has a rate constant of k = (2.20 ± 0.6) × 10-12 exp (453 ± 98/T) cm3 molecule-1 s-1 over the range 298-523 K. Hydrogen abstraction to produce HCN + CH2Br is only a minor reaction product, with a branching fraction of 0.12 ± 0.02. Other product channels, including BrCN + CH3, CH2CN + HBr, CH3CN + Br are likely. An upper limit of 0.01 was established for the HBr yield. These results are in qualitative agreement with recent ab initio calculations.

  9. 4-Meth­oxy­benzamidinium bromide

    PubMed Central

    Irrera, Simona; Portalone, Gustavo

    2013-01-01

    The title salt, C8H11N2O+·Br−, was synthesized by the reaction between 4-meth­oxy­benzamidine (4-amidino­anisole) and hydro­bromic acid. In the cation, the amidinium group has two similar C—N bonds [1.304 (2) and 1.316 (2) Å], and its plane forms a dihedral angle of 31.08 (5)° with the benzene ring. The ions are associated in the crystal into a three-dimension hydrogen-bonded supra­molecular network featuring N—H+⋯Br− inter­actions. PMID:23476438

  10. Methyl bromide: ocean sources, ocean sinks, and climate sensitivity

    NASA Technical Reports Server (NTRS)

    Anbar, A. D.; Yung, Y. L.; Chavez, F. P.

    1996-01-01

    The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

  11. Methyl bromide: ocean sources, ocean sinks, and climate sensitivity

    NASA Technical Reports Server (NTRS)

    Anbar, A. D.; Yung, Y. L.; Chavez, F. P.

    1996-01-01

    The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

  12. Methyl bromide: ocean sources, ocean sinks, and climate sensitivity.

    PubMed

    Anbar, A D; Yung, Y L; Chavez, F P

    1996-03-01

    The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

  13. Otilonium bromide enhances sensory thresholds of volume and pressure in patients with irritable bowel syndrome.

    PubMed

    Czimmer, J; Süto, G; Király, A; Mózsik, G

    2001-01-01

    Visceral hyperalgesia has been suggested to play a role in the development of symptoms presented by irritable bowel syndrome patients. Otilonium bromide was developed to block smooth muscle Ca release to control cramping pain of these patients. to determine whether otilonium bromide can influence sensory thresholds of patients suffering from irritable bowel syndrome. 15 patients with Rome-II positive IBS were tested by Synectics Visceral Stimulator Barostat using rapid phasic distension (870 ml/min). The sensory threshold for first sensation, stool, pain and maximum tolerable volume and pressure were measured. All of the parameters were tested before and 1 week after the initiation of otilonium bromide (Spasmomen, Berlin Chemie, 3x40 mg) therapy. The perceptual thresholds for first sensation, stool, pain and maximum tolerable distention were, 8.8+/-1.7 Hgmm, 19.2+/-2.1 Hgmm, 26.3+/-2.8 Hgmm, 28.7+/-2.8 Hgmm for pressure, 90+/-21 ml, 145+/-28 ml, 208+/-25 ml, 213+/-28 ml for volume, before treatment, respectively. Otilonium bromide treatment did not influence the thresholds for first sensation and stool, 7.4+/-1.4 Hgmm, 20.7+/-4.6 Hgmm and 83+/-21 ml, 178+/-35.8 ml, respectively. The pressure threshold of pain was significantly higher 1 week after treatment (26.3+/-2.8 Hgmm vs. 29.1+/-5.5 Hgmm, P<0.05), but the volume threshold of this sensation remained unchanged (208+/-25 ml vs. 234+/-39 ml, not significant). The pressure (28.7+/-2.8 Hgmm vs. 38.1+/-3.4 Hgmm, P<0.05) and volume (213+/-28 ml vs. 278+/-27 ml, P<0.05) thresholds for maximum tolerable volume were increased by 7 days otilonium bromide treatment. These data suggest that otilonium bromide enhances sensory thresholds to recto-sigmoideal distention.

  14. Hydrogen supply system

    SciTech Connect

    Teitel, R.J.

    1981-11-24

    A system for supplying hydrogen to an apparatus which utilizes hydrogen contains a metal hydride hydrogen supply component and a microcavity hydrogen storage hydrogen supply component which in tandem supply hydrogen for the apparatus. The metal hydride hydrogen supply component includes a first storage tank filled with a composition which is capable of forming a metal hydride of such a nature that the hydride will release hydrogen when heated but will absorb hydrogen when cooled. This first storage tank is equipped with a heat exchanger for both adding heat to and extracting heat from the composition to regulate the absorption/deabsorption of hydrogen from the composition. The microcavity hydrogen storage hydrogen supply component includes a second tank containing the microcavity hydrogen supply. The microcavity hydrogen storage contains hydrogen held under high pressure within individual microcavities. The hydrogen is released from the microcavities by heating the cavities. This heating is accomplished by including within the tank for the microcavity hydrogen storage a heating element.

  15. Hydrogen sulphide.

    PubMed

    Guidotti, T L

    1996-10-01

    Hydrogen sulphide (H2S) is the primary chemical hazard in natural gas production in 'sour' gas fields. It is also a hazard in sewage treatment and manure-containment operations, construction in wetlands, pelt processing, certain types of pulp and paper production, and any situation in which organic material decays or inorganic sulphides exist under reducing conditions. H2S dissociates into free sulphide in the circulation. Sulphide binds to many macromolecules, among them cytochrome oxidase. Although this is undoubtedly an important mechanism of toxicity due to H2S, there may be others H2S provides little opportunity for escape at high concentrations because of the olfactory paralysis it causes, the steep exposure-response relationships, and the characteristically sudden loss of consciousness it can cause which is colloquially termed 'knockdown.' Other effects may include mucosal irritation, which is associated at lower concentrations with a keratoconjunctivitis called 'gas eye' and at higher concentrations with risk of pulmonary oedema. Chronic central nervous system sequelae may possibly follow repeated knockdowns: this is controversial and the primary effects of H2S may be confounded by anoxia or head trauma. Treatment is currently empirical, with a combination of nitrite and hyperbaric oxygen preferred. The treatment regimen is not ideal and carries some risk.

  16. Active Control of Interface Shape During the Crystal Growth of Lead Bromide

    NASA Technical Reports Server (NTRS)

    Duval, W. M. B.; Batur, C.; Singh, N. B.

    2003-01-01

    A thermal model for predicting and designing the furnace temperature profile was developed and used for the crystal growth of lead bromide. The model gives the ampoule temperature as a function of the furnace temperature, thermal conductivity, heat transfer coefficients, and ampoule dimensions as variable parameters. Crystal interface curvature was derived from the model and it was compared with the predicted curvature for a particular furnace temperature and growth parameters. Large crystals of lead bromide were grown and it was observed that interface shape was in agreement with the shape predicted by this model.

  17. Bromide, Chloride, and Sulfate Concentrations, and Specific Conductance, Lake Texoma, Texas and Oklahoma, 2007-08

    USGS Publications Warehouse

    Baldys, Stanley

    2009-01-01

    The U.S. Geological Survey, in cooperation with the City of Dallas Water Utilities Division, collected water-quality data from 11 sites on Lake Texoma, a reservoir on the Texas-Oklahoma border, during April 2007-September 2008. At 10 of the sites, physical properties (depth, specific conductance, pH, temperature, dissolved oxygen, and alkalinity) were measured and samples were collected for analysis of selected dissolved constituents (bromide, calcium, magnesium, potassium, sodium, carbonate, bicarbonate, chloride, and sulfate); at one site, only physical properties were measured. The primary constituent of interest was bromide. Bromate can form when ozone is used to disinfect raw water containing bromide, and bromate is a suspected human carcinogen. Chloride and sulfate were of secondary interest. Only the analytical results for bromide, chloride, sulfate, and measured specific conductance are discussed in this report. Median dissolved bromide concentrations ranged from 0.28 to 0.60 milligrams per liter. The largest median dissolved bromide concentration (0.60 milligram per liter at site 11) was from the Red River arm of Lake Texoma. Dissolved bromide concentrations generally were larger in the Red River arm of Lake Texoma than in the Washita arm of the lake. Median dissolved chloride concentrations were largest in the Red River arm of Lake Texoma at site 11 (431 milligrams per liter) and smallest at site 8 (122 milligrams per liter) in the Washita arm. At site 11 in the Red River arm, the mean and median chloride concentrations exceeded the secondary maximum contaminant level of 300 milligrams per liter for chloride established by the 'Texas Surface Water Quality Standards' for surface-water bodies designated for the public water supply use. Median dissolved sulfate concentrations ranged from 182 milligrams per liter at site 4 in the Big Mineral arm to 246 milligrams per liter at site 11 in the Red River arm. None of the mean or median sulfate concentrations

  18. Improved light olefin yield from methyl bromide coupling over modified SAPO-34 molecular sieves.

    PubMed

    Zhang, Aihua; Sun, Shouli; Komon, Zachary J A; Osterwalder, Neil; Gadewar, Sagar; Stoimenov, Peter; Auerbach, Daniel J; Stucky, Galen D; McFarland, Eric W

    2011-02-21

    As an alternative to the partial oxidation of methane to synthesis gas followed by methanol synthesis and the subsequent generation of olefins, we have studied the production of light olefins (ethylene and propylene) from the reaction of methyl bromide over various modified microporous silico-aluminophosphate molecular-sieve catalysts with an emphasis on SAPO-34. Some comparisons of methyl halides and methanol as reaction intermediates in their conversion to olefins are presented. Increasing the ratio of Si/Al and incorporation of Co into the catalyst framework improved the methyl bromide yield of light olefins over that obtained using standard SAPO-34.

  19. [Suppression of non-specific bronchial hyperreactivity by DSCG (Disodium cromoglycate) and ipratropium bromide (author's transl)].

    PubMed

    Götz, M; Popow, C

    1980-09-26

    The protective activity of DSCG was investigated in 18 children with established non-specific bronchial hyperreactivity induced by bronchial challenge with acetylcholine. Ipratropium bromide, the anticholinergic agent, was used for comparison. DSCG showed a statistically significant inhibitory action on the decrease in specific airway conductance. Besides the well-established inhibition of mast cell degranulation a direct action on cholinergic irritative receptors seems likely. Application of DSCG in immunologically ill-defined forms of bronchial asthma may be considered. As expected, the direct acetylcholine antagonist, ipratropium bromide, showed an overall protective effect.

  20. Structure and dynamics of cetyltrimethylammonium bromide water-in-oil microemulsions

    SciTech Connect

    Lang, J.; Zana, R. ); Mascolo, G.; Luisi, P.L. )

    1990-04-05

    The state of water, the droplet size, and interdroplet exchange of reactants between colliding droplets have been investigated by NMR, time-resolved fluorescence quenching, and electrical conductivity in water-in-oil microemulsions made of cetyltrimethylammonium bromide (CTAB) in chloroform/isooctane (2/1, v/v). The effect of the two additives cetyl bromide (CB) and trimethylamine (TMA) on the properties of the droplets has also been investigated. No interdroplet exchange of reactants has been detected in the absence of additives.

  1. Lithium bromide-induced structural changes in a nickel bis-alkoxide complex.

    PubMed

    Ichiokai, Hiromi; Vicic, David A

    2013-01-01

    The bis-alkoxide [(DEAMP)2Ni] (1, DEAMP = 1-(diethylamino)-2-methylpropan-2-olate) was found to react with trace amounts of lithium bromide to afford the bis-LiBr adduct 2, in which the oxygens of the DEAMP ligand coordinate to lithium to form a chiral-at-metal complex. This new complex is five-coordinate at nickel, and contains nickel and oxygen atoms which are all chiral. One diastereomer precipitates from pentane solution. The two lithium ions rigidify the new structure in the solid state by coordinating to the oxygen and bromide atoms.

  2. One-pot synthesis of 1-iodoalkynes and trisubstituted alkenes from benzylic and allylic bromides.

    PubMed

    Pelletier, Guillaume; Lie, Sharon; Mousseau, James J; Charette, André B

    2012-11-02

    1-Iodoalkynes are formed in moderate to high yields from readily accessible benzylic and allylic alkyl bromides by a one-pot homologation/double elimination procedure with iodoform (CHI(3)). The developed conditions include facile purification and avoid the use of an excess of triphenylphosphine (PPh(3)), as described in classical Corey-Fuchs iodoalkynylation conditions. Replacing CHI(3) with CHI(2)Cl allows the isolation of the corresponding gem-(Z)-chloro-(E)-iodoalkene in good yield and stereoselectivity. Moreover, the use of benzhydryl bromides as nucleophiles enables the synthesis of trisubstituted alkenes under similar reaction conditions.

  3. Breakdown of ionic character of molecular alkali bromides in inner-valence photoionization

    SciTech Connect

    Karpenko, A. Iablonskyi, D.; Kettunen, J. A.; Cao, W.; Huttula, M.; Aksela, H.; Urpelainen, S.

    2014-05-28

    The inner-valence region of alkali bromide XBr (X=Li, Na, K, Rb) vapours has been studied experimentally by means of synchrotron radiation excited photoelectron spectroscopy. Experimental spectra were analyzed by comparing them with available theoretical results and previous experiments. Ionic character of alkali bromides is seen to change in the inner-valence region with increasing atomic number of the alkali atom. A mechanism involving mixing between Br 4s and Rb 4p orbitals has been suggested to account for the fine structure observed in inner-valence ionization region of RbBr.

  4. Mechanism of the lanthanum bromide assisted electrochemical aldolization of. alpha. -bromo ketones

    SciTech Connect

    Fry, A.J.; Susla, M. )

    1989-04-26

    Linear sweep voltammetry, preparative electrolyses under a variety of experimental conditions, and trapping experiments have been used to explore the mechanism of the formation of the aldol 2-benzoyl-1-phenylpropanol by electrochemical reduction of {alpha}-bromopropiophenone in the presence of benzaldehyde and lanthanum bromide. The aldol condensation occurs by reaction of the free (lithio) enolate with a lanthanum bromide-benzaldehyde-tetrahydrofuran complex. Electrochemical reduction of the bromo ketone forms the Z enolate highly stereospecifically. The erythro aldol is formed stereoselectively initially, but the condensation is reversible, and the equilibrium mixture of aldols, containing mostly the threo isomer, is isolated from the electrolysis.

  5. Improved synthesis of aryltriethoxysilanes via palladium(0)-catalyzed silylation of aryl iodides and bromides with triethoxysilane.

    PubMed

    Manoso, A S; DeShong, P

    2001-11-02

    The scope of the palladium-catalyzed silylation of aryl halides with triethoxysilane has been expanded to include aryl bromides. A more general Pd(0) catalyst/ligand system has been developed that activates bromides and iodides: palladium(0) dibenzylideneacetone (Pd(dba)(2)) is activated with 2-(di-tert-butylphosphino)biphenyl (Buchwald's ligand) (1:2 mol ratio of Pd/phosphine). Electron-rich para- and meta-substituted aryl halides (including unprotected aniline and phenol derivatives) undergo silylation to form the corresponding aryltriethoxysilane in fair to excellent yield; however, ortho-substituted aryl halides failed to be silylated.

  6. In-Depth Assessment of the Palladium-Catalyzed Fluorination of Five-Membered Heteroaryl Bromides

    PubMed Central

    2015-01-01

    A thorough investigation of the challenging Pd-catalyzed fluorination of five-membered heteroaryl bromides is presented. Crystallographic studies and density functional theory (DFT) calculations suggest that the challenging step of this transformation is C–F reductive elimination of five-membered heteroaryl fluorides from Pd(II) complexes. On the basis of these studies, we have found that various heteroaryl bromides bearing phenyl groups in the ortho position can be effectively fluorinated under catalytic conditions. Highly activated 2-bromoazoles, such as 8-bromocaffeine, are also viable substrates for this reaction. PMID:27056379

  7. In-Depth Assessment of the Palladium-Catalyzed Fluorination of Five-Membered Heteroaryl Bromides.

    PubMed

    Milner, Phillip J; Yang, Yang; Buchwald, Stephen L

    2015-10-12

    A thorough investigation of the challenging Pd-catalyzed fluorination of five-membered heteroaryl bromides is presented. Crystallographic studies and density functional theory (DFT) calculations suggest that the challenging step of this transformation is C-F reductive elimination of five-membered heteroaryl fluorides from Pd(II) complexes. On the basis of these studies, we have found that various heteroaryl bromides bearing phenyl groups in the ortho position can be effectively fluorinated under catalytic conditions. Highly activated 2-bromoazoles, such as 8-bromocaffeine, are also viable substrates for this reaction.

  8. An efficient method for the preparation of tertiary esters by palladium-catalyzed alkoxycarbonylation of aryl bromides.

    PubMed

    Xin, Zhuo; Gøgsig, Thomas M; Lindhardt, Anders T; Skrydstrup, Troels

    2012-01-06

    The palladium-catalyzed alkoxycarbonylation of aryl bromides is described for the efficient preparation of tertiary esters. The protocol proved compatible with a wide variety of functionalized (hetero)aromatic bromides, as well as several different sterically hindered tertiary alcohols, affording the alkoxycarbonylated products in high yields. Finally, the formation of aromatic trityl esters is discussed. © 2011 American Chemical Society

  9. 75 FR 11549 - Determination That PRO-BANTHINE (Propantheline Bromide) Tablets and 14 Other Drug Products Were...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Determination That PRO-BANTHINE (Propantheline Bromide..., (propantheline Inc.,725 Chesterbrook bromide) Tablets, 7.5 Blvd., Wayne, PA milligrams (mg) and 15 19087) mg NDA...

  10. Composition for absorbing hydrogen

    DOEpatents

    Heung, L.K.; Wicks, G.G.; Enz, G.L.

    1995-05-02

    A hydrogen absorbing composition is described. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

  11. Composition for absorbing hydrogen

    DOEpatents

    Heung, Leung K.; Wicks, George G.; Enz, Glenn L.

    1995-01-01

    A hydrogen absorbing composition. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

  12. Photosensitized Production of Hydrogen by Hydrogenase in Reversed Micelles

    NASA Astrophysics Data System (ADS)

    Hilhorst, Riet; Laane, Colja; Veeger, Cees

    1982-06-01

    Hydrogenase (hydrogen:ferricytochrome c3 oxidoreductase, EC 1.12.2.1) from Desulfovibrio vulgaris was encapsulated in reversed micelles with cetyltrimethylammonium bromide as surfactant and a chloroform/octane mixture as solvent. Reducing equivalents for hydrogenase-catalyzed hydrogen production were provided by vectorial photosensitized electron transfer from a donor (thiophenol) in the organic phase through a surfactant-Ru2+ sensitizer located in the interphase to methyl viologen concentrated in the aqueous core of the reversed micelle. The results show that reversed micelles provide a microenvironment that (i) stabilizes hydrogenase against inactivation and (ii) allows an efficient vectorial photosensitized electron and proton flow from the organic phase to hydrogenase in the aqueous phase.

  13. A Few Facts about Hydrogen [and] Hydrogen Bibliography.

    ERIC Educational Resources Information Center

    Hinds, H. Roger

    Divided into two sections, this publication presents facts about and the characteristics of hydrogen and a bibliography on hydrogen. The first section lists nine facts on what hydrogen is, four on where hydrogen is found, nine on how hydrogen is used, nine on how hydrogen can be used, and 14 on how hydrogen is made. Also included are nine…

  14. TRIBROMOPYRROLE, BROMINATED ACIDS, AND OTHER DISINFECTION BYPRODUCTS PRODUCED BY DISINFECTION OF DRINKING WATER RICH IN BROMIDE

    EPA Science Inventory

    Using gas chromatography/mass spectrometry (GC/MS), we investigated the formation of disinfection byproducts (DBPs) from high bromide waters (2 mg/L) treated with chlorine or chlorine dioxide used in combination with chlorine and chloramines. This study represents the first comp...

  15. In situ Study of Bromide Tracer and Oxygen Flux in Coastal Sediments

    NASA Astrophysics Data System (ADS)

    Forster, S.; Glud, R. N.; Gundersen, J. K.; Huettel, M.

    1999-12-01

    Laboratory and in situ experiments were performed to assess the use of bromide as a tracer forin situ studies of benthic solute exchange. Bromide was used in the benthic chamber lander ' Elinor ' for flux measurements in coastal sediments of the German Bight, Kiel Bight and Skagerrak (28-700 m water depth). Tracer and total oxygen uptake were monitored simultaneously in the same chamber incubation. Concurrently, in situ oxygen micro-profiles were recorded at the same locations by the profiling lander ' Profilur '. Deployment in an anoxic silt (Kiel Bight) confirmed that in the absence of bioturbation and advection, tracer transport into the sediment was driven solely by molecular diffusion. This flux could be well described by a simple box model accounting for molecular diffusion only. In oxic sediments (German Bight and Skagerrak) enhanced exchange of bromide tracer due to bioirrigation parallelled enhanced oxygen uptake equivalent to a 4-fold molecular diffusive flux. Our experiments showed that incubations can be short. Depending on irrigation activity of the fauna, however, incubation length should exceed 3 h in order to provide a useful data base for flux calculations. The method demonstrating caveats is discussed and indicate possible improvements. The results show how the bromide tracer addition can be used as a tool for determining solute fluxes exceeding diffusive flux in benthic chamber incubations.

  16. Iron-catalyzed cross-coupling of N-heterocyclic chlorides and bromides with arylmagnesium reagents.

    PubMed

    Kuzmina, Olesya M; Steib, Andreas K; Flubacher, Dietmar; Knochel, Paul

    2012-09-21

    A simple, practical iron salt catalyzed procedure allows fast cross-couplings of N-heterocyclic chlorides and bromides with various electron-rich and -poor arylmagnesium reagents. A solvent mixture of THF and tBuOMe is found to be essential for achieving high yields mainly by avoiding homocoupling side reactions.

  17. Headspace gas chromatographic method for determination of methyl bromide in food ingredients

    SciTech Connect

    DeVries, J.W.; Broge, J.M.; Schroeder, J.P.; Bowers, R.H.; Larson, P.A.; Burns, N.M.

    1985-11-01

    A headspace gas chromatographic (GC) method, which can be automated, has been developed for determination of methyl bromide. This method has been applied to wheat, flour, cocoa, and peanuts. Samples to be analyzed are placed in headspace sample vials, water is added, and the vials are sealed with Teflon-lined septa. After an appropriate equilibration time at 32 degrees C, the samples are analyzed within 10 h. A sample of the headspace is withdrawn and analyzed on a gas chromatograph equipped with an electron capture detector (ECD). Methyl bromide levels were quantitated by comparison of peak area with a standard. The standard was generated by adding a known amount of methyl bromide to a portion of the matrix being analyzed and which was known to be methyl bromide free. The detection limit of the method was 0.4 ppb. The coefficient of variation (CV) was 6.5% for wheat, 8.3% for flour, 3.3% for cocoa, and 11.6% for peanuts.

  18. The history and future of methyl bromide alternatives in the southern United States

    Treesearch

    Tom E. Starkey

    2012-01-01

    This article gives a brief history of the efforts of the Southern Forest Nursery Management Cooperative (SFNMC) in testing methyl bromide (MBr) alternatives for soil fumigation. In the southeastern United States, fumigation with MBr has been the most commonly used method for producing high quality, pest-free forest seedlings in an environment that is conducive for soil...

  19. An improved palladium-catalyzed conversion of aryl and vinyl triflates to bromides and chlorides.

    PubMed

    Pan, Jun; Wang, Xinyan; Zhang, Yong; Buchwald, Stephen L

    2011-09-16

    A facile Pd-catalyzed conversion of aryl and vinyl triflates to aryl and vinyl halides (bromides and chlorides) is described. This method allows convenient access to a variety of aryl, heteroaryl, and vinyl halides in good to excellent yields and with greatly simplified conditions relative to our previous report. © 2011 American Chemical Society

  20. An Improved Palladium-Catalyzed Conversion of Aryl and Vinyl Triflates to Bromides and Chlorides

    PubMed Central

    Pan, Jun; Wang, Xinyan; Zhang, Yong; Buchwald, Stephen L.

    2011-01-01

    A facile Pd-catalyzed conversion of aryl and vinyl triflates to aryl and vinyl halides (bromides and chlorides) is described. This method allows convenient access to a variety of aryl, heteroaryl, and vinyl halides in good to excellent yields and with greatly simplified conditions relative to our previous report. PMID:21863838

  1. Highly efficient synthesis of phenols by copper-catalyzed hydroxylation of aryl iodides, bromides, and chlorides.

    PubMed

    Yang, Kai; Li, Zheng; Wang, Zhaoyang; Yao, Zhiyi; Jiang, Sheng

    2011-08-19

    8-Hydroxyquinolin-N-oxide was found to be a very efficient ligand for the copper-catalyzed hydroxylation of aryl iodides, aryl bromides, or aryl chlorides under mild reaction conditions. This methodology provides a direct transformation of aryl halides to phenols and to alkyl aryl ethers. The inexpensive catalytic system showed great functional group tolerance and excellent selectivity. © 2011 American Chemical Society

  2. Efficient palladium-catalyzed coupling reactions of aryl bromides and chlorides with phenols.

    PubMed

    Hu, Tongjie; Schulz, Thomas; Torborg, Christian; Chen, Xiaorong; Wang, Jun; Beller, Matthias; Huang, Jun

    2009-12-21

    A convenient and general palladium-catalyzed coupling reaction of aryl bromides and chlorides with phenols was developed. Various functional groups such as nitriles, aldehydes, ketones and esters are well tolerated and the corresponding products are obtained in good to excellent yield.

  3. Palladium-catalyzed carbonylative synthesis of quinazolinones from 2-aminobenzamide and aryl bromides.

    PubMed

    Wu, Xiao-Feng; He, Lin; Neumann, Helfried; Beller, Matthias

    2013-09-16

    C from CO! A straightforward procedure for the carbonylative synthesis of quinazolinones from readily available 2-aminobenzamide and aryl bromides has been developed. In the presence of a palladium catalyst, various quinazolinones were produced in moderate to excellent yields. Remarkably, no chromatography was needed for purification (see scheme).

  4. Unexpected formation of aryl ketones by palladium-catalyzed coupling of aryl bromides with vinylic acetates.

    PubMed

    Jean, Mickaël; Renault, Jacques; Uriac, Philippe; Capet, Marc; van de Weghe, Pierre

    2007-08-30

    A palladium-catalyzed coupling reaction of aryl bromides with vinylic acetates in the presence of tributyltin methoxide has been described. Unexpected formation of aryl ketones was obtained. Preliminary mechanistic studies indicated that the reaction proceeded by the addition of the aryl moiety in the coordination sphere of palladium to a ketene.

  5. Study of the antibacterial and antifungal activities of synthetic benzyl bromides, ketones, and corresponding chalcone derivatives.

    PubMed

    Shakhatreh, Muhamad Ali K; Al-Smadi, Mousa L; Khabour, Omar F; Shuaibu, Fatima A; Hussein, Emad I; Alzoubi, Karem H

    2016-01-01

    Several applications of chalcones and their derivatives encouraged researchers to increase their synthesis as an alternative for the treatment of pathogenic bacterial and fungal infections. In the present study, chalcone derivatives were synthesized through cross aldol condensation reaction between 4-(N,N-dimethylamino)benzaldehyde and multiarm aromatic ketones. The multiarm aromatic ketones were synthesized through nucleophilic substitution reaction between 4-hydroxy acetophenone and benzyl bromides. The benzyl bromides, multiarm aromatic ketones, and corresponding chalcone derivatives were evaluated for their activities against eleven clinical pathogenic Gram-positive, Gram-negative bacteria, and three pathogenic fungi by the disk diffusion method. The minimum inhibitory concentration was determined by the microbroth dilution technique. The results of the present study demonstrated that benzyl bromide derivatives have strong antibacterial and antifungal properties as compared to synthetic chalcone derivatives and ketones. Benzyl bromides (1a and 1c) showed high ester activity against Gram-positive bacteria and fungi but moderate activity against Gram-negative bacteria. Therefore, these compounds may be considered as good antibacterial and antifungal drug discovery. However, substituted ketones (2a-b) as well as chalcone derivatives (3a-c) showed no activity against all the tested strains except for ketone (2c), which showed moderate activity against Candida albicans.

  6. Microwave-enhanced cross-coupling reactions involving alkynyltrifluoroborates with aryl bromides.

    PubMed

    Coltuclu, Vitali; Dadush, Eric; Naravane, Abhijit; Kabalka, George W

    2013-01-29

    Palladium-catalyzed alkynylation has emerged as one of the most reliable methods for the synthesis of alkynes which are often used in natural product syntheses and material science. An efficient method for coupling alkynyltrifluoroborates with various aryl bromides in the presence of a palladium catalyst has been developed using microwave irradiation. The microwave reactions are rapid and efficient.

  7. Palladium-catalyzed conversion of aryl and vinyl triflates to bromides and chlorides.

    PubMed

    Shen, Xiaoqiang; Hyde, Alan M; Buchwald, Stephen L

    2010-10-13

    The palladium-catalyzed conversion of aryl and vinyl triflates to aryl and vinyl halides (bromides and chlorides) has been developed using dialkylbiaryl phosphine ligands. A variety of aryl, heteroaryl, and vinyl halides can be prepared via this method in good to excellent yields.

  8. Nickel-catalyzed sonogashira reactions of non-activated secondary alkyl bromides and iodides.

    PubMed

    Yi, Jun; Lu, Xi; Sun, Yan-Yan; Xiao, Bin; Liu, Lei

    2013-11-18

    A nicked reaction: The title reaction of terminal alkynes with non-activated secondary alkyl iodides and bromides was accomplished for the first time. This reaction provides a new and practical approach for the synthesis of substituted alkynes (see scheme; cod=cyclo-1,5-octadiene). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Palladium-Catalyzed Conversion of Aryl and Vinyl Triflates to Bromides and Chlorides

    PubMed Central

    Shen, Xiaoqiang; Hyde, Alan M.; Buchwald, Stephen L.

    2010-01-01

    The palladium-catalyzed conversion of aryl and vinyl triflates to aryl and vinyl halides (bromides and chlorides) has been developed using dialkylbiaryl phosphine ligands. A variety of aryl, heteroaryl and vinyl halides can be prepared via this method in good to excellent yields. PMID:20857936

  10. EVALUATION OF CONTAINMENT AND CONTROL OPTIONS FOR METHYL BROMIDE IN COMMODITY TREATMENT

    EPA Science Inventory

    The report gives results of an investigation of means for methyl bromide (MeBr) recovery, reuse, and destruction to prevent atmospheric emissions if its limited use were still allowed. (NOTE: MeBr is an ozone-depleting chemical scheduled to be phased out by the Clean Air Act by t...

  11. Palladium-catalyzed carbonylation reaction of aryl bromides with 2-hydroxyacetophenones to form flavones.

    PubMed

    Wu, Xiao-Feng; Neumann, Helfried; Beller, Matthias

    2012-10-01

    Flavone of the month: a general and efficient method for the palladium-catalyzed carbonylative synthesis of flavones has been developed. Starting from aryl bromides and 2-hydroxyacetophenones, the corresponding flavones have been isolated in good yields. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Valence photoelectron spectra of alkali bromides calculated within the propagator theory.

    PubMed

    Karpenko, Alexander; Iablonskyi, Denys; Aksela, Helena

    2013-04-28

    The valence ionization spectra covering the binding energy range 0-45 eV of alkali bromide XBr (X = Li, Na, K, Rb) vapors are studied within the framework of the propagator theory. Relativistic Algebraic Diagrammatic Construction calculations have been carried out in order to investigate photoionization processes and to describe molecular electronic structure. Theoretical results are compared with available experimental data.

  13. Eradicating European pine shoot moth on ornamental pines with methyl bromide.

    Treesearch

    V.M. Carolin; W.H. Klein; R.M. Thompson

    1962-01-01

    The recent introduction of the European pine shoot moth into this region poses a serious threat to natural pine stands. To combat this threat, quarantines were invoked and eradication programs undertaken. Destruction of infested trees has been used tentatively as an eradication technique. In the meantime, fumigation with methyl bromide was tested over the period of a...

  14. EPA Takes Action Against Illegal Methyl Bromide Use in Puerto Rico

    EPA Pesticide Factsheets

    (New York, N.Y.) As part of its ongoing work to address the illegal use of toxic pesticides containing methyl bromide in the Caribbean, the U.S. Environmental Protection Agency has issued legal complaints against two individuals and a pest control company

  15. 76 FR 34700 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... AGENCY Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications... FURTHER INFORMATION CONTACT: General Information: U.S. EPA Stratospheric Ozone Information Hotline, 1-800-296-1996; also http://www.epa.gov/ozone/mbr . Technical Information: Bill Chism, U.S....

  16. Methyl bromide release from activated carbon and the soil/water/carbon interface

    USDA-ARS?s Scientific Manuscript database

    Methyl Bromide (MB) is a major source of stratospheric bromine radical, a known depletor of ozone. The use of ozone-depleting chemicals, including MB, is regulated by the Montreal Protocol. Critical uses of MB are permitted, such as when postharvest fumigation is mandated by an importing country. Fo...

  17. Steam disinfestation as a methyl bromide alternative in California cut flower nurseries

    USDA-ARS?s Scientific Manuscript database

    Steam may be an effective alternative to methyl bromide in cut flower production in California. Advantages of steam include broad spectrum pest control and a zero hour re-entry interval. The principle disadvantage of sheet steaming is cost effectiveness due to current energy prices and application...

  18. SYBR safe(TM) efficiently replaces ethidium bromide in Aspergillus fumigatus gene disruption.

    PubMed

    Canela, H M S; Takami, L A; Ferreira, M E S

    2017-02-08

    Invasive aspergillosis is a disease responsible for high mortality rates, caused mainly by Aspergillus fumigatus. The available drugs are limited and this disease continues to occur at an unacceptable frequency. Gene disruption is essential in the search for new drug targets. An efficient protocol for A. fumigatus gene disruption was described but it requires ethidium bromide, a genotoxic agent, for DNA staining. Therefore, the present study tested SYBR safe(TM), a non-genotoxic DNA stain, in A. fumigatus gene disruption protocol. The chosen gene was cipC, which has already been disrupted successfully in our laboratory. A deletion cassette was constructed in Saccharomyces cerevisiae and used in A. fumigatus transformation. There was no statistical difference between the tested DNA stains. The success rate of S. cerevisiae transformation was 63.3% for ethidium bromide and 70% for SYBR safe(TM). For A. fumigatus gene disruption, the success rate for ethidium bromide was 100 and 97% for SYBR safe(TM). In conclusion, SYBR safe(TM) efficiently replaced ethidium bromide, making this dye a safe and efficient alternative for DNA staining in A. fumigatus gene disruption.

  19. Experimental study of negative temperatures in lithium-bromide absorption refrigerating machines

    NASA Astrophysics Data System (ADS)

    Stepanov, K. I.; Mukhin, D. G.; Alekseenko, S. V.; Volkova, O. V.

    2015-07-01

    The authors have developed a method and presented experimental data for obtaining negative temperatures of evaporation in lithium-bromide absorption chillers driven by heat recovery. It has been found that the attainable temperature of the refrigerated medium is the value of -5 °C.

  20. Ultraviolet absorption cross-sections of methyl bromide at stratospheric temperatures

    NASA Astrophysics Data System (ADS)

    Gillotay, D.; Simon, P. C.

    1988-04-01

    The absorption cross-sections of methyl bromide (CH3Br) are measured between 180 nm and 260 nm at temperatures of 295 K, 255 K, 227 K, and 209 K. A parametrical formula is proposed to compute the absorption cross-sections for wavelengths between 200 nm and 260 nm and for temperatures between 210 K and 300 K.

  1. Ninety-Day Subchronic Oral Toxicity Study of Pyridostigmine Bromide in Rats. Volume 1

    DTIC Science & Technology

    1990-05-01

    myasthenia gravis because of its relative lack of untoward effects in comparison with other anticholinesterases (2). This relative lack of clinical...treatment of myasthenia gravis . Objecrive of Study The objective of this study was to determine the 90-day subchronic toxicity of pyridostigmine bromide in

  2. Strontium and bromide as tracers in X-ray microanalysis of biological tissue

    SciTech Connect

    Wroblewski, J.; Sagstroem, S.M.; Mulders, H.; Roomans, G.M. )

    1989-09-01

    Since energy dispersive X-ray microanalysis cannot distinguish between isotopes of the same element, alternative methods have to be used to get information similar to that obtained in experiments with radioactive tracers. In the present study, strontium was used as a tracer for calcium, and bromide as a tracer for chloride. Rats were injected with strontium chloride in vivo, and the uptake of strontium in the acinar cells of the submandibular gland was studied. Eventually a Sr/Ca ratio of 0.3 was reached. In some animals, secretion of mucus had been elicited by stimulation with isoproterenol 4 h prior to injection of strontium chloride. Exchange of calcium for strontium was enhanced by prior injection with isoproterenol. In a second experiment, rats were injected with sodium bromide, and the uptake of bromide by the submandibular acinar cells was followed in time, both in pilocarpine-stimulated and unstimulated glands. Under the experimental conditions, bromide was rapidly taken up by the cells, and the cellular Br/Cl ratio was close to that found in serum. Submandibular glands take up Br somewhat faster than other tissues (liver, heart muscle, skeletal muscle). The uptake of Br in pancreatic acinar cells was studied in vitro. These experiments showed a 1:1 ratio (molar) exchange of Cl for Br.

  3. IDENTIFICATION OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS FORMED IN THE PRESENCE OF BROMIDE

    EPA Science Inventory

    Using a combination of mass spectrometry and infrared spectroscopy, disinfection by-products (DBPs) were identified in ozonated drinking water containing elevated bromide levels, and in ozonated water treated with secondary chlorine or chloramine. Only one brominated by-product-d...

  4. IDENTIFICATION OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS FORMED IN THE PRESENCE OF BROMIDE

    EPA Science Inventory

    Using a combination of mass spectrometry and infrared spectroscopy, disinfection by-products (DBPs) were identified in ozonated drinking water containing elevated bromide levels, and in ozonated water treated with secondary chlorine or chloramine. Only one brominated by-product-d...

  5. Methyl bromide and sulfuryl fluoride effectiveness against red flour beetle life stages

    USDA-ARS?s Scientific Manuscript database

    The efficacy of methyl bromide (MB) and sulfuryl fluoride (SF) for managing all life stages of the red flour beetle, Tribolium castaneum, was investigated in the Hal Ross Flour Mill at Kansas State University. Eggs, young larvae, large larvae, pupae, and adults confined in plastic compartments with ...

  6. Comments on alternatives to methyl bromide for quarantine purposes in forest nurseries

    Treesearch

    David B. South

    2008-01-01

    Viewpoints will vary in regards to the best alternative to methyl bromide (CH3Br) fumigation. In some cases, crop value will determine the best alternative. As the value of the crop increases, the rate (and cost) of the "best" treatment might increase as well. In addition, the recommendation will depend on if the individual has a "...

  7. Study of the antibacterial and antifungal activities of synthetic benzyl bromides, ketones, and corresponding chalcone derivatives

    PubMed Central

    Shakhatreh, Muhamad Ali K; Al-Smadi, Mousa L; Khabour, Omar F; Shuaibu, Fatima A; Hussein, Emad I; Alzoubi, Karem H

    2016-01-01

    Several applications of chalcones and their derivatives encouraged researchers to increase their synthesis as an alternative for the treatment of pathogenic bacterial and fungal infections. In the present study, chalcone derivatives were synthesized through cross aldol condensation reaction between 4-(N,N-dimethylamino)benzaldehyde and multiarm aromatic ketones. The multiarm aromatic ketones were synthesized through nucleophilic substitution reaction between 4-hydroxy acetophenone and benzyl bromides. The benzyl bromides, multiarm aromatic ketones, and corresponding chalcone derivatives were evaluated for their activities against eleven clinical pathogenic Gram-positive, Gram-negative bacteria, and three pathogenic fungi by the disk diffusion method. The minimum inhibitory concentration was determined by the microbroth dilution technique. The results of the present study demonstrated that benzyl bromide derivatives have strong antibacterial and antifungal properties as compared to synthetic chalcone derivatives and ketones. Benzyl bromides (1a and 1c) showed high ester activity against Gram-positive bacteria and fungi but moderate activity against Gram-negative bacteria. Therefore, these compounds may be considered as good antibacterial and antifungal drug discovery. However, substituted ketones (2a–b) as well as chalcone derivatives (3a–c) showed no activity against all the tested strains except for ketone (2c), which showed moderate activity against Candida albicans. PMID:27877017

  8. Effect of increasing bromide concentration on toxicity in treated drinking water.

    PubMed

    Sawade, Emma; Fabris, Rolando; Humpage, Andrew; Drikas, Mary

    2016-04-01

    Research is increasingly indicating the potential chronic health effects of brominated disinfection by-products (DBPs). This is likely to increase with elevated bromide concentrations resulting from the impacts of climate change, projected to include extended periods of drought and the sudden onset of water quality changes. This will demand more rigorous monitoring throughout distribution systems and improved water quality management at water treatment plants (WTPs). In this work the impact of increased bromide concentration on formation of DBPs following conventional treatment and chlorination was assessed for two water sources. Bioanalytical tests were utilised to determine cytotoxicity of the water post disinfection. Coagulation was shown to significantly reduce the cytotoxicity of the water, indicating that removal of natural organic matter DBP precursors continues to be an important factor in drinking water treatment. Most toxic species appear to form within the first half hour following disinfectant addition. Increasing bromide concentration across the two waters was shown to increase the formation of trihalomethanes and shifted the haloacetic acid species distribution from chlorinated to those with greater bromine substitution. This correlated with increasing cytotoxicity. This work demonstrates the challenges faced by WTPs and the possible effects increasing levels of bromide in source waters could have on public health.

  9. Charging of silver bromide aqueous interface: evaluation of interfacial equilibrium constants from surface potential data.

    PubMed

    Preočanin, Tajana; Supljika, Filip; Kallay, Nikola

    2010-06-01

    A single crystal silver bromide electrode (SCr-AgBr) was used to measure the inner surface potential (Ψ(0)) at the silver bromide aqueous electrolyte interface as a function of the activities of Br(-) and Ag(+). Absolute values of the surface potential were calculated from electrode potentials of SCr-AgBr using the value of point of zero charge (pBr(pzc)=6.9 [H.A. Hoyen, R.M. Cole, J. Colloid Interface Sci. 41 (1972) 93.]) as the value of point of zero potential. Measurements were performed in potassium nitrate aqueous solutions. The Ψ(0)(pBr) function was linear and slightly dependent on the ionic strength. The reduction values of the slope with respect to the Nernst equation, expressed by the α coefficient, were 0.880,0.935, and 0.950 at ionic strengths of 10(-4), 10(-3), and 10(-2) mol dm(-3), respectively. The results were successfully interpreted by employing the surface complexation model, developed originally for metal oxides and adapted for silver halides. The thermodynamic ("intrinsic") equilibrium constants for binding of bromide (K(n)(∘)) and silver (K(p)(∘)) ions on the corresponding sites at the silver bromide surface were evaluated as lgK(n)(∘)=3.98; lgK(p)(∘)=2.48. Symmetrical counterion surface association was assumed and equilibrium constants were obtained as lgK(NO(3)(-))(∘)=lgK(K(+))(∘)=4.30.

  10. The use of agricultural by-products to capture methyl bromide following post-harvest fumigation

    USDA-ARS?s Scientific Manuscript database

    Activated carbons were prepared from plum and peach stone as well as almond and walnut shell and comparatively evaluated as sorbents to minimize the atmospheric emission of methyl bromide following postharvest fumigations. A variety of methods were used to make the activated carbons and each is desc...

  11. Chlorine utilization during trihalomethane formation in the presence of ammonia and bromide

    SciTech Connect

    Amy, G.L.; Chadik, P.A.; King, P.H.; Cooper, W.J.

    1984-10-01

    The chlorination of humic substances in the presence of ammonia and bromide and the resultant formation of trihalomethanes (THM) are described. The presence of ammonia substantially reduced but did not eliminate THM production during the chlorination of waters containing humic substances. The presence of bromide ion in waters containing humic substances leads to increased THM formation, both in the presence and in the absence of ammonia. In waters containing ammonia, bromide, and humic substances, brominated haloforms can form upon chlorination. Brominated species comprise a larger portion of the total THMs at higher chlorine doses within the free chlorine region of the breakpoint curve than at lower dose in the subbreakpoint region. Although the THM formation reaction is slow and may not be complete even after 1 week of reaction time, the initial rate of formation is competitive with the relatively rapid reactions of bromide oxidation and chloramine formation. After free chlorine is converted to chloramines, THM production should theoretically cease. THMs will form in parallel with chloramine formation. This behavior has important implications for water utilities that use a raw water source containing low but significant levels of ammonia such as the Biscayne Aquifer, or are considering chloramine disinfection as a THM control strategy.

  12. Removal of methyl bromide in coastal seawater: Chemical and biological rates

    NASA Astrophysics Data System (ADS)

    King, Daniel B.; Saltzman, Eric S.

    1997-08-01

    A stable isotope tracer technique was used to investigate the loss rate of methyl bromide in surface ocean waters. Unfiltered and 0.2 μm-filtered or autoclaved aliquants of Biscayne Bay seawater samples were spiked with 13CH3Br at roughly 10-100 times ambient concentrations (50-800 pM) and incubated for 10-30 hours. The concentration of 13CH3Br was monitored using gas chromatography with isotope dilution mass spectrometry, with CD3Br as the isotope spike. Removal rates in unfiltered aliquants were significantly faster than in the 0.2 μm-filtered or autoclaved aliquants, indicating that some of the loss of methyl bromide was associated with particulate matter. Filtration experiments indicate that the particulate material responsible for methyl bromide loss is between 0.2 and 1.2 μm in diameter, suggesting that bacteria are likely to be responsible. The particulate-related removal of methyl bromide was inhibited by autoclaving, supporting a biological mechanism.

  13. Reduced rates and alternatives to methyl bromide for snapdragon production in Florida

    USDA-ARS?s Scientific Manuscript database

    A field trial was conducted to evaluate soil solarization, Midas™ (iodomethane:chloropicrin 50:50, Arysta LifeScience Corp., Cary, NC) and different rates and formulations of methyl bromide under standard and metalized films for the production of snapdragon (Antirrhinum majus) in Martin County, Flor...

  14. OZONATION BYPRODUCTS: IDENTIFICATION OF BROMOHYDRINS FROM THE OZONATION OF NATURAL WATERS WITH ENHANCED BROMIDE LEVELS

    EPA Science Inventory

    When ozone is used in the treatment of drinking water, it reacts with both inorganic and organic compounds to form byproducts. f bromide is present, it may be oxidized to hydrobromous acid, which may than react with natural organic matter to form brominated organic compounds. he ...

  15. Methods to facilitate the adoption of alternatives to methyl bromide soil fumigation by California strawberry growers

    USDA-ARS?s Scientific Manuscript database

    The goal of this project is to facilitate the adoption of strawberry production systems that do not use methyl bromide (MB). The five year project initially focused on fumigant alternatives to MB. The project has resulted in increased use of barrier films that reduce fumigant emission. The focus s...

  16. Synthesis of Vinyl Trifluoromethyl Thioethers via Copper-Mediated Trifluoromethylthiolation of Vinyl Bromides.

    PubMed

    Huang, Yangjie; Ding, Jianping; Wu, Chuyi; Zheng, Huidong; Weng, Zhiqiang

    2015-03-06

    A copper-mediated trifluoromethylthiolation of vinyl bromides has been developed. This method provides ready access to vinyl trifluoromethyl thioethers in good to high yields from simple, inexpensive starting materials. A broad substrate scope is achieved, and the reaction is compatible with various functional groups, including cyano, nitro, trifluoromethyl, alkoxy, amino, halide, and heterocyclic groups.

  17. Forest nurseries face critical choices with the loss of methyl bromide fumigation

    USDA-ARS?s Scientific Manuscript database

    Forest nurseries in the western United States have relied for decades on methyl bromide for the control of soilborne pathogens such as Cylindrocarpoin, Fusarium, and Pythium species that affect bareroot tree seedling production. However, increased state and federal regulations have led to a substan...

  18. Methyl Bromide Alternatives Area-Wide Pest Management Project - South Atlantic Progress Report

    USDA-ARS?s Scientific Manuscript database

    Protocols and Standard Operational Procedures (SOPs) were developed for collecting environmental and soil edaphic information during and after application of methyl bromide alternatives. Parameters measured included soil moisture, soil bulk density, percent moisture at field capacity (-0.3 bars wat...

  19. Practical Cross-Coupling between O-Based Electrophiles and Aryl Bromides via Ni Catalysis.

    PubMed

    Cao, Zhi-Chao; Luo, Qin-Yu; Shi, Zhang-Jie

    2016-12-02

    Cross-coupling of various O-based electrophiles with aryl bromides was developed through Ni-catalyzed C-O activation in the presence of magnesium. Beside carboxylates, carbamates, and ethers, phenols exhibited excellent reactivity under modified conditions. This chemistry was featured as a simple and environmentally benign process with low catalyst loading and easy manipulations. The method exhibited broad substrate scopes.

  20. EVALUATION OF CONTAINMENT AND CONTROL OPTIONS FOR METHYL BROMIDE IN COMMODITY TREATMENT

    EPA Science Inventory

    The report gives results of an investigation of means for methyl bromide (MeBr) recovery, reuse, and destruction to prevent atmospheric emissions if its limited use were still allowed. (NOTE: MeBr is an ozone-depleting chemical scheduled to be phased out by the Clean Air Act by t...

  1. Effects exerted by otilonium bromide administration on precipitated opioid withdrawal syndrome in rats.

    PubMed

    Pinelli, A; Trivulzio, S; Vignati, S

    1997-09-26

    An opioid withdrawal syndrome was induced in rats by repeated morphine administration and final naloxone injection. The withdrawal causes alteration of several physiological signs. The aim of the study was to prevent the altered physiological profiles by utilising otilonium bromide. Morphine was administered in three daily i.p. injections for 4 days at doses of 9, 16 and 25 mg/kg (1st day), 25, 25 and 50 mg/kg (2nd day), 50, 50 and 50 mg/kg (3rd day) and 50, 50 and 100 mg/kg (4th day). Naloxone was injected (30 mg/kg) i.p. 180 min after the last morphine injection. Otilonium bromide was administered orally at 0, 2, 4 and 8 mg/kg, 120 min before the naloxone administration. Signs like faecal and urine excretion, rectal temperature and pain threshold levels, salivation, jumping and wet dog shakes were affected in different ways. Notably the administration of otilonium bromide in rats receiving morphine together with naloxone decreased the intensity of certain withdrawal symptoms, such as excretion of faeces, wet dog shake behaviour, and elevated the nociceptive threshold values. The effects exhibited by otilonium bromide administration may be explained through its calcium antagonist activity interfering with a mechanism involved in the regulation of these previously mentioned withdrawal symptoms. The use of this drug is thus suggested as a possible control of some acute opioid withdrawal signs in heroin addicts.

  2. Otilonium bromide inhibits calcium entry through L-type calcium channels in human intestinal smooth muscle.

    PubMed

    Strege, P R; Evangelista, S; Lyford, G L; Sarr, M G; Farrugia, G

    2004-04-01

    Otilonium bromide (OB) is used as an intestinal antispasmodic. The mechanism of action of OB is not completely understood. As Ca(2+) entry into intestinal smooth muscle is required to trigger contractile activity, our hypothesis was that OB blocked Ca(2+) entry through L-type Ca(2+) channels. Our aim was to determine the effects of OB on Ca(2+), Na(+) and K(+) ion channels in human jejunal circular smooth muscle cells and on L-type Ca(2+) channels expressed heterologously in HEK293 cells. Whole cell currents were recorded using standard patch clamp techniques. Otilonium bromide (0.09-9 micromol L(-1)) was used as this reproduced clinical intracellular concentrations. In human circular smooth muscle cells, OB inhibited L-type Ca(2+) current by 25% at 0.9 micromol L(-1) and 90% at 9 micromol L(-1). Otilonium bromide had no effect on Na(+) or K(+) currents. In HEK293 cells, 1 micromol L(-1) OB significantly inhibited the expressed L-type Ca(2+) channels. Truncation of the alpha(1C) subunit C and N termini did not block the inhibitory effects of OB. Otilonium bromide inhibited Ca(2+) entry through L-type Ca(2+) at concentrations similar to intestinal tissue levels. This effect may underlie the observed muscle relaxant effects of the drug.

  3. Simultaneous determination of otilonium bromide and diazepam by first-derivative spectroscopy.

    PubMed

    Mannucci, C; Bertini, J; Cocchini, A; Perico, A; Salvagnini, F; Triolo, A

    1992-12-01

    A rapid, simple assay procedure was developed for simultaneous analysis of otilonium bromide, a smooth-muscle relaxant, and diazepam in tablets containing 20 mg of otilonium bromide and 2 mg of diazepam (20:2 tablets) or 40 mg of otilonium bromide and 2 mg of diazepam (40:2 tablets) by "zero-crossing" first-derivative spectroscopy. The tablets were dissolved in 0.01 N HCl, mixtures were centrifuged at 3500 rpm (2472 x g) for 5 min, and first-derivative spectra were recorded. The absolute values of the derivative were measured at 264 nm for determination of otilonium bromide and between 406 and 408 nm (380 nm for analysis of 40:2 tablets) for determination of diazepam. The method is linear, quantitative, and reproducible and can also be used for the tablet dissolution test. Ten tablets of the same batch were analyzed by the described method and by a high-performance liquid chromatographic method, and the results were in good agreement.

  4. TRIBROMOPYRROLE, BROMINATED ACIDS, AND OTHER DISINFECTION BYPRODUCTS PRODUCED BY DISINFECTION OF DRINKING WATER RICH IN BROMIDE

    EPA Science Inventory

    Using gas chromatography/mass spectrometry (GC/MS), we investigated the formation of disinfection byproducts (DBPs) from high bromide waters (2 mg/L) treated with chlorine or chlorine dioxide used in combination with chlorine and chloramines. This study represents the first comp...

  5. Evaluation of non-fumigant pesticides as methyl bromide alternatives for managing weeds in vegetables

    USDA-ARS?s Scientific Manuscript database

    The phase out of methyl bromide challenged vegetable growers’ abilities to control weeds in low-density polyethylene (LDPE) mulch production systems. The herbicides halosulfuron, fomesafen, s-metolachlor, and clomazone are needed as part of the pesticide program in LDP vegetable production to contr...

  6. Hydrology and Water Quality near Bromide Pavilion in Chickasaw National Recreation Area, Murray County, Oklahoma, 2000

    USGS Publications Warehouse

    Andrews, William J.; Burrough, Steven P.

    2002-01-01

    The Bromide Pavilion in Chickasaw National Recreation Area drew many thousands of people annually to drink the mineral-rich waters piped from nearby Bromide and Medicine Springs. Periodic detection of fecal coliform bacteria in water piped to the pavilion from the springs, low yields of the springs, or flooding by adjacent Rock Creek prompted National Park Service officials to discontinue piping of the springs to the pavilion in the 1970s. Park officials would like to resume piping mineralized spring water to the pavilion to restore it as a visitor attraction, but they are concerned about the ability of the springs to provide sufficient quantities of potable water. Pumping and sampling of Bromide and Medicine Springs and Rock Creek six times during 2000 indicate that these springs may not provide sufficient water for Bromide Pavilion to supply large numbers of visitors. A potential problem with piping water from Medicine Spring is the presence of an undercut, overhanging cliff composed of conglomerate, which may collapse. Evidence of intermittent inundation of the springs by Rock Creek and seepage of surface water into the spring vaults from the adjoining creek pose a threat of contamination of the springs. Escherichia coli, fecal coliform, and fecal streptococcal bacteria were detected in some samples from the springs, indicating possible fecal contamination. Cysts of Giardia lamblia and oocysts of Cryptosporidium parvum protozoa were not detected in the creek or the springs. Total culturable enteric viruses were detected in only one water sample taken from Rock Creek.

  7. OZONATION BYPRODUCTS: IDENTIFICATION OF BROMOHYDRINS FROM THE OZONATION OF NATURAL WATERS WITH ENHANCED BROMIDE LEVELS

    EPA Science Inventory

    When ozone is used in the treatment of drinking water, it reacts with both inorganic and organic compounds to form byproducts. f bromide is present, it may be oxidized to hydrobromous acid, which may than react with natural organic matter to form brominated organic compounds. he ...

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

    PubMed

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

    2006-08-01

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

  9. Evaluation of a hydrogen chloride detector for environmental monitoring

    NASA Technical Reports Server (NTRS)

    Gregory, G. L.; Moyer, R. H.

    1977-01-01

    The paper describes a hydrogen chloride detector designed to monitor concentrations of hydrogen chloride gas in the ambient environment. The detector was developed for NASA for use in launch vehicle effluent monitoring. The detector operates on chemiluminescence principles with a lower detection limit of less than 5 x 10 to the -3rd ppm (by volume). The hydrogen chloride in the air sample reacts with a bromide-bromate coating in the inlet tube of the instrument producing bromine. Bromine is then quantitated by chemiluminescent oxidation of luminol. The visible light generated in the chemiluminescent reaction is proportional to the hydrogen chloride concentration of the sampled airstream. The detector is most suited to laboratory or field studies where hydrogen chloride is the dominant pollutant, as compared to the interfering species. Interferences include strong acids, acid-forming gases, and halogen gases. Of the interferences investigated the most serious in these groups are hydrochloric and sulfuric acid, sulfur dioxide, and chlorine, respectively. The detector has been in use since 1974 and has been found to be highly portable, rugged, and stable under extreme environmental conditions.

  10. Sum Frequency Generation Vibrational Spectroscopy of Pyridine Hydrogenation on Platinum Nanoparticles

    SciTech Connect

    Bratlie, Kaitlin M.; Komvopoulos, Kyriakos; Somorjai, Gabor A.

    2008-02-22

    Pyridine hydrogenation in the presence of a surface monolayer consisting of cubic Pt nanoparticles stabilized by tetradecyltrimethylammonium bromide (TTAB) was investigated by sum frequency generation (SFG) vibrational spectroscopy using total internal reflection (TIR) geometry. TIR-SFG spectra analysis revealed that a pyridinium cation (C{sub 5}H{sub 5}NH{sup +}) forms during pyridine hydrogenation on the Pt nanoparticle surface, and the NH group in the C{sub 5}H{sub 5}NH{sup +} cation becomes more hydrogen bound with the increase of the temperature. In addition, the surface coverage of the cation decreases with the increase of the temperature. An important contribution of this study is the in situ identification of reaction intermediates adsorbed on the Pt nanoparticle monolayer during pyridine hydrogenation.

  11. Utility of Bromide and Heat Tracers for Aquifer Characterization Affected by Highly Transient Flow Conditions

    SciTech Connect

    Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew J.

    2012-08-29

    A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained “noise” caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.

  12. Comparison of salbutamol and ipratropium bromide versus salbutamol alone in the treatment of acute severe asthma.

    PubMed

    Hossain, A S; Barua, U K; Roy, G C; Sutradhar, S R; Rahman, I; Rahman, G

    2013-04-01

    The use of nebulized Ipratropium bromide, quaternary anticholinergic bronchodilators in combination with beta-agonist for the treatment of acute asthma in adults is controversial. In a view of different recommendation the present study is undertaken in Bangladeshi patients. Combination of inhaled Ipratropium bromide and Salbutamol provides greater bronchodilatation than mono therapy with Salbutamol alone in acute severe asthma. Patients of severe asthma (PEFR <50% of predicted) were enrolled into control group (Salbutamol only) and case (Salbutamol + Ipratropium bromide) group. After measurement of peak expiratory flow, patient received 3 doses of 2.5 mg Salbutamol (n=40) only or 3 doses of both 2.5mg Salbutamol and 500mcg Ipratropium bromide at an interval of 20 minutes (n=40) through a jet nebulizer. Peak flow was reassessed 30 & 60 minutes after treatment. Peak flow at baseline was similar in two groups. Then at 30 minutes after nebulization, the mean±SD percentage increase in peak flow was greater in combination group (60.01±35.01%) than Salbutamol group (44.47±25.03%) with difference of 16% (p=0.025). At 60 minutes the percentage increase in peak flow was about 32% greater in combination group than Salbutamol group (94.44±33.70% vs. 62.57±29.26%, p=0.000) and combination group reached percentage predicted peak flow more than 60% while Sabutamol group did not. Ipratropium Bromide and Salbutamol nebulized combinedly have better bronchodilating effect than Salbultamol alone in acute severe asthma.

  13. Kinetics of Chlorination of Benzophenone-3 in the Presence of Bromide and Ammonia.

    PubMed

    Abdallah, Pamela; Deborde, Marie; Dossier Berne, Florence; Karpel Vel Leitner, Nathalie

    2015-12-15

    The aim of this study was to assess the impact of chlorination on the degradation of one of the most commonly used UV filters (benzophenone-3 (BP-3)) and the effects of bromide and ammonia on the kinetics of BP-3 elimination. Bromide and ammonia are rapidly converted to bromine and chloramines during chlorination. At first, the rate constants of chlorine, bromine and monochloramine with BP-3 were determined at various pH levels. BP-3 was found to react rapidly with chlorine and bromine, with values of apparent second order rate constants equal to 1.25(±0.14) × 10(3) M(-1)·s(-1) and 4.04(±0.54) × 10(6) M(-1)·s(-1) at pH 8.5 for kChlorine/BP-3 and kBromine/BP-3, respectively, whereas low monochloramine reactivity was observed (kNH2Cl/BP-3 = 0.112 M(-1)·s(-1)). To assess the impact of the inorganic content of water on BP-3 degradation, chlorination experiments with different added concentrations of bromide and/or ammonia were conducted. Under these conditions, BP-3 degradation was found to be enhanced in the presence of bromide due to the formation of bromine, whereas it was inhibited in the presence of ammonia. However, the results obtained were pH dependent. Finally, a kinetic model considering 18 reactions was developed using Copasi to estimate BP-3 degradation during chlorination in the presence of bromide and ammonia.

  14. A novel explicit approach to model bromide and pesticide transport in connected soil structures

    NASA Astrophysics Data System (ADS)

    Klaus, J.; Zehe, E.

    2011-07-01

    The present study tests whether an explicit treatment of worm burrows and tile drains as connected structures is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils at hillslope scale. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in a hillslope model. A recent Monte Carlo study (Klaus and Zehe, 2010, Hydrological Processes, 24, p. 1595-1609) revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide for the 13 spatial model setups that performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of Isoproturon, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

  15. Chemical alternatives for soil fumigation with methyl bromide on tobacco seedbeds in nematode and weed control.

    PubMed

    Kutywayo, V

    2003-01-01

    The proposed phase out of methyl bromide necessitated the evaluation of a number of chemical alternatives to replace it. The recommended rate of application for methyl bromide, 50 g/m2 was evaluated over three years against various rates of 65% 1,3-Dichloropropene mixed with 35% chloropicrin (1,3-D/C-35); a combination of metham sodium and ethylene dibromide (EDB) and 65% 1,3-Dichloropropene (1,3-D) alone. Chloropicrin and 1,3-D have long been registered and used in Zimbabwe as individual chemicals and their combination as a single product had never been tested. 1,3-D/C-35 at 36.9 ml/m2 was as effective as methyl bromide in nematode and weed control and led to similar seed germination and seedling growth rate. A combination of EDB at 21 ml/m2 and metham sodium at 35 ml/m2 was also equally effective. The use of 1,3-D alone at 35 ml/m2 gave unsatisfactory weed control and led to a reduced seedling growth rate. Metham sodium alone at 35 ml/m2 gave comparable weed control, seed germination and seedling growth comparable with methyl bromide. However nematode control evaluated using a gall rating scale was reduced. 1,3-D/C-35 at 36.9 ml/m2 and metham sodium at 35 ml/m2 used in combination with EDB at 21 ml/m2 are therefore, possible replacements for methyl bromide soil fumigation in tobacco seedbeds.

  16. Innovative Monitoring of Atmospheric Gaseous Hydrogen Fluoride

    PubMed Central

    Bonari, Alessandro; Pompilio, Ilenia; Monti, Alessandro; Arcangeli, Giulio

    2016-01-01

    Hydrogen fluoride (HF) is a basic raw material for a wide variety of industrial products, with a worldwide production capacity of more than three million metric tonnes. A novel method for determining particulate fluoride and gaseous hydrogen fluoride in air is presented herewith. Air was sampled using miniaturised 13 mm Swinnex two-stage filter holders in a medium-flow pumping system and through the absorption of particulate fluoride and HF vapours on cellulose ester filters uncoated or impregnated with sodium carbonate. Furthermore, filter desorption from the holders and the extraction of the pentafluorobenzyl ester derivative based on solid-phase microextraction were performed using an innovative robotic system installed on an xyz autosampler on-line with gas chromatography (GC)/mass spectrometry (MS). After generating atmospheres of a known concentration of gaseous HF, we evaluated the agreement between the results of our sampling method and those of the conventional preassembled 37 mm cassette (±8.10%; correlation coefficient: 0.90). In addition, precision (relative standard deviation for n = 10, 4.3%), sensitivity (0.2 μg/filter), and linearity (2.0–4000 μg/filter; correlation coefficient: 0.9913) were also evaluated. This procedure combines the efficiency of GC/MS systems with the high throughput (96 samples/day) and the quantitative accuracy of pentafluorobenzyl bromide on-sample derivatisation. PMID:27829835

  17. Hydrogen energy systems studies

    SciTech Connect

    Ogden, J.M.; Kreutz, T.G.; Steinbugler, M.

    1996-10-01

    In this report the authors describe results from technical and economic assessments carried out during the past year with support from the USDOE Hydrogen R&D Program. (1) Assessment of technologies for small scale production of hydrogen from natural gas. Because of the cost and logistics of transporting and storing hydrogen, it may be preferable to produce hydrogen at the point of use from more readily available energy carriers such as natural gas or electricity. In this task the authors assess near term technologies for producing hydrogen from natural gas at small scale including steam reforming, partial oxidation and autothermal reforming. (2) Case study of developing a hydrogen vehicle refueling infrastructure in Southern California. Many analysts suggest that the first widespread use of hydrogen energy is likely to be in zero emission vehicles in Southern California. Several hundred thousand zero emission automobiles are projected for the Los Angeles Basin alone by 2010, if mandated levels are implemented. Assuming that hydrogen vehicles capture a significant fraction of this market, a large demand for hydrogen fuel could evolve over the next few decades. Refueling a large number of hydrogen vehicles poses significant challenges. In this task the authors assess near term options for producing and delivering gaseous hydrogen transportation fuel to users in Southern California including: (1) hydrogen produced from natural gas in a large, centralized steam reforming plant, and delivered to refueling stations via liquid hydrogen truck or small scale hydrogen gas pipeline, (2) hydrogen produced at the refueling station via small scale steam reforming of natural gas, (3) hydrogen produced via small scale electrolysis at the refueling station, and (4) hydrogen from low cost chemical industry sources (e.g. excess capacity in refineries which have recently upgraded their hydrogen production capacity, etc.).

  18. Concentration of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2006-01-01

    Methods for concentrating hydrogen peroxide solutions have been described. The methods utilize a polymeric membrane separating a hydrogen peroxide solution from a sweep gas or permeate. The membrane is selective to the permeability of water over the permeability of hydrogen peroxide, thereby facilitating the concentration of the hydrogen peroxide solution through the transport of water through the membrane to the permeate. By utilizing methods in accordance with the invention, hydrogen peroxide solutions of up to 85% by volume or higher may be generated at a point of use without storing substantial quantities of the highly concentrated solutions and without requiring temperatures that would produce explosive mixtures of hydrogen peroxide vapors.

  19. Hydrogen conference: Workshop proceedings

    SciTech Connect

    Serfass, J.; Bugel, L. )

    1989-10-01

    This meeting was designed to encourage discussion of today's US industrial, utility, space and environmental interests in hydrogen and tommorrow's use of hydrogen as an energy system. The meeting began with a general session during which speakers gave presentations on a variety of hydrogen topics. Discussion following each presentation was lively. Some of the major points of discussion were: interpretation of global warming evidence; relevance of global warming to the interest in hydrogen; cost of hydrogen derived from fossil fuels vs. nuclear vs. solar; likely future importance of hydrogen -- major energy system vs. niche player. A number of interesting points were raised and data presented by speakers and participants. Highlights are presented.

  20. Strategies for designing supported gold-palladium bimetallic catalysts for the direct synthesis of hydrogen peroxide.

    PubMed

    Edwards, Jennifer K; Freakley, Simon J; Carley, Albert F; Kiely, Christopher J; Hutchings, Graham J

    2014-03-18

    Hydrogen peroxide is a widely used chemical but is not very efficient to make in smaller than industrial scale. It is an important commodity chemical used for bleaching, disinfection, and chemical manufacture. At present, manufacturers use an indirect process in which anthraquinones are sequentially hydrogenated and oxidized in a manner that hydrogen and oxygen are never mixed. However, this process is only economic at a very large scale producing a concentrated product. For many years, the identification of a direct process has been a research goal because it could operate at the point of need, producing hydrogen peroxide at the required concentration for its applications. Research on this topic has been ongoing for about 100 years. Until the last 10 years, catalyst design was solely directed at using supported palladium nanoparticles. These catalysts require the use of bromide and acid to arrest peroxide decomposition, since palladium is a very active catalyst for hydrogen peroxide hydrogenation. Recently, chemists have shown that supported gold nanoparticles are active when gold is alloyed with palladium because this leads to a significant synergistic enhancement in activity and importantly selectivity. Crucially, bimetallic gold-based catalysts do not require the addition of bromide and acids, but with carbon dioxide as a diluent its solubility in the reaction media acts as an in situ acid promoter, which represents a greener approach for peroxide synthesis. The gold catalysts can operate under intrinsically safe conditions using dilute hydrogen and oxygen, yet these catalysts are so active that they can generate peroxide at commercially significant rates. The major problem associated with the direct synthesis of hydrogen peroxide concerns the selectivity of hydrogen usage, since in the indirect process this factor has been finely tuned over decades of operation. In this Account, we discuss how the gold-palladium bimetallic catalysts have active sites for the

  1. Copper(II) bromide, nitrate and perchlorate complexes with sterically demanding N-(6-methylpyridin-2-yl)acetamide ligands.

    PubMed

    Smolentsev, Anton I

    2017-08-01

    Functionalized acid amides are widely used in biology, medicine, environmental chemistry and many other areas. Among them, pyridine-substituted amides, in particular N-(pyridin-2-yl)acetamide and its derivatives, play an important role due to their excellent chelating properties. The donor properties of these ligands can be effectively modified by introducing electron-donating substituents (e.g. alkyl groups) into the heterocycle. On the other hand, substituents in the α-position of the pyridine ring can create steric hindrance, which significantly influences the coordination number and geometry. To achieve a better understanding of these effects, copper(II) complexes with sterically demanding N-(6-methylpyridin-2-yl)acetamide ligands (L) and monoanions of different size, shape and coordination ability have been chosen as model compounds. The crystal structures of three new compounds, bromidobis[N-(6-methylpyridin-2-yl-κN)acetamide-κO]copper(II) bromide, [CuBr(C8H10N2O)]Br, (I), aquabis[N-(6-methylpyridin-2-yl-κN)acetamide-κO]copper(II) dinitrate, [Cu(C8H10N2O)(H2O)](NO3)2, (II), and aquabis[N-(6-methylpyridin-2-yl-κN)acetamide-κO]copper(II) bis(perchlorate), [Cu(C8H10N2O)(H2O)](ClO4)2, (III), have been determined by single-crystal X-ray diffraction analysis. It has been shown that the presence of the 6-methyl group results in either a distorted square-pyramidal or a distorted trigonal-bipyramidal coordination geometry around the Cu(II) centres instead of the typical octahedral geometry observed when the methyl substituent is absent or occupies any other position on the pyridine ring. Moreover, due to the steric hindrance provided by the L ligands, only the bromide ligand, the smallest of the series, enters into the first coordination sphere of the Cu(II) ion in (I). In (II) and (III), the vacant coordination site of the Cu(II) ion is occupied by a water molecule, while the nitrate and perchlorate anions are not involved in coordination to the metal centre

  2. Crystal structure of hexa­kis­(urea-κO)chromium(III) dichromate bromide monohydrate from synchrotron X-ray data

    PubMed Central

    Moon, Dohyun; Tanaka, Shinnosuke; Akitsu, Takashiro; Choi, Jong-Ha

    2015-01-01

    The title bromide salt, [Cr{CO(NH2)2}6](Cr2O7)Br·H2O, is isotypic to the corresponding chloride salt. Within the complex cation, the CrIII atom is coordinated by six O atoms of six urea ligands, displaying a slightly distorted octa­hedral coordination environment. The Cr—O bond lengths involving the urea ligands are in the range 1.9534 (13)–1.9776 (12) Å. The Cr2O7 2− anion has a nearly staggered conformation, with a bridging angle of 130.26 (10)°. The individual components are arranged in rows extending parallel to [100]. The Br− anion links the complex cation, as well as the solvent water mol­ecule, through N—H⋯Br and O—H⋯Br hydrogen-bonding inter­actions. The supra­molecular architecture also includes N—H⋯O and O—H⋯O hydrogen bonding between urea N—H and water O—H donor groups and the O atoms of the Cr2O7 2− anion as acceptor atoms, leading to a three-dimensional network structure. PMID:26594505

  3. Chemical/hydrogen energy systems analysis

    NASA Astrophysics Data System (ADS)

    Beller, M.

    1982-12-01

    Four hydrogen energy technologies are addressed including: hydrogen recovery from hydrogen separation using hydride technology, photochemical hydrogen production, anode depolarization in electrolytic hydrogen production.

  4. Once-daily glycopyrronium bromide (Seebri Breezhaler(®)) for the treatment of chronic obstructive pulmonary disease (COPD).

    PubMed

    Ulrik, Charlotte Suppli

    2015-01-01

    Long-acting bronchodilators are the mainstay of pharmacological therapy for patients with chronic obstructive pulmonary disease (COPD). The choice of optimal bronchodilator therapy for COPD is increasingly difficult for clinicians as new treatments are marketed. Inhaled glycopyrronium bromide (Seebri Breezhaler®) is a well-tolerated long-acting anti-muscarinic agent (LAMA) with a fast onset of action. In patients with moderate to severe COPD, glycopyrronium bromide has clinically important effects on level of FEV1, use of relief medication, day-time dyspnea scores, and probably also on health status. Furthermore, glycopyrronium bromide also has beneficial effects on dynamic hyperinflation and, probably by that, exercise tolerance. Glycopyrronium bromide has been shown to reduce the rate of exacerbations in patients with moderate to severe COPD, although as a secondary outcome only. Once-daily inhaled glycopyrronium bromide has positive impact on important COPD outcomes, comparable to the effects of other marketed LAMAs. Once-daily administration may improve adherence, and glycopyrronium bromide has the potential for a role in the future management of COPD similar to that of other long-acting anti-muscarinic agents, including tiotropium. Studies of glycopyrronium bromide with exacerbation rate as the primary outcome of interest is needed.

  5. Factors affecting petite induction and the recovery of respiratory competence in yeast cells exposed to ethidium bromide.

    PubMed

    Hall, R M; Trembath, M K; Linnane, A W; Wheelis, L; Criddle, R S

    1976-03-30

    When growing cultures of S. cerevisiae are treated with high concentrations of ethidium bromide (greater than 50 mug/ml), three phases of petite induction may be observed: I. the majority of cells are rapidly converted to petite, II. subsequently a large proportion of cells recover the ability to form respiratory competent clones, and III. slow, irreversible conversion of all cells to petite. The extent of recovery of respiratory competence observed is dependent on the strain of S. cerevisiae employed and the temperature and the carbon source used in the growth medium. The effects of 100 mug/ml ethidium bromide are also produced by 10 mug/ml ethidium bromide in the presence of the detergent, sodium dodecyl sulphate, and recovery is also observed when cells are treated with 10 mug/ml ethidium bromide under starvation conditions. Genetic analysis of strain differences indicates that a number of nuclear genes influence petite induction by ethidium bromide. In one strain, S288C, petite induction by 100 mug/ml ethidium bromide is extremely slow under certain conditions. Mitochondria isolated from from S288C lack the ethidium bromide stimulated nuclease activity found in D243-4A, a strain which shows triphasic kinetics of petite formation. This enzyme may, therefore, be responsible for the initial phase of rapid petite formation.

  6. Improvement of Quality of Nonanesthetic Colonoscopy by Preoperative Administration of Pinaverium Bromide

    PubMed Central

    Wang, Xiao-Lin; Zhou, Jian-Ning; Ren, Li; Pan, Xiao-Li; Ren, Hong-Yu; Liu, Jun

    2017-01-01

    Background: Nonanesthetic colonoscopy is popular in clinical practice in China. However, intestinal spasms often result in a prolonged examination time, increased operating difficulties, decreased polyp detection rate, and failure to complete the procedure clinically. Therefore, exploring alternative approaches that can reduce the pain in patients during colonoscopy is of utmost importance, and finding the optimal preoperative administration to improve the quality of nonanesthetic colonoscopy is also necessary. This study aimed to investigate the effects of the prophylactic administration of pinaverium bromide before colonoscopy and the effects of pinaverium bromide alone at different time points or combined with scopolamine butylbromide. Methods: A randomized controlled trial was performed on a cohort of 1000 patients who underwent colonoscopy in outpatient clinic of Wuhan Union Hospital. The patients were randomly assigned to the following groups: Group A, given oral pinaverium bromide (100 mg, three times a day) one day before examination combined with intramuscular injection of scopolamine butylbromide (20 mg) 10 min before colonoscopy; Group B0, given pinaverium bromide alone on the day of colonoscopy (100 mg, three times a day); Group B1, given pinaverium bromide alone (100 mg, three times a day) one day before colonoscopy; Group B2, given pinaverium bromide alone (100 mg, three times a day) two days before colonoscopy; and Group C, given scopolamine butylbromide alone (20 mg) before colonoscopy. The successful rate of colonoscopy, procedure time, degree of abdominal pain, and polyp detection rate were recorded and compared among all groups. Results: The successful rate of colonoscopy in Group B1 (82.0%) and Group B2 (83.0%) was significantly higher than that in Group B0 (62.0%, all P < 0.01). The time to reach the ileocecal region in Group B1 and Group B2 were lower than those in Group B0 (all P < 0.05). However, no significant differences were observed in

  7. Structures and spectroscopic characterization of calcium chloride-nicotinamide, -isonicotinamide, -picolinamide and praseodymium bromide-nicotinamide complexes

    NASA Astrophysics Data System (ADS)

    Xue, Junhui; Jiang, Ye; Li, Weihong; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Zhang, Gaohui; Bu, Xiaoxia; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

    2015-02-01

    The coordination structures formed by calcium complexes with nicotinamide (na), isonicotinamide (ina) and picolinamide (pa) and praseodymium bromide-na are reported. The structures of CaCl2·(C6H6N2O)2·2H2O (Ca-na), CaCl2·(C6H6N2O)2·4H2O (Ca-ina), CaCl2·(C6H6N2O)2·5H2O (Ca-pa) and PrBr3·(C6H6N2O)2·6H2O (PrBr-na) in the solid state have been characterized by X-ray single crystal diffraction, FTIR, FIR, THz and Raman spectroscopies. Carbonyl oxygen of nicotinamide is coordinated to Ca2+, but it is O-monodentate (carbonyl oxygen) and N,O-bidentate ligand (pyridyl nitrogen and carbonyl oxygen) for Pr3+ to form a chain structure in PrBr-na. For isonicotinamide, only carbonyl oxygen atom is coordinated to Ca2+. Pyridyl nitrogen and carbonyl oxygen of picolinamide are coordinated to Ca2+ to form a five-membered ring structure. The crystal structure and spectroscopic results indicate the differences of the coordination of Ca and Pr ions, the changes of hydrogen bonds and conformation of the ligands induced by complexation. Unlike transition metal ions, Sr2+ or lanthanide ions, Ca2+ is inclined to coordinate to carbonyl oxygen atoms of the ligands.

  8. Structures and spectroscopic characterization of calcium chloride-nicotinamide, -isonicotinamide, -picolinamide and praseodymium bromide-nicotinamide complexes.

    PubMed

    Xue, Junhui; Jiang, Ye; Li, Weihong; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Zhang, Gaohui; Bu, Xiaoxia; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

    2015-02-25

    The coordination structures formed by calcium complexes with nicotinamide (na), isonicotinamide (ina) and picolinamide (pa) and praseodymium bromide-na are reported. The structures of CaCl2·(C6H6N2O)2·2H2O (Ca-na), CaCl2·(C6H6N2O)2·4H2O (Ca-ina), CaCl2·(C6H6N2O)2·5H2O (Ca-pa) and PrBr3·(C6H6N2O)2·6H2O (PrBr-na) in the solid state have been characterized by X-ray single crystal diffraction, FTIR, FIR, THz and Raman spectroscopies. Carbonyl oxygen of nicotinamide is coordinated to Ca(2+), but it is O-monodentate (carbonyl oxygen) and N,O-bidentate ligand (pyridyl nitrogen and carbonyl oxygen) for Pr(3+) to form a chain structure in PrBr-na. For isonicotinamide, only carbonyl oxygen atom is coordinated to Ca(2+). Pyridyl nitrogen and carbonyl oxygen of picolinamide are coordinated to Ca(2+) to form a five-membered ring structure. The crystal structure and spectroscopic results indicate the differences of the coordination of Ca and Pr ions, the changes of hydrogen bonds and conformation of the ligands induced by complexation. Unlike transition metal ions, Sr(2+) or lanthanide ions, Ca(2+) is inclined to coordinate to carbonyl oxygen atoms of the ligands.

  9. Severe Illness from Methyl Bromide Exposure at a Condominium Resort--U.S. Virgin Islands, March 2015.

    PubMed

    Kulkarni, Prathit A; Duncan, Mary Anne; Watters, Michelle T; Graziano, Leah T; Vaouli, Elena; Cseh, Larry F; Risher, John F; Orr, Maureen F; Hunte-Ceasar, Tai C; Ellis, Esther M

    2015-07-24

    On March 22, 2015, the Agency for Toxic Substances and Disease Registry (ATSDR) was notified by the U.S. Environmental Protection Agency (EPA) of four cases of suspected acute methyl bromide toxicity among family members vacationing at a condominium resort in the U.S. Virgin Islands. Methyl bromide is a pesticide that has been banned in the United States for use in homes and other residential settings. An investigation conducted by the U.S. Virgin Islands Department of Health (VIDOH), the U.S. Virgin Islands Department of Planning and Natural Resources (DPNR), and EPA confirmed that methyl bromide had been used as a fumigant on March 18 in the building where the family had been residing, 2 days before they were transported to the hospital; three family members had life-threatening illness. On March 25, 2015, a stop-use order for methyl bromide was issued by DPNR to the pest control company that had performed the fumigation. Subsequent investigation revealed that previous fumigation with methyl bromide had occurred on October 20, 2014, at the same condominium resort. In addition to the four ill family members, 37 persons who might have been exposed to methyl bromide as a result of the October 2014 or March 2015 fumigations were identified by VIDOH and ATSDR. Standardized health questionnaires were administered to 16 of the 20 persons for whom contact information was available; six of 16 had symptoms consistent with methyl bromide exposure, including headache and fatigue. Pest control companies should be aware that use of methyl bromide is banned in homes and other residential settings, and clinicians should be aware of the toxicologic syndrome that exposure to methyl bromide can cause.

  10. Comparison of phenobarbital with bromide as a first-choice antiepileptic drug for treatment of epilepsy in dogs.

    PubMed

    Boothe, Dawn Merton; Dewey, Curtis; Carpenter, David Mark

    2012-05-01

    To compare efficacy and safety of treatment with phenobarbital or bromide as the first-choice antiepileptic drug (AED) in dogs. Double-blinded, randomized, parallel, clinical trial. 46 AED-naïve dogs with naturally occurring epilepsy. Study inclusion was based on age, history, findings on physical and neurologic examinations, and clinicopathologic test results. For either phenobarbital treatment (21 dogs) or bromide treatment (25), a 7-day loading dose period was initiated along with a maintenance dose, which was adjusted on the basis of monthly monitoring. Efficacy and safety outcomes were compared between times (baseline and study end [generally 6 months]) and between drugs. Phenobarbital treatment resulted in eradication of seizures (17/20 [85%]) significantly more often than did bromide (12/23 [52%]); phenobarbital treatment also resulted in a greater percentage decrease in seizure duration (88 ± 34%), compared with bromide (49 ± 75%). Seizure activity worsened in 3 bromide-treated dogs only. In dogs with seizure eradication, mean ± SD serum phenobarbital concentration was 25 ± 6 μg/mL (phenobarbital dosage, 4.1 ± 1.1 mg/kg [1.9 ± 0.5 mg/lb], p.o., q 12 h) and mean serum bromide concentration was 1.8 ± 0.6 mg/mL (bromide dosage, 31 ± 11 mg/kg [14 ± 5 mg/lb], p.o., q 12 h). Ataxia, lethargy, and polydipsia were greater at 1 month for phenobarbital-treated dogs; vomiting was greater for bromide-treated dogs at 1 month and study end. Both phenobarbital and bromide were reasonable first-choice AEDs for dogs, but phenobarbital was more effective and better tolerated during the first 6 months of treatment.

  11. Hydrogenation of passivated aluminum with hydrogen fluid

    NASA Astrophysics Data System (ADS)

    Saitoh, H.; Machida, A.; Katayama, Y.; Aoki, K.

    2009-04-01

    Hydrogenation conditions of passivated aluminum were examined in a pressure and temperature range of 6-10 GPa and 300-800 °C, respectively. The relationship between the hydrogenation reaction yields and holding time was analyzed by Johnson-Mehl-Avrami equation. An Avrami exponent n of 0.3 indicated that the reaction decreased with time due to the low diffusivity of hydrogen in AlH3. The oxide layer on passivated aluminum seemed to be partly removed or modified by pressure-temperature treatment above 6 GPa and 600 °C in hydrogen fluid. The hydrogenation pressure of 9 GPa for the passivated aluminum was reduced to 6 GPa.

  12. Hydrogen Hotspots on Vesta

    NASA Image and Video Library

    2012-09-20

    This image shows that NASA Dawn mission detected abundances of hydrogen in a wide swath around the equator of the giant asteroid Vesta. The hydrogen probably exists in the form of hydroxyl or water bound to minerals in Vesta surface.

  13. Hydrogen production by Cyanobacteria.

    PubMed

    Dutta, Debajyoti; De, Debojyoti; Chaudhuri, Surabhi; Bhattacharya, Sanjoy K

    2005-12-21

    The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical), Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source.

  14. Hydrogen production by Cyanobacteria

    PubMed Central

    Dutta, Debajyoti; De, Debojyoti; Chaudhuri, Surabhi; Bhattacharya, Sanjoy K

    2005-01-01

    The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical), Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source. PMID:16371161

  15. Freezing WISE Hydrogen

    NASA Image and Video Library

    2009-11-12

    A scaffolding structure built around NASA Wide-field Infrared Survey Explorer allows engineers to freeze its hydrogen coolant. The WISE infrared instrument is kept extremely cold by a bottle-like tank filled with frozen hydrogen, called the cryostat.

  16. Hydrogen transport membranes

    DOEpatents

    Mundschau, Michael V.

    2005-05-31

    Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

  17. Bromate formation in bromide-containing water through the cobalt-mediated activation of peroxymonosulfate.

    PubMed

    Li, Zhaobing; Chen, Zhi; Xiang, Yingying; Ling, Li; Fang, Jingyun; Shang, Chii; Dionysiou, Dionysios D

    2015-10-15

    Bromate formation in bromide-containing water through the cobalt (Co)-mediated activation of peroxymonosulfate (PMS) was investigated. Increasing the PMS dosage and the cobalt dosage increased the formation of bromate and bromate yields of up to 100% were recorded under the test conditions. The bromate yield increased to a maximum as the pH rose from 2.7 to 6 before decreasing by over 90% as the pH rose further from 6 to above 9. The bromate formation is a two-step process involving free bromine as a key intermediate and bromate as the final product. In the first step, apart from the known oxidation of bromide to free bromine and of free bromine to bromate by sulfate radicals (SO4(-)), Co(III) produced from the oxidation of Co(II) by PMS and SO4(-) also oxidizes bromide to free bromine. The contribution of Co(III) to the bromate formation was verified with the addition of methanol and EDTA, a radical scavenger and a Co(III) ligand, respectively. In the presence of methanol, free bromine formation increased with increasing Co(II) dosage but no bromate was detected, indicating that Co(III) oxidized bromide to form free bromine but not bromate. In the presence of both EDTA and methanol, no free bromine or bromate was detected, as Co(III) was stabilized by EDTA to form the Co(III)EDTA(-) complex, which could not oxidize bromide. Mathematical simulation further suggested that Co(III) outweighed SO4(-) to oxidize bromide to free bromine. On the other hand, SO4(-) is essential for the oxidation of free bromine to bromate in the second step. In real water, the presence of NOM significantly decreased the bromate formation but caused the brominated organic DBP formation with high quantity. This is the first study to demonstrate the significant bromate formation in the Co/PMS system and the substantial contribution of Co(III) to the formation.

  18. Transport of Bromide, Simazine, and MS-2 Coliphage in a Lysimeter Containing Undisturbed, Unsaturated Soil

    NASA Astrophysics Data System (ADS)

    Poletika, Nicholas N.; Jury, William A.; Yates, Marylynn V.

    1995-04-01

    The effect of rate-limited adsorption on transport of environmental contaminants is difficult to characterize at the field scale. This study investigated transport, during unsaturated water flow, of pulse inputs of bromide, simazine (2-chloro-4,6- bis(ethylamino)-s-triazine), and MS-2 coliphage in a field lysimeter (0.8 m × 0.8 m square) containing undisturbed Tujunga loamy sand (mixed, thermic, Typic Xeropsamment). Sixty-four fiberglass wick soil solution samplers collected drainage fractions from the exit surface (30 cm depth) following daily 2-cm water inputs applied at 0.5 cm h-1. After 19.7 cm of cumulative drainage, the soil above 10 of the 64 locations was sampled to determine final depth distributions of simazine and virus. Most of the bromide was leached from the transport volume, while the sorbing pesticide and virus remained in the soil. Variance analysis indicated that local dispersion processes contributed more to the observed bromide spreading than did differences in local water velocities. A linear, first-order, kinetic adsorption submodel was incorporated into a generalized linear transport model relating the bromide flux concentrations to the simazine and virus final resident concentrations. Least squares fitting showed that area-averaged bromide transport could be described reasonably well by the two-parameter convection-dispersion model (CDM), although the mobile-immobile water model provided a slightly better representation of effluent tailing. The CDM parameters fitted to the bromide data were then held constant while the two parameters of the adsorption submodel were varied to fit the pesticide soil concentrations at the end of the experiment at 10 days. A good fit was obtained for simazine, and the fitted value 0.54 d-1 of the rate coefficient was in the range characterizing nonequilibrium adsorption. A batch adsorption/desorption experiment produced Freundlich isotherms describing nonlinear adsorption (exponent m = 0.85) and hysteresis in

  19. Cobalt-Catalyzed Cross-Coupling of Grignards with Allylic and Vinylic Bromides: Use of Sarcosine as a Natural Ligand.

    PubMed

    Frlan, Rok; Sova, Matej; Gobec, Stanislav; Stavber, Gaj; Časar, Zdenko

    2015-08-07

    Sarcosine was discovered to be an excellent ligand for cobalt-catalyzed carbon-carbon cross-coupling of Grignard reagents with allylic and vinylic bromides. The Co(II)/sarcosine catalytic system is shown to perform efficiently when phenyl and benzyl Grignards are coupled with alkenyl bromides. Notably, previously unachievable Co-catalyzed coupling of allylic bromides with Grignards to linearly coupled α-products was also realized with Co(II)/sarcosine catalyst. This method was used for efficient preparation of the key intermediate in an alternative synthesis of the antihyperglycemic drug sitagliptin.

  20. Synthesis of polyhydroxylated pyrrolidines from sugar-derived bromonitriles through a cascade addition of allylmagnesium bromide/cyclization/reduction.

    PubMed

    Malik, Michał; Jarosz, Sławomir

    2016-02-07

    The synthesis of polyhydroxylated 2-allylpyrrolidines from sugar-derived bromonitriles in a cascade addition of allylmagnesium bromide/SN2 cyclization/reduction with Zn(BH4)2 is described. The stereochemical course of the reduction step is rationalized. Two of the obtained compounds are transformed into stereoisomers of naturally-occurring iminosugar (+)-lentiginosine. In an alternative approach, 2,2-diallylpyrrolidines are obtained from bromonitriles in a cascade addition of allylmagnesium bromide/SN2 cyclization/addition of another equivalent of allylmagnesium bromide.