WorldWideScience

Sample records for bromine bromides

  1. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Science.gov (United States)

    2010-07-01

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

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

    Science.gov (United States)

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

    2016-08-01

    Monitoring total bromine and bromide concentrations in soils is significant in many environmental studies. Thus fast analytical methodologies that entail simple sample preparation and low-cost analyses are desired. In the present work, the possibilities and drawbacks of low-power total reflection X-ray fluorescence spectrometry (TXRF) for the determination of total bromine and bromide contents in soils were evaluated. The direct analysis of a solid suspension using 20 mg of fine ground soil (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. PMID:27179429

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

    International Nuclear Information System (INIS)

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

  4. Formation pathways of brominated products from benzophenone-4 chlorination in the presence of bromide ions

    Institute of Scientific and Technical Information of China (English)

    Ming Xiao; Dongbin Wei; Liping Li; Qi Liu; Huimin Zhao; Yuguo Du

    2014-01-01

    The brominated products,formed in chlorination treatment of benzophenone-4 in the presence of bromide ions,were identified,and the formation pathways were proposed.Under disinfection conditions,benzophenone-4 would undertake electrophilic substitution generating mono-or di-halogenated products,which would be oxidized to esters and further hydrolyzed to phenol derivatives.The generated catechol intermediate would be transformed into furan-like heterocyclic product.The product species were pH-dependent,while benzophenone-4 ehmination was chlorine dose-dependent.When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions,most of brominated byproducts could be detected,and the acute toxicity significantly increased as well.

  5. Natural Oxidation of Bromide to Bromine in Evaporated Dead Sea Brines

    Science.gov (United States)

    Gavrieli, Ittai; Golan, Rotem; Lazar, Boaz; Baer, Gidi; Zakon, Yevgeni; Ganor, Jiwchar

    2016-04-01

    Highly evaporated Dead Sea brines are found in isolated sinkholes along the Dead Sea. Many of these brines reach densities of over 1.3 kg/L and pHacidic with a value of ~6.3. In comparison, seawater with the same alkalinity would have a pH value well above 8.3, meaning that H+ activity is 100 fold lower than that of Dead Sea brine. In the present work we assess the apparent dissociation constant value of boric acid (K`B) for the Dead Sea brine and use it to explain the brine's low pH value. We then show that pH decreases further as the brine evaporates and salinity increases. Finally we explain the reddish hue of the hypersaline brines in the sinkholes as due to the presence of dissolved bromine. The latter is the product of oxidation of dissolved bromide, a process that is enabled by the low pH of the hypersaline brines and their high bromide concentration.

  6. Bromine

    Science.gov (United States)

    Ober, J.A.

    2013-01-01

    The element bromine is found principally as a dissolved species in seawater, evaporitic (salt) lakes and underground brines associated with petroleum deposits. Seawater contains about 65 parts per million of bromine or an estimated 907 Gt (100 trillion st). In the Middle East, the highly saline waters of the Dead Sea are estimated to contain 907 Mt (1 billion st) of bromine. Bromine also may be recovered from seawater as a coproduct during evaporation to produce salt.

  7. Bromine and bromide in rainfall, cloud, stream and groundwater in the Plynlimon area of mid-Wales

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Bromine in rainfall, cloud water, stream water and groundwater were measured in the upper River Severn catchments at Plynlimon in mid-Wales using two analytical procedures for bromide determination: a colorimetric method and, later, ion chromatography. Discrepancies between the methods indicated that the colorimetric method was measuring more than just bromide so it was "dissolved labile bromine" (DLBr (Neal et al., 2007. This paper reports the variation in DLBr and bromide across the Plynlimon region and assesses the differences between these two measures. The average DLBr concentration in the streams ranges between 18.3 and 27.8 µg l−1 compared with a rainfall average concentration of 15.6 µg l−1. The corresponding bromide concentrations in the streams are 13.8–18.6 µg l−1 and 13.2 µg l−1 in rainfall. For cloud water, throughfall and stemflow, DLBr concentrations are an order of magnitude higher than in rainfall and the concentrations are strongly correlated with chloride. Average values of bromide in rainfall and cloud water are similar to those of DLBr and are strongly correlated with chloride: unfortunately, no bromide measurements were taken in throughfall and stemflow. These results indicate that marine aerosol inputs are high and that the DLBr in these inputs is dominated by bromide. For cloud water, DLBr was correlated with dissolved organic carbon (DOC as well as with chloride; hence, there may well be an organic-associated component. Within the streams draining the forested areas, DLBr increases with time as DOC increases. DLBr concentrations in the streams are correlated with DOC in most cases and, to a lesser degree, with chloride. However, for bromide there is no correlation with DOC, but a weak correlation with chloride remains and the gradient is higher than for the DLBr case. Increasing concentrations of both DLBr and DOC may well reflect the wetting up of the catchments as transpiration diminshes as the trees age

  8. Formation potentials of bromate and brominated disinfection by-products in bromide-containing water by ozonation.

    Science.gov (United States)

    Lin, Tao; Wu, Shouke; Chen, Wei

    2014-12-01

    The ozonation involved in drinking water treatment raises issues of water quality security when the raw water contains bromide (Br(-)). Br(-) ions may be converted to bromate (BrO3 (-)) during ozonation and some brominated disinfection by-products (Br-DBPs) in the following chlorination. In this study, the effects of ozone (O3) dosage, contact time, pH, and Br(-) and ammonia (NH3-N) concentrations on the formation of BrO3 (-) and Br-DBPs have been investigated. The results show that decreasing the initial Br(-) concentration is an effective means of controlling the formation of BrO3 (-). When the concentration of Br(-) was lower than 100 μg/L, by keeping the ratio of O3 dosage to dissolved organic carbon (DOC) concentration at less than 1, BrO3 (-) production was effectively suppressed. The concentration of BrO3 (-) steadily increased with increasing O3 dosage at high Br(-) concentration (>900 μg/L). Additionally, a longer ozonation time increased the concentrations of BrO3 (-) and total organic bromine (TOBr), while it had less impact on the formation potentials of brominated trihalomethanes (Br-THMFP) and haloacetic acids (Br-HAAFP). Higher pH value and the presence of ammonia may lead to an increase in the formation potential of BrO3 (-) and Br-DBPs.

  9. Sensitive Spectrophotometric Determination of Atenolol in Pharmaceutical Formulations Using Bromate-Bromide Mixture as an Eco-Friendly Brominating Agent

    Directory of Open Access Journals (Sweden)

    Kudige N. Prashanth

    2012-01-01

    Full Text Available Three simple and sensitive spectrophotometric methods are proposed for the determination of atenolol (ATN in bulk drug and tablets. The methods are based on the bromination of ATN by the bromine generated in situ by the action of the acid on the bromate–bromide mixture followed by the determination of unreacted bromine by reacting with a fixed amount of either meta-cresol purple (MCP and measuring the absorbance at 540 nm (method A and 445 nm (method B or erioglaucine (EGC and measuring the absorbance at 630 nm (method C. Beer's law is valid within the concentration ranges of 1.0–20.0, 2.0–40.0 and 1.0–8.0 μg/mL for method A, method B and method C, respectively. The calculated molar absorptivities were found to be 1.20×104, 4.51×103 and 3.46×104  L/mol⋅cm for method A, method B and method C, respectively. Sandell’s sensitivity values, correlation coefficients, limits of detection and quantification are also reported. Recovery results were statistically compared with those of a reference method by applying Student’s t- and F-test. The novelty of the present study is the measurement of two different colors using MCP, that is, red-pink color of MCP in acid medium at 540 nm and yellowish-orange color of brominated MCP at 445 nm.

  10. TRIBROMOPYRROLE, BROMINATED ACIDS, AND OTHER DISINFECTION BYPRODUCTS PRODUCED BY DISINFECTION OF DRINKING WATER RICH IN BROMIDE

    Science.gov (United States)

    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...

  11. Oxidative treatment of bromide-containing waters: formation of bromine and its reactions with inorganic and organic compounds--a critical review.

    Science.gov (United States)

    Heeb, Michèle B; Criquet, Justine; Zimmermann-Steffens, Saskia G; von Gunten, Urs

    2014-01-01

    Bromide (Br(-)) is present in all water sources at concentrations ranging from ≈ 10 to >1000 μg L(-1) in fresh waters and about 67 mg L(-1) in seawater. During oxidative water treatment bromide is oxidized to hypobromous acid/hypobromite (HOBr/OBr(-)) and other bromine species. A systematic and critical literature review has been conducted on the reactivity of HOBr/OBr(-) and other bromine species with inorganic and organic compounds, including micropollutants. The speciation of bromine in the absence and presence of chloride and chlorine has been calculated and it could be shown that HOBr/OBr(-) are the dominant species in fresh waters. In ocean waters, other bromine species such as Br2, BrCl, and Br2O gain importance and may have to be considered under certain conditions. HOBr reacts fast with many inorganic compounds such as ammonia, iodide, sulfite, nitrite, cyanide and thiocyanide with apparent second-order rate constants in the order of 10(4)-10(9)M(-1)s(-1) at pH 7. No rate constants for the reactions with Fe(II) and As(III) are available. Mn(II) oxidation by bromine is controlled by a Mn(III,IV) oxide-catalyzed process involving Br2O and BrCl. Bromine shows a very high reactivity toward phenolic groups (apparent second-order rate constants kapp ≈ 10(3)-10(5)M(-1)s(-1) at pH 7), amines and sulfamides (kapp ≈ 10(5)-10(6)M(-1)s(-1) at pH 7) and S-containing compounds (kapp ≈ 10(5)-10(7)M(-1)s(-1) at pH 7). For phenolic moieties, it is possible to derive second-order rate constants with a Hammett-σ-based QSAR approach with [Formula in text]. A negative slope is typical for electrophilic substitution reactions. In general, kapp of bromine reactions at pH 7 are up to three orders of magnitude greater than for chlorine. In the case of amines, these rate constants are even higher than for ozone. Model calculations show that depending on the bromide concentration and the pH, the high reactivity of bromine may outweigh the reactions of chlorine during

  12. Bromination of Aromatic Compounds by Residual Bromide in Sodium Chloride Matrix Modifier Salt During Heated Headspace GC/MS Analysis

    Science.gov (United States)

    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 rea...

  13. The impact of commercially treated oil and gas produced water discharges on bromide concentrations and modeled brominated trihalomethane disinfection byproducts at two downstream municipal drinking water plants in the upper Allegheny River, Pennsylvania, USA.

    Science.gov (United States)

    Landis, Matthew S; Kamal, Ali S; Kovalcik, Kasey D; Croghan, Carry; Norris, Gary A; Bergdale, Amy

    2016-01-15

    In 2010, a dramatic increase in the levels of total trihalomethane (THM) and the relative proportion of brominated species was observed in finished water at several Pennsylvania water utilities (PDW) using the Allegheny River as their raw water supply. An increase in bromide (Br(-)) concentrations in the Allegheny River was implicated to be the cause of the elevated water disinfection byproducts. This study focused on quantifying the contribution of Br(-) from a commercial wastewater treatment facility (CWTF) that solely treats wastes from oil and gas producers and discharges into the upper reaches of the Allegheny River, and impacts on two downstream PDWs. In 2012, automated daily integrated samples were collected on the Allegheny River at six sites during three seasonal two-week sampling campaigns to characterize Br(-) concentrations and river dispersion characteristics during periods of high and low river discharges. The CWTF discharges resulted in significant increases in Br(-) compared to upstream baseline values in PDW raw drinking water intakes during periods of low river discharge. During high river discharge, the assimilative dilution capacity of the river resulted in lower absolute halide concentrations, but significant elevations Br(-) concentrations were still observed at the nearest downstream PDW intake over baseline river levels. On days with active CWTF effluent discharge the magnitude of bromide impact increased by 39 ppb (53%) and 7 ppb (22%) for low and high river discharge campaigns, respectively. Despite a declining trend in Allegheny River Br(-) (2009-2014), significant impacts from CWTF and coal-fired power plant discharges to Br(-) concentrations during the low river discharge regime at downstream PDW intakes was observed, resulting in small modeled increases in total THM (3%), and estimated positive shifts (41-47%) to more toxic brominated THM analogs. The lack of available coincident measurements of THM, precursors, and physical parameters

  14. The impact of commercially treated oil and gas produced water discharges on bromide concentrations and modeled brominated trihalomethane disinfection byproducts at two downstream municipal drinking water plants in the upper Allegheny River, Pennsylvania, USA.

    Science.gov (United States)

    Landis, Matthew S; Kamal, Ali S; Kovalcik, Kasey D; Croghan, Carry; Norris, Gary A; Bergdale, Amy

    2016-01-15

    In 2010, a dramatic increase in the levels of total trihalomethane (THM) and the relative proportion of brominated species was observed in finished water at several Pennsylvania water utilities (PDW) using the Allegheny River as their raw water supply. An increase in bromide (Br(-)) concentrations in the Allegheny River was implicated to be the cause of the elevated water disinfection byproducts. This study focused on quantifying the contribution of Br(-) from a commercial wastewater treatment facility (CWTF) that solely treats wastes from oil and gas producers and discharges into the upper reaches of the Allegheny River, and impacts on two downstream PDWs. In 2012, automated daily integrated samples were collected on the Allegheny River at six sites during three seasonal two-week sampling campaigns to characterize Br(-) concentrations and river dispersion characteristics during periods of high and low river discharges. The CWTF discharges resulted in significant increases in Br(-) compared to upstream baseline values in PDW raw drinking water intakes during periods of low river discharge. During high river discharge, the assimilative dilution capacity of the river resulted in lower absolute halide concentrations, but significant elevations Br(-) concentrations were still observed at the nearest downstream PDW intake over baseline river levels. On days with active CWTF effluent discharge the magnitude of bromide impact increased by 39 ppb (53%) and 7 ppb (22%) for low and high river discharge campaigns, respectively. Despite a declining trend in Allegheny River Br(-) (2009-2014), significant impacts from CWTF and coal-fired power plant discharges to Br(-) concentrations during the low river discharge regime at downstream PDW intakes was observed, resulting in small modeled increases in total THM (3%), and estimated positive shifts (41-47%) to more toxic brominated THM analogs. The lack of available coincident measurements of THM, precursors, and physical parameters

  15. METHOD OF SEPARATING URANIUM, PLUTONIUM AND FISSION PRODUCTS BY BROMINATION AND DISTILLATION

    Science.gov (United States)

    Jaffey, A.H.; Seaborg, G.T.

    1958-12-23

    The method for separation of plutonium from uranium and radioactive fission products obtained by neutron irradiation of uranlum consists of reacting the lrradiated material with either bromine, hydrogen bromide, alumlnum bromide, or sulfur and bromine at an elevated temperature to form the bromides of all the elements, then recovering substantlally pure plutonium bromide by dlstillatlon in combinatlon with selective condensatlon at prescribed temperature and pressure.

  16. Electrical polarization of lead bromide crystals. I

    NARCIS (Netherlands)

    Schoonman, A.; Macke, A.J.H.

    1972-01-01

    An attempt was made to measure electronic conductivity in lead bromide in equilibrium with lead, since experimental data on the cell −Pb/PbBr2/C+ in the literature are not consistent with existing theories. Combination of our results with published data for bromine-induced hole conduction in lead br

  17. The Impact of Commercially Treated Oil and Gas Produced Water Discharges on Bromide Concentrations and Modeled Brominated Trihalomethane Disinfection Byproducts at two Downstream Municipal Drinking Water Plants in the Upper Allegheny River, Pennsylvania, USA

    Science.gov (United States)

    In 2010, a dramatic increase in the levels of total trihalomethane (THM) and the relative proportion of brominated species were observed in finished water at several Western Pennsylvania water utilities (PDW) using the Allegheny River as their raw water supply. An increase in br...

  18. Conversion of Alcohols to Bromides by Trimethylsilane and lithium Bromide in Acetone

    Institute of Scientific and Technical Information of China (English)

    Wei Feng; Zhang Xiao-xia; Zhang Qing; Wang Ji-yu; Chen Dai-mo

    2004-01-01

    Conversion of alcohols to alkyl bromides is one of the most frequently used functional group transformation reactions. Phosphorus tribromide is one of the most popular classical reagents.Triphenylphosphine has been used in combination with bromine,carbon tetrabromide,N-halo imides and other bromide compounds as a mild reagents for the preparation of alkyl bromides.More reacently, halotrimethylsilanes were found to be useful for halogenation of alcohols. George A.Olah successfully converted alcohols to bromides with chlorotrimethylsilane/lithium bromide in acetonitrile. But in our research, we found that we got no bromides but methylation products when we planed to convered our substances to bromides according to Gerge's method. We did some experiments, and we found that when the substituent group in the 2-N was donor group,we got the methylation products,but when it was acceptor group,the bromide could be got.(Scheme 1).Then we did some experiments with several other solvents, we found excitedly that when the solvent was acetone ,the bromides could be got even the substituent group was donor.(Scheme 2).When we changed the substances to normal alcohols ,such as ethyl alcohol,benzyl alcohol,isopropyl alcohol and 3,4-dimethoxy benzyl alcohol,we also got the bromides.In conclusion, we found a simple method to convert alcohols to bromides with trimethylsilane/li thium bromide in acetone,which was better than Geroge's method.

  19. Abiotic Bromination of Soil Organic Matter.

    Science.gov (United States)

    Leri, Alessandra C; Ravel, Bruce

    2015-11-17

    Biogeochemical transformations of plant-derived soil organic matter (SOM) involve complex abiotic and microbially mediated reactions. One such reaction is halogenation, which occurs naturally in the soil environment and has been associated with enzymatic activity of decomposer organisms. Building on a recent finding that naturally produced organobromine is ubiquitous in SOM, we hypothesized that inorganic bromide could be subject to abiotic oxidations resulting in bromination of SOM. Through lab-based degradation treatments of plant material and soil humus, we have shown that abiotic bromination of particulate organic matter occurs in the presence of a range of inorganic oxidants, including hydrogen peroxide and assorted forms of ferric iron, producing both aliphatic and aromatic forms of organobromine. Bromination of oak and pine litter is limited primarily by bromide concentration. Fresh plant material is more susceptible to bromination than decayed litter and soil humus, due to a labile pool of mainly aliphatic compounds that break down during early stages of SOM formation. As the first evidence of abiotic bromination of particulate SOM, this study identifies a mechanistic source of the natural organobromine in humic substances and the soil organic horizon. Formation of organobromine through oxidative treatments of plant material also provides insights into the relative stability of aromatic and aliphatic components of SOM.

  20. Bromine Safety

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, B

    2001-04-09

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

  1. Bromination of Phenol

    Science.gov (United States)

    Talbot, Christopher

    2013-01-01

    This "Science note" examines the bromination of phenol, a reaction that is commonly taught at A-level and IB (International Baccalaureate) as an example of electrophilic substitution. Phenol undergoes bromination with bromine or bromine water at room temperature. A white precipitate of 2,4,6-tribromophenol is rapidly formed. This…

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

    Institute of Scientific and Technical Information of China (English)

    薛伟华; 张立芬

    2012-01-01

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

  3. Bromination of selected pharmaceuticals in water matrices.

    Science.gov (United States)

    Benitez, F Javier; Acero, Juan L; Real, Francisco J; Roldan, Gloria; Casas, Francisco

    2011-11-01

    The bromination of five selected pharmaceuticals (metoprolol, naproxen, amoxicillin, phenacetin, and hydrochlorothiazide) was studied with these compounds individually dissolved in ultra-pure water. The apparent rate constants for the bromination reaction were determined as a function of the pH, obtaining the sequence amoxicillin>naproxen>hydrochlorothiazide≈phenacetin≈metoprolol. A kinetic mechanism specifying the dissociation reactions and the species formed for each compound according to its pK(a) value and the pH allowed the intrinsic rate constants to be determined for each elementary reaction. There was fairly good agreement between the experimental and calculated values of the apparent rate constants, confirming the goodness of the proposed reaction mechanism. In a second stage, the bromination of the selected pharmaceuticals simultaneously dissolved in three water matrices (a groundwater, a surface water from a public reservoir, and a secondary effluent from a WWTP) was investigated. The pharmaceutical elimination trend agreed with the previously determined rate constants. The influence of the main operating conditions (pH, initial bromine dose, and characteristics of the water matrix) on the degradation of the pharmaceuticals was established. An elimination concentration profile for each pharmaceutical in the water matrices was proposed based on the use of the previously evaluated apparent rate constants, and the theoretical results agreed satisfactorily with experiment. Finally, chlorination experiments performed in the presence of bromide showed that low bromide concentrations slightly accelerate the oxidation of the selected pharmaceuticals during chlorine disinfection.

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

  5. Elemental Bromine Production by TiO2 Photocatalysis and/or Ozonation.

    Science.gov (United States)

    Parrino, Francesco; Camera Roda, Giovanni; Loddo, Vittorio; Palmisano, Leonardo

    2016-08-22

    Significant production of elemental bromine (Br2 ) was observed for the first time when treating bromide containing solutions at acidic pH, with TiO2 photocatalyst, ozone, or a combination thereof. Br2 selectivities up to approximately 85 % were obtained and the corresponding bromine mass balance values satisfied. The process is general and may be applied at a laboratory scale for green bromination reactions, or industrially as a cheap, safe, and environmentally sustainable alternative to the currently applied bromine production methods.

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

    OpenAIRE

    Ayman A. Gouda

    2013-01-01

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

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

    OpenAIRE

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

    2016-01-01

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

  8. Synthesis of Dimethyl Aryl Acylsulfonium Bromides from Aryl Methyl Ketones in a DMSO-HBr System

    OpenAIRE

    Zhiling Cao; Dahua Shi; Yingying Qu; Chuanzhou Tao; Weiwei Liu; Guowei Yao

    2013-01-01

    A new, simplified method for the synthesis of dimethyl aryl acylsulfonium salts has been developed. A series of dimethyl aryl acylsulfonium bromides were prepared by the reaction of aryl methyl ketones with hydrobromic acid and dimethylsulfoxide (DMSO). This sulfonium salt confirms that bromine production and the bromination reaction take place in the DMSO-HBr oxidation system. What’s more, it is also a key intermediate for the synthesis of arylglyoxals.

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

    Directory of Open Access Journals (Sweden)

    J. A. Neuman

    2010-07-01

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

  10. The application of activation analysis for the control of bromide accumulation in vegetable

    International Nuclear Information System (INIS)

    Soil desinfestation with methyl bromide increases the uptake of bromine by plants. The natural bromine content of crops and fruits was found in the range of 1 up to 5 ppm in fresh weight. The highest acceptable level is 50 ppm in fresh weight. By using methyl bromide as a soil fumigant, a bromine accumulation was found in the crops to levels up to 20-500 ppm in fresh matter. The uptake of bromine differs in various parts of the vegetable crops. The highest bromine concentration could be observed in the leaves. The bromine uptake by plants depends on (a) the fumigation technique (applied amounts, reaction time, date of cultivation); (b) the growing conditions (soil type, climate and irrigation); (c) the plants (species, rotation, harvesting time etc.). The INAA is a simple and rapid method to analyse bromine in vegetables within a wide range using Br-80 and Br-82. Since several years this method has also been used to control imported crops. The samples were subjected to a short irradiation (1-3 minutes at 1013ncm-2sec-1). After the decay time of a few minutes the induced activity was measured with a Ge(Li) detector coupled to a multi-channel analyzer. The limit of detection varies between 0.1 and 0.5 ppm Br in fresh vegetable samples. (T.G.)

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

    International Nuclear Information System (INIS)

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

  12. Vanadate-dependent bromoperoxidases from Ascophyllum nodosum in the synthesis of brominated phenols and pyrroles.

    Science.gov (United States)

    Wischang, Diana; Radlow, Madlen; Hartung, Jens

    2013-09-01

    Bromoperoxidases from the brown alga Ascophyllum nodosum, abbreviated as V(Br)PO(AnI) and V(Br)PO(AnII), show 41% sequence homology and differ by a factor of two in the percentage of α-helical secondary structures. Protein monomers organize into homodimers for V(Br)PO(AnI) and hexamers for V(Br)PO(AnII). Bromoperoxidase II binds hydrogen peroxide and bromide by approximately one order of magnitude stronger than V(Br)PO(AnI). In oxidation catalysis, bromoperoxidases I and II turn over hydrogen peroxide and bromide similarly fast, yielding in morpholine-4-ethanesulfonic acid (MES)-buffered aqueous tert-butanol (pH 6.2) molecular bromine as reagent for electrophilic hydrocarbon bromination. Alternative compounds, such as tribromide and hypobromous acid are not sufficiently electrophilic for being directly involved in carbon-bromine bond formation. A decrease in electrophilicity from bromine via hypobromous acid to tribromide correlates in a frontier molecular orbital (FMO) analysis with larger energy gaps between the π-type HOMO of, for example, an alkene and the σ*(Br,X)-type LUMO of the bromination reagent. By using this approach, the reactivity of substrates and selectivity for carbon-bromine bond formation in reactions mediated by vanadate-dependent bromoperoxidases become predictable, as exemplified by the synthesis of bromopyrroles occurring naturally in marine sponges of the genera Agelas, Acanthella, and Axinella. PMID:23881071

  13. Methyl bromide release from activated carbon and the soil/water/carbon interface

    Science.gov (United States)

    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...

  14. Inorganic bromine in the marine boundary layer: a critical review

    Directory of Open Access Journals (Sweden)

    R. Sander

    2003-06-01

    Full Text Available The cycling of inorganic bromine in the marine boundary layer (mbl has received increased attention in recent years. Bromide, a constituent of sea water, is injected into the atmosphere in association with sea-salt aerosol by breaking waves on the ocean surface. Measurements reveal that supermicrometer sea-salt aerosol is depleted in bromine by about 50% relative to conservative tracers, whereas marine submicrometer aerosol is often enriched in bromine. Model calculations, laboratory studies, and field observations strongly suggest that these depletions reflect the chemical transformation of particulate bromide to reactive inorganic gases that influence the processing of ozone and other important constituents of marine air. However, currently available techniques cannot reliably quantify many chem{Br}-containing compounds at ambient concentrations and, consequently, our understanding of inorganic Br cycling over the oceans and its global significance are uncertain. To provide a more coherent framework for future research, we have reviewed measurements in marine aerosol, the gas phase, and in rain. We also summarize sources and sinks, as well as model and laboratory studies of chemical transformations. The focus is on inorganic bromine over the open oceans, excluding the polar regions. The generation of sea-salt aerosol at the ocean surface is the major tropospheric source producing about 6.2 Tg/a of bromide. The transport of  Br from continents (as mineral aerosol, and as products from biomass-burning and fossil-fuel combustion can be of local importance. Transport of degradation products of long-lived Br-containing compounds from the stratosphere and other sources contribute lesser amounts. Available evidence suggests that, following aerosol acidification, sea-salt bromide reacts to form Br2 and BrCl that volatilize to the gas phase and photolyze in daylight to produce atomic Br and Cl. Subsequent transformations can destroy

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

    International Nuclear Information System (INIS)

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

  16. Kinetics of Chlorination of Benzophenone-3 in the Presence of Bromide and Ammonia.

    Science.gov (United States)

    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.

  17. Methyl bromide: Ocean sources, ocean sinks, and climate sensitivity

    OpenAIRE

    A. D. Anbar; Yung, Y. L.; Chavez, F.P.

    1996-01-01

    The oceans play an important role in the geochemical cycle of methyl bromide (CH_3Br), the major carrier of O_3-destroying bromine to the stratosphere. The quantity of CH_3Br 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 CH_3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmo...

  18. Reactivity of BrCl, Br₂, BrOCl, Br₂O, and HOBr toward dimethenamid in solutions of bromide + aqueous free chlorine.

    Science.gov (United States)

    Sivey, John D; Arey, J Samuel; Tentscher, Peter R; Roberts, A Lynn

    2013-02-01

    HOBr, formed via oxidation of bromide by free available chlorine (FAC), is frequently assumed to be the sole species responsible for generating brominated disinfection byproducts (DBPs). Our studies reveal that BrCl, Br(2), BrOCl, and Br(2)O can also serve as brominating agents of the herbicide dimethenamid in solutions of bromide to which FAC was added. Conditions affecting bromine speciation (pH, total free bromine concentration ([HOBr](T)), [Cl(-)], and [FAC](o)) were systematically varied, and rates of dimethenamid bromination were measured. Reaction orders in [HOBr](T) ranged from 1.09 (±0.17) to 1.67 (±0.16), reaching a maximum near the pK(a) of HOBr. This complex dependence on [HOBr](T) implicates Br(2)O as an active brominating agent. That bromination rates increased with increasing [Cl(-)], [FAC](o) (at constant [HOBr](T)), and excess bromide (where [Br(-)](o)>[FAC](o)) implicate BrCl, BrOCl, and Br(2), respectively, as brominating agents. As equilibrium constants for the formation of Br(2)O and BrOCl (aq) have not been previously reported, we have calculated these values (and their gas-phase analogues) using benchmark-quality quantum chemical methods [CCSD(T) up to CCSDTQ calculations plus solvation effects]. The results allow us to compute bromine speciation and hence second-order rate constants. Intrinsic brominating reactivity increased in the order: HOBr ≪ Br(2)O water and wastewater chlorination.

  19. Rapid Formation of Molecular Bromine from Deliquesced NaBr Aerosol in the Presence of Ozone and UV Light

    Science.gov (United States)

    The formation of gas-phase bromine from aqueous sodium bromide aerosols is investigated through a combination of chamber experiments and chemical kinetics modeling. Experiments show that Br2(g) is produced rapidly from deliquesced NaBr aerosols in the presence of OH radicals prod...

  20. Impact of bromide on halogen incorporation into organic moieties in chlorinated drinking water treatment and distribution systems.

    Science.gov (United States)

    Tan, J; Allard, S; Gruchlik, Y; McDonald, S; Joll, C A; Heitz, A

    2016-01-15

    The impact of elevated bromide concentrations (399 to 750 μg/L) on the formation of halogenated disinfection by-products (DBPs), namely trihalomethanes, haloacetic acids, haloacetonitriles, and adsorbable organic halogen (AOX), in two drinking water systems was investigated. Bromine was the main halogen incorporated into all of the DBP classes and into organic carbon, even though chlorine was present in large excess to maintain a disinfectant residual. Due to the higher reactivity of bromine compared to chlorine, brominated DBPs were rapidly formed, followed by a slower increase in chlorinated DBPs. Higher bromine substitution and incorporation factors for individual DBP classes were observed for the chlorinated water from the groundwater source (lower concentration of dissolved organic carbon (DOC)), which contained a higher concentration of bromide, than for the surface water source (higher DOC). The molar distribution of adsorbable organic bromine to chlorine (AOBr/AOCl) for AOX in the groundwater distribution system was 1.5:1 and almost 1:1 for the surface water system. The measured (regulated) DBPs only accounted for 16 to 33% of the total organic halogen, demonstrating that AOX measurements are essential to provide a full understanding of the formation of halogenated DBPs in drinking waters. In addition, the study demonstrated that a significant proportion (up to 94%) of the bromide in source waters can be converted AOBr. An evaluation of AOBr and AOCl through a second groundwater treatment plant that uses conventional treatment processes for DOC removal produced 70% of AOX as AOBr, with 69% of the initial source water bromide converted to AOBr. Exposure to organobromine compounds is suspected to result in greater adverse health consequences than their chlorinated analogues. Therefore, this study highlights the need for improved methods to selectively reduce the bromide content in source waters.

  1. Development of a miniature dielectric barrier discharge–optical emission spectrometric system for bromide and bromate screening in environmental water samples

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Dielectric barrier discharge (DBD) is for the first time used as a radiation source for the excitation of bromine and its emission. •A DBD–optical emission spectrometric (OES) system was developed for the detection of bromide and bromate. •The DBD–OES system has been demonstrated by screening trace bromide and bromate in a series of environmental water samples. -- Abstract: Dielectric barrier discharge (DBD) at atmospheric pressure provides an efficient radiation source for the excitation of bromine and it is used for the first time for optical emission spectrometric (OES) detection of bromide and bromate. A portable DBD–OES system is developed for screening potential pollution from bromide and bromate in environmental waters. Bromide is on-line oxidized to bromine for in-situ generation of volatile bromine. Meanwhile, a helium stream carries bromine into the DBD micro-plasma for its excitation at a discharging voltage of 3.7 kV and optical emission spectrometric detection with a QE65000 charge-coupled device (CCD) spectrometer in the near-infrared spectral region. Similarly, the quantification of bromate is performed by its pre-reduction into bromide and then oxidized to bromine. The spectral characteristics and configuration of the DBD micro-plasma excitation source in addition to the oxidation vapor generation of bromine have been thoroughly investigated. With a sampling volume of 1 mL, a linear range of 0.05–10.0 mg L−1 is obtained with a detection limit of 0.014 mg L−1 by measuring the emission at 827 nm. A precision of 2.3% is achieved at 3 mg L−1 bromide. The system is validated by bromine detection in certified reference material of laver (GBW10023) at mg L−1 level, giving rise to satisfactory agreement. In addition, it is further demonstrated by screening trace bromide and bromate as well as spiking recoveries in a series of environmental water samples

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-01

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

  3. Rapacuronium bromide (Organon Teknika).

    Science.gov (United States)

    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].

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Cong-Cong [Research Center For Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhang, Fu-Shen, E-mail: fszhang@rcees.ac.cn [Research Center For Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)

    2012-06-30

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

  5. Characterization of unknown brominated disinfection byproducts during chlorination using ultrahigh resolution mass spectrometry.

    Science.gov (United States)

    Zhang, Haifeng; Zhang, Yahe; Shi, Quan; Zheng, Hongdie; Yang, Min

    2014-03-18

    Brominated disinfection byproducts (Br-DBPs), formed from the reaction of disinfectant(s) with natural organic matter in the presence of bromide in raw water, are generally more cytotoxic and genotoxic than their chlorinated analogues. To date, only a few Br-DBPs in drinking water have been identified, while a significant portion of Br-DBPs in drinking water is still unknown. In this study, negative ion electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown Br-DBPs in artificial drinking water. In total, 441 formulas for one-bromine-containing products and 37 formulas for two-bromine-containing products, most of which had not been previously reported, were detected in the chlorinated sample. Most Br-DBPs have corresponding chlorine-containing analogues with identical CHO composition. In addition, on-resonance collision-induced dissociation (CID) of single ultrahigh resolved bromine containing mass peaks was performed in the ICR cell to isolate single bromine-containing components in a very complex natural organic matter spectrum and provide structure information. Relatively abundant neutral loss of CO2 was observed in MS-MS spectra, indicating that the unknown Br-DBPs are rich in carboxyl groups. The results demonstrate that the ESI FT-ICR MS method could provide valuable molecular composition and structure information on unknown Br-DBPs.

  6. Methylnaltrexone bromide methanol monosolvate

    Directory of Open Access Journals (Sweden)

    Xinbo Zhou

    2012-03-01

    Full Text Available In the title compound [systematic name: (4R,4aS,7aR,12bS-3-cyclopropylmethyl-4a,9-hydroxy-7-oxo-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium bromide methanol monosolvate], C21H26NO4+·Br−·CH3OH, two of the three six-membered rings adopt chair conformations while the third, which contains a C=C double bond, adopts an approximate half-boat conformation. The 2,3-dihydrofuran ring adopts an envelope conformation. In the crystal, the components are linked by O—H...O and O—H...Br hydrogen bonds. The absolute stereochemistry was inferred from one of the starting materials.

  7. Iron bromide vapor laser

    Science.gov (United States)

    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.

  8. Effect of increasing bromide concentration on toxicity in treated drinking water.

    Science.gov (United States)

    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. PMID:27105403

  9. Bromate formation from bromide oxidation by the UV/persulfate process.

    Science.gov (United States)

    Fang, Jing-Yun; Shang, Chii

    2012-08-21

    Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO(4)(•-)) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr(-)) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO(4)(•-) is slower than that of the second step. Direct UV photolysis of HOBr/OBr(-) to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4-7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with bromine atoms, HOBr/OBr(-) and SO(4)(•-). The extent of bromate formation and degradation of micropollutants are nevertheless coupled processes unless intermediate bromine species are consumed by NOM in real water. PMID:22831804

  10. Effect of increasing bromide concentration on toxicity in treated drinking water.

    Science.gov (United States)

    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.

  11. Thermal Recycling of Brominated Flame Retardants with Fe2O3.

    Science.gov (United States)

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

    2016-08-01

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

  12. Non-conservative behavior of bromide in surface waters and brines of Central Andes : a release into the atmosphere ?

    OpenAIRE

    Risacher, François; Fritz, B; Alonso, H.

    2006-01-01

    The transfer of reactive bromine into the atmosphere was recently observed by Honninger et al. [Honninger, G., Bobrowski, N., Palenque, E.R., Torrez, R., Platt, U., 2004. Reactive bromine and sulfur emission at salar de Uyuni, Bolivia. Geophys. Res. Lett. 31, doi:10.1029/2003GL018818] in a large salt pan of the Bolivian Altiplano: the salar de Uyuni. However, bromide is considered to be an excellent conservative tracer, which leads to the questioning of its actual conservation in surficial ge...

  13. Electrochemical Recognition of Metalloproteins by Bromide-modified Silver Electrode - A New Method

    Directory of Open Access Journals (Sweden)

    Abbas Ali Rostami

    2007-07-01

    Full Text Available A bromide–modified silver electrode is reported, in the present study, to catalyzethe redox reactions of metalloproteins. This study describes that the bromide ions showvery good redox behavior with silver electrode. The cathodic and anodic peak potentialswere related to the concentration of bromide ions involved in making bromide-modifiedsilver electrode. The electrode reaction in the bromine solution was a diffusion-controlledprocess. Positive potential shift of the bromide ions was seen when different proteins wereadded to the solution using a silver electrode. New cathodic and anodic peaks wereobserved at different potential ranges for myoglobin, cytochrome c and catalase. A linearlyincreasing cathodic peak current of bromide ions was seen when the concentration ofsuperoxide dismutase was increased in the test solution. However, no change for albuminwas observed when its concentration was increased in the test solution. Present data provesour methodology as an easy-to-use analysis for comparing the redox potentials of differentmetalloproteins and differentiating the metallo- from non-metalloproteins. In this study, weintroduced an interesting method for bio-electrochemical analyses.

  14. Effect of ferric and bromide ions on the formation and speciation of disinfection byproducts during chlorination

    Institute of Scientific and Technical Information of China (English)

    Shaogang Liu; Zhiliang Zhu; Yanling Qiu; Jianfu Zhao

    2011-01-01

    The effects of ferric ion, pH, and bromide on the formation and distribution of disinfection byproducts (DBPs) during chlorination were studied. Two raw water samples from Huangpu River and Yangtze River, two typical drinking water sources of Shanghai, were used for the investigation. Compared with the samples from Huangpu River, the raw water samples from Yangtze River had lower content of total organic carbon (TOC) and ferric ions, but higher bromide concentrations. Under controlled chlorination conditions,four trihalomethanes (THMs), nine haloacetic acids (HAAs), total organic halogen (TOX) and its halogen species fractions, including total organic chlorine (TOC1) and total organic bromide (TOBr), were determined. The results showed that co-existent ferric and bromide ions significantly promoted the formation of total THMs and HAAs for both raw water samples. Higher concentration of bromide ions significantly changed the speciation of the formed THMs and HAAs. There was an obvious shift to brominated species,which might result in a more adverse influence on the safety of drinking water. The results also indicated that high levels of bromide ions in raw water samples produced higher percentages of unknown TOBr.

  15. Effect of ferric and bromide ions on the formation and speciation of disinfection byproducts during chlorination.

    Science.gov (United States)

    Liu, Shaogang; Zhu, Zhiliang; Qiu, Yanling; Zhao, Jianfu

    2011-01-01

    The effects of ferric ion, pH, and bromide on the formation and distribution of disinfection byproducts (DBPs) during chlorination were studied. Two raw water samples from Huangpu River and Yangtze River, two typical drinking water sources of Shanghai, were used for the investigation. Compared with the samples from Huangpu River, the raw water samples from Yangtze River had lower content of total organic carbon (TOC) and ferric ions, but higher bromide concentrations. Under controlled chlorination conditions, four trihalomethanes (THMs), nine haloacetic acids (HAAs), total organic halogen (TOX) and its halogen species fractions, including total organic chlorine (TOC1) and total organic bromide (TOBr), were determined. The results showed that co-existent ferric and bromide ions significantly promoted the formation of total THMs and HAAs for both raw water samples. Higher concentration of bromide ions significantly changed the speciation of the formed THMs and HAAs. There was an obvious shift to brominated species, which might result in a more adverse influence on the safety of drinking water. The results also indicated that high levels of bromide ions in raw water samples produced higher percentages of unknown TOBr.

  16. Enhancement of the carbon electrode capacitance by brominated hydroquinones

    Science.gov (United States)

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

    2016-09-01

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

  17. Predictive models for water sources with high susceptibility for bromine-containing disinfection by-product formation: implications for water treatment.

    Science.gov (United States)

    Watson, Kalinda; Farré, Maria José; Birt, James; McGree, James; Knight, Nicole

    2015-02-01

    This study examines a matrix of synthetic water samples designed to include conditions that favour brominated disinfection by-product (Br-DBP) formation, in order to provide predictive models suitable for high Br-DBP forming waters such as salinity-impacted waters. Br-DBPs are known to be more toxic than their chlorinated analogues, in general, and their formation may be favoured by routine water treatment practices such as coagulation/flocculation under specific conditions; therefore, circumstances surrounding their formation must be understood. The chosen factors were bromide concentration, mineral alkalinity, bromide to dissolved organic carbon (Br/DOC) ratio and Suwannee River natural organic matter concentration. The relationships between these parameters and DBP formation were evaluated by response surface modelling of data generated using a face-centred central composite experimental design. Predictive models for ten brominated and/or chlorinated DBPs are presented, as well as models for total trihalomethanes (tTHMs) and total dihaloacetonitriles (tDHANs), and bromide substitution factors for the THMs and DHANs classes. The relationships described revealed that increasing alkalinity and increasing Br/DOC ratio were associated with increasing bromination of THMs and DHANs, suggesting that DOC lowering treatment methods that do not also remove bromide such as enhanced coagulation may create optimal conditions for Br-DBP formation in waters in which bromide is present. PMID:25163557

  18. Distribution and speciation of bromine in mammalian tissue and fluids by X-ray fluorescence imaging and X-ray absorption spectroscopy.

    Science.gov (United States)

    Ceko, Melanie J; Hummitzsch, Katja; Hatzirodos, Nicholas; Bonner, Wendy; James, Simon A; Kirby, Jason K; Rodgers, Raymond J; Harris, Hugh H

    2015-05-01

    Bromine is one of the most abundant and ubiquitous trace elements in the biosphere and until recently had not been shown to perform any essential biological function in animals. A recent study demonstrated that bromine is required as a cofactor for peroxidasin-catalysed formation of sulfilimine crosslinks in Drosophila. In addition, bromine dietary deficiency is lethal in Drosophila, whereas bromine replenishment restores viability. The aim of this study was to examine the distribution and speciation of bromine in mammalian tissues and fluids to provide further insights into the role and function of this element in biological systems. In this study we used X-ray fluorescence (XRF) imaging and inductively coupled plasma-mass spectrometry (ICP-MS) to examine the distribution of bromine in bovine ovarian tissue samples, follicular fluid and aortic serum, as well as human whole blood and serum and X-ray absorption spectroscopy (XAS) to identify the chemical species of bromine in a range of mammalian tissue (bovine, ovine, porcine and murine), whole blood and serum samples (bovine, ovine, porcine, murine and human), and marine samples (salmon (Salmo salar), kingfish (Seriola lalandi) and Scleractinian coral). Bromine was found to be widely distributed across all tissues and fluids examined. In the bovine ovary in particular it was more concentrated in the sub-endothelial regions of arterioles. Statistical comparison of the near-edge region of the X-ray absorption spectra with a library of bromine standards led to the conclusion that the major form of bromine in all samples analysed was bromide. PMID:25675086

  19. Titrimetric, spectrophotometric and kinetic methods for the assay of atenolol using bromate–bromide and methyl orange

    Directory of Open Access Journals (Sweden)

    KANAKAPURA BASAVAIAH

    2006-05-01

    Full Text Available Three new methods have been developed for the determination of atenolol in bulk drug and in tablet formulation. The methods are based on the oxidation–bromination reaction of the drug by bromine, generated in situ by the action of acid on a bromate–bromide mixture. In the titrimetric method, the drug is treated with a known excess of bromate–bromide mixture in hydrochloric acid medium, followed by the determination of the unreacted bromine iodometrically. The spectrophotometric method involves the addition of a measured excess of bromate–bromide reagent in hydrochloric acid medium to atenolol, and after ensuring the reaction had gone to completion, the unreacted bromine is treated with a fixed amount of methyl orange, and absorbance measured at 520 nm. The absorbance was found to increase linearly with increasing concentration of atenolol. The kinetic method depends on the existence of a linear relationship between the concentration of the drug and the time of the oxidation–bromination reaction, as indicated by the bleaching of methyl orange acid colour. The working conditions were optimized. The titrimetric method is based on a 1:1 reaction stoichiometry (atenolol:bromate and is applicable over the 3–20 mg range. The spectrophotometric method permits micro determination of the drug (0.5–4.0 mg ml-1with an apparentmolar absorptivity of 4.13x104 lmol-1 cm-1 and detection limit of 0.07 mg ml-1. The kinetic method is applicable in the concentration range 5–25 mg ml-1 with a detection limit of 3.72 mg ml-1. The proposed methods were successfully applied to the determination of atenolol in tablet preparations with mean recoveries of 97.63 to 101.78 %. The reliability of the assay was established by parallel determination by the reference method and by recovery studies using the standard addition technique.

  20. Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

    Science.gov (United States)

    Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

    2014-10-21

    Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

  1. Formation and distribution of disinfection by-products during chlorine disinfection in the presence of bromide ion

    Institute of Scientific and Technical Information of China (English)

    LI Bo; QU JiuHui; LIU HuiJuan; ZHAO Xu

    2008-01-01

    The influences of contact time and pH value on the formation and distribution of four species of triha-lomethanes and five species of haloacetic acids during chlorination in the presence of bromine were investigated. Results showed that the distribution of molar fraction of trihalomethanes varied with contact time due to the change of bromide ion concentration during chlorination. Most of the triha-lomethanes comprising bromine-containing species and the favored products of the haloacetic acids were chlorine-containing species after 24 h of chlorination. The extent of bromine incorporation in tri-halomethanes and haloacetic acids both decreased with time. The contact time also had influence on the formation rate of different species of haloacetic acids. The formation and distribution of triha-lomethanes and haloacetic acids strongly depended on the chlorination pH value. All of the triha-lomethanes species formation increased with the increase of pH value except the bromoform that had not been detected. The molar fraction of bromodichloromethane and dibromochloromethane contain-ing bromine increased with pH value while chloroform without bromine decreased. Under the pH range studied in this experiment, the predominant haloacetic acids species were trichloroacetic acid and dichloroacetic acid which all decreased with the increase of pH value and the level of TCAA was higher than that of DCAA.

  2. Distribution of copper, silver and gold during thermal treatment with brominated flame retardants

    Energy Technology Data Exchange (ETDEWEB)

    Oleszek, Sylwia, E-mail: sylwia_oleszek@yahoo.com [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Sendai 980-8577 (Japan); Institute of Environmental Engineering of the Polish Academy of Sciences, 34 M. Sklodowska-Curie St., 41-819 Zabrze (Poland); Grabda, Mariusz, E-mail: mariusz@mail.tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Sendai 980-8577 (Japan); Institute of Environmental Engineering of the Polish Academy of Sciences, 34 M. Sklodowska-Curie St., 41-819 Zabrze (Poland); Shibata, Etsuro, E-mail: etsuro@tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Sendai 980-8577 (Japan); Nakamura, Takashi, E-mail: ntakashi@tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Sendai 980-8577 (Japan)

    2013-09-15

    Highlights: • Copper, silver and gold during thermal treatment with brominated flame retardants. • Distribution of copper, silver and gold during thermal processing. • Thermodynamic considerations of the bromination reactions. - Abstract: The growing consumption of electric and electronic equipment results in creating an increasing amount of electronic waste. The most economically and environmentally advantageous methods for the treatment and recycling of waste electric and electronic equipment (WEEE) are the thermal techniques such as direct combustion, co-combustion with plastic wastes, pyrolysis and gasification. Nowadays, this kind of waste is mainly thermally treated in incinerators (e.g. rotary kilns) to decompose the plastics present, and to concentrate metals in bottom ash. The concentrated metals (e.g. copper, precious metals) can be supplied as a secondary raw material to metal smelters, while the pyrolysis of plastics allows the recovery of fuel gases, volatilising agents and, eventually, energy. Indeed, WEEE, such as a printed circuit boards (PCBs) usually contains brominated flame retardants (BFRs). From these materials, hydrobromic acid (HBr) is formed as a product of their thermal decomposition. In the present work, the bromination was studied of copper, silver and gold by HBr, originating from BFRs, such as Tetrabromobisphenol A (TBBPA) and Tetrabromobisphenol A-Tetrabromobisophenol A diglycidyl ether (TTDE) polymer; possible volatilization of the bromides formed was monitored using a thermo-gravimetric analyzer (TGA) and a laboratory-scale furnace for treating samples of metals and BFRs under an inert atmosphere and at a wide range of temperatures. The results obtained indicate that up to about 50% of copper and silver can evolve from sample residues in the form of volatile CuBr and AgBr above 600 and 1000 °C, respectively. The reactions occur in the molten resin phase simultaneously with the decomposition of the brominated resin. Gold is

  3. Iodine and bromine speciation in snow and the effect of orographically induced precipitation

    Directory of Open Access Journals (Sweden)

    H. Biester

    2007-05-01

    Full Text Available Iodine is an essential trace element for all mammals and may also influence climate through new aerosol formation. Atmospheric bromine cycling is also important due to its well-known ozone depletion capabilities. Despite precipitation being the ultimate source of iodine in the terrestrial environment, the processes effecting its distribution, speciation and transport are relatively unknown. The aim of this study was to determine the effect of orographically induced precipitation on iodine concentrations in snow and also to quantify the inorganic and organic iodine and bromine species. Snow samples were collected over an altitude profile (~840 m from the northern Black Forest and were analysed by ion-chromatography - inductively coupled plasma mass spectrometry (IC-ICP-MS for iodine and bromine species and trace metals (ICP-MS. All elements and species concentrations in snow showed significant (r2>0.65 exponential decrease relationships with altitude despite the short (5 km horizontal distance of the transect. In fact, total iodine more than halved (38 to 13 nmol/l over the 840 m height change. The results suggest that orographic lifting and subsequent precipitation has a major influence on iodine concentrations in snow. This orographically induced removal effect may be more important than lateral distance from the ocean in determining iodine concentrations in terrestrial precipitation. The microphysical removal process was common to all elements indicating that the iodine and bromine are internally mixed within the snow crystals. We also show that organically bound iodine is the dominant iodine species in snow (61–75%, followed by iodide. Iodate was only found in two samples despite a detection limit of 0.3 nmol/l. Two unknown but most likely anionic organo-I species were also identified in IC-ICP-MS chromatograms and comprised 2–10% of the total iodine. The majority of the bromine was inorganic bromide with a max. of 32% organo-Br.

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

    Science.gov (United States)

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

    2016-04-01

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

  5. The photodissociation of methyl bromide chemisorbed on Cu{111}: influence of pre-adsorbed bromine

    Science.gov (United States)

    Lamont, C. L. A.; Conrad, H.; Bradshaw, A. M.

    1993-05-01

    The photodissociation cross-section of CH 3Br chemisorbed on a Cu{111} surface pre-covered with Br has been measured as a function of wavelength. The onset for the reaction shifts to higher energy with increasing Br coverage and can be correlated with the increase in work function. The data are compatible with the charge-transfer mechanism involving excitation of an electron from the d-band in the substrate directly into the σ ∗ CBr orbital.

  6. Two new brominated diterpenes from Laurencia decumbens

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  7. Stability and metastability of bromine clathrate polymorphs.

    Science.gov (United States)

    Nguyen, Andrew H; Molinero, Valeria

    2013-05-23

    Clathrate hydrates are crystals in which water forms a network of fully hydrogen-bonded polyhedral cages that contain small guests. Clathrate hydrates occur mostly in two cubic crystal polymorphs, sI and sII. Bromine is one of two guests that yield a hydrate with the tetragonal structure (TS), the topological dual of the Frank-Kasper σ phase. There has been a long-standing disagreement on whether bromine hydrate also forms metastable sI and sII crystals. To date there are no data on the thermodynamic range of stability (e.g., the melting temperatures) of the metastable polymorphs. Here we use molecular dynamics simulations with the coarse-grained model of water mW to (i) investigate the thermodynamic stability of the empty and guest-filled the sI, sII, TS, and HS-I hydrate polymorphs, (ii) develop a coarse-grained model of bromine compatible with mW water, and (iii) evaluate the stability of the bromine hydrate polymorphs. The mW model predicts the same relative energy of the empty clathrate polymorphs and the same phase diagram as a function of water-guest interaction than the fully atomistic TIP4P water model. There is a narrow region in water-guest parameter space for which TS is marginally more stable than sI or sII. We parametrize a coarse-grained model of bromine compatible with mW water and use it to determine the order of stability of the bromine hydrate polymorphs. The melting temperatures of the bromine hydrate polymorphs predicted by the coarse-grained model are 281 ± 1 K for TS, 279 ± 1 K for sII, and 276 ± 1 K for sI. The closeness of the melting temperatures supports the plausibility of formation of metastable sII and sI bromine hydrates.

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

  10. Production of HBR from bromine and steam for off-peak electrolytic hydrogen generation

    Energy Technology Data Exchange (ETDEWEB)

    Schlief, R.E.; Hanrahan, R.J.; Stoy, M.A. [Univ. of Florida, Gainesville, FL (United States)] [and others

    1995-09-01

    Progress is reported on the development of a renewable energy source based solar-electrolytic system for production of hydrogen and oxygen. It employs water, bromine, solar energy and supplemental electrical power. The concept is being developed by Solar Reactor Technologies, Inc., (SRT), with the U.S. Department of Energy (DOE). An overview of the nature and objectives of this program is provided here, and technical progress made during the first (three-month) performance period of the Phase I work effort is reported. The SRT concept entails (1) absorption of concentrated solar radiation by bromine vapor Br{sub 2(g)} in a high-temperature reactor producing Br{sub (g)} atoms, (2) reaction of Br{sub (g)} with water yielding hydrogen bromide (HBr), and (3) electrolysis of stored hydrogen bromide for production of H{sub 2(g)} and recovery of Br{sub 2(I)}. Incorporation of solar radiation in the primary photochemical step (1) reduces by 50 - 70% the electrical power required to split water. The SRT concept is very attractive from an economic viewpoint as well. The reversible fuel cell, employed in the SRT electrolysis concept is capitalized via its use in load leveling by the utility. A 1 kW solar reactor was designed and constructed during the first three-month performance period by SRT personnel at the University of Florida, Gainesville. It was employed in taking survey data of the reaction between bromine and steam at temperatures between 900 and 1300 K. This reaction was run under purely thermal conditions, i.e. in the absence of solar photons. The experimental data are reported and interpreted employing concomitant thermodynamic calculations. The anticipated improvement is discussed briefly as well as the effect of a photochemical boost to the reaction. The amount of this enhancement will be studied in the next three month performance period.

  11. Different speciation for bromine in brown and red algae, revealed by in vivo X-ray absorption spectroscopic studies.

    Science.gov (United States)

    Küpper, Frithjof C; Leblanc, Catherine; Meyer-Klaucke, Wolfram; Potin, Philippe; Feiters, Martin C

    2014-08-01

    Members of various algal lineages are known to be strong producers of atmospherically relevant halogen emissions, that is a consequence of their capability to store and metabolize halogens. This study uses a noninvasive, synchrotron-based technique, X-ray absorption spectroscopy, for addressing in vivo bromine speciation in the brown algae Ectocarpus siliculosus, Ascophyllum nodosum, and Fucus serratus, the red algae Gracilaria dura, G. gracilis, Chondrus crispus, Osmundea pinnatifida, Asparagopsis armata, Polysiphonia elongata, and Corallina officinalis, the diatom Thalassiosira rotula, the dinoflagellate Lingulodinium polyedrum and a natural phytoplankton sample. The results highlight a diversity of fundamentally different bromine storage modes: while most of the stramenopile representatives and the dinoflagellate store mostly bromide, there is evidence for Br incorporated in nonaromatic hydrocarbons in Thalassiosira. Red algae operate various organic bromine stores - including a possible precursor (by the haloform reaction) for bromoform in Asparagopsis and aromatically bound Br in Polysiphonia and Corallina. Large fractions of the bromine in the red algae G. dura and C. crispus and the brown alga F. serratus are present as Br(-) defects in solid KCl, similar to what was reported earlier for Laminaria parts. These results are discussed according to different defensive strategies that are used within algal taxa to cope with biotic or abiotic stresses. PMID:26988449

  12. Iodine and Bromine speciation in snow and the effect of elevation

    Directory of Open Access Journals (Sweden)

    B. S. Gilfedder

    2007-01-01

    Full Text Available Iodine is an essential trace element for all mammals and may also influence climate through new aerosol formation. Atmospheric bromine cycling is also important due to its well-known ozone depletion capabilities. Despite precipitation being the ultimate source of iodine in the terrestrial environment, the processes effecting the distribution, speciation and transport of these elements are relatively unknown. The aim of this study was to determine the effect of orographic lifting on iodine concentrations and also quantify inorganic and organic iodine and bromine species. Snow samples were collected over an altitude profile (~800 m from the northern Black Forest and were analysed (IC-ICP-MS for iodine and bromine species and trace metals (ICP-MS. All elements and species showed a significant (r2>0.65 inverse relationship with altitude despite the short (5 km horizontal distance of the transect. In fact, total iodine more than halved (38 to 13 nmol/l over the 800 m height change. The results suggest that orographic lifting of cloud masses has a major influence on iodine levels in precipitation and is perhaps more important than lateral distances in determining iodine concentrations in terrestrial precipitation. The microphysical removal process was common to all elements. We also show that organically bound iodine is the dominant iodine species in snow (61–75%, followed by iodide. Iodate was only found in two samples despite a detection limit of 0.3 nmol/l. Two unknown but most likely anionic organo-I species were also identified in IC-ICP-MS chromatograms and comprised 2–10% of the total iodine. The majority of the bromine was inorganic bromide with a max.~of 32% organo-Br.

  13. A, a Brominated Flame Retardant

    Directory of Open Access Journals (Sweden)

    Tomomi Takeshita

    2013-01-01

    Full Text Available Tetrabromobisphenol A (TBBPA, a brominated flame retardant, has been found to exacerbate pneumonia in respiratory syncytial virus- (RSV- infected mice. We examined the effect of Brazilian propolis (AF-08 on the exacerbation of RSV infection by TBBPA exposure in mice. Mice were fed a powdered diet mixed with 1% TBBPA alone, 0.02% AF-08 alone, or 1% TBBPA and 0.02% AF-08 for four weeks and then intranasally infected with RSV. TBBPA exposure increased the pulmonary virus titer and level of IFN-γ, a representative marker of pneumonia due to RSV infection, in the lungs of infected mice without toxicity. AF-08 was significantly effective in reducing the virus titers and IFN-γ level increased by TBBPA exposure. Also, AF-08 significantly reduced proinflammatory cytokine (TNF-α and IL-6 levels in the lungs of RSV-infected mice with TBBPA exposure, but Th2 cytokine (IL-4 and IL-10 levels were not evidently increased. Neither TBBPA exposure nor AF-08 treatment affected the anti-RSV antibody production in RSV-infected mice. In flow cytometry analysis, AF-08 seemed to be effective in reducing the ratio of pulmonary CD8a+ cells in RSV-infected mice with TBBPA exposure. TBBPA and AF-08 did not exhibit anti-RSV activity in vitro. Thus, AF-08 probably ameliorated pneumonia exacerbated by TBBPA exposure in RSV-infected mice by limiting excess cellular immune responses.

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

    Science.gov (United States)

    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). PMID:27012419

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

    Science.gov (United States)

    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).

  16. Spectrophotometric Method for Estimation of Tamsulosin Hydrochloride in Pharmaceutical Dosage Form Using Bromate-Bromide and Methyl Orange Reagent

    Directory of Open Access Journals (Sweden)

    Bharatkumar Ganeshbhai Chaudhari

    2012-09-01

    Full Text Available A simple, rapid, accurate and precise assay procedure based on Spectrophotometric method has been developed for the estimation of Tamsulosin hydrochloride in Pharmaceutical formulation. The method was based on the bromination of Tamsulosin hydrochloride with a known excess amount of Bromate-bromide mixture in acidic medium followed by the determination of surplus bromine by reacting with dye methyl orange and measuring the absorbance at 513 nm. Validation was carried out in compliance with International Conference on Harmonization guidelines. Linear regression analysis of method showed good linearity with the correlation co-efficient (r of 0.9978 with respect to absorbance in the concentration range of 2-12 μg/mL and the mean recovery for Tamsulosin hydrochloride was 99.65% ± 0.47 . The proposed method can be successfully applied for the analysis of tablet formulations.

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

    Directory of Open Access Journals (Sweden)

    M. Wachsmuth

    2002-01-01

    Full Text Available 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.

  18. 21 CFR 180.30 - Brominated vegetable oil.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Brominated vegetable oil. 180.30 Section 180.30... Brominated vegetable oil. The food additive brominated vegetable oil may be safely used in accordance with... used on an interim basis as a stabilizer for flavoring oils used in fruit-flavored beverages, for...

  19. 40 CFR 721.9740 - Brominated triazine derivative.

    Science.gov (United States)

    2010-07-01

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

  20. Atmospheric bromine flux from the coastal Abu Dhabi sabkhat: A ground-water mass-balance investigation

    Science.gov (United States)

    Wood, W.W.; Sanford, W.E.

    2007-01-01

    A solute mass-balance study of ground water of the 3000 km2 coastal sabkhat (salt flats) of the Emirate of Abu Dhabi, United Arab Emirates, documents an annual bromide loss of approximately 255 metric tons (0.0032 Gmoles), or 85 kg/km2. This value is an order of magnitude greater than previously published direct measurements from the atmosphere over an evaporative environment of a salar in Bolivia. Laboratory evidence, consistent with published reports, suggests that this loss is by vapor transport to the atmosphere. If this bromine flux to the atmosphere is representative of the total earth area of active salt flats then it is a significant, and generally under recognized, input to the global atmospheric bromide flux.

  1. PHONONS IN GRAPHITE INTERCALATED WITH BROMINE

    OpenAIRE

    Batallan, F.; Rosenman, I.; Simon, C; Furdin, G.; Lauter, H.

    1981-01-01

    We have investigated the phonon spectrum in stage 2 graphite intercalate with bromine by using inelastic neutron scattering. We have observed longitudinal and transverse phonons along the c direction as well as in the layer plane. Results are presented for energies up to 15 THz at 300 K. A linear chain model explains most of our results.

  2. Brominated flame retardants and endocrine disruption

    NARCIS (Netherlands)

    Vos, J.G.; Becher, G.; Berg, van den M.; Boer, de J.; Leonards, P.E.G.

    2003-01-01

    From an environmental point of view, an increasing important group of organohalogen compounds are the brominated flame retardants (BFRs), which are widely used in polymers and textiles and applied in construction materials, furniture, and electronic equipment. BFRs with the highest production volume

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

    Science.gov (United States)

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

    2013-04-01

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

  4. Formation of halogenated organic byproducts during medium-pressure UV and chlorine coexposure of model compounds, NOM and bromide.

    Science.gov (United States)

    Zhao, Quan; Shang, Chii; Zhang, Xiangru; Ding, Guoyu; Yang, Xin

    2011-12-01

    When chlorine is applied before or during UV disinfection of bromide-containing water, interactions between chlorine, bromide and UV light are inevitable. Formation of halogenated organic byproducts was studied during medium-pressure UV (MPUV) and chlorine coexposure of phenol, nitrobenzene and benzoic acid and maleic acid, chosen to represent electron-donating aromatics, electron-withdrawing aromatics, and aliphatic structures in natural organic matter (NOM), respectively. All were evaluated in the presence and absence of bromide. MPUV and chlorine coexposure of phenol produced less total organic halogen (TOX, a collective parameter for halogenated organic byproducts) than chlorination in the dark, and more haloacetic acids instead of halophenols. Increases in TOX were found in the coexposure of nitrobenzene and benzoic acid, but maleic acid was rather inert during coexposure. The presence of bromide increased the formation of brominated TOX but did not significantly affect total TOX formation, in spite of the fact that it reduced hydroxyl radical levels. MPUV and chlorine coexposure of NOM gave a higher differential UV absorbance of NOM and a larger shift to lower molecular weight compounds than chlorination in the dark. However, TOX formation with NOM remained similar to that observed from dark chlorination.

  5. [Effects of bromide and ferric ions on formation of tri-halomethanes during disinfection of drinking water by chlorine].

    Science.gov (United States)

    Zhu, Zhi-Liang; Wang, Jing; Ge, Yuan-Xin; Ma, Hong-Mei; Zhao, Jian-Fu

    2007-06-01

    Effects of bromide and ferric ions on the formation and distribution of tri-halomethanes (THMs) have been investigated. As disinfection by-product (DBP) model precursors of natural water, humic acid solutions were used and a series of experiments were conducted. The results showed that bromide in this reaction system not only contributed to the increase of brominated species, but also the total tri-halomethanes. When the concentration of Br(-) was 1.0 mg/L, the total amount of produced THMs reached to 270% of that without bromide ions. In the presence of bromide, ferric ions decreased the production of THMs at pH 6, but increased the production of THMs at pH 8, especially for the amount of tri-bromomethanes. When the concentration of Fe3+ was 5 mg/L, the amount of produced tri-bromomethanes had an increment of 54% (from 51.7 microg/L to 79.4 microg/L), and the total amount of THMs increased from 113.49 microg/L to 162.09 microg/L. Bromide ions had a significant effect on carcinogenicity risk in disinfection of drinking water by chlorine, and the co-existence of ferric ion and bromide in alkalescent environment can result in the biggest challenge on carcinogenicity risk. Under the condition of 0.2 mg/L Br(-), 5 mg/L Fe3+ and pH 6, the carcinogenicity risk increased 2.5 times than that without Br(-) and Fe3+, and much higher increment of 5.1 times appeared when pH was 8.

  6. UTILIZATION OF BROMINATION REACTION FOR THE SPECTROPHOTOMETRIC ASSAY OF DOMPERIDONE IN PHARMACEUTICALS

    Directory of Open Access Journals (Sweden)

    O. ZENITA DEVI

    2011-03-01

    Full Text Available Three simple and sensitive spectrophotometric methods are described for the determination of domperidone (DOM in bulk drug and in dosage forms using bromate-bromide mixture as brominating agent in acid medium and three dyes, meta-cresol purple (MCP, amaranth (AMR and erioglaucine (EGC. The methods involve the addition of a known excess of bromate-bromide mixture to an acidified solution of DOM followed by the determination of the residual bromine by reacting with a fixed amount of either MCP dye and measuring the absorbance at 530 nm (method A or AMR dye and measuring the absorbance at 520 nm (method B or EGC dye and measuring the absorbance at 630 nm (method C. Beer’s law is obeyed over the concentration ranges, 0.63–10.0, 0.25-4.0 and 0.13-2.0 µg mL-1 for method A, B and C, respectively. The ap¬parent molar absorptivities are calculated to be 3.751x104, 6.604x104 and 1.987x105 L mol-1cm-1 for method A, B and C, respectively, and the corresponding sandell sensitivity values are 0.011, 0.006 and 0.002 μg cm-2. The limit of detection and the limit of quantification are also reported for all the three methods. No interference was observed from common additives found in pharmaceutical preparations. Statistical comparisons of the results with those of the reference method showed excellent agreement, and indicated no significant difference in accuracy and precision. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standardaddition technique.

  7. Investigation of drug interactions with pinaverium bromide.

    Science.gov (United States)

    Devred, C; Godeau, P; Guerot, C; Librez, P; Mougeot, G; Orsetti, A; Segrestaa, J M

    1986-01-01

    A series of studies was carried out at 6 centres to investigate possible drug interaction between the spasmolytic, pinaverium bromide, and cardiac glycosides, anticoagulants and hypoglycaemic agents given to patients as part of the long-term treatment of their condition. The results of clinical and laboratory investigations did not show any evidence of pinaverium bromide interfering with the action or activity of any of the drugs studied. PMID:3084176

  8. Determination of total chlorine and bromine in solid wastes by sintering and inductively coupled plasma-sector field mass spectrometry.

    Science.gov (United States)

    Osterlund, Heléne; Rodushkin, Ilia; Ylinenjärvi, Karin; Baxter, Douglas C

    2009-04-01

    A sample preparation method based on sintering, followed by analysis by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) for the simultaneous determination of chloride and bromide in diverse and mixed solid wastes, has been evaluated. Samples and reference materials of known composition were mixed with a sintering agent containing Na(2)CO(3) and ZnO and placed in an oven at 560 degrees C for 1h. After cooling, the residues were leached with water prior to a cation-exchange assisted clean-up. Alternatively, a simple microwave-assisted digestion using only nitric acid was applied for comparison. Thereafter the samples were prepared for quantitative analysis by ICP-SFMS. The sintering method was evaluated by analysis of certified reference materials (CRMs) and by comparison with US EPA Method 5050 and ion chromatography with good agreement. Median RSDs for the sintering method were determined to 10% for both chlorine and bromine, and median recovery to 96% and 97%, respectively. Limits of detection (LODs) were 200mg/kg for chlorine and 20mg/kg for bromine. It was concluded that the sintering method is suitable for chlorine and bromine determination in several matrices like sewage sludge, plastics, and edible waste, as well as for waste mixtures. The sintering method was also applied for determination of other elements present in anionic forms, such as sulfur, arsenic, selenium and iodine. PMID:19091539

  9. Symproportionation versus Disproportionation in Bromine Redox Systems

    International Nuclear Information System (INIS)

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

  10. Membrane-less hydrogen bromine flow battery

    CERN Document Server

    Braff, W A; Buie, C R

    2014-01-01

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

  11. Formation of brominated disinfection byproducts from natural organic matter isolates and model compounds in a sulfate radical-based oxidation process

    KAUST Repository

    Wang, Yuru

    2014-12-16

    A sulfate radical-based advanced oxidation process (SR-AOP) has received increasing application interest for the removal of water/wastewater contaminants. However, limited knowledge is available on its side effects. This study investigated the side effects in terms of the production of total organic bromine (TOBr) and brominated disinfection byproducts (Br-DBPs) in the presence of bromide ion and organic matter in water. Sulfate radical was generated by heterogeneous catalytic activation of peroxymonosulfate. Isolated natural organic matter (NOM) fractions as well as low molecular weight (LMW) compounds were used as model organic matter. Considerable amounts of TOBr were produced by SR-AOP, where bromoform (TBM) and dibromoacetic acid (DBAA) were identified as dominant Br-DBPs. In general, SR-AOP favored the formation of DBAA, which is quite distinct from bromination with HOBr/OBr- (more TBM production). SR-AOP experimental results indicate that bromine incorporation is distributed among both hydrophobic and hydrophilic NOM fractions. Studies on model precursors reveal that LMW acids are reactive TBM precursors (citric acid > succinic acid > pyruvic acid > maleic acid). High DBAA formation from citric acid, aspartic acid, and asparagine was observed; meanwhile aspartic acid and asparagine were the major precursors of dibromoacetonitrile and dibromoacetamide, respectively.

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

    Directory of Open Access Journals (Sweden)

    Ayman A. Gouda

    2013-01-01

    Full Text Available Five simple, accurate, and sensitive spectrophotometric methods (A–E have been described for the indirect assay of pipazethate HCl (PZT either in pure form or in pharmaceutical preparations. The proposed methods are based on the bromination of pipazethate HCl with a solution of excess bromate-bromide mixture in hydrochloric acid medium and subsequent estimation of the residual bromine by different reaction schemes. In the first three methods (A–C, the determination of the residual bromine is based on its ability to bleach the color of methyl orange, indigo carmine, or thymol blue dyes and measuring the absorbance at 520, 610, and 550 nm for methods A, B, and C, respectively. Methods D and E involves treating the unreacted bromine with a measured excess of iron(II, and the remaining iron(II is complexed with 1,10-phenanthroline, and the increase in absorbance is measured at 510 nm for method D and the resulting iron(III is complexed with thiocyanate and the absorbance is measured at 480 nm for method E. The different experimental parameters affecting the development and stability of the color are carefully studied and optimized. Regression analysis of the Beer-Lambert plots showed good correlation in the concentration ranges of 0.5–8.0 μg . The apparent molar absorptivity, Sandell's sensitivity, detection and quantitation limits were evaluated. The proposed methods have been applied and validated successfully for the analysis of the drug in its pure form and pharmaceutical formulations with mean recoveries of 99.94%–100.15% and relative standard deviation ≤1.53. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

  13. An investigation into the sensitivity of the atmospheric chlorine and bromine loading using a globally averaged mass balance model

    Science.gov (United States)

    Dowdell, David C.; Matthews, G. Peter; Wells, Ian

    Two globally averaged mass balance models have been developed to investigate the sensitivity and future level of atmospheric chlorine and bromine as a result of the emission of 14 chloro- and 3 bromo-carbons. The models use production, growth, lifetime and concentration data for each of the halocarbons and divide the production into one of eight uses, these being aerosol propellants, cleaning agents, blowing agents in open and closed cell foams, non-hermetic and hermetic refrigeration, fire retardants and a residual "other" category. Each use category has an associated emission profile which is built into the models to take into account the proportion of halocarbon retained in equipment for a characteristic period of time before its release. Under the Montreal Protocol 3 requirements, a peak chlorine loading of 3.8 ppb is attained in 1994, which does not reduce to 2.0 ppb (the approximate level of atmospheric chlorine when the ozone hole formed) until 2053. The peak bromine loading is 22 ppt, also in 1994, which decays to 12 ppt by the end of next century. The models have been used to (i) compare the effectiveness of Montreal Protocols 1, 2 and 3 in removing chlorine from the atmosphere, (ii) assess the influence of the delayed emission assumptions used in these models compared to immediate emission assumptions used in previous models, (iii) assess the relative effect on the chlorine loading of a tightening of the Montreal Protocol 3 restrictions, and (iv) calculate the influence of chlorine and bromine chemistry as well as the faster phase out of man-made methyl bromide on the bromine loading.

  14. Stereoselective Chlorination and Bromination of Enamides and Enamines via an Electrostatic Attraction Effect Using (1,1-Diacetoxyiodo)benzene and a Halide Source.

    Science.gov (United States)

    Xing, Linlin; Li, Chunbao

    2015-10-16

    The direct chlorination and bromination of (E)-enamines and (Z)-enamides to the corresponding (Z)-configurated α-chloroenamines, α-bromoenamines, and α-chloroenamides have been realized using NiCl2·6H2O or tetrabutyl ammonium bromide as a halide source and (1,1-diacetoxyiodo)benzene as an oxidant. The high stereoselective reactions which produce products with only (Z)-configurations can be attributed to the structure of the intermediates, the conformations of which are controlled by the electrostatic attractions between the positively charged nitrogen atoms and the oxygen atoms of the carbonyl group. This type of electrostatic effect has never been reported in olefin halogenations. For this reason, the three-membered bromonium ion is only a minor intermediate in the enamine bromination pathway. These methods open pathways to prepare α-chloroenamines and α-chloroenamides, which are not accessible via the currently used methods. PMID:26421836

  15. The influence of nitrogen oxides on the activation of bromide and chloride in salt aerosol

    Science.gov (United States)

    Bleicher, S.; Buxmann, J. C.; Sander, R.; Riedel, T. P.; Thornton, J. A.; Platt, U.; Zetzsch, C.

    2014-04-01

    Experiments on salt aerosol with different salt contents were performed in a Teflon chamber under tropospheric light conditions with various initial contents of nitrogen oxides (NOx = NO + NO2). A strong activation of halogens was found at high NOx mixing ratios, even in samples with lower bromide contents such as road salts. The ozone depletion by reactive halogen species released from the aerosol, was found to be a function of the initial NOx mixing ratio. Besides bromine, large amounts of chlorine have been released in our smog chamber. Time profiles of the halogen species Cl2, Br2, ClNO2, BrNO2 and BrO, ClO, OClO and Cl atoms were simultaneously measured by various techniques (chemical ionization mass spectrometry, differential optical absorption spectrometry coupled with a multi-reflection cell and gas chromatography of hydrocarbon tracers for Cl and OH, employing cryogenic preconcentration and flame ionization detection). Measurements are compared to calculations by the CAABA/MECCA 0-D box model, which was adapted to the chamber conditions and took the aerosol liquid water content and composition into account. The model results agree reasonably with the observations and provide important information about the prerequisites for halogen release, such as the time profiles of the aerosol bromide and chloride contents as well as the aerosol pH.

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

    Science.gov (United States)

    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. PMID:8028745

  17. Effects of pinaverium bromide on Oddi's sphincter.

    Science.gov (United States)

    DiSomma, C; Reboa, G; Patrone, M G; Mortola, G P; Sala, G; Ciampini, M

    1986-01-01

    Twelve to 15 days after cholecystectomy, endocholedochal pressure was measured in ten patients before and one hour after oral administration of 15 mg of pinaverium bromide (six patients) or placebo. The mean endocholedochal pressure was 7.1 +/- 0.25 mmHg before and 3.1 +/- 0.2 mmHg after pinaverium (P less than 0.01), and 7.0 +/- 0.2 and 6.8 +/- 1.2 mmHg in the placebo-treated patients. The results suggest that pinaverium bromide has a specific effect on the common bile duct and probably on Oddi's sphincter. PMID:3815457

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

    Science.gov (United States)

    Thiemann, Thies; Tanaka, Yasuko; Iniesta, Jesus

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Thies Thiemann

    2009-03-01

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

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

    OpenAIRE

    Thies Thiemann; Jesus Iniesta; Yasuko Tanaka

    2009-01-01

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

  1. Polyvinylpolypyrrolidone-bromine complex: Mild and efficient polymeric reagent for bromination of activated aromatic compounds

    Institute of Scientific and Technical Information of China (English)

    Masoud Mokhtary; Moslem M. Lakouraj

    2011-01-01

    Mild and efficient method for bromination of electron-rich aromatic compounds is described using polyvinylpolypyrrolidonebromine complex (PVPP-Br2). The reaction proceeded smoothly with phenols and N,N-alkylated amines to afford the corresponding monobrominated product in good yields at ambient temperature.

  2. CdTe quantum dots functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide as luminescent nanoprobe for the sensitive recognition of bromide ion

    Energy Technology Data Exchange (ETDEWEB)

    Adegoke, Oluwasesan [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa); Hosten, Eric; McCleland, Cedric [Department of Chemistry, Nelson Mandela Metropolitan University (South Campus), Port Elizabeth 6031 (South Africa); Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa)

    2012-04-06

    Graphical abstract: A bromide ion-selective modified nanoprobe sensor based on 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4AT)-functionalized CdTe quantum dots (QDs-4AT) showed a high selectivity and sensitivity for the determination of bromide ion using fluorescence recovery. Highlights: Black-Right-Pointing-Pointer Water soluble CdTe quantum dots interact with tetramethylpiperidine-N-oxide. Black-Right-Pointing-Pointer Quantum dots fluorescence is quenched by the radical. Black-Right-Pointing-Pointer In the presence of bromide ions the fluorescence is restored. Black-Right-Pointing-Pointer The sensor is more selective to bromine ions than other common ions. - Abstract: A novel bromide ion-selective modified nanoprobe sensor based on 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4AT)-functionalized CdTe quantum dots (QDs-4AT) has been developed. Fluorescence quenching of the QDs by 4AT was observed. The functionalized QDs-4AT nanoprobe allowed a highly sensitive determination of bromide ion via analyte-induced change in the photoluminescence (fluorescence recovery) of the modified QDs. A detection limit of 0.6 nM of bromide ion was obtained, while the interfering effect of other inorganic cations and anions was investigated to examine the selectivity of the nanoprobe. The linear range was between 0.01 and 0.13 {mu}M. Combined fluorescence lifetime and electron paramagnetic resonance measurements confirmed electron transfer processes between bromide ion and QDs-4AT.

  3. Fire-retardant coatings based on organic bromine/phenoxy or brominated epoxy systems

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.M.; Chiu, Ing L.

    1989-06-01

    Thin phenoxy and brominated epoxy/curing agent films were prepared by solvent casting on Mylar and Kapton. Thicknesses were approximated assuming volume additivity. Important parameters were uniformity of thickness, distribution of the bromine-containing fire retardant, adhesion to carrier substrate (either Mylar or Kapton), and uniformity of the coating, i.e., absence of pinholes, blush, blistering, etc. Wetting behavior was modified using fluoro, silicone or polyurea surfactants. Several solvent systems were examined and a ternary solvent system was ultimately used. Distribution of fire-retardant bromine was analyzed using electron microprobe, x-ray fluorescence and wet chemical methods. Significant discrepancies in the /mu/m-scale analyses of the microprobe measurements have not been resolved. Some of the brominated fire retardants were insoluble in the resin systems and the phase separation was immediately obvious. Similarly, some of the crystallizable epoxies could not be cast easily into homogeneous, amorphous films. Castings were made on a standard 8'' /times/ 10'' aluminum vacuum plate polished with jeweler's rouge prior to every casting. Solvent was removed in a forced air or vacuum oven. Removal and/or curing was accelerated with temperature. The fire-retardant bromine was required to be stable in alcohol/salt solutions. Final formulation used after a significant amount of testing was phenoxy resin PKHC in a ternary solvent system composed of methylethyl ketone, cellosolve acetate and toluene. Tetrabromobisphenol A was used as the flame retardant with FC-430 as surfactant. The dying schedule was 30 minutes at 150/degree/C. 4 refs., 6 figs., 3 tabs.

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

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

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

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

    Science.gov (United States)

    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. PMID:1756286

  6. New infrared spectroscopic database for bromine nitrate

    Science.gov (United States)

    Wagner, Georg; Birk, Manfred

    2016-08-01

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

  7. A chemical probe technique for the determination of reactive halogen species in aqueous solution: Part 2 – chloride solutions and mixed bromide/chloride solutions

    Directory of Open Access Journals (Sweden)

    C. Anastasio

    2006-02-01

    Full Text Available Although reactive halogen species (X*=X●, ●X2−, X2 and HOX, where X=Br, Cl, or I are important environmental oxidants, relatively little is known about their kinetics in condensed phases such as seawater and sea-salt particles. Here we describe a new technique to determine reactive chlorine and bromine species in aqueous solutions by using allyl alcohol (CH2=CHCH2OH as a chemical probe. This probe is combined with competition kinetics in order to determine steady state concentrations of X*(aq. In some cases the technique also can be used to determine the rates of formation and lifetimes of X* in aqueous solution. In a companion paper we reported the results of our method development for aqueous solutions containing only bromide (Br−. In this paper, we discuss method development for solutions containing chloride (Cl− alone, and for solutions containing both bromide and chloride.

  8. Use of Bromine and Bromo-Organic Compounds in Organic Synthesis.

    Science.gov (United States)

    Saikia, Indranirekha; Borah, Arun Jyoti; Phukan, Prodeep

    2016-06-22

    Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

  9. Bromine content and brominated flame retardants in food and animal feed from the UK.

    Science.gov (United States)

    Fernandes, A R; Mortimer, D; Rose, M; Smith, F; Panton, S; Garcia-Lopez, M

    2016-05-01

    Current occurrence data for polybrominated diphenyl ethers (PBDE) and hexa-bromocyclododecane (HBCD) measured in most commonly consumed foods (n = 156) and animal feeds (n = 51) sampled in the UK, demonstrates an ongoing ubiquity of these contaminants in human and animal diets. PBDE concentrations for the sum of 17 measured congeners ranged from 0.02 ng/g to 8.91 ng/g whole weight for food, and 0.11 ng/g to 9.63 ng/g whole weight for animal feeds. The highest concentration ranges, and mean values were detected in fish, processed foods and fish feeds. HBCD diastereomers (alpha-HBCD was the most commonly detected) generally occurred at lower concentrations (from animal feed) and less frequently than PBDEs, but tetrabromobisphenol A which was also measured, was rarely detected. The total bromine content of the samples was also determined in an attempt to use a mass balance approach to investigate some of these samples for the occurrence of novel and emerging BFRs. Although the approach was further refined by measuring organic bromine content, the concentrations of bromine were too high (in most cases by orders of magnitude) to allow use of the approach. A selected sub-set of samples was screened by GC-MS, for the presence of novel/emerging brominated flame retardants (PBT, TBX, PBEB, DBHCTD, HCTBPH and OBTMPI) but these were not detected at the higher limits of detection that result from full scan (GC-MS) screening. This data will contribute to the EU wide risk assessment on these contaminants.

  10. Methyl bromide residues in fumigated cocoa beans

    International Nuclear Information System (INIS)

    The 14C activity in unroasted [14C]-methyl bromide fumigated cocoa beans was used to study the fate and persistence of CH3Br in the stored beans. About 70% of the residues occurred in the shells. Unchanged CH3Br could not be detected, all the sorbed CH3Br having reacted with bean constituents apparently to form 14C-methylated derivatives and inorganic bromide. No 14C activity was found in the lipid fraction. Roasting decreased the bound (non-volatile) residues, with corresponding changes in the activities and amounts of free sugars, free and protein amino acids. Roasted nibs and shells showed a two-fold increase in the volatile fraction of the 14C residue. This fraction may be related to the volatile aroma compounds formed by Maillard-type reactions. (author)

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

    Science.gov (United States)

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

    2015-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    Science.gov (United States)

    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. PMID:25876424

  14. Magnetic Trapping of Cold Bromine Atoms

    CERN Document Server

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

    2014-01-01

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

  15. Temperature dependence of bromine activation due to reaction with ozone in a proxy for organic aerosols

    Science.gov (United States)

    Edebeli, Jacinta; Ammann, Markus; Gilgen, Anina; Eichler, Anja; Schneebeli, Martin; Bartels-Rausch, Thorsten

    2016-04-01

    The discovery of boundary layer ozone depletion events in the Polar Regions [1] and in the mid-latitudes [2], two areas of very different temperature regimes, begs the question of temperature dependence of reactions responsible for these observations [3]. These ODEs have been attributed to ozone reacting with halides leading to reactive halogens (halogen activation) of which bromide is extensively studied, R1 - R3 [4, 5] (R1 is a multiphase reaction). O3 + Br‑→ O2 + OBr‑ (R1) OBr‑ + H+ ↔ HOBr (R2) HOBr + H+ + Br‑→ Br2 + H2O (R3) Despite extensive studies of ozone-bromide interactions, the temperature dependence of bromine activation is not clear [3]. This limits parameterization of the involved reactions and factors in atmospheric models [3, 6]. Viscosity changes in the matrix (such as organic aerosols) due to temperature have been shown to influence heterogeneous reaction rates and products beyond pure temperature effect [7]. With the application of coated wall flow-tubes, the aim of this study is therefore to investigate the temperature dependence of bromine activation by ozone interaction while attempting to characterize the contributions of the bulk and surface reactions to observed ozone uptake. Citric acid is used in this study as a hygroscopically characterized matrix whose viscosity changes with temperature and humidity. Here, we present reactive ozone uptake measured between 258 and 289 K. The data show high reproducibility. Comparison of measured uptake with modelled bulk uptake at different matrix compositions (and viscosities) indicate that bulk reactive uptake dominates, but there are other factors which still need further consideration in the model. References 1. Barrie, L.A., et al., Nature, 1988. 334: p. 138 - 141. 2. Hebestreit, K., et al., Science, 1999. 283: p. 55-57. 3. Simpson, W.R., et al., Atmospheric Chemistry and Physics, 2007. 7: p. 4375 - 4418. 4. Haag, R.W. and J. Hoigné, Environ Sci Technol, 1983. 17: p. 261-267. 5. Oum

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  17. Cobalt catalyzed peroxymonosulfate oxidation of tetrabromobisphenol A: Kinetics, reaction pathways, and formation of brominated by-products.

    Science.gov (United States)

    Ji, Yuefei; Kong, Deyang; Lu, Junhe; Jin, Hao; Kang, Fuxing; Yin, Xiaoming; Zhou, Quansuo

    2016-08-01

    Degradation of tetrabromobisphenol A (TBBPA), a flame retardant widely spread in the environment, in Co(II) catalyzed peroxymonosulfate (PMS) oxidation process was systematically explored. The second-order-rate constant for reaction of sulfate radical (SO4(-)) with TBBPA was determined to be 5.27×10(10)M(-1)s(-1). Apparently, degradation of TBBPA showed first-order kinetics to the concentrations of both Co(II) and PMS. The presence of humic acid (HA) and bicarbonate inhibited TBBPA degradation, most likely due to their competition for SO4(-). Degradation of TBBPA was initiated by an electron abstraction from one of the phenolic rings. Detailed transformation pathways were proposed, including β-scission of isopropyl bridge, phenolic ring oxidation, debromination and coupling reactions. Further oxidative degradation of intermediates in Co(II)/PMS process yielded brominated disinfection by-products (Br-DBPs) such as bromoform and brominated acetic acids. Evolution profile of Br-DBPs showed an initially increasing and then decreasing pattern with maximum concentrations occurring around 6-10h. The presence of HA enhanced the formation of Br-DBPs significantly. These findings reveal potentially important, but previously unrecognized, formation of Br-DBPs during sulfate radical-based oxidation of bromide-containing organic compounds that may pose toxicological risks to human health. PMID:27107323

  18. Europium-doped barium bromide iodide

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Formation of brominated trihalomethanes in chlorinated drinking-water from Lake Constance

    International Nuclear Information System (INIS)

    The formation of trihalomethanes (THMs) in raw water and drinking water from Lake Constance containing low amounts of DOC and bromide was studied with special emphasis on brominated trihalomethanes (Br-THMs). If the raw water was ozonated prior to chlorination, the formation of THMs was reduced by 37%, and if a rapid sandfiltration was interposed, the THM-formation was again slightly enhanced. The percentage of Br-THMs on total-THMs increased from 16% to 35% during the treatment process. In the drinking water distribution system of BWV the formation of Br-THMs and CHCl3 was studied with respect to residence time and post-chlorination. Unless the post-chlorination was performed, the THM-formation in the distribution system resembled that obtained from laboratory studies, except for small amounts of THMs being purged due to transport in the mains and residence in the reservoirs. Post-chlorination increased CHCl3- and the CHBrCl2-formation, but there was no effect on the formation of CHBr2Cl and CHBr3. However, the total THM-concentration in the drinking water never exceeded the German drinking water standard of 10 μg/L. (orig.)

  20. Determination of bromide, chloride, fluoride, nitrate and sulphate by ion chromatography: comparisons of methodologies for rainfall, cloud water and river waters at the Plynlimon catchments of mid-Wales

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The results of determination of bromide, chloride, fluoride, nitrate and sulphate using ion chromatography (IC are compared with those obtained by colorimetric and inductively coupled plasma optical emission spectroscopy (ICPOES for rainfall, cloud water and stream waters in the Plynlimon experimental catchments of mid-Wales. For bromide, the concentrations determined by IC are lower than those for the colorimetric method used; the colorimetric method probably determined bromide plus organo-bromine compounds. It is suggested that the values determined by the colorimetric method be termed dissolved labile bromine (DLBr. The study shows that sulphate is the overriding form of sulphur in the waters. For chloride and nitrate, measurements by both methods approach a 1:1 relationship that is barely statistically significantly different from unity. For fluoride, the IC method gives lower values than the colorimetric, especially for the stream waters. However, the colorimetric method determines total fluorine so that a difference is to be expected (for example, fluoride strongly complexes with aluminium that is present, especially in the streamwater.

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Indian Academy of Sciences (India)

    Rajendra Dongre; Minakshi Thakur; Dinesh Ghugal; Jostna Meshram

    2012-10-01

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

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  4. Methyl chloride and methyl bromide emissions from baking: an unrecognized anthropogenic source.

    Science.gov (United States)

    Thornton, Brett F; Horst, Axel; Carrizo, Daniel; Holmstrand, Henry

    2016-05-01

    Methyl chloride and methyl bromide (CH3Cl and CH3Br) are the largest natural sources of chlorine and bromine, respectively, to the stratosphere, where they contribute to ozone depletion. We report the anthropogenic production of CH3Cl and CH3Br during breadbaking, and suggest this production is an abiotic process involving the methyl ester functional groups in pectin and lignin structural polymers of plant cells. Wide variations in baking styles allow only rough estimates of this flux of methyl halides on a global basis. A simple model suggests that CH3Br emissions from breadbaking likely peaked circa 1990 at approximately 200tonnes per year (about 0.3% of industrial production), prior to restrictions on the dough conditioner potassium bromate. In contrast, CH3Cl emissions from breadbaking may be of similar magnitude as acknowledged present-day CH3Cl industrial emissions. Because the mechanisms involve functional groups and compounds widely found in plant materials, this type of methyl halide production may occur in other cooking techniques as well. PMID:26878644

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

    Science.gov (United States)

    2012-04-06

    ..., which means EPA will not know your identity or contact information unless you provide it in the body of... include your name and other contact information in the body of your comment and with any disk or CD-ROM... methyl bromide. And, although methyl bromide tends to be lipid soluble, the low octanol-water...

  6. Environmental monitoring of brominated flame retardants

    Science.gov (United States)

    Vagula, Mary C.; Kubeldis, Nathan; Nelatury, Charles F.

    2011-06-01

    Brominated flame retardants (BFRs) are synthetic organobromide compounds which inhibit ignition and combustion processes. Because of their immense ability to retard fire and save life and property, they have been extensively used in many products such as TVs, computers, foam, plastics etc. The five major classes of BFRs are tetrabromobisphenol-A (TBBPA), hexabromocyclododecane (HBCD), pentabromodiphenyl ether, octabromodiphenyl ether, and decabromodiphenyl ether. The last three are also commonly called PBDEs. BDE-85 and BDE-209 are the two prominent congeners of PBDEs and this study reports the adverse effects of these congeners in rodents. Exposure of rat sciatic nerves to 5 μg/mL and 20 μg/mL of BDE-85 and BDE-209 respectively lead to significant, concentration dependent reduction in nerve conduction function. Glucose absorption in the rat intestinal segments exposed to 5 μg/mL of BDE-85 and BDE-209 was significantly reduced for both the compounds tested. Lastly, mice when exposed to 0.25 mg/kg body weight for four days showed a disruption in oxidant and antioxidant equilibrium. The tissues namely liver and brain have shown increase in the levels of lipid hydroperoxides indicating oxidative stress. Moreover, all the protective enzymes namely superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase, and glutathione S transferase (GST) have shown tissue specific alterations indicating the induction of damaging oxidative stress and setting in of lipid peroxidation in exposed animals. The results indicate monitoring of PBDEs in the environment is essential because levels as low as 5 μg/mL and 0.25 mg/kg body weight were able to cause damage to the functions of rodents.

  7. Degradation of methyl bromide in anaerobic sediments

    Science.gov (United States)

    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.

  8. The geochemistry of stable chlorine and bromine isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Eggenkamp, Hans [Onderzock and Beleving, Bussum (Netherlands)

    2014-11-01

    First book solely dedicated to the geochemistry of chlorine and bromine isotopes. Detailed description of analytical techniques, including their advantages and disadvantages. Indication of research fields where measurement of these isotopes is especially useful. This book provides detailed information on the history, analysis and applications of chlorine and bromine isotope geochemistry. Chlorine and bromine are geochemically unique as they prefer to exist as single charged negative ions. For this reason isotope fractionation reflects mostly processes that are not related to changes in the redox state and this fractionation is generally modest. The book will describe the processes that are most easily detected using these isotopes. Also isotope variations, and processes that cause them, measured in oxidised species such as perchlorates and in organic molecules will be described in this book.

  9. Kinetic spectrophotometric determination of bromide in clidinium-c drug

    Institute of Scientific and Technical Information of China (English)

    Ali Sheibani; M. Reza Shishehbore; Zahra Tavakolian Ardakani

    2011-01-01

    A simple, rapid and sensitive method has been described for the determination of the trace amounts of bromide. The method is based on the catalytic effect of bromide ion on the oxidation of methylene blue by bromate in sulfuric acid media. The reaction is monitored spectrophotometrically by measuring the decrease in the absorbance of methylene blue at 665 nm. Bromide was determined in the range of 0.05-1.90 μg/mL with the detection limit of 0.03 μg/mL. The relative standard deviations of five replicate determinations of 0.20 and 10.0 μg/mL of bromide were 2.4% and 1.8%, respectively. The influence of potential interfering ions and substances was studied. The method is applied to the analysis of bromide in clidinium-c tablet as a real sample.

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

    International Nuclear Information System (INIS)

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

  11. Thymol bromination: a comparison between enzymatic and chemical catalysis

    NARCIS (Netherlands)

    F. Sabuzi; E. Churakova; P. Galloni; R. Wever; F. Hollmann; B. Floris; V. Conte

    2015-01-01

    The catalytic activity of the vanadium-dependent bromoperoxidase isolated from the brown alga Ascophyllum nodosum is compared with the activity of a cheap, commercially available V-catalyst precursor in the bromination of thymol. Organic solvents have been avoided to make the system appealing from a

  12. Bromine provides new weapons to combat mercury emissions

    Energy Technology Data Exchange (ETDEWEB)

    Hardtke, W. [Albermarle Europe (Germany)

    2011-04-15

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

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

    Directory of Open Access Journals (Sweden)

    Piskorska-Pliszczyńska Jadwiga

    2014-10-01

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

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

    OpenAIRE

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

    2010-01-01

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

  15. Airborne measurements of organic bromine compounds in the Pacific tropical tropopause layer.

    Science.gov (United States)

    Navarro, Maria A; Atlas, Elliot L; Saiz-Lopez, Alfonso; Rodriguez-Lloveras, Xavier; Kinnison, Douglas E; Lamarque, Jean-Francois; Tilmes, Simone; Filus, Michal; Harris, Neil R P; Meneguz, Elena; Ashfold, Matthew J; Manning, Alistair J; Cuevas, Carlos A; Schauffler, Sue M; Donets, Valeria

    2015-11-10

    Very short-lived brominated substances (VSLBr) are an important source of stratospheric bromine, an effective ozone destruction catalyst. However, the accurate estimation of the organic and inorganic partitioning of bromine and the input to the stratosphere remains uncertain. Here, we report near-tropopause measurements of organic brominated substances found over the tropical Pacific during the NASA Airborne Tropical Tropopause Experiment campaigns. We combine aircraft observations and a chemistry-climate model to quantify the total bromine loading injected to the stratosphere. Surprisingly, despite differences in vertical transport between the Eastern and Western Pacific, VSLBr (organic + inorganic) contribute approximately similar amounts of bromine [∼6 (4-9) parts per trillion] [corrected] to the stratospheric input at the tropical tropopause. These levels of bromine cause substantial ozone depletion in the lower stratosphere, and any increases in future abundances (e.g., as a result of aquaculture) will lead to larger depletions. PMID:26504212

  16. Chloride, bromide and iodide scintillators with europium

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. A new convenient access to highly functionalized ()-2-arylvinyl bromides

    Indian Academy of Sciences (India)

    Yubo Jiang; Chunxiang Kuang

    2009-11-01

    Highly functionalized ()-2-arylvinyl bromides were prepared in high yields through a new convenient access by acylation of ()-4-(2-bromovinyl)phenol with fatty and aromatic acids at room temperature using dicyclohexyl carbodiimide (DCC) and dimethylaminopyridine (DMAP).

  18. Bromide space, total body water, and sick cell syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Schober, O.; Hundeshagen, H.; Lehr, L.

    1982-01-01

    Displacements of the bromide space (Br-82-C, as a marker for the extracellular fluid compartment) are caused by an enhanced anatomical space and/or increased permeability of cells to bromide. The ratio Br-82-C: total body water (TBW) was evaluated to be 0.83 +- 0.17 in critically ill patients (n = 38) compared with the normal value of 0.46 +- 0.04 (n = 10). Because of normal TBW in critically ill patients (TBW = 505 +- 68 ml/kg), an increased bromide penetration into cells seems to be responsible for the enlarged ratio Br-82-C: TBW. Taking into consideration measurements in patients with malabsorption (Br-82-C: TBW = 0.56 +- 0.13; n = 13) and carcinoma of the rectum and colon (Br-82-C: TBW = 0.66 +- 0.24; n = 18) we think that the bromide space is a good measurement of the effective extracellular water.

  19. Effects of ipratropium bromide and fenoterol aerosols in pulmonary emphysema.

    OpenAIRE

    Hughes, J A; Tobin, M. J.; Bellamy, D; Hutchison, D. C.

    1982-01-01

    In patients with radiological evidence of pulmonary emphysema the bronchodilator drugs fenoterol and ipratropium bromide produced a considerable increase in vital capacity and reduction in residual volume. The response to fenoterol was virtually complete 15 minutes after administration, but after ipratropium bromide vital capacity was still increasing at 60 minutes. The change in vital capacity was slightly greater with a combination of the two drugs than with either used alone. Changes in FE...

  20. Quantum Chemistry Study on Dissociation of Oxalyl Bromide

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The multi-bond dissociation dynamics of oxalyl bromide ((BrCO)2) has been investigated by DFT and CIS calculations. Upon the results, conclusion could be drawn that dissociation of C-Br bond of oxalyl bromide at the ground state (S0) is of barrierless. After the absorption of a photon, (BrCO)2 is excited to the first excited state and one of its C-Br bonds is broken to yield dissociate.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vainikka, P.

    2011-12-15

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

  2. Formation of new brominated disinfection byproducts during chlorination of saline sewage effluents.

    Science.gov (United States)

    Ding, Guoyu; Zhang, Xiangru; Yang, Mengting; Pan, Yang

    2013-05-15

    Chlorination could be the most cost-effective method for disinfecting saline sewage effluents resulting from toilet flushing with seawater. Upon chlorination, the high levels of bromide ions in saline sewage effluents (up to 32 mg/L) can be oxidized to hypobromous acid/hypobromite, which could then react with organic matter in the sewage effluents to form brominated disinfection byproducts (Br-DBPs). In this study, primary and secondary saline sewage effluents were collected and chlorinated at different chlorine doses, and a powerful precursor ion scan method using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry was adopted for detection and identification of polar Br-DBPs in these samples. With the new method, 54 major polar Br-DBPs were detected in the chlorinated saline effluents and six of them were newly identified as wastewater DBPs, including bromomaleic acid, 5-bromosalicylic acid, 3,5-dibromo-4-hydroxybenzaldehyde, 3,5-dibromo-4-hydroxybenzoic acid, 2,6-dibromo-4-nitrophenol, and 2,4,6-tribromophenol. The formation of polar Br-DBPs, especially those newly detected ones, during chlorination of the saline effluents was studied. For the secondary saline effluent, various polar Br-DBPs formed and reached their maximum levels at different chlorine doses, whereas for the primary saline effluent, the formation of polar Br-DBPs basically kept increasing with increasing chlorine dose. Compared with the secondary saline effluent, the primary saline effluent generated fewer and less Br-DBPs and rarely generated nitrogenous Br-DBPs.

  3. Assessment of Ethidium bromide and Ethidium monoazide bromide removal from aqueous matrices by adsorption on cupric oxide nanoparticles.

    Science.gov (United States)

    Fakhri, Ali

    2014-06-01

    The present study was undertaken to develop an effective adsorbent and to study the adsorption of Ethidium bromide and Ethidium monoazide bromide from aqueous solution using the CuO nanoparticles. The characteristics of CuO nanoparticles were determined and found to have a surface area 89.59m(2)/g. Operational parameters such as pH, contact time and adsorbent concentration, initial concentration and temperature were also studied. The amount of removal increases with the increase in pH from one to seven and reaches the maximum when the pH is nine. Adsorption data fitted well with the Langmuir, Freundlich and Florry-Huggins models. The results show that the best fit was achieved with the Langmuir isotherm equation with maximum adsorption capacities of 0.868 and 0.662mg/g for Ethidium bromide and Ethidium monoazide bromide, respectively. The adsorption process was found to follow pseudo-second-order kinetics. The calculated thermodynamic parameters, namely ΔG, ΔH and ΔS showed that adsorption of Ethidium bromide and Ethidium monoazide bromide was spontaneous and endothermic under examined conditions. PMID:24630576

  4. Electrophysiological study of intravenous pinaverium bromide in cardiology.

    Science.gov (United States)

    Guerot, C; Khemache, A; Sebbah, J; Noel, B

    1988-01-01

    Pinaverium bromide is a musculotropic spasmolytic agent which acts by inhibiting transmembrane calcium movements, an effect similar to that of verapamil. Because of this, an investigation was carried out to see if it had any electrophysiological effects in patients with various cardiac disorders. In an open study, 10 patients received 2 mg pinaverium bromide intravenously. In a double-blind study, 10 patients received 4 mg pinaverium bromide intravenously and 10 patients placebo. Patients included those with either normal or pathological basal conduction, such as bundle-branch block and 1st degree atrioventricular block. Measurements were made of electrophysiological parameters before and 10 minutes after injection. The results showed that neither of the two doses of pinaverium bromide had any effect on atrial excitability, sino-atrial conduction, node and trunk atrioventricular conduction or on intraventricular conduction. No significant difference was seen in comparison with placebo. Pinaverium bromide had no anti-arrhythmic properties in these studies. Local, cardiac and general clinical tolerability was good in all patients. PMID:3219882

  5. Bromination of hydrocarbons with CBr4, initiated by light-emitting diode irradiation

    Directory of Open Access Journals (Sweden)

    Yuta Nishina

    2013-08-01

    Full Text Available The bromination of hydrocarbons with CBr4 as a bromine source, induced by light-emitting diode (LED irradiation, has been developed. Monobromides were synthesized with high efficiency without the need for any additives, catalysts, heating, or inert conditions. Action and absorption spectra suggest that CBr4 absorbs light to give active species for the bromination. The generation of CHBr3 was confirmed by NMR spectroscopy and GC–MS spectrometry analysis, indicating that the present bromination involves the homolytic cleavage of a C–Br bond in CBr4 followed by radical abstraction of a hydrogen atom from a hydrocarbon.

  6. Specific heat of pristine and brominated graphite fibers, composites and HOPG. [Highly Oriented Pyrolytic Graphite

    Science.gov (United States)

    Hung, Ching-Chen; Maciag, Carolyn

    1987-01-01

    Differential scanning calorimetry was used to obtain specific heat values of pristine and brominated P-100 graphite fibers and brominated P-100/epoxy composite as well as pristine and brominated highly oriented pyrolytic graphite (HOPG) for comparison. Based on the experimental results obtained, specific heat values are calculated for several different temperatures, with a standard deviation estimated at 1.4 percent of the average values. The data presented here are useful in designing heat transfer devices (such as airplane de-icing heaters) from bromine fibers.

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

    OpenAIRE

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

    2006-01-01

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

  8. Critical rate of electrolyte circulation for preventing zinc dendrite formation in a zinc-bromine redox flow battery

    Science.gov (United States)

    Yang, Hyeon Sun; Park, Jong Ho; Ra, Ho Won; Jin, Chang-Soo; Yang, Jung Hoon

    2016-09-01

    In a zinc-bromine redox flow battery, a nonaqueous and dense polybromide phase formed because of bromide oxidation in the positive electrolyte during charging. This formation led to complicated two-phase flow on the electrode surface. The polybromide and aqueous phases led to different kinetics of the Br/Br- redox reaction; poor mixing of the two phases caused uneven redox kinetics on the electrode surface. As the Br/Br- redox reaction was coupled with the zinc deposition reaction, the uneven redox reaction on the positive electrode was accompanied by nonuniform zinc deposition and zinc dendrite formation, which degraded battery stability. A single-flow cell was operated at varying electrolyte circulation rates and current densities. Zinc dendrite formation was observed after cell disassembly following charge-discharge testing. In addition, the flow behavior in the positive compartment was observed by using a transparent version of the cell. At low rate of electrolyte circulation, the polybromide phase clearly separated from the aqueous phase and accumulated at the bottom of the flow frame. In the corresponding area on the negative electrode, a large amount of zinc dendrites was observed after charge-discharge testing. Therefore, a minimum circulation rate should be considered to avoid poor mixing of the positive electrolyte.

  9. IR, Raman and SERS spectra of propantheline bromide.

    Science.gov (United States)

    Baraldi, C; Freguglia, G; Tinti, A; Sparta, M; Alexandrova, A N; Gamberini, M C

    2013-02-15

    The two known propantheline bromide polymorphs (form I and form II) were studied and characterized by a multianalytical approach. In the present work, the identification of propantheline bromide polymorphic forms through vibrational IR spectroscopies are presented and for the first time Raman microscopy and hot stage Raman microscopy (HSRM) studies are reported. Finally, quantum mechanical calculations were performed. For assisting the assignment of the experimental picks, the two IR spectra of the most and least stable representatives of a set of 56 conformers are calculated and studied. DSC thermograms data, are also reported. The surface enhanced Raman scattering (SERS) spectrum was also recorded in a silver colloid; it could be inferred that propantheline bromide is adsorbed on silver colloid through the oxygen atom with the molecular plane perpendicular to the metal surface.

  10. Glycosylation with Disarmed Glycosyl Bromides Promoted by Iodonium Ions

    DEFF Research Database (Denmark)

    Lanz, Gyrithe; Madsen, Robert

    2016-01-01

    Iodonium ions have been developed for activating glycosyl bromides in the coupling to glycosyl acceptors. The iodonium ions are generated from N-iodosuccinimide and a protic acid such as camphorsulfonic acid or triflic acid, where the latter gives the most reactive promoter system. The couplings...... occur with the release of iodine monobromide, and the best results are obtained with benzoylated glycosyl donors and acceptors. In this way, disarmed glycosyl bromides can serve as glycosyl donors without the use of heavy-metal salts....

  11. Action of pinaverium bromide on calmodulin-regulated functions.

    Science.gov (United States)

    Wuytack, F; De Schutter, G; Casteels, R

    1985-08-01

    Pinaverium bromide at concentrations below 10(-5) M did not inhibit calmodulin-dependent enzymes such as phosphodiesterase and the Ca transport ATPase of the plasma membrane. At higher concentrations the compound interacted with the stimulation of those enzymes by calmodulin and also inhibited the calmodulin-independent activity. A similar inhibitory action was observed for the NaK ATPase. It is concluded that the inhibitory action of pinaverium bromide on smooth muscle concentration at concentrations below 10(-5) M was due to its interaction with the voltage-dependent Ca channels and not to its interference with the calmodulin-dependent activation of the contractile proteins. PMID:2995077

  12. Investigation of possible interaction between pinaverium bromide and digoxin.

    Science.gov (United States)

    Weitzel, O; Seidel, G; Engelbert, S; Berksoy, M; Eberhardt, G; Bode, R

    1983-01-01

    A single-blind study was carried out in 25 patients, who were receiving maintenance therapy for congestive heart failure with digoxin, to investigate the effect on steady-state plasma digoxin levels of concomitant administration of the spasmolytic, pinaverium bromide (50 mg 3-times daily). Patients received pinaverium bromide for 12 days followed by placebo for a further 7 days. Assessment of the results in 21 patients showed no evidence of any statistically significant variations in plasma digoxin levels during either treatment period or in the clinical observations which might indicate drug interaction. PMID:6653138

  13. 40 CFR 721.775 - Brominated aromatic com-pound (generic name).

    Science.gov (United States)

    2010-07-01

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

  14. Visible-light photoredox catalysis enabled bromination of phenols and alkenes

    Directory of Open Access Journals (Sweden)

    Yating Zhao

    2014-03-01

    Full Text Available A mild and efficient methodology for the bromination of phenols and alkenes has been developed utilizing visible light-induced photoredox catalysis. The bromine was generated in situ from the oxidation of Br− by Ru(bpy33+, both of which resulted from the oxidative quenching process.

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

    Science.gov (United States)

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

    2005-01-01

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

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

    Science.gov (United States)

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

    2013-03-26

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

  17. The Cyclotron Production and Nuclear Imaging of BROMINE-77.

    Science.gov (United States)

    Galiano, Eduardo

    In this investigation, bromine-77 was produced with a medical cyclotron and imaged with gamma cameras. Br -77 emits a 240 kev photon with a half life of 56 hours. The C-Br bond is stronger than the C-I bond and bromine is not collected in the thyroid. Bromine can be used to label many organic molecules by methods analogous to radioiodination. The only North American source of Br-77 in the 70's and 80's was Los Alamos National Laboratory, but it discontinued production in 1989. In this method, a p,3n reaction on Br-77 produces Kr-77 which decays with a 1.2 hour half life to Br-77. A cyclotron generated 40 MeV proton beam is incident on a nearly saturated NaBr or LiBr solution contained in a copper or titanium target. A cooling chamber through which helium gas is flowed separates the solution from the cyclotron beam line. Helium gas is also flowed through the solution to extract Kr-77 gas. The mixture flows through a nitrogen trap where Kr-77 freezes and is allowed to decay to Br-77. Eight production runs were performed, three with a copper target and five with a titanium target with yields of 40, 104, 180, 679, 1080, 685, 762 and 118 uCi respectively. Gamma ray spectroscopy has shown the product to be very pure, however corrosion has been a major obstacle, causing the premature retirement of the copper target. Phantom and in-vivo rat nuclear images, and an autoradiograph in a rat are presented. The quality of the nuclear scans is reasonable and the autoradiograph reveals high isotope uptake in the renal parenchyma, a more moderate but uniform uptake in pulmonary and hepatic tissue, and low soft tissue uptake. There is no isotope uptake in the brain or the gastric mucosa.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  20. Preozonation of bromide-bearing source water in south China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effectiveness of preozonation was evaluated on treating a bromide-bearing dam source water in south China through batch-scale experiments. Preozonation at ozone doses of 0.5-1.0 mg/L (at ozone consumption base) enhanced total organic carbon(TOC) removal through coagulation, and resulted in an almost linear reduction of ultraviolet absorbance at 254 nm (UV254). The removals of TOC (after coagulation) and UV254 at the ozone dose of 1.0 mg/L were 36% and 70%, respectively. Preozonation at an ozone dose between 0.5 and 1.0 mg/L resulted in the removal of disinfection byproducts formation potential (DBFP) including trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP) for about 50%. The removals of THMFP and HAAFP decreased with the further increase of ozone dose. Ozonation of bromide-bearing water (bromide concentration,34 μg/L) produced a bromate concentration under the detection limit(2 μg/L) at ozone doses < 1.5 mg/L. However, bromate >10 μg/L could be produced when the bromide concentration was increased to 96 μg/L.

  1. 7 CFR 305.6 - Methyl bromide fumigation treatment schedules.

    Science.gov (United States)

    2010-01-01

    ... to air temperature within the chamber. Fruit taken from a cooling room may have to be prewarmed... pure, type “Q” (for quarantine use only) methyl bromide per 1,000 cubic feet of chamber space. Dosage.... Water temperature in the volatilizer must never fall below 65.6 °C (150 °F) at any time during...

  2. Residues resulting from fumigation of food commodities with methyl bromide

    International Nuclear Information System (INIS)

    An investigation was undertaken to determine the nature and significance of residues remaining in methyl bromide-fumigated commodities using radiotracer techniques (14C-methyl bromide). Experiments with corn showed that the germ part of the kernel contained nearly half of the total 14C-residue remaining in the seed. Also preliminary tests with granny smith apples revealed that considerable residue may remain in seeds of treated apples with less in skin and the least in the fleshy pulp. In fumigated corn, fractionation revealed that radioactive residues were distributed throughout albumins, globulins, Zein 1, Zein 2 and glutelin with a large part in the aqueous extract (amino acids). Further investigation emphasized the characterization of volatile substances resulting from alkali treatment. It was found that methyl bromide readily methylated methionine and this constitutes a major site of methylation. A component of the volatile fraction was dimethyl sulfoxide, probably a product of oxidation of dimethyl sulphide. Work is in progress to determine whether methyl bromide will methylate purine and pyrimidine components. (author)

  3. Methyl bromide phase out could affect future reforestation efforts

    Science.gov (United States)

    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...

  4. Preparation of bromine-77 labeled proteins using bromoperoxidase

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, F.; Slegers, G. (Ghent Univ. (Belgium). Lab. of Radiopharmacy)

    1994-01-01

    The halogenating enzyme bromoperoxidase, isolated from the brown algae Ascophyllum nodosum, was used to catalyze the radiobromination of an anti-hPLAP monoclonal antibody. Radiobromination of bovine serum albumin was also performed and used as control method. The proteins are labeled with bromine-77, produced by the [sup 75]As ([alpha], 2n) [sup 77]Br reaction. The essential reaction parameters, such as concentration of protein and hydrogen peroxide, the amount of bromoperoxidase, the pH of the reaction mixture, the reaction time and temperature were optimized. The immunoreactivity of the radiolabeled monoclonal antibody was checked with a ''Sandwich'' ELISA. (author).

  5. Future chlorine-bromine loading and ozone depletion

    Science.gov (United States)

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

    1991-01-01

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

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

    International Nuclear Information System (INIS)

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

  7. Een ionchromatografische methode voor de simultane bepaling van nitriet, bromide en sulfiet in water

    NARCIS (Netherlands)

    Beld WA van den; Cleven RFMJ; LAC

    1996-01-01

    Betreft resultaten van een onderzoek naar het ontwikkelen van een geautomatiseerde ionchromatografische methode voor de bepaling van nitriet, bromide en sulfiet. Het onderzoek heeft geresulteerd in een betrouwbare, selectieve en gevoelige methode voor de simultane bepaling van nitriet, bromide e

  8. Effect of bromine substituents in the formation of PXDD from poly halogenated phenols

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, T.; Ohono, T.; Weber, R.

    2002-07-01

    The condensation of chlorophenols has been studied extensively in the last two decades and was discussed as one mechanism in particular for the formation of PCDD in thermal processes. Brominated flame retardants and brominated and brominated-chlorinated dibenzodioxins and dibenzofurans have received increased attention recently due to the growing use of brominated flame retardants during the last decade. This is resulting than increase of brominated compounds in waste (e.g. Electric and electronic shredder waste), containing a considerable amount of bromine, in the form of brominated flame retardants. Many studies reported on the formation of PBDD/PBDF from brominated diphenylethers, or bromophenosl. However with the exception of Sodhu et al, a comparison of the condensation behaviour of bromophenols and chlorophenols was not done. The condensation of brominated phenols is interesting from several aspects. Bromophenols are used as flame retardants and might be a source of PBDD/F during thermal stress. Bromophenols can also be generated during the combustion/pyrolysis of bromodiphenylether or tetrabromobisphenol A containing material, serving as potential precursors for the formation of PBDD/PBDF. Further, in municipal waste incinerators with sufficient secondary combustion, the largest amount of chlorinated aromatic compounds (PCDD, PCDF, PCBs, PCNs, and chlorophenols) are formed in the cooling section (boiler, duct, dust filtration). Therefore in combustion processes involving high concentrations of brominated flame retardants, mixed PXDD/PXDF might be formed by condensation reactions of precursors or de novo synthesis in the cooling zone. Therefore we investigated the condensation of abrominated phenol in more detail and compare it to the condensation reaction of the analogous chlorophenol. (Author)

  9. Association of defects in lead chloride and lead bromide: Ionic conductivity and dielectric loss measurements

    NARCIS (Netherlands)

    Brom, W.E. van den; Schoonman, J.; Wit, J.H.W. de

    1972-01-01

    The ionic conductivity data of pure and doped lead bromide without associated defects are used in order to explain the anomalous conductivity behaviour of copper (I) bromide and lead oxide-doped lead-bromide crystals. In these crystals precipitated dopant and associated defects are present. The asso

  10. Detection of lipopolysaccharides by ethidium bromide staining after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

    OpenAIRE

    Kido, N; Ohta, M; Kato, N

    1990-01-01

    A rapid and easy method for staining lipopolysaccharides with ethidium bromide is described. Lipopolysaccharides could be visualized by ethidium bromide with almost the same sensitivity as found with the silver-staining method in less than 30 min. The ethidium bromide-staining method was particularly suitable for staining lipopolysaccharides possessing acidic O-specific polysaccharides, which were poorly visualized by silver staining.

  11. Algae form brominated organic compounds in surface waters

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-09-15

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

  12. Comparative environmental analysis of waste brominated plastic thermal treatments

    International Nuclear Information System (INIS)

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

  13. Maternal exposure to brominated flame retardants and infant Apgar scores.

    Science.gov (United States)

    Terrell, Metrecia L; Hartnett, Kathleen P; Lim, Hyeyeun; Wirth, Julie; Marcus, Michele

    2015-01-01

    Brominated flame retardants (BFRs) and other persistent organic pollutants have been associated with adverse health outcomes in humans and may be particularly toxic to the developing fetus. We investigated the association between in utero polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB) exposures and infant Apgar scores in a cohort of Michigan residents exposed to PBB through contaminated food after an industrial accident. PBB and PCB concentrations were measured in serum at the time the women were enrolled in the cohort. PBB concentrations were also estimated at the time of conception for each pregnancy using a validated elimination model. Apgar scores, a universal measure of infant health at birth, measured at 1 and 5min, were taken from birth certificates for 613 offspring born to 330 women. Maternal PCB concentrations at enrollment were not associated with below-median Apgar scores in this cohort. However, maternal PBB exposure was associated with a dose-related increase in the odds of a below-median Apgar score at 1min and 5min. Among infants whose mothers had an estimated PBB at conception above the limit of detection of 1 part per billion (ppb) to Apgar score increased with higher maternal PBB at conception. It remains critical that future studies examine possible relationships between in utero exposures to brominated compounds and adverse health outcomes.

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

    Science.gov (United States)

    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

  15. A comparison of the effect of intranasal desmopressin and intramuscular hyoscine N-butyl bromide combination with intramuscular hyoscine N-butyl bromide alone in acute renal colic

    OpenAIRE

    Abdol-Reza Kheirollahi; Mohammad Tehrani; Mohammad Bashashati

    2010-01-01

    Background: Patients with acute renal colic usually require immediate diagnosis and treatment. In this clinical trial analgesic effect of hyoscine N-butyl bromide and desmopressin combination in comparison with hyoscine N-butyl bromide alone in patients with acute renal colic induced by urinary stones was assessed. Methods: The study included 114 patients randomly allocated in two groups (A and B). Patients in group A received 20 mg intramuscular hyoscine N-butyl bromide at admission tim...

  16. Flash preparation of carbenoids: A different performance of cyanogen bromide

    Directory of Open Access Journals (Sweden)

    Mohammad Jalilzadeh Hedayati

    2014-12-01

    Full Text Available Cyanogen halides are known substances for the cyanating reaction. There are a few evidences for bromination reaction too. On the other hand carbenes are known as very important substances due to their remarkable reactions. Unfortunately carbenes at room temperature are very unstable and there is not a simple method for preparation of them. In most cases the isolation is not possible. We have reported a new reliable and fast preparation method of almost stable carbenoids. The mechanism of the formation has been discussed.

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

    International Nuclear Information System (INIS)

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

  18. Aluminium Electroplating on Steel from a Fused Bromide Electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. [2,6-Bis(dimethylaminomethylphenyl]selenium bromide monohydrate

    Directory of Open Access Journals (Sweden)

    Richard A. Varga

    2010-04-01

    Full Text Available In the title hydrated molecular salt, C12H19N2Se+·Br−·H2O, the two independent bromide anions lie on a twofold rotation axis. Strong intramolecular N→Se interactions [2.185 (3 and 2.181 (3 Å] are established by both N atoms of the organic group in the cation, in trans positions to each other, with an N—Se—N angle of 161.6 (1°, resulting in a T-shaped (C,N,N′Se core. In the crystal, dimeric associations are formed by Br...Se [3.662 (2 Å] and Br...H interactions [2.56 (6 and 2.63 (7 Å] involving two bromide anions, two cations and two water molecules.

  20. Preparation of ethyl magnesium bromide for regiospecific analysis of triacylglycerols.

    Science.gov (United States)

    Ando, Yasuhiro; Tomita, Yuki; Haba, Yusuke

    2008-01-01

    This paper presents a procedure for preparation of a Grignard reagent, ethyl magnesium bromide, used for partial deacylation of triacylglycerols (TAG) in their regiospecific analysis. Magnesium turnings were reacted with ethereal solution of bromoethane in a screw-capped test tube to synthesize 2 mL of 1 M ethyl magnesium bromide. Continuously stirred with a vortex mixer, the reaction smoothly proceeded at room temperature. Regiospecific analysis of 1,3-distearoyl-2-oleoylglycerol using this product showed that fatty acid compositions of the sn-1(3) and sn-2 positions were contaminated by less than 2 mol% of fatty acids migrated from isomeric positions. The analyses of lard and cod liver/mackerel oil TAG showed typical distribution patterns of 16:0, 22:5n-3 and 22:6n-3 in pig and fish depot TAG. These results confirmed the view that the freshly prepared reagent is usable for regiospecific analysis of TAG.

  1. Modelling the site of bromide binding in vanadate-dependent bromoperoxidases.

    Science.gov (United States)

    Kraehmer, Verena; Rehder, Dieter

    2012-05-01

    Treatment of Boc-protected (S)-serine (Ser) methyl ester with triphenylphosphine bromide Ph(3)PBr (intermittently generated from PPh(3) and N-bromosuccinimide) yields Boc-3-bromoalanine (R)-Boc-BrAlaMe and, after deprotection, bromoalanine methyl ester (R)-BrAlaMe in the form of its hydrobromide. Boc-BrAlaMe and BrAlaMe have been structurally characterised. The reaction between BrAlaMe, salicylaldehyde (sal) and VO(2+) results in the formation of Schiff base complexes of composition [VO(sal-BrAlaMe)solv](+) (solv = CH(3)OH: 3, THF: 5) and [VO(sal-BrAla)THF] 4. DFT calculations of the structures of 3, 4 and 5, based on the B3LYP functional and employing the triple zeta basis set 6-311++g(d,p), provide distances Br···V = 4.0 ± 0.1 Å, if some distortion of the dihedral angle ∠N-C-C-Br is allowed (affording a maximum energy of ca. 45 kJ mol(-1)), and thus model Br···V distances detected by X-ray methods in bromoperoxidases from the marine algae Ascophyllum nodosum and Corallina pilulifera. The DFT calculations have been validated by comparing calculated and found structures, including the new complex [V(V)O(Amp-sal)OMe(MeOH)] (1, Amp is the aminophenol moiety) and the known complex [VO(L-Ser-van)H(2)O] (van = vanillin). Additional validation has been undertaken by checking experimental against calculated (BHandHLYP) EPR spectroscopic hyperfine coupling constants. Complexes containing bromine as a substituent at the phenyl moiety of a Schiff base ligand do not allow for an appropriate simulation of the Br···V distance in peroxidases. The closest agreement, d(Br···V) = 4.87 Å, is achieved with [VO(3Br-salSer)THF] (6), where 3Brsal-Ser is the dianionic Schiff base formed between 3-Br-5-NO(2)-salicylaldehyde and serine. PMID:22415551

  2. Formation of bromate during ferrate(VI) oxidation of bromide in water.

    Science.gov (United States)

    Huang, Xin; Deng, Yang; Liu, Shuang; Song, Yali; Li, Nanzhu; Zhou, Jizhi

    2016-07-01

    Ferrate (VI) is traditionally recognized as a safe oxidant without production of disinfection byproducts (DBPs). However, here we detected probable carcinogenic bromate (BrO3(-)) during ferrate(VI) oxidation of bromide (Br(-))-containing water, and evaluated the effects of pH, ferrate(VI) dose, initial Br(-) concentration, and co-existing anions on the BrO3(-) formation. BrO3(-) was produced at a moderately-weakly acidic pH condition and in the absence of phosphate that was commonly applied as a buffer and stabilizing agent in previous ferrate(VI) studies. At pH 5.0, the produced BrO3(-) was increased from 12.5 to 273.8 μg/L with the increasing initial Br(-) concentration from 200 to 1000 μg/L at 10 mg/L Fe(VI), corresponding to an increase in the molar conversion ([BrO3(-)]/initial [Br(-)]) from 2.3% to 10.3%, in a bicarbonate-buffered solution. As pH increased to 7.0, the BrO3(-) concentration gradually dropped. The BrO3(-) production appeared to be associated with the oxidation by high valence iron species (i.e. Fe(VI), Fe(V) and Fe(IV)). Two key intermediate products (i.e. hypobromous acid/hypobromite (HOBr/OBr(-)) and hydrogen peroxide (H2O2)) relevant to the bromate formation were identified. The production of HOBr, a requisite intermediate for the ensuing bromate formation, was indirectly validated through identification of bromine-containing trihalomethanes and haloacetic acids during ferrate oxidation in a natural water, though these bromo-organic DBPs produced were insignificant. Furthermore, the inhibition effects of various anions on the formation of BrO3(-) followed chloride H2O2 was detected at higher phosphate concentration. It could reduce HOBr to Br(-), thereby inhibiting the bromate formation. PMID:27153235

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

    Directory of Open Access Journals (Sweden)

    B.-M. Sinnhuber

    2009-04-01

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

  4. High-speed Laser Micromachining with Copper Bromide Laser

    CERN Document Server

    Balchev, I I; Minkovski, N I; Sabotinov, N V; Balchev, Ivaylo I.; Kostadinov, Ivan K.; Minkovski, Nikolai I.; Sabotinov, Nikola V.

    2006-01-01

    The application of the copper bromide (CuBr) laser as an attractive tool in the micro-machining of different materials has been demonstrated. High-quality drilling by trepanning and precision cutting was established on several materials with a negligible heat-affected zone (HAZ). That good performance was a result of the combination of high power visible radiation, short pulses, and close to the diffraction-limited laser beam quality with high-speed galvo scanner beam steering.

  5. Criticality in aqueous solutions of 3-methylpyridine and sodium bromide.

    Science.gov (United States)

    Kostko, A F; Anisimov, M A; Sengers, J V

    2004-08-01

    We address a controversial issue regarding the nature of critical behavior in ternary electrolyte solutions of water, 3-methylpyridine, and sodium bromide. Earlier light-scattering studies showed an anomalous critical behavior in this system that was attributed to the formation of a microheterogeneous phase associated with ion-molecule clustering [M.A. Anisimov, J. Jacob, A. Kumar, V.A. Agayan, and J. V. Sengers, Phys. Rev. Lett. 85, 2336 (2000)

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

    Science.gov (United States)

    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 (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.

  7. Use of 82Br and 131I radionuclides in studies of goitrogenic effects of exogenous bromide

    International Nuclear Information System (INIS)

    The interference of excessive bromide intake with iodine metabolism in the rat was studied using 82Br and 131I radionuclides. Mainly lactating rat dams and their pups were used, in addition to adult male rats, in the present studies. Particularly, the influence of high bromide intake in lactating rat dams on the transfer of iodine and bromide to suckling young through breast milk was evaluated. The induction of hypothyroid status in the pups by high bromide intake in the mothers was proved unambiguously. Excessive bromide in lactating rat dams caused a marked decrease in plasma levels of thyroid hormones both, in the mothers and in their sucklings. The effects of an enhanced bromide intake on the thyroid function in relation to iodine status in the animals were also followed. Marked goitrogenic and thyrotoxic effects of excessive bromide in adult rats were significantly enhanced under the conditions of simultaneous iodine deficiency in the experimental animals. (author)

  8. Brominated lipids identify lipid binding sites on the surface of the reaction center from Rhodobacter sphaeroides.

    Science.gov (United States)

    Roszak, Aleksander W; Gardiner, Alastair T; Isaacs, Neil W; Cogdell, Richard J

    2007-03-20

    This study describes the use of brominated phospholipids to distinguish between lipid and detergent binding sites on the surface of a typical alpha-helical membrane protein. Reaction centers isolated from Rhodobacter sphaeroides were cocrystallized with added brominated phospholipids. X-ray structural analysis of these crystals has revealed the presence of two lipid binding sites from the characteristic strong X-ray scattering from the bromine atoms. These results demonstrate the usefulness of this approach to mapping lipid binding sites at the surface of membrane proteins.

  9. [Manometric effects of pinaverium bromide in irritable bowel syndrome].

    Science.gov (United States)

    Soifer, L; Varela, E; Olmos, J

    1992-01-01

    The effects of pinaverium bromide on colonic motility were investigated in a controlled, controlled, cross-over study in 32 patients with irritable bowel syndrome. Constipation was clearly predominant in one group of 16 patients, and diarrhea in the other group of 16. Manometric measurements were taken of the colonic motor response generated by distention of a balloon inserted to the rectosigmoid junction. Measurements were taken before and one hour after ingestion of two tablets containing placebo or two tablets each containing 50 mg of pinaverium bromide. Following intake of placebo the motility index increased from the basal value in patients with constipation, and resistance to distention decreased in the diarrhea group. These changes were attributable to repetition of the mechanical stimulus within a relatively brief time lapse, or more probably to the ingestion of liquid which accompanied intake of tablets. Compared with placebo, pinaverium bromide induced inhibition of both effects. From the therapeutic point of view, the decrease in motility index seen in patients with irritable bowel syndrome and constipation is particularly interesting. PMID:1295286

  10. 4-Hydroxy-1,2,6-trimethylpyridinium bromide monohydrate

    Directory of Open Access Journals (Sweden)

    T. Seethalakshmi

    2013-06-01

    Full Text Available The title salt, C8H12NO+·Br−·H2O, is isomorphous with the chloride analogue [Seethalakshmi et al. (2013. Acta Cryst. E69, o835–o836]. In the solid state, the cations, anions and water molecules are interlinked by a network of O—H...O, O—H...Br and C—H...Br interactions. The water molecule makes two O—H...Br hydrogen bonds, generating [010] zigzag chains of alternating water molecules and bromide anions. The cation is involved in two intermolecular C—H...Cl interactions in the chloride salt, whereas three intermolecular C—H...Br interactions are observed in the title bromide salt. This additional intermolecular C—H...Br interaction links the adjacent water and bromide zigzag chains via cationic molecules. In addition, weak π–π stacking interactions are observed between pyridinium rings [centroid–centroid distance = 3.5664 (13 Å].

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

    Science.gov (United States)

    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.

  12. Oral teratogenicity studies of methyl bromide in rats and rabbits.

    Science.gov (United States)

    Kaneda, M; Hojo, H; Teramoto, S; Maita, K

    1998-05-01

    Teratogenicity studies of methyl bromide, a widely used fumigant, were conducted in rats and rabbits. Methyl bromide was dissolved in corn oil and administered orally to groups of 24 copulated female Crj:CD (SD) rats at dose levels of 0 (corn oil), 3, 10 or 30 mg/kg/day on days 6-15 of gestation and to groups of 18 artificially inseminated female Kbl:JW rabbits at 0, 1, 3 or 10 mg/kg/day on days 6-18 of gestation. Maternal rats and rabbits were euthanized on respective days 20 and 27 of gestation. Foetuses were examined for survival, growth and teratological alterations. Maternal toxicity was evident in the high-dose groups for both species. In these groups, maternal body weight gains and food consumption were significantly decreased during the dosing and post-dosing periods. Necropsy of maternal rats also revealed erosive lesions in the stomach and the surrounding organs. However, no treatment-related adverse effects were found in foetuses of the treated groups for both rat and rabbit studies. These results led to the conclusion that methyl bromide was not foetotoxic or teratogenic to rat and rabbit foetuses up to dose levels of 30 and 10 mg/kg/day, respectively, at which maternal toxicity was evident for both species.

  13. Bromine-80m-labeled estrogens: Auger-electron emitting, estrogen receptor-directed ligands with potential for therapy of estrogen receptor positive cancers

    International Nuclear Information System (INIS)

    A triphenylbromoethylene, 1,1-bis(p-hydroxyphenyl)-2-bromo-2-phenylethylene, Br-BHPE, and a bromosteroidal estrogen, 17α- bromovinylestradiol, BrVE2, were labeled with the Auger electron emitting nuclide bromine-80m, prepared by the [p,n] reaction with 80Se. To assess their potential as estrogen receptor (ER) directed therapeutic substrates the bromine-80m labeled estrogens were injected into immature female rats and the tissue distribution studied at 0.5 and 2 hours. Both radiobromoestrogens showed substantial diethylstilbesterol (DES)-inhibitable localization in the ER rich tissues, uterus, pituitary, ovary and vagina at both time points. While the percent dose per gram tissue was higher for the Br-BHPE, the BrVE2 showed higher tissue to blood ratios, especially at 2 hr, reflecting the lower blood concentrations of radiobromine following administration of the steroidal bromoestrogen. Comparing intraperitoneal, intravenous and subcutaneous routes of administration for the radiobromine labeled Br-BHPE, the intraperitoneal route was particularly advantageous to provide maximum, DES-inhibitable concentrations in the peritoneal, ER-rich target organs, the uterus, ovary and vagina. While uterine concentrations after BrBHPE were from 10--48% dose/g and after BrVE2 were 15--25% dose/g, similar treatment with /sup 80m/Br as sodium bromide showed uniform low concentrations in all tissues at about the levels seen in blood. The effective specific activity of [/sup 80m/Br]BrBHPE, assayed by specific binding to ER in rat uterine cytosol, was 8700 Ci/mmole. 23 refs., 9 figs., 2 tabs

  14. Bromine-80m-labeled estrogens: Auger-electron emitting, estrogen receptor-directed ligands with potential for therapy of estrogen receptor positive cancers

    Energy Technology Data Exchange (ETDEWEB)

    DeSombre, E.R.; Mease, R.C.; Hughes, A.; Harper, P.V.; DeJesus, O.T.; Friedman, A.M.

    1988-01-01

    A triphenylbromoethylene, 1,1-bis(p-hydroxyphenyl)-2-bromo-2-phenylethylene, Br-BHPE, and a bromosteroidal estrogen, 17..cap alpha..- bromovinylestradiol, BrVE/sub 2/, were labeled with the Auger electron emitting nuclide bromine-80m, prepared by the (p,n) reaction with /sup 80/Se. To assess their potential as estrogen receptor (ER) directed therapeutic substrates the bromine-80m labeled estrogens were injected into immature female rats and the tissue distribution studied at 0.5 and 2 hours. Both radiobromoestrogens showed substantial diethylstilbesterol (DES)-inhibitable localization in the ER rich tissues, uterus, pituitary, ovary and vagina at both time points. While the percent dose per gram tissue was higher for the Br-BHPE, the BrVE/sub 2/ showed higher tissue to blood ratios, especially at 2 hr, reflecting the lower blood concentrations of radiobromine following administration of the steroidal bromoestrogen. Comparing intraperitoneal, intravenous and subcutaneous routes of administration for the radiobromine labeled Br-BHPE, the intraperitoneal route was particularly advantageous to provide maximum, DES-inhibitable concentrations in the peritoneal, ER-rich target organs, the uterus, ovary and vagina. While uterine concentrations after BrBHPE were from 10--48% dose/g and after BrVE/sub 2/ were 15--25% dose/g, similar treatment with /sup 80m/Br as sodium bromide showed uniform low concentrations in all tissues at about the levels seen in blood. The effective specific activity of (/sup 80m/Br)BrBHPE, assayed by specific binding to ER in rat uterine cytosol, was 8700 Ci/mmole. 23 refs., 9 figs., 2 tabs.

  15. Selective nitration and bromination of surprisingly ruffled phosphorus corroles.

    Science.gov (United States)

    Pomarico, Giuseppe; Tortora, Luca; Fronczek, Frank R; Smith, Kevin M; Paolesse, Roberto

    2016-05-01

    Phosphorus complexes of corrole have recently attracted increasing interest since these compounds can be easily prepared in good yields, are stable, and show unusual optical properties. For these reasons, phosphorus corroles represent a class of interesting compounds to be exploited in the field of material science or for biomedical investigations and the definition of synthetic pathways for their functionalization is an important step to optimize their properties for various applications. We report here the reactivity of the phosphorus complex of 5,10,15-tritolylcorrole in the nitration or bromination reaction. Both these attempts were successful, allowing the preparation of substituted phosphorus corroles, which can be used as intermediates of more complex architectures endowed with useful properties. Furthermore, the crystallographic characterization of both complexes shows that they have an unusual ruffled geometry of the corrole core, a conformation that has not been considered possible for such a macrocycle.

  16. The third international interlaboratory study on brominated flame retardants

    Energy Technology Data Exchange (ETDEWEB)

    Boer, J. de [Netherlands Institute for Fisheries Research, IJmuiden (Netherlands); Wells, D. [FRS Marine Laboratory, Aberdeen (United Kingdom)

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs) have been produced as brominated flame retardants (BFRs) since the early 1970s and have been found in the aquatic environment since the late 1970s. However, as a result of their detection in sperm whales from deeper Atlantic waters and in human milk, many laboratories are now measuring PBDEs in environmental samples. A first international interlaboratory study (ILS) on the analysis of PBDEs, organised by the Bromine Science and Environmental Forum (BSEF), Brussels, Belgium, in collaboration with the Netherlands Institute for Fisheries Research (RIVO) was conducted in 1999-2000. The results showed that the 18 participating laboratories produced comparable results for BDE 47 in various matrices but had analytical difficulties for other BDEs, in particular for the BDEs 99 and 209. A second study was organised in 2001-2002 by BSEF, QUASIMEME and RIVO. That study showed improvement in comparability of the participating laboratories for BDE99 and some other BDEs. However, there was no improvement for BDE209. Hexabromocyclododecane (HBCD), tetrabromobisphenol-A (TBBP-A) and the dimethyl derivative of TBBP-A (dimethyl TBBP-A) were included in the second study. However, it appeared that only two or three laboratories were able to analyse these determinands. Others laboratories were still in the development phase with their methods for these BFRs. This third study was organised as a development exercise by QUASIMEME, in collaboration with RIVO between September and December 2003. The BFRs selected were the same as in the second study. Two biota test materials, a harbor sediment, a sewage sludge, and two standard solutions were dispatched to the participants.

  17. Formation of bromate and halogenated disinfection byproducts during chlorination of bromide-containing waters in the presence of dissolved organic matter and CuO

    KAUST Repository

    Liu, Chao

    2015-12-02

    Previous studies showed that significant bromate (BrO3-) can be formed via the CuO-catalyzed disproportionation of hypobromous acid (HOBr) pathway. In this study, the influence of CuO on the formation of BrO3- and halogenated disinfection byproducts (DBPs) (e.g., trihalomethanes, THMs and haloacetic acids, HAAs) during chlorination of six dissolved organic matter (DOM) isolates was investigated. Only in the presence of slow reacting DOM (from treated Colorado River water, i.e., CRW-BF-HPO), significant BrO3- formation is observed, which competes with bromination of DOM (i.e., THM and HAA formation). Reactions between HOBr and 12 model compounds in the presence of CuO indicates that CuO-catalyzed HOBr disproportionation is completely inhibited by fast reacting phenols, while it predominates in the presence of practically unreactive compounds (acetone, butanol, propionic, and butyric acids). In the presence of slow reacting di- and tri-carboxylic acids (oxalic, malonic, succinic, and citric acids), BrO3- formation varies, depending on its competition with bromoform and dibromoacetic acid formation (i.e., bromination pathway). The latter pathway can be enhanced by CuO due to the activation of HOBr. Therefore, increasing CuO dose (0-0.2 g L-1) in a reaction system containing chlorine, bromide, and CRW-BF-HPO enhances the formation of BrO3-, total THMs and HAAs. Factors including pH and initial reactant concentrations influence the DBP formation. These novel findings have implications for elevated DBP formation during transportation of chlorinated waters in copper-containing distribution systems.

  18. Solid miscibility of common-anion lithium and sodium halides. Experimental determination of the region of demixing in lithium bromide + sodium bromide

    NARCIS (Netherlands)

    Oonk, H.A.J.; Wijk, H.J. van; Doornhof, D.

    1984-01-01

    The region of demixing of solid lithium bromide + sodium bromide mixtures has been measured by X-ray diffraction. The critical temperature of mixing corresponding to a thermodynamic fit of the experimental data is 513 K. Estimates are given of the regions of demixing in solid lithium chloride + sodi

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

    Directory of Open Access Journals (Sweden)

    2007-10-01

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

  20. Potent competitive interactions of some brominated flame retardants and related compounds with human transthyretin in vitro

    NARCIS (Netherlands)

    Meerts, I.A.T.M.; Zanden, van J.J.; Luijks, E.A.C.; Leeuwen-Bol, van I.; Marsh, G.; Jakobsson, E.; Bergman, A.; Brouwer, A.

    2000-01-01

    Brominated flame retardants such as polybrominated diphenyl ethers (PBDEs), pentabromophenol (PBP), and tetrabromobisphenol A (TBBPA) are produced in large quantities for use in electronic equipment, plastics, and building materials. Because these compounds have some structural resemblance to the th

  1. Bromine-lithium exchange: An efficient tool in the modular construction of biaryl ligands.

    Science.gov (United States)

    Bonnafoux, Laurence; Leroux, Frédéric R; Colobert, Françoise

    2011-01-01

    Regioselective bromine-lithium exchange reactions on polybrominated biaryls enable the modular synthesis of various polysubstituted biphenyls such as bis(dialkylphosphino)-, bis(diarylphosphino)- and dialkyl(diaryl)phosphinobiphenyls. All permutations of substituents at the ortho positions of the biphenyls are possible. In a similar manner, one can gain access to monophosphine analogues. So far, such a process, based on the effective discrimination between bromine atoms as a function of their chemical environment, has been observed only sporadically.

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

    OpenAIRE

    Iudin, M.

    2008-01-01

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

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

    OpenAIRE

    Bai, Peng; Bazant, Martin Z.

    2016-01-01

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

  4. Full scale calcium bromide injection with subsequent mercury oxidation and removal within wet flue gas desulphurization system: Experience at a 700 MW coal-fired power facility

    Science.gov (United States)

    Berry, Mark Simpson

    The Environmental Protection Agency promulgated the Mercury and Air Toxics Standards rule, which requires that existing power plants reduce mercury emissions to meet an emission rate of 1.2 lb/TBtu on a 30-day rolling average and that new plants meet a 0.0002 lb/GWHr emission rate. This translates to mercury removals greater than 90% for existing units and greater than 99% for new units. Current state-of-the-art technology for the control of mercury emissions uses activated carbon injected upstream of a fabric filter, a costly proposition. For example, a fabric filter, if not already available, would require a 200M capital investment for a 700 MW size unit. A lower-cost option involves the injection of activated carbon into an existing cold-side electrostatic precipitator. Both options would incur the cost of activated carbon, upwards of 3M per year. The combination of selective catalytic reduction (SCR) reactors and wet flue gas desulphurization (wet FGD) systems have demonstrated the ability to substantially reduce mercury emissions, especially at units that burn coals containing sufficient halogens. Halogens are necessary for transforming elemental mercury to oxidized mercury, which is water-soluble. Plants burning halogen-deficient coals such as Power River Basin (PRB) coals currently have no alternative but to install activated carbon-based approaches to control mercury emissions. This research consisted of investigating calcium bromide addition onto PRB coal as a method of increasing flue gas halogen concentration. The treated coal was combusted in a 700 MW boiler and the subsequent treated flue gas was introduced into a wet FGD. Short-term parametric and an 83-day longer-term tests were completed to determine the ability of calcium bromine to oxidize mercury and to study the removal of the mercury in a wet FGD. The research goal was to show that calcium bromine addition to PRB coal was a viable approach for meeting the Mercury and Air Toxics Standards rule

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-01

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

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

    Science.gov (United States)

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

    1988-01-01

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

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

    International Nuclear Information System (INIS)

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

  8. Interaction between gaseous ozone and crystalline potassium bromide

    Science.gov (United States)

    Levanov, A. V.; Maksimov, I. B.; Isaikina, O. Ya.; Antipenko, E. E.; Lunin, V. V.

    2016-07-01

    The formation of nonvolatile products of the oxidation of a bromide ion during the interaction between gaseous ozone and powdered crystalline KBr is studied. It is found that potassium bromate KBrO3 is the main product of the reaction. The influence of major experimental factors (the duration of ozonation, the concentration of ozone, the humidity of the initial gas, and the temperature) on the rate of formation of bromate is studied. The effective constants of the formation of bromate during the interaction between O3 and Br- in a heterogeneous gas-solid body system and in a homogeneous aqueous solution are compared.

  9. Suicide by intravenous injection of rocuronium-bromide: Case report

    Directory of Open Access Journals (Sweden)

    Nikolić Slobodan

    2005-01-01

    Full Text Available Suicides by intravenous injection of an overdose of medicaments are uncommon. In this paper, we present the case of a suicide by rocuronium-bromide injection in combination with an oral overdose of metoprolol. Unfortunately, in Belgrade, there is no toxicological laboratory capable of detecting rocuronium. The interpretation of autopsy and toxicological data in this case was made difficult due to the extreme putrefaction of the body of the deceased. So, by forensic investigation, the case was solved indirectly, through circumstantial evidence: an empty ampoule of rocuronium found near the body, as well as a plastic syringe and cloth-bandage found in the left hand of the deceased.

  10. Enzyme activities in agricultural soils fumigated with methyl bromide alternatives

    OpenAIRE

    Klose, Susanne; Ajwa, H A

    2004-01-01

    Pre-plant fumigation of agricultural soils with a combination of methyl bromide (MeBr) and chloropicrin (CP) to control nematodes, soil-borne pathogens and weeds has been a common practice in strawberry (Fragaria X ananassa Duchesne) production since the 1960s. MeBr will be phased out by 2005, but little is known about the impacts of alternative fumigants on soil microbial processes. We investigated the response of microbial biomass and enzyme activities in soils fumigated over two years with...

  11. XPS STUDIES ON SURFACE MODIFIED POLY[1-(TRIMETHYLSILYL)-1-PROPYNE] MEMBRANES Ⅱ SURFACE MODIFICATION BY BROMINE VAPOR

    Institute of Scientific and Technical Information of China (English)

    XU Guanfan; SUN Xiaoguang; QIU Xuepeng; ZHANG Jinlan; ZHENG Guodong

    1994-01-01

    Surface modification of poly [ 1-(trimethylsilyl )-1-propyne ] ( PTMSP ) membranes by bromine vapor has been studied. It is shown that Br/C atomic ratio at the surfacesincreased with the time of bromination until about 60 min, then it reached a plateau. The results of XPS and IR studies indicated that the addition of bromine to double bonds and the replacement of H on CH3 by bromine had taken place so that a new peak at 286.0 eV (C-Br)in C1sspectra and some new bands, e. g. at 1220 and 580cm-1,in IR spectra were formed. The fact, Po2, permeability of oxygen, decreased and αO2/N2, separation factor of oxygen relative to nitrogen, increased with bromination time, shows that surface modification of PTMSP by bromine may be an efficient approachto prepare PTMSP membranes used for practical gas separations.

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

    Science.gov (United States)

    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.

  13. Effects of pinaverium bromide and verapamil on the motility of the rat isolated colon.

    Science.gov (United States)

    Baumgartner, A; Drack, E; Halter, F; Scheurer, U

    1985-09-01

    Pinaverium bromide was 30 times less potent than verapamil in inhibiting intraluminal pressure responses of in vitro rat colonic segments to barium chloride, acetylcholine, FK 33-824 or field stimulation. The inhibitory effects of both verapamil and pinaverium bromide on the pressure responses to field stimulation were antagonized similarly by exogenous calcium administration. These results support the concept that pinaverium bromide acts on calcium channels in the smooth muscle cell membrane. PMID:4052731

  14. Effects of pinaverium bromide and verapamil on the motility of the rat isolated colon.

    OpenAIRE

    Baumgartner, A.; Drack, E.; Halter, F; Scheurer, U.

    1985-01-01

    Pinaverium bromide was 30 times less potent than verapamil in inhibiting intraluminal pressure responses of in vitro rat colonic segments to barium chloride, acetylcholine, FK 33-824 or field stimulation. The inhibitory effects of both verapamil and pinaverium bromide on the pressure responses to field stimulation were antagonized similarly by exogenous calcium administration. These results support the concept that pinaverium bromide acts on calcium channels in the smooth muscle cell membrane.

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

    Directory of Open Access Journals (Sweden)

    Steinmetz Sonja

    2012-12-01

    Full Text Available Abstract 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.

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Copper, W.J. (Florida International Univ., Miami (United States)); Amy, G.L. (Univ. of Arizona, Tucson (United States)); Moore, C.A.; Zika, R.G. (Univ. of Miami, FL (United States))

    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.

  19. Synthesis and Characterization of Mercuric Bromide-Phenothiazine Complexes

    Directory of Open Access Journals (Sweden)

    Vidisha A. Alwani

    2014-12-01

    Full Text Available N-alkylphenothiazines (NAPTZs are biologically active heterocyclic compounds that find extensive applications in the field of medicine. In the pharmaceutical industry, they are used as psychotherapeutic, antiemetic, and antihistaminic drugs. In this study, complexation reactions of mercuric bromide with NAPTZs as principal ligands have been investigated in MeOH medium. Five mercuric bromide complexes of the NAPTZ ligands namely, chlorpromazine hydrochloride (CP.HCl, promethazine hydrochloride (PM.HCl, ethopropazine hydrochloride (EP.HCl, trifluoperazine dihydrochloride (TF.2HCl and thioridazine hydrochloride (TR.HCl have been synthesized. These complexes were subjected to elemental analysis, solubility, molar conductance and magnetic susceptibility, U.V-Vis, I.R, and NMR spectroscopy. The molecular formulations of the complexes have been found to be: [HgBr2(CP2].4H2O; [HgBr2(PM2].2H2O; [HgBr2(EP2]; [HgBr2(TF2].2H2O and [HgBr2(TR2]. Tentative molecular structures have been proposed and presented.

  20. Modeling water/lithium bromide absorption chillers in ASPEN Plus

    International Nuclear Information System (INIS)

    Highlights: → Single- and double-effect water/lithium bromide absorption chiller designs are numerically modeled using ASPEN. → The modeling procedure is described and the results are compared to published modeling data to access prediction accuracy. → Predictions for the single- and double-effect designs are within 3% and 5%, respectively of published data for all cycle parameters of interest. → The absorption cycle models presented allow investigation of using absorption chillers for waste heat utilization in the oil and gas industry. -- Abstract: Absorption chillers are a viable option for providing waste heat-powered cooling or refrigeration in oil and gas processing plants, thereby improving energy efficiency. In this paper, single- and double-effect water/lithium bromide absorption chiller designs are numerically modeled using ASPEN. The modeling procedure is described and the results are compared to published modeling data to access prediction accuracy. Predictions for the single- and double-effect designs are within 3% and 5%, respectively of published data for all cycle parameters of interest. The absorption cycle models presented not only allow investigation into the benefits of using absorption chillers for waste heat utilization in the oil and gas industry, but are also generically applicable to a wide range of other applications.

  1. Development of copper bromide laser master oscillator power amplifier system

    Indian Academy of Sciences (India)

    G N Tiwari; R K Mishra; R Khare; S V Nakhe

    2014-02-01

    Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at 110 W average power is reported. The spectral distribution of power at green (510.6 nm) and yellow (578.2 nm) components in the output of a copper bromide laser is studied as a function of operating parameters. The electrical input power was varied from 2.6 to 4.3 kW, the pulse repetition frequency (PRF) was changed from 16 to 19 kHz, and the pressure of the buffer gas (neon) was kept fixed at 20 mbar. When the electrical input power was increased to 4.3 kW from 2.6 kW, the tube-wall temperature also increased to 488°C from 426°C but the ratio of the green to yellow power decreased to 1.53 from 3.73. The ratio of green to yellow power decreased to 1.53 from 1.63 when the PRF of the laser was increased to 19 kHz from 16 kHz. These observations are explained in terms of electron temperature, energy levels of transitions, and voltage and current waveforms across the laser head.

  2. Bromine partitioning between olivine and melt at OIB source conditions: Indication for volatile recycling

    Science.gov (United States)

    Joachim, Bastian; Ruzié, Lorraine; Burgess, Ray; Pawley, Alison; Clay, Patricia L.; Ballentine, Christopher J.

    2016-04-01

    Halogens play a key role in our understanding of volatile transport processes in the Earth's mantle. Their moderate (fluorine) to highly (iodine) incompatible and volatile behavior implies that their distribution is influenced by partial melting, fractionation and degassing processes as well as fluid mobilities. The heavy halogens, particularly bromine and iodine, are far more depleted in the Earth's mantle than expected from their condensation temperature (Palme and O'Neill 2014), so that their very low abundances in basalts and peridotites (ppb-range) make it analytically challenging to investigate their concentrations in Earth's mantle reservoirs and their behavior during transport processes (Pyle and Mather, 2009). We used a new experimental technique, which combines the irradiation technique (Johnson et al. 2000), laser ablation and conventional mass spectrometry. This enables us to present the first experimentally derived bromine partition coefficient between olivine and melt. Partitioning experiments were performed at 1500° C and 2.3 GPa, a P-T condition that is representative for partial melting processes in the OIB source region (Davis et al. 2011). The bromine partition coefficient between olivine and silicate melt at this condition has been determined to DBrol/melt = 4.37•10-4± 1.96•10-4. Results show that bromine is significantly more incompatible than chlorine (˜1.5 orders of magnitude) and fluorine (˜2 orders of magnitude) due to its larger ionic radius. We have used our bromine partitioning data to estimate minimum bromine abundances in EM1 and EM2 source regions. We used minimum bromine bulk rock concentrations determined in an EM1 (Pitcairn: 1066 ppb) and EM2 (Society: 2063 ppb) basalt (Kendrick et al. 2012), together with an estimated minimum melt fraction of 0.01 in OIB source regions (Dasgupta et al. 2007). The almost perfect bromine incompatibility results in minimum bromine abundances in EM1 and EM2 OIB source regions of 11 ppb and 20

  3. Role of bromine doping on the photovoltaic properties and microstructures of CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsushi; Okada, Hiroshi; Oku, Takeo [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga, 522-8533 (Japan)

    2016-02-01

    Organic-inorganic hybrid heterojunction solar cells containing CH{sub 3}NH{sub 3}PbI{sub 3} perovskite compound were fabricated using mesoporous TiO{sub 2} as the electronic transporting layer and spirobifluorence as the hole-transporting layer. The purpose of the present study is to investigate role of bromine (Br) doping on the photovoltaic properties and microstructure of CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells. Photovoltaic, optical properties and microstructures of perovskite-based solar cells were investigated. The X-ray diffraction identified crystal structure of the perovskite layer doped with Br in the solar cell. Scanning electron microscopy observation showed a different behavior of surface morphology and the perovskite crystal structure on the TiO{sub 2} mesoporous structure depending on extent amount of hydrogen doping of Br. The role of bromide halogen doping on the perovskite crystal structure and photovoltaic properties was due to improvement of carrier mobility, optimization of electron structure, band gap related with the photovoltaic parameters of V{sub oc}, J{sub sc} and η. Energy diagram and photovoltaic mechanism of the perovskite solar cells varied with halogen doping was discussed by experimental results.

  4. Role of bromine doping on the photovoltaic properties and microstructures of CH3NH3PbI3 perovskite solar cells

    International Nuclear Information System (INIS)

    Organic-inorganic hybrid heterojunction solar cells containing CH3NH3PbI3 perovskite compound were fabricated using mesoporous TiO2 as the electronic transporting layer and spirobifluorence as the hole-transporting layer. The purpose of the present study is to investigate role of bromine (Br) doping on the photovoltaic properties and microstructure of CH3NH3PbI3 perovskite solar cells. Photovoltaic, optical properties and microstructures of perovskite-based solar cells were investigated. The X-ray diffraction identified crystal structure of the perovskite layer doped with Br in the solar cell. Scanning electron microscopy observation showed a different behavior of surface morphology and the perovskite crystal structure on the TiO2 mesoporous structure depending on extent amount of hydrogen doping of Br. The role of bromide halogen doping on the perovskite crystal structure and photovoltaic properties was due to improvement of carrier mobility, optimization of electron structure, band gap related with the photovoltaic parameters of Voc, Jsc and η. Energy diagram and photovoltaic mechanism of the perovskite solar cells varied with halogen doping was discussed by experimental results

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

    Science.gov (United States)

    Vetter, Walter; Jun, Wu

    2003-07-01

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

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

    Science.gov (United States)

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

    2016-02-01

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

  7. Excited atomic bromine energy transfer and quenching mechanisms

    Science.gov (United States)

    Johnson, Ray O.

    1993-08-01

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

  8. Untypical bromine corrosion in boilers co-firing biomass

    Directory of Open Access Journals (Sweden)

    A. Hernas

    2012-09-01

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

  9. Brominated flame retardants in Belgian little owl (Athene noctua) eggs

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, V.; Covaci, A.; Maervoet, J.; Dauwe, T.; Schepens, P.; Eens, M. [Antwerp Univ. (Belgium)

    2004-09-15

    Since the 1960s, polybrominated diphenylethers (PBDEs), a class of brominated flame retardants (BFRs), are widely used in textiles, plastics, electronic equipment and other materials. Their massive use has led to the ubiquitous presence of PBDEs in the environment and in biota in which the PBDE levels seem to increase rapidly. High concentrations of some congeners may cause adverse effects in both wildlife and in human populations1 and this has led to the growing concern of scientists over the last decade and to the need for more data on environmental levels of PBDEs. The little owl (Athene noctua) is a small sedentary predator, which makes it a very suitable biomonitoring species. This owl species feeds on a variety of preys, including small mammals and birds, reptiles, amphibians, earthworms and beetles, depending on the season and the local circumstances. Because very limited information is available about contamination levels in the little owl, a study was conducted to determine the concentrations of PBDEs, polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in deserted or addled eggs of little owls in Belgium. Eggs have been used successfully as a monitoring tool for persistent organic pollutants (POPs) in several studies. Although the analysis of POPs in deserted or addled eggs has clear limitations, these can be partially avoided by analysing only highly persistent components, for which the original composition will not change due to 'posthatching' microbiological degradation.

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

    Directory of Open Access Journals (Sweden)

    E. Tas

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Pour Biazar

    2006-06-01

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

  12. Vapour pressures, densities, and viscosities of the (water + lithium bromide + potassium acetate) system and (water + lithium bromide + sodium lactate) system

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Antonio de [Department of Chemical Engineering, University of Castilla - La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain); Donate, Marina [Department of Chemical Engineering, University of Castilla - La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain); Rodriguez, Juan F. [Department of Chemical Engineering, University of Castilla - La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain)]. E-mail: juan.rromero@uclm.es

    2006-02-15

    Measurements of thermophysical properties (vapour pressure, density, and viscosity) of the (water + lithium bromide + potassium acetate) system LiBr:CH{sub 3}COOK = 2:1 by mass ratio and the (water + lithium bromide + sodium lactate) system LiBr:CH{sub 3}CH(OH)COONa = 2:1 by mass ratio were measured. The system, a possible new working fluid for absorption heat pump, consists of absorbent (LiBr + CH{sub 3}COOK) or (LiBr + CH{sub 3}CH(OH)COONa) and refrigerant H{sub 2}O. The vapour pressures were measured in the ranges of temperature and absorbent concentration from T = (293.15 to 333.15) K and from mass fraction 0.20 to 0.50, densities and viscosities were measured from T = (293.15 to 323.15) K and from mass fraction 0.20 to 0.40. The experimental data were correlated with an Antoine-type equation. Densities and viscosities were measured in the same range of temperature and absorbent concentration as that of the vapour pressure. Regression equations for densities and viscosities were obtained with a minimum mean square error criterion.

  13. Brominated flame retardants in end-of-life management not problematic regarding formation of brominated dioxins/furans (PBDD/F)

    Energy Technology Data Exchange (ETDEWEB)

    Drohmann, D. [Great Lakes Chemical, Bergisch Gladbach (Germany); Tange, L. [Eurobrom B.V., Rijswijk (Netherlands); Rothenbacher, K. [Bromine Science and Environmental Forum, Brussels (Belgium)

    2004-09-15

    Bromine is used as the building block for some of the most effective flame retarding agents available to the plastics industry today. They are used to protect against the risk of accidental fires in a wide range of products. Brominated flame retardants (BFRs), as all flame retardants, act to decrease the risk of fire by increasing the fire resistance of the materials in which they are applied. There is a perception that BFRs affect adversely the end-of-life management of plastics through formation of brominated dioxins and furans (PBDD/F). In fact, there exists a wide range of data and practical experience demonstrating that the end-of-life management of plastics containing BFRs are fully compliant with legislation setting the strictest limit values for PBDD/F and is fully compatible with an integrated waste management concept. Furthermore, all existing EU Risk Assessments on BFRs according to the European Existing Substance Regulations include an assessment of the potential formation of dioxins and furans. All assessments conclude that the risks along the life-cycle of the chemicals for human health and the environment associated with the potential formation of PBDD/F are negligible. Moreover, two recent Swedish studies found, that consumer products with BFRs emit less pollutants than the same products without any FRs. This paper summarises available studies and presents the latest results regarding potential formation of brominated dioxins and furans in end-of-life management of plastics containing brominated flame retardants. Additionally, before BFR products enter the market they are tested for PBDD/F according to the ''German Dioxin Ordinance''. Depending on the substitution pattern the limit values for PBDD/F are set at <1{mu}g/kg (ppb) respectively <5{mu}g/kg (ppb).

  14. Terminal elimination half-lives of the brominated flame retardants TBBPA, HBCD, and lower brominated PBDEs in humans

    Energy Technology Data Exchange (ETDEWEB)

    Geyer, H.J.; Schramm, K.W.; Feicht, E.A.; Fried, K.W.; Henkelmann, B.; Lenoir, D. [GSF-National Research Center, Institute of Ecological Chemistry, Neuherberg (Germany); Darnerud, P.O.; Aune, M. [Swedish National Food Administration, Uppsala (Sweden); Schmid, P. [Swiss Federal Laboratories for Materials Testing and Research, Laboratory of Organic Chemistry, EMPA Duebendorf (Switzerland); McDonald, T.A. [Office of Environmental Health Assessment, California EPA, Oakland, CA (United States)

    2004-09-15

    Brominated flame retardants (BFRs) are widely used in polymers and textiles and applied in electronic equipment, construction materials, and furniture for the purpose of fire prevention. BFRs with the highest production volume are tetrabromobisphenol A (TBBPA), 1,2,5,6,9,10- hexabromocyclododecanes (HBCDs: {alpha}-HBCD + {beta}-HBCD + {gamma}-HBCD), and polybrominated diphenyl ethers (PBDEs). Several BFRs are highly lipophilic persistent organic pollutants (POPs) which have been identified in the aquatic and terrestrial environment including wildlife and humans. In exposed organisms including humans toxic effects, bioaccumulation, metabolism, and pharmacokinetics (especially half-life t{sub 1/2}) are important criterions in the hazard assessment. The aim of the present study was to estimate the terminal elimination half-lives (t{sub 1/2H}) of the main BFRs from the whole body (also named body-burden half-life) and/or from the adipose tissue (fat) of adult humans. The t{sub 1/2H} data for the following BFRs were evaluated: TBBPA, HBCD, 2,2',4,4'- tetrabromodiphenyl ether (BDE-47), 2,2',4,4',5-pentaBDE (BDE-99), 2,2',4,4',6-pentaBDE (BDE- 100), 2,2',4,4',5,5'-hexaBDE (BDE-153), and 2,2',4,4',5,6-hexaBDE (BDE-154).

  15. GAS SORPTION AND TRANSPORT IN POLY (PHENYLENE OXIDE )(PPO)AND ARYL-BROMINATED PPO MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    JIA Lianda; F.R.SHEU, R.T. CHERN; H.B. HOPFENBERG

    1989-01-01

    The apparent solubility (S), concentration- average diffusivity (D), and permeability (P), for CO2,CH4 and N2 through PPO and aryl- brominated PPO at 35 ℃ for pressure ranging from 1 to 26 atm are reported. It is found that P,D, and Sof the membranes to all the three gases vary with the extent of bromination. S increases with the increase of the perecnt of bromine in each case, but D to CO2 increases remarkably only at higher degree of bromination, and therefore, P to CO2 is increased by more than 100% over a wide range of pressure in the case .The solubility data are well described by the dual mode sorption model. It is found that the gas molecules sorbed by the Langmuir mode are relatively more immobilized and the contribution of the nonequilibrium character of the polymer to gas permeation increases obviously for CO2 and is hardly changed for CH4 with increasing bromine content. These observations are interpreted in terms of changes in specific free volume (SFV)and the cohesive energy density (CED) of the polymers.

  16. Effect of the Bromine-Based Flame Retardant Plastic Pyrolysis of Hydrotalcite

    Directory of Open Access Journals (Sweden)

    Morita N.

    2016-01-01

    Full Text Available In this study, a method is presented to decrease halogen compounds in the product oil from thermolysis of polystyrene and polypropylene mixed plastic spiked with tetrabromobisphenol A. A mixture of hydrotalcite and plastic was pyrolyzed in a glass reactor at 400 °C under a nitrogen atmosphere. Bromine compounds in the residual substances were measured. The yield of product oil increased using hydrotalcite as an additive. The bromine compounds that were the major ingredients in the oil after thermolysis at 400 °C from the mixed plastic, which also included toluene, ethyl benzene, styrene, and 1-methylethyl benzene, were 2-bromohexane, 3-bromo-1-propenyl benzene, 4,5-dibromodecane, 1-bromomethylbenzene, 3-bromophenol, and 4-bromo-2,6-dimethylbenzaniline. However, bromine compounds were not detected in the product oil, residue, or gas when hydrotalcite was added. After the thermolysis of the plastic, bromine compounds in the product oil may decrease because bromine was captured by the added hydrotalcite.

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

    Directory of Open Access Journals (Sweden)

    Eike Brunner

    2013-04-01

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

  18. 76 FR 7200 - Methyl Bromide; Notice of Receipt of Requests To Voluntarily Amend Registrations To Terminate...

    Science.gov (United States)

    2011-02-09

    ... Professional Products to voluntarily amend methyl bromide product registration 8536-12 to terminate or delete... identity or contact information unless you provide it in the body of your comment. If you send an e- mail... Cardinal Professional Products, and Trical, Inc.) to delete certain uses of methyl bromide...

  19. SYNTHESIS AND CATALYTIC PROPERTIES OF HYDROPHOBICALLY MODIFIED POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES)

    NARCIS (Netherlands)

    YANG, YJ; ENGBERTS, JBFN

    1991-01-01

    A series of hydrophobically modified homo- and copolymers of the poly(alkylmethyldiallylammonium bromide) type has been prepared by free-radical cyclo(co)polymerization of alkylmethyldiallylammonium bromide monomers in aqueous solution. Depending on the length of the alkyl side chain (varied between

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

    Science.gov (United States)

    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...

  1. Determination of micro-amount bromide in uranium trioxide by spectrophotometric method

    International Nuclear Information System (INIS)

    The content of bromide in the production of uranium trioxide is one of the most important control factors, so determining it accurately seems important. When uranium trioxide is dissolved in nitric acid, in the presence of AgNO3 solution, micro-amount bromide can be co- precipitated with AgCl. Bromide can be separated by centrifugation from a large amount of UO22+ and other anions. In the existing of KOH and H2O2, AgCl can be changed into free bromide. By adding ammonium molybdate as catalyst, bromide and excessive KBrO3 can react and produce Br2. In the medium of tert-butanol-ethanol, Br2 can react with basic fuchsine and produce a purple compound which is stable, the bromide content is determined by spectrophotometric method. The results show that it is a highly sensitive method with low detection limit. Its apparent molar absorption coefficient κ' is 1.7 x 104 L/(mol·cm). Its detection limit is 9 μg/L and determination limit is 0.13 mg/L. The linear relationship is in the range of 0.2-1.6 mg/L with a correlation coefficient of 0.997. The relative standard deviation is less than 10% after it is determed six times at the same time. For bromide content of 4.00 and 8.00 μg, the bromide recovery obtained are between 94% and 103%. (authors)

  2. Solvent effects in the reaction between piperazine and benzyl bromide

    Indian Academy of Sciences (India)

    S Ranga Reddy; P Manikyamba

    2007-11-01

    The reaction between piperazine and benzyl bromide was studied conductometrically and the second order rate constants were computed. These rate constants determined in 12 different protic and aprotic solvents indicate that the rate of the reaction is influenced by electrophilicity (), hydrogen bond donor ability () and dipolarity/polarizability (*) of the solvent. The LSER derived from the statistical analysis indicates that the transition state is more solvated than the reactants due to hydrogen bond donation and polarizability of the solvent while the reactant is more solvated than the transition state due to electrophilicity of the solvent. Study of the reaction in methanol, dimethyl formamide mixtures suggests that the rate is maximum when dipolar interactions between the two solvents are maximum.

  3. Mechanism of the Deaquation of Aquopentaaminocobalt(Ⅲ) Bromide

    Institute of Scientific and Technical Information of China (English)

    MA,Li-Dun(马礼敦); CHENG,Guang-Hui(程广辉); WU,Hong-Xiang(吴宏翔); LIN,Han-Yi(林涵毅); SHEN,Xiao-Liang(沈孝良); SHI,Guo-Shun(施国顺)

    2002-01-01

    There are two theories, SN1 and SN2, for the mechanism of the deaquation of aquopentaamincobalt(Ⅲ) bromide (AAC-B).Both of the theories are supported by some experimental and calculated data. But there are not any experiments to determine directly the structure of the intermediates at different reaction time. In this paper the structures of the intermediates at different reaction time in deaquation-anation of AACB were de-termined by extended X-ray absorption fine structure (EXAFS)and the reaction process wes studied by the combination of Xray powder diffraction and EXAFS. It was demonstrated that the deaquation-anation of AACB obeys the SN2 theory.

  4. Design and Fabrication of Externally heated Copper Bromide Laser

    Directory of Open Access Journals (Sweden)

    J.P. Dudeja

    1993-04-01

    Full Text Available An externally-heated, longitudinally-discharged, low-repetition-rate copper bromide laser, was designed and fabricated. The green-coloured wavelength at 5106 A from this laser can be used for underwater ranging and detection of submerged objects. Several new changes in the design of discharge tube, heating technique, buffer-gas-flow sub-system and electrical circuit have been conceived and incorporated advantageously in our system. Various parameters, for example, the type of buffer gas and its flow rate, mixture of gases, temperature of the discharge tube, delay between dissociation and excitation pulses, dissociation and excitation energies, and various resonator configurations are being optimised to get the maximum output power/energy from the laser system.

  5. Xanthine Biosensor Based on Didodecyldimethylammonium Bromide Modified Pyrolytic Graphite Electrode

    Institute of Scientific and Technical Information of China (English)

    TANG,Ji-Lin(唐纪琳); HAN,Xiao-Jun(韩晓军); HUANG,Wei-Min(黄卫民); WANG,Er-Kang(汪尔康)

    2002-01-01

    The vesicle of didodecyldimethylammonium bromide (DDAB)which contained tetrathiafulvalene (TTF) was mixed with xanthine oxidase, and the mixture was cast on the pyrolytic graphite electrode. The lipid films were used to supply a biological environment resembling biomembrane on the surface of the electrode. TTF was used as a mediator because of its high electron-transfer efficiency. A novel xanthine biosensor based on cast DDAB film was developed. The effects of pH and operating potential were explored for optimum analytical performance by using the amperometric method. The response time of the biosensor was less than 10 s. The detection limit of the biosensor was 3.2 × 10-7 mol/L and the liner range was from 4 × 10-7 mol/L to 2.4 × 10-6 mol/L.

  6. Irradiation as an alternative to methyl bromide: the Australian situation

    International Nuclear Information System (INIS)

    International agreement to phase out the fumigant Methyl bromide (MeBr) will have serious implications for pest and disease control in Australia, particularly grain pest control, quarantine usage on fresh horticultural produce and control of soil pathogens or nematodes. Irradiation is a practical alternative but is not currently approved for use in Australia. Other options are available but none of the viable methods except irradiation have the short application time needed for treatment of grams found to be infested during loading at export. This usage is vital, as Australian grain is exported at very high standards of freedom from insects, assured by Government regulatory requirements. Irradiation is contrasted against other alternatives including heat and cold, especially for fresh horticultural produce. (author)

  7. Mechanism of the Deaquation of Aquopentaaminocobalt(Ⅲ)Bromide

    Institute of Scientific and Technical Information of China (English)

    MA,Li-Dun; CHENG,Guang-Hui; 等

    2002-01-01

    There are two theories,SN1 and SN2, for the mechanism of the deaquation of aquopentaamincobalt(Ⅲ) bromide(AAC-B). Both of the theories are supported by some experimental and calculated data. But there are not any experiments to determine directly the structure of the intermediates at dififferent reaction time.In this paper the structures of the intermediates at different reaction time in deaquation-anation of AACB were determined by extended X-ray absorption fine structure (EXAFS) and the reaction process was studied by the combination of X-ray powder diffraction and EXAFS.It was demonstrated that the deaquation-anation of AACB obeys the SN2 theory.

  8. Action of pinaverium bromide, a calcium-antagonist, on gastrointestinal motility disorders.

    Science.gov (United States)

    Christen, M O

    1990-01-01

    1. The evidence reviewed here indicates that pinaverium bromide (Dicetel) relaxes gastrointestinal (GI) structures primarily by inhibiting Ca2+ influx through potential-dependent channels of surface membranes of smooth muscle cells. 2. The in vivo selectivity of pinaverium bromide for the GI tract appears to be due mainly to its pharmacokinetic properties. Because of its low absorption (typical for quaternary ammonium compounds) and marked hepatobiliary excretion, most of the orally-administered dose of pinaverium bromide remains in the GI tract. 3. Orally-administered pinaverium bromide does not elicit adverse cardiovascular side-effects at doses that effectively relieve GI spasm, pain, transit disturbances and other symptoms related to motility disorders. 4. Pinaverium bromide is the only Ca2(+)-antagonist with known therapeutic efficacy in the treatment of irritable bowel syndrome and certain other functional intestinal disorders. PMID:2177709

  9. The NBS Reaction: A Simple Explanation for the Predominance of Allylic Substitution over Olefin Addition by Bromine at Low Concentrations.

    Science.gov (United States)

    Wamser, Carl C.; Scott, Lawrence T.

    1985-01-01

    Examines mechanisms related to use of N-bromosuccinimide (NBS) for bromination at an allylic position. Also presents derived rate laws for three possible reactions of molecular bromine with an alkene: (1) free radical substitution; (2) free radical addition; and (3) electrophilic addition. (JN)

  10. Bromination of Marine Dissolved Organic Matter following Full Scale Electrochemical Ballast Water Disinfection.

    Science.gov (United States)

    Gonsior, Michael; Mitchelmore, Carys; Heyes, Andrew; Harir, Mourad; Richardson, Susan D; Petty, William Tyler; Wright, David A; Schmitt-Kopplin, Philippe

    2015-08-01

    An extensively diverse array of brominated disinfection byproducts (DBPs) were generated following electrochemical disinfection of natural coastal/estuarine water, which is one of the main treatment methods currently under consideration for ballast water treatment. Ultra-high-resolution mass spectrometry revealed 462 distinct brominated DBPs at a relative abundance in the mass spectra of more than 1%. A brominated DBP with a relative abundance of almost 22% was identified as 2,2,4-tribromo-5-hydroxy-4-cyclopentene-1,3-dione, which is an analogue to several previously described 2,2,4-trihalo-5-hydroxy-4-cyclopentene-1,3-diones in drinking water. Several other brominated molecular formulas matched those of other known brominated DBPs, such as dibromomethane, which could be generated by decarboxylation of dibromoacetic acid during ionization, dibromophenol, dibromopropanoic acid, dibromobutanoic acid, bromohydroxybenzoic acid, bromophenylacetic acid, bromooxopentenoic acid, and dibromopentenedioic acid. Via comparison to previously described chlorine-containing analogues, bromophenylacetic acid, dibromooxopentenoic acid, and dibromopentenedioic acid were also identified. A novel compound at a 4% relative abundance was identified as tribromoethenesulfonate. This compound has not been previously described as a DBP, and its core structure of tribromoethene has been demonstrated to show toxicological implications. Here we show that electrochemical disinfection, suggested as a candidate for successful ballast water treatment, caused considerable production of some previously characterized DBPs in addition to novel brominated DBPs, although several hundred compounds remain structurally uncharacterized. Our results clearly demonstrate that electrochemical and potentially direct chlorination of ballast water in estuarine and marine systems should be approached with caution and the concentrations, fate, and toxicity of DBP need to be further characterized.

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

    OpenAIRE

    KUŞ, Nermin Şimşek

    2009-01-01

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

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

    OpenAIRE

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

    2013-01-01

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

  13. Absorber performance of a water/lithium-bromide absorption chiller

    Energy Technology Data Exchange (ETDEWEB)

    Xie Guozhen [Beijing University of Civil Engineering and Architecture, Beijing 100044 (China)], E-mail: xieguozhen@bucea.edu.cn; Sheng Guogang [Beijing University of Civil Engineering and Architecture, Beijing 100044 (China); Bansal, Pradeep Kumar [Department of Mechanical Engineering, The University of Auckland, Private Bag 92019 (New Zealand); Li, Guang [Beijing University of Civil Engineering and Architecture, Beijing 100044 (China)

    2008-09-15

    An absorber is one of the most important components of a lithium-bromide absorption chiller (LBAC) as its absorbing characteristics directly influence the performance of the whole chiller. It has been indicated that the absorbing efficiency and cooling capacity could be improved by increasing the solution concentration. In this paper, based on the mechanism of falling film absorption on horizontal tubes, the theoretical models of falling film absorption on horizontal tubes have been established. A series of programs used for computing the theoretical mathematical models, including simulation of LBAC cycle and falling film absorption, have been programmed. The models have been validated reasonably by the experimental data. The results show that the cooling capacity of the LBAC varies in parabola shape of curve with the solution concentration from 52.5% to 58.5%, and that the best coefficient of performance (COP) occurs at concentration of 57%. The investigation proposes the absorbing process of sub-steady thermodynamic equilibrium for the duality solution under increase absorbing pressure.

  14. Absorber performance of a water/lithium-bromide absorption chiller

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Guozhen; Sheng, Guogang; Li, Guang [Beijing University of Civil Engineering and Architecture, Beijing 100044 (China); Bansal, Pradeep Kumar [Department of Mechanical Engineering, The University of Auckland, Private Bag 92019 (New Zealand)

    2008-09-15

    An absorber is one of the most important components of a lithium-bromide absorption chiller (LBAC) as its absorbing characteristics directly influence the performance of the whole chiller. It has been indicated that the absorbing efficiency and cooling capacity could be improved by increasing the solution concentration. In this paper, based on the mechanism of falling film absorption on horizontal tubes, the theoretical models of falling film absorption on horizontal tubes have been established. A series of programs used for computing the theoretical mathematical models, including simulation of LBAC cycle and falling film absorption, have been programmed. The models have been validated reasonably by the experimental data. The results show that the cooling capacity of the LBAC varies in parabola shape of curve with the solution concentration from 52.5% to 58.5%, and that the best coefficient of performance (COP) occurs at concentration of 57%. The investigation proposes the absorbing process of sub-steady thermodynamic equilibrium for the duality solution under increase absorbing pressure. (author)

  15. Water-lithium bromide double-effect absorption cooling analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vliet, G.C.; Lawson, M.B.; Lithgow, R.A.

    1980-12-01

    A numerical model was developed for the transient simulation of the double-effect, water-lithium bromide absorption cooling machine, and the use of the model to determine the effect of the various design and input variables on the absorption unit performance. The performance parameters considered were coefficient of performance and cooling capacity. The sensitivity analysis was performed by selecting a nominal condition and determining performance sensitivity for each variable with others held constant. The variables considered in the study include source hot water, cooling water, and chilled water temperatures; source hot water, cooling water, and chilled water flow rates; solution circulation rate; heat exchanger areas; pressure drop between evaporator and absorber; solution pump characteristics; and refrigerant flow control methods. The performance sensitivity study indicated in particular that the distribution of heat exchanger area among the various (seven) heat exchange components is a very-important design consideration. Moreover, it indicated that the method of flow control of the first effect refrigerant vapor through the second effect is a critical design feature when absorption units operate over a significant range of cooling capacity. The model was used to predict the performance of the Trane absorption unit with fairly good accuracy.

  16. Chloride, bromide and iodide scintillators with europium doping

    Science.gov (United States)

    Zhuravleva, Mariya; Yang, Kan

    2014-08-26

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

  17. 4-Bromophenacyl bromide specifically inhibits rhoptry secretion during Toxoplasma invasion.

    Science.gov (United States)

    Ravindran, Sandeep; Lodoen, Melissa B; Verhelst, Steven H L; Bogyo, Matthew; Boothroyd, John C

    2009-01-01

    Toxoplasma gondii is a eukaryotic parasite of the phylum Apicomplexa that is able to infect a wide variety of host cells. During its active invasion process it secretes proteins from discrete secretory organelles: the micronemes, rhoptries and dense granules. Although a number of rhoptry proteins have been shown to be involved in important interactions with the host cell, very little is known about the mechanism of secretion of any Toxoplasma protein into the host cell. We used a chemical inhibitor of phospholipase A2s, 4-bromophenacyl bromide (4-BPB), to look at the role of such lipases in the secretion of Toxoplasma proteins. We found that 4-BPB was a potent inhibitor of rhoptry secretion in Toxoplasma invasion. This drug specifically blocked rhoptry secretion but not microneme secretion, thus effectively showing that the two processes can be de-coupled. It affected parasite motility and invasion, but not attachment or egress. Using propargyl- or azido-derivatives of the drug (so-called click chemistry derivatives) and a series of 4-BPB-resistant mutants, we found that the drug has a very large number of target proteins in the parasite that are involved in at least two key steps: invasion and intracellular growth. This potent compound, the modified "click-chemistry" forms of it, and the resistant mutants should serve as useful tools to further study the processes of Toxoplasma early invasion, in general, and rhoptry secretion, in particular. PMID:19956582

  18. Organomontmorillonites Modified with 2-Methacryloyloxy Ethyl Alkyl Dimethyl Ammonium Bromide

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-quan; WU Wen-hui

    2007-01-01

    Organomontmorillonites (organo-MMT) were synthesized by means of montmorillonites (MMT) modified with a series of 2-methacryloyloxy ethyl alkyl dimethyl ammonium bromide (MAAB) having different alkyl chain lengths as cationic surfactants through a cationic exchanging reaction, and were characterized by FTIR, TG, elemental analysis, and XRD. The microenvironment of the organic interlayer such as the orientation and arrangement of the alkyl chains of MAAB, as well as the properties of nanocomposite hydrogels, were also investigated. The amount of organic components absorbed on interlayer and the basal spacing of organo-MMT both increase with the increasing of alkyl length of MAAB. When carbon number of alkyl chain is in the region of 8 to 14, the alkyl chains between layers would adopt a disordered gauche conformation; while the carbon number is 16, an ordered all-trans conformation with a vertical orientation would be found together with the disordered gauche conformation according to the results of XRD and FTIR. Due to the difference of microenvironment of organic interlayer, the Young's moduli of the nanocomposite hydrogels increased as the alkyl chains of MAAB became longer.

  19. Bioreactors for removing methyl bromide following contained fumigations

    Science.gov (United States)

    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.

  20. Evaluation of Alkali Bromide Salts for Potential Pyrochemical Applications

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    CERN Document Server

    Bai, Peng

    2016-01-01

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

  2. Bromine partitioning in the tropical tropopause layer: implications for stratospheric injection

    Directory of Open Access Journals (Sweden)

    R. P. Fernandez

    2014-07-01

    Full Text Available Very short-lived (VSL bromocarbons are produced at a prodigious rate by ocean biology and these source compounds (SGVSL, together with their degradation inorganic products (PGVSL, are lofted by vigorous convection to the tropical tropopause layer (TTL. Using a state-of-the-art photochemical mechanism within a global model, we calculate annual average stratospheric injection of total bromine due to VSL sources to be 5 pptv, with ~3 pptv entering the stratosphere as PGVSL and ~2 pptv as SGVSL. The geographic distribution and partitioning of VSL bromine within the TTL, and its consequent stratospheric injection, is highly dependent on the oceanic flux, the strength of convection and the occurrence of heterogeneous recycling reactions. Our calculations indicate atomic Br should be the dominant inorganic species in large regions of the TTL during daytime, due to the low ozone and cold conditions of this region. We propose the existence of a "tropical ring of atomic bromine" located approximately between 15 and 19 km and 30° N to 30° S. Daytime Br / BrO ratios of up to ~4 are predicted within the Br ring in regions of highly convective transport, such as the tropical Western Pacific. Then, we suggest experimental programs designed to quantify the bromine budget of the TTL and the stratospheric injection of VSL biogenic bromocarbons should include a strategy for the measurement of atomic Br during daytime and HOBr or BrCl during nighttime.

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

    OpenAIRE

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Han Wang

    2012-05-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2015-05-01

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

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

    Science.gov (United States)

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  10. Canadian Arctic sea ice reconstructed from bromine in the Greenland NEEM ice core.

    Science.gov (United States)

    Spolaor, Andrea; Vallelonga, Paul; Turetta, Clara; Maffezzoli, Niccolò; Cozzi, Giulio; Gabrieli, Jacopo; Barbante, Carlo; Goto-Azuma, Kumiko; Saiz-Lopez, Alfonso; Cuevas, Carlos A; Dahl-Jensen, Dorthe

    2016-09-21

    Reconstructing the past variability of Arctic sea ice provides an essential context for recent multi-year sea ice decline, although few quantitative reconstructions cover the Holocene period prior to the earliest historical records 1,200 years ago. Photochemical recycling of bromine is observed over first-year, or seasonal, sea ice in so-called "bromine explosions" and we employ a 1-D chemistry transport model to quantify processes of bromine enrichment over first-year sea ice and depositional transport over multi-year sea ice and land ice. We report bromine enrichment in the Northwest Greenland Eemian NEEM ice core since the end of the Eemian interglacial 120,000 years ago, finding the maximum extension of first-year sea ice occurred approximately 9,000 years ago during the Holocene climate optimum, when Greenland temperatures were 2 to 3 °C above present values. First-year sea ice extent was lowest during the glacial stadials suggesting complete coverage of the Arctic Ocean by multi-year sea ice. These findings demonstrate a clear relationship between temperature and first-year sea ice extent in the Arctic and suggest multi-year sea ice will continue to decline as polar amplification drives Arctic temperatures beyond the 2 °C global average warming target of the recent COP21 Paris climate agreement.

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

    International Nuclear Information System (INIS)

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

  12. In vitro profiling of the endocrine-disrupting potency of brominated flame retardants

    NARCIS (Netherlands)

    Hamers, T.H.M.; Kamstra, J.H.; Sonneveld, E.; Murk, A.J.; Kester, M.H.A.; Andersson, P.L.; Legler, J.; Brouwer, A.

    2006-01-01

    Over the last years, increasing evidence has become available that some brominated flame retardants (BFRs) may have endocrine disrupting (ED) potencies. The goal of the current study was to perform a systematic in vitro screening of the ED potencies of BFRs (1) to elucidate possible modes of action

  13. Molecular characterization of brominated persistent pollutants using extended X-ray absorption fine structure (EXAFS) spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bergknut, Magnus; Skyllberg, Ulf [Swedish University of Agricultural Sciences (SLU), Department of Forest Ecology and Management, Umeaa (Sweden); Persson, Per [Umeaa University, Department of Chemistry, Umeaa (Sweden)

    2008-02-15

    X-ray absorption fine structure (EXAFS) spectroscopy spectra were collected for three brominated persistent pollutants: 6-bromo-2,4,5-trichlorophenol (BrTriClP), pentabromophenol (PentaBrP) and 3,3',5,5'-tetrabromobisphenol A (TBBA). The substances were selected to be symmetrical (BrTriClP and TBBA) or asymmetrical (PentaBrP) with respect to the atomic Br positions and to differ in the number of bromine and other halide atoms, as well as their relative positions. The asymmetrical PentaBrP was modelled with special detail as not all bromine atoms have identical coordination environments. The studied substances displayed unique EXAFS spectra, which could be used to determine the molecular structure in fair detail. We conclude that EXAFS spectroscopy is a suitable technique for molecular characterization of the comparatively complex molecules within the class of compounds of brominated organic persistent pollutants. A detailed understanding of the EXAFS spectra of the pure compounds opens up possibilities to study the interactions with soil and sediment matrices by means of EXAFS spectroscopy. (orig.)

  14. Deposition history of brominated flame retardant compounds in an ice core from Holtedahlfonna, Svalbard, Norway

    NARCIS (Netherlands)

    Hermanson, M.H.; Isaksson, E.; Forsström, S.; Teixeira, C.; Muir, D.C.G.; Pohjola, V.A.; van de Wal, R.S.W.

    2010-01-01

    Brominated flame retardants (BFRs) have been found in Arctic wildlife, lake sediment, and air. To identify the atmospheric BFR deposition history on Svalbard, Norway, we analyzed 19 BFRs, including hexabromocyclododecane (HBCD), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane

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

    Science.gov (United States)

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

    2016-05-15

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

  16. Toxicity of brominated flame retardants in fish, with emphasis on endocrine effects and reproduction

    NARCIS (Netherlands)

    Kuiper, R.V.

    2007-01-01

    Abstract The abundant use of brominated flame retardants (BFRs) in modern polymers has over the passed decades resulted in contamination of the environment, and BFRs are increasingly found in fish. Laboratory studies have shown that a number of BFRs and BFR-metabolites can interfere with thyroid and

  17. Brominated Flame Retardants in the Environment - The Price for our Convenience?

    NARCIS (Netherlands)

    Boer, de J.

    2004-01-01

    This paper reviews information on the occurrence of brominated flame retardants (BFRs) in various environmental compartments. The lack of information on BFRs other than pentabrominated diphenylethers (pentaBDEs) is emphasized, as well as the need for better analytical methods and the need for more t

  18. Brominated Flame Retardants and their metabolites: Novel insights into endocrine disruptive properties.

    NARCIS (Netherlands)

    Fernández Cantón, R.

    2008-01-01

    Brominated flame retardants (BFRs) are chemicals that are added to materials to inhibit or suppress ignition and are incorporated during the manufacture of e.g. electronic equipment, furniture, construction materials and textiles. BFRs have become an increasingly important group of organohalogen com

  19. Canadian Arctic sea ice reconstructed from bromine in the Greenland NEEM ice core

    Science.gov (United States)

    Spolaor, Andrea; Vallelonga, Paul; Turetta, Clara; Maffezzoli, Niccolò; Cozzi, Giulio; Gabrieli, Jacopo; Barbante, Carlo; Goto-Azuma, Kumiko; Saiz-Lopez, Alfonso; Cuevas, Carlos A.; Dahl-Jensen, Dorthe

    2016-01-01

    Reconstructing the past variability of Arctic sea ice provides an essential context for recent multi-year sea ice decline, although few quantitative reconstructions cover the Holocene period prior to the earliest historical records 1,200 years ago. Photochemical recycling of bromine is observed over first-year, or seasonal, sea ice in so-called “bromine explosions” and we employ a 1-D chemistry transport model to quantify processes of bromine enrichment over first-year sea ice and depositional transport over multi-year sea ice and land ice. We report bromine enrichment in the Northwest Greenland Eemian NEEM ice core since the end of the Eemian interglacial 120,000 years ago, finding the maximum extension of first-year sea ice occurred approximately 9,000 years ago during the Holocene climate optimum, when Greenland temperatures were 2 to 3 °C above present values. First-year sea ice extent was lowest during the glacial stadials suggesting complete coverage of the Arctic Ocean by multi-year sea ice. These findings demonstrate a clear relationship between temperature and first-year sea ice extent in the Arctic and suggest multi-year sea ice will continue to decline as polar amplification drives Arctic temperatures beyond the 2 °C global average warming target of the recent COP21 Paris climate agreement. PMID:27650478

  20. Thermoelectric properties of bromine filled CoSb3 skutterudite

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-01

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

  1. The Effects of Bromination Methods on the Microstructure of Brominated Natural Rubbers from Latex%溴化方式对胶乳法溴化天然橡胶结构的影响

    Institute of Scientific and Technical Information of China (English)

    赵法敏; 薛行华; 张子琦; 张利伟; 李光

    2013-01-01

    为改善溴化天然橡胶(BNR)的溶解性能,在胶乳法的基础上改变溴化方式,以常规溴化方式和分步溴化方式分别制备了BNR.通过实验发现,体系溴浓度相同时分步溴化方式的溴含量比常规溴化方式高,而凝胶含量较低,所以分步溴化方式在甲苯中的溶解性能较好.通过傅里叶红外光谱对样品进行表征,并使用核磁共振对其微观结构进行了定性定量分析.红外光谱分析表明,2种溴化方式制备的BNR产物均发生了一定程度的溴加成反应和溴取代反应;核磁共振的分析证实了在体系溴浓度较低的情况下,与胶乳法常规溴化相反,胶乳法分步溴化的溴化过程主要以溴加成反应为主,少量发生溴取代反应.%In order to improve the solubility property of the brominated natural rubbers (BNR)from latex, BNR were prepared by changing the bromination ways from conventional bromination to step bromination. Through the experiment, it was discovered that the bromine content of the latter was higher than the former, but the gel content was less under the same bromine concentration. The latter showed much better solubility in the solvent of toluene. The structure of the procured sample was characterized by Fourier transform infrared spectroscopy (FTIR), and the microstructures of brominated nature rubber were qualitatively and quantitatively analyzed by nuclear magnetic resonance (NMR). FTIR showed that there were both a degree of brominated addition reaction and brominated substitution reaction in the obtained BNR by two different methods; Contrary to the conventional bromination from latex, the analysis of NMR proved that the bromination process of step bromination from latex was mainly in the form of addition reaction, and only a small amount of the substitution reaction did occur.

  2. A comparison of the effect of intranasal desmopressin and intramuscular hyoscine N-butyl bromide combination with intramuscular hyoscine N-butyl bromide alone in acute renal colic

    Directory of Open Access Journals (Sweden)

    Abdol-Reza Kheirollahi

    2010-01-01

    Full Text Available Background: Patients with acute renal colic usually require immediate diagnosis and treatment. In this clinical trial analgesic effect of hyoscine N-butyl bromide and desmopressin combination in comparison with hyoscine N-butyl bromide alone in patients with acute renal colic induced by urinary stones was assessed. Methods: The study included 114 patients randomly allocated in two groups (A and B. Patients in group A received 20 mg intramuscular hyoscine N-butyl bromide at admission time and patients in group B received 20 μg of intranasal desmopressin in combination with 20 mg intramuscular hyoscine N-butyl bromide. A visual analogue scale (VAS; a 10-cm horizontal scale ranging from "zero or no pain" to "10 or unbearable pain" was hired to assess the patients′ pain severity at baseline, 30 and 60 minutes after the treatments. Results: On admission, the pain level was similar in both groups (group A: 8.95 ± 0.11 and group B: 8.95 ± 0.12. In group A, the mean of pain level showed a decrease after 30 minutes (group A: 7.26 ± 0.25 and group B: 5.95 ± 0.28 but further decreasing did not occur; however in group B, the pain consistently decreased and the mean after 60 minutes was significantly decreased (group A: 6.80 ± 0.31 and group B: 3.71 ± 0.31. No side effects were detected in this study. Conclusions: The combination of hyoscine N-butyl bromide and desmopressin is more effective than hyoscine N-butyl bromide alone in patients with renal colic. Further studies are recommended to validate these findings and compare the different doses of desmopressin.

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

    Directory of Open Access Journals (Sweden)

    C. R. Thompson

    2014-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-15

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2015-08-01

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

  7. Amines and ammonium compounds. CXCVIII. Reaction of ammonium salts containing a 2-alkynyl group with bromine and iodine

    Energy Technology Data Exchange (ETDEWEB)

    Gyul' nazaryan, A.K.; Khachatryan, N.G.; Saakyan, T.A.; Kinoyan, F.S.; Panosyan, G.A.; Babayan, A.T.

    1988-08-10

    The reactions of monoammonium, 1,4-and 1,5-bistertiaryammonium, and bisquaternary ammonium salts containing a 2-alkynyl group with bromine and iodine were studied. It was shown that these salts form molecular complexes with iodine and that addition of iodine at the triple bond does not occur. In reaction with bromine in all cases except 1,4-bistrimethylammonio-2-butyne dihalides one molecule of the halogen adds at the triple bond with the formation of salts containing the 2,3-dibromo-2-alkenyl group, which then form a 1:1 complex with bromine.

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

    Science.gov (United States)

    Jaworske, D. A.; Maciag, C.

    1987-01-01

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

  9. Plasmid DNA induces dodecyl triethyl ammonium bromide to aggregate into vesicle

    Institute of Scientific and Technical Information of China (English)

    Xiang Mei Ran; Xia Guo; Jia Tong Ding

    2012-01-01

    Single-chained cationic surfactant dodecyl triethyl ammonium bromide and plasmid DNA together can form vesicles once the concentration of plasmid DNA reaches a critical value (Ccvc).Bigger the size of plasmid DNA,higher the value of Ccvc.

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

    Directory of Open Access Journals (Sweden)

    C. D. Holmes

    2010-12-01

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

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

    Directory of Open Access Journals (Sweden)

    C. D. Holmes

    2010-08-01

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

  12. Corrosion Behavior of Austenitic and Duplex Stainless Steels in Lithium Bromide

    OpenAIRE

    Ayo Samuel AFOLABI; Alaneme, K.K.; Samson Oluwaseyi BADA

    2009-01-01

    The corrosion behavior of austenitic and duplex stainless steels in various concentrations of lithium, bromide solution was investigated by using the conventional weight loss measurement method. The results obtained show that corrosion of these steels occurred due to the aggressive bromide ion in the medium. Duplex stainless steel shows a greater resistance to corrosion than austenitic stainless steel in the medium. This was attributed to equal volume proportion of ferrite and austenite in th...

  13. A case report of QT prolongation with glycopyrronium bromide in a patient with chronic tamoxifen use

    OpenAIRE

    Chiu, Michael H.; Al-Majed, Nawaf S.; Stubbins, Ryan; Pollmann, Dylan; Sandhu, Roopinder K.

    2016-01-01

    Background Glycopyrronium bromide has recently been approved as a once daily maintenance inhalation therapy for moderate to severe chronic obstructive pulmonary disease (COPD). Efficacy and safety trial data have found rare cases of significant QT prolongation. To our knowledge, we describe the first case report of QT prolongation >600 ms with initiation of glycopyrronium bromide in a real world setting. Case presentation A 78-year-old female with moderate COPD recently started on glycopyrron...

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

    Science.gov (United States)

    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.

  15. The effect of pinaverium bromide (LA 1717) on the lower oesophageal sphincter.

    Science.gov (United States)

    Wöltje, M; Huchzermeyer, H

    1982-01-01

    An acute, double-blind study was carried out in 8 healthy male volunteers to investigate any effect of a new antispasmodic, pinaverium bromide, compared with placebo on the lower oesophageal sphincter. Manometric measurements showed no significant differences in resting pressures either after placebo or a therapeutic dose (200 mg) of pinaverium bromide, suggesting that the active drug does not cause any impairment of function of the lower oesophageal sphincter. PMID:7128186

  16. Inhibition of methoxamine-induced bronchoconstriction by ipratropium bromide and disodium cromoglycate in asthmatic subjects.

    OpenAIRE

    Black, J.; Vincenc, K; Salome, C.

    1985-01-01

    We compared the effects of pretreatment with saline, ipratropium bromide, and disodium cromoglycate (DSCG) on bronchoconstriction induced by methoxamine--an alpha-adrenoceptor agonist, in asthmatic subjects. All 12 patients bronchoconstricted in response to methoxamine after saline. The PD20 (the dose of methoxamine causing a 20% fall in forced expiratory volume in 1 s [FEV1]) ranged from 0.3-18 mumol. Ipratropium bromide (200 micrograms administered by aerosol) significantly inhibited (P les...

  17. Tribromoisocyanuric acid/triphenylphosphine: a new system for conversion of alcohols into alkyl bromides

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Vitor S.C. de; Mattos, Marcio C.S. de, E-mail: mmattos@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica. Departamento de Quimica Organica

    2014-05-15

    An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzilic and allylic alcohols, and their corresponding bromides are obtained in 67-82 % yield. Tertiary alcohols do not react under these conditions. (author)

  18. Bacterial oxidation of methyl bromide in fumigated agricultural soils

    Science.gov (United States)

    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.

  19. The killing of African trypanosomes by ethidium bromide.

    Directory of Open Access Journals (Sweden)

    Arnab Roy Chowdhury

    Full Text Available 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.

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

  3. Method development for the determination of bromine in coal using high-resolution continuum source graphite furnace molecular absorption spectrometry and direct solid sample analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Éderson R.; Castilho, Ivan N.B. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Welz, Bernhard, E-mail: w.bernardo@terra.com.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Gois, Jefferson S. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Borges, Daniel L.G. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Carasek, Eduardo [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2014-06-01

    This work reports a simple approach for Br determination in coal using direct solid sample analysis in a graphite tube furnace and high-resolution continuum source molecular absorption spectrometry. The molecular absorbance of the calcium mono-bromide (CaBr) molecule has been measured using the rotational line at 625.315 nm. Different chemical modifiers (zirconium, ruthenium, palladium and a mixture of palladium and magnesium nitrates) have been evaluated in order to increase the sensitivity of the CaBr absorption, and Zr showed the best overall performance. The pyrolysis and vaporization temperatures were 800 °C and 2200 °C, respectively. Accuracy and precision of the method have been evaluated using certified coal reference materials (BCR 181, BCR 182, NIST 1630a, and NIST 1632b) with good agreement (between 98 and 103%) with the informed values for Br. The detection limit was around 4 ng Br, which corresponds to about 1.5 μg g{sup −1} Br in coal, based on a sample mass of 3 mg. In addition, the results were in agreement with those obtained using electrothermal vaporization inductively coupled plasma mass spectrometry, based on a Student t-test at a 95% confidence level. A mechanism for the formation of the CaBr molecule is proposed, which might be considered for other diatomic molecules as well. - Highlights: • Bromine has been determined in coal using direct solid sample analysis. • Calibration has been carried out against aqueous standard solutions. • The coal samples and the molecule-forming reagent have been separated in order to avoid interferences. • The results make possible to draw conclusions about the mechanisms of molecule formation.

  4. Hydroxylated polybrominated diphenyl ethers exhibit different activities on thyroid hormone receptors depending on their degree of bromination

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Xiao-Min, E-mail: rxm200318@gmail.com; Guo, Liang-Hong, E-mail: LHGuo@rcees.ac.cn; Gao, Yu, E-mail: francesscototti@gmail.com; Zhang, Bin-Tian, E-mail: nktianster@gmail.com; Wan, Bin, E-mail: binwan@rcees.ac.cn

    2013-05-01

    Polybrominated diphenyl ethers (PBDEs) have been shown to disrupt thyroid hormone (TH) functions in experimental animals, and one of the proposed disruption mechanisms is direct binding of hydroxylated PBDE (OH-PBDE) to TH receptors (TRs). However, previous data on TH receptor binding and TH activity of OH-PBDEs were very limited and sometimes inconsistent. In the present paper, we examined the binding potency of ten OH-PBDEs with different degrees of bromination to TR using a fluorescence competitive binding assay. The results showed that the ten OH-PBDEs bound to TR with potency that correlated to their bromination level. We further examined their effect on TR using a coactivator binding assay and GH3 cell proliferation assay. Different TR activities of OH-PBDEs were observed depending on their degree of bromination. Four low-brominated OH-PBDEs (2′-OH-BDE-28, 3′-OH-BDE-28, 5-OH-BDE-47, 6-OH-BDE-47) were found to be TR agonists, which recruited the coactivator peptide and enhanced GH3 cell proliferation. However, three high-brominated OH-PBDEs (3-OH-BDE-100, 3′-OH-BDE-154, 4-OH-BDE-188) were tested to be antagonists. Molecular docking was employed to simulate the interactions of OH-PBDEs with TR and identify the structural determinants for TR binding and activity. According to the docking results, low-brominated OH-PBDEs, which are weak binders but TR agonists, bind with TR at the inner side of its binding pocket, whereas high-brominated compounds, which are potent binders but TR antagonists, reside at the outer region. These results indicate that OH-PBDEs have different activities on TR (agonistic or antagonistic), possibly due to their different binding geometries with the receptor. - Highlights: ► Thyroid hormone (TH) activity of OH-PBDEs with different Br number was evaluated. ► Four different experimental approaches were employed to investigate the mechanism. ► Low-brominated OH-PBDEs were agonists, but high-brominated ones were antagonists.

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

    Science.gov (United States)

    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.

  6. Aclidinium bromide combined with formoterol inhibits remodeling parameters in lung epithelial cells through cAMP.

    Science.gov (United States)

    Lambers, Christopher; Costa, Luigi; Ying, Qi; Zhong, Jun; Lardinois, Didier; Dekan, Gerhard; Schuller, Elisabeth; Roth, Michael

    2015-12-01

    Combined muscarinic receptor antagonists and long acting β2-agonists improve symptom control in chronic obstructive pulmonary disease (COPD) significantly. In clinical studies aclidinium bromide achieved better beneficial effects than other bronchodilators; however, the underlying molecular mechanisms are unknown. This study assessed the effect of aclidinium bromide combined with formoterol on COPD lung (n=20) and non-COPD lung (n=10) derived epithelial cells stimulated with TGF-β1+carbachol on: (i) the generation of mesenchymal cells in relation to epithelial cells, (II) extracellular matrix (ECM) deposition, and (iii) the interaction of ECM on the generation of epithelial and mesenchymal cells. TGF-β1+carbachol enhanced the generation of mesenchymal cells, which was significantly reduced by aclidinium bromide or formoterol. The effect of combined drugs was additive. Inhibition of p38 MAP kinase and Smad by specific inhibitors or aclidinium bromide reduced the generation of mesenchymal cells. In mesenchymal cells, TGF-β1+carbachol induced the deposition of collagen-I and fibronectin which was prevented by both drugs dose-dependently. Formoterol alone reduced collagen-I deposition via cAMP, this however, was overruled by TGF-β1+carbachol and rescued by aclidinium bromide. Inhibition of fibronectin was cAMP independent, but involved p38 MAP kinase and Smad. Seeding epithelial cells on ECM collagen-I and fibronectin induced mesenchymal cell generation, which was reduced by aclidinium bromide and formoterol. Our results suggest that the beneficial effect of aclidinium bromide and formoterol involves cAMP affecting both, the accumulation of mesenchymal cells and ECM remodeling, which may explain the beneficial effect of the drugs on lung function in COPD. PMID:26546746

  7. The effect of representing bromine from VSLS on the simulation and evolution of Antarctic ozone

    Science.gov (United States)

    Oman, Luke D.; Douglass, Anne R.; Salawitch, Ross J.; Canty, Timothy P.; Ziemke, Jerald R.; Manyin, Michael

    2016-09-01

    We use the Goddard Earth Observing System Chemistry-Climate Model, a contributor to both the 2010 and 2014 World Meteorological Organization Ozone Assessment Reports, to show that inclusion of 5 parts per trillion (ppt) of stratospheric bromine (Bry) from very short lived substances (VSLS) is responsible for about a decade delay in ozone hole recovery. These results partially explain the significantly later recovery of Antarctic ozone noted in the 2014 report, as bromine from VSLS was not included in the 2010 Assessment. We show multiple lines of evidence that simulations that account for VSLS Bry are in better agreement with both total column BrO and the seasonal evolution of Antarctic ozone reported by the Ozone Monitoring Instrument on NASA's Aura satellite. In addition, the near-zero ozone levels observed in the deep Antarctic lower stratospheric polar vortex are only reproduced in a simulation that includes this Bry source from VSLS.

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

    Science.gov (United States)

    Prather, Michael J.; Watson, Robert T.

    1990-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

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

    OpenAIRE

    Thuresson, Kaj

    2004-01-01

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

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

    OpenAIRE

    ČULIN, Jelena; Bielić, Toni

    2015-01-01

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

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

    OpenAIRE

    Taylor, G R; Butler, M

    1982-01-01

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

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

    OpenAIRE

    N. Bobrowski; Giuffrida, G

    2012-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    J. P. Parrella

    2012-04-01

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

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

    Directory of Open Access Journals (Sweden)

    J. P. Parrella

    2012-08-01

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

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

    OpenAIRE

    Litens Karlsson, Sabina

    2015-01-01

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

  18. Bromine-catalyzed conversion of CO2 and epoxides to cyclic carbonates under continuous flow conditions.

    Science.gov (United States)

    Kozak, Jennifer A; Wu, Jie; Su, Xiao; Simeon, Fritz; Hatton, T Alan; Jamison, Timothy F

    2013-12-11

    A continuous method for the formation of cyclic carbonates from epoxides and carbon dioxide (CO2) is described. The catalysts used are inexpensive and effective in converting the reagents to the products in a residence time (t(R)) of 30 min. The cyclic carbonate products are obtained in good to excellent yield (51-92%). On the basis of a series of kinetics experiments, we propose a reaction mechanism involving epoxide activation by electrophilic bromine and CO2 activation by an amide.

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

    OpenAIRE

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kajiwara, Natsuko, E-mail: kajiwara.natsuko@nies.go.jp [Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Noma, Yukio; Takigami, Hidetaka [Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)

    2011-09-15

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

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

    OpenAIRE

    Woolf, A; Shannon, M.

    1999-01-01

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

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

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2011-01-01

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

  6. Reversed phase-high performance liquid chromatographic method to measure migration of semivolatile compound, vanillin, in ipratropium bromide inhalation solution

    OpenAIRE

    Conkins, Dennis; Economou, Julia E; Boersma, James A; Dedhiya, Mehendra G; Hansen, Gordon

    1999-01-01

    Ipratropium bromide, a bronchodilator, is used as an inhalation solution. Commercial ipratropium bromide solution products are packaged in low-density polyethylene (LDPE) vials, through which semivolatile compounds are reported to migrate. In this article, a specific reversed phase-high performance liquid chromatographic method to assay vanillin, a semivolatile compound, in ipratropium bromide solution is described. The method was validated for a concentration range for vanillin from 30 ng/mL...

  7. Brominating activity of the seaweed Ascophyllum nodosum: Impact on the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Wever, R.; Tromp, M.G.M.; Krenn, B.E.; Marjani, A.; Van Tol, M. (Univ. of Amsterdam (Netherlands))

    1991-03-01

    Macroalgae are an important source of volatile halogenated organic compounds, such as bromoform and dibromomethane. The mechanism by which these compounds are formed is still elusive. The authors report that the brown seaweeds Laminaria saccharina, Laminaria digitata, Fucus vesiculosis, Pelvetia canaliculata, and Ascophyllum nodosum and the red seaweeds Chondrus crispus and Plocamium hamatum contain bromoperoxidases. The intact plants are able to brominate exogeneous organic compounds when H{sub 2}O{sub 2} and Br{sup {minus}} are added to seawater. Further, the authors show that the brominating activity of the brown macroalga A. nodosum, which contains a vanadium bromoperoxidase located on the thallus surface, occurs when the plant is exposed to light and not in the dark. The rate of bromination of exogenous organic compounds in seawater by this plant is 68 nmol (g of wet alga){sup {minus}1} h{sup {minus}1}. HOBr is a strong biocidal agent and the authors propose that the formation of HOBr by this seaweed is part of a host defense system.

  8. Discrimination of hexabromocyclododecane from new polymeric brominated flame retardant in polystyrene foam by nuclear magnetic resonance.

    Science.gov (United States)

    Jeannerat, Damien; Pupier, Marion; Schweizer, Sébastien; Mitrev, Yavor Nikolaev; Favreau, Philippe; Kohler, Marcel

    2016-02-01

    Hexabromocyclododecane (HBCDD) is a brominated flame retardant (BFR) and major additive to polystyrene foam thermal insulation that has recently been listed as a persistent organic pollutant by the Stockholm Convention. During a 2013/2014 field analytical survey, we measured HBCDD content ranging from 0.2 to 2.4% by weight in 98 polystyrene samples. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses indicated that expandable (EPS) and extruded (XPS) polystyrene foams significantly differed in the α/γ HBCDD isomer ratio, with a majority of α and γ isomers in XPS and EPS, respectively. Interestingly, this technique indicated that some recent materials did not contain HBCDD, but demonstrated bromine content when analysed with X-ray fluorescence (XRF). Further investigation by Nuclear Magnetic Resonance (NMR) was able to discriminate between the BFRs present. In addition to confirming the absence or presence of HBCDD in polystyrene samples, high-field NMR spectroscopy provided evidence of the use of brominated butadiene styrene (BBS) as copolymer in the production of polystyrene. Use of this alternative flame retardant is expected to cause fewer health and environmental concerns. Our results highlight a trend towards the use of copolymerized BFRs as an alternative to HBCDD in polystyrene foam boards. In addition to providing a rapid NMR method to identify polymeric BFR, our analytical approach is a simple method to discriminate between flame-retardants in polystyrene foam insulating materials.

  9. Heterogeneous processing of bromine compounds by atmospheric aerosols: Relation to the ozone budget

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, J.M.; Henson, B.F.; Dubey, M.K.; Casson, J.L.; Johal, M.S. [Los Alamos National Lab., NM (US); Wilson, K.R. [Univ. of California, Berkeley, CA (US)

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The depletion of ozone, particularly above Antarctica, has been investigated extensively to formulate public policy on the use of halocarbons. While it has been shown that heterogeneous reactions of chlorine compounds on stratospheric particulates cause the ozone hole, little is known of the analogous bromine mechanisms, even though it has been recognized for two decades that catalytic destruction of ozone by bromine could be more efficient than chlorine. Furthermore, field measurements and modeling calculations suggest that these heterogeneous (gas/surface) reactions are not restricted to the Antarctic regions but occur globally. The authors have performed laboratory measurements of the uptake of bromine compounds and other halogens on simulated stratospheric aerosols to help elucidate their role in catalytic ozone destruction cycles. Their studies contribute to the data base required to make assessments of the effects of human activities on global change, including the Montreal Protocol.

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

    Institute of Scientific and Technical Information of China (English)

    王伟; 邹海魁; 初广文; 向阳; 彭晗; 陈建峰

    2014-01-01

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

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

    Science.gov (United States)

    Aldrian, Alexia; Ledersteger, Alfred; Pomberger, Roland

    2015-02-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

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

    2015-09-15

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

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

    International Nuclear Information System (INIS)

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

  15. Discrimination of hexabromocyclododecane from new polymeric brominated flame retardant in polystyrene foam by nuclear magnetic resonance.

    Science.gov (United States)

    Jeannerat, Damien; Pupier, Marion; Schweizer, Sébastien; Mitrev, Yavor Nikolaev; Favreau, Philippe; Kohler, Marcel

    2016-02-01

    Hexabromocyclododecane (HBCDD) is a brominated flame retardant (BFR) and major additive to polystyrene foam thermal insulation that has recently been listed as a persistent organic pollutant by the Stockholm Convention. During a 2013/2014 field analytical survey, we measured HBCDD content ranging from 0.2 to 2.4% by weight in 98 polystyrene samples. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses indicated that expandable (EPS) and extruded (XPS) polystyrene foams significantly differed in the α/γ HBCDD isomer ratio, with a majority of α and γ isomers in XPS and EPS, respectively. Interestingly, this technique indicated that some recent materials did not contain HBCDD, but demonstrated bromine content when analysed with X-ray fluorescence (XRF). Further investigation by Nuclear Magnetic Resonance (NMR) was able to discriminate between the BFRs present. In addition to confirming the absence or presence of HBCDD in polystyrene samples, high-field NMR spectroscopy provided evidence of the use of brominated butadiene styrene (BBS) as copolymer in the production of polystyrene. Use of this alternative flame retardant is expected to cause fewer health and environmental concerns. Our results highlight a trend towards the use of copolymerized BFRs as an alternative to HBCDD in polystyrene foam boards. In addition to providing a rapid NMR method to identify polymeric BFR, our analytical approach is a simple method to discriminate between flame-retardants in polystyrene foam insulating materials. PMID:26492426

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

    Institute of Scientific and Technical Information of China (English)

    A.E.Galashev; O.R.Rakhmanova

    2012-01-01

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

  17. Mechanochemical conversion of brominated POPs into useful oxybromides: a greener approach

    Science.gov (United States)

    Cagnetta, Giovanni; Liu, Han; Zhang, Kunlun; Huang, Jun; Wang, Bin; Deng, Shubo; Wang, Yujue; Yu, Gang

    2016-06-01

    Brominated organic pollutants are considered of great concern for their adverse effect on human health and the environment, so an increasing number of such compounds are being classified as persistent organic pollutants (POPs). Mechanochemical destruction is a promising technology for POPs safe disposal because it can achieve their complete carbonization by solvent-free high energy ball milling at room temperature. However, a large amount of co-milling reagent usually is necessary, so a considerable volume of residue is produced. In the present study a different approach to POPs mechanochemical destruction is proposed. Employing stoichiometric quantities of Bi2O3 or La2O3 as co-milling reagent, brominated POPs are selectively and completely converted into their corresponding oxybromides (i.e. BiOBr and LaOBr), which possess very peculiar properties and can be used for some actual and many more potential applications. In this way, bromine is beneficially reused in the final product, while POPs carbon skeleton is safely destroyed to amorphous carbon. Moreover, mechanochemical destruction is employed in a greener and more sustainable manner.

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

    International Nuclear Information System (INIS)

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  20. [Bowel obstruction-induced cholinergic crisis with progressive respiratory failure following distigmine bromide treatment].

    Science.gov (United States)

    Kobayashi, Kazuki; Sekiguchi, Hiroshi; Sato, Nobuhiro; Hirose, Yasuo

    2016-03-01

    A 54-year-old female experienced rapid respiratory failure while being transported in an ambulance to our emergency department for evaluation and management of constipation and abdominal pain. The patient was on treatment with distigmine bromide for postoperative urination disorder and magnesium oxide for constipation. Increased salivary secretions, diminished respiratory excursion, type 2 respiratory failure (PaCO2 : 65 mmHg), low serum cholinesterase, and hypermagnesemia were detected. Imaging studies revealed that the patient had bilateral aspiration pneumonia, fecal impaction in the rectum, and a distended colon causing ileus. The patient was mechanically ventilated and was weaned off the ventilator on day 3. Therapeutic drug monitoring after discharge revealed that the serum level of distigmine bromide on admission was markedly elevated (377.8 ng/mL vs. the normal therapeutic level of 5-10 ng/mL). Distigmine bromide induced a cholinergic crisis with a resultant increase in airway secretions and respiratory failure. In this particular case, orally administered distigmine bromide was excessively absorbed because of prolonged intestinal transit time secondary to fecal impaction and sluggish bowel movement; this caused a cholinergic crisis and hypermagnesemia contributing to respiratory failure. Clinicians should be aware that bowel obstruction in a patient treated with distigmine bromide can increase the risk of a cholinergic crisis. PMID:27255021

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

    Directory of Open Access Journals (Sweden)

    G. Giuffrida

    2012-12-01

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

  2. Brominated flame retardants and organochlorine pollutants in eggs of little owls (Athene noctua) from Belgium

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, Veerle [Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Covaci, Adrian [Toxicological Centre, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium)]. E-mail: adrian.covaci@ua.ac.be; Maervoet, Johan [Toxicological Centre, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Dauwe, Tom [Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Voorspoels, Stefan [Toxicological Centre, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Schepens, Paul [Toxicological Centre, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Eens, Marcel [Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2005-07-15

    Residues of brominated diphenylethers (PBDEs), organochlorinated pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in 40 eggs of little owls (Athene noctua), a terrestrial top predator from Belgium. The major organohalogens detected were PCBs (median 2,600 ng/g lipid, range 790-23000 ng/g lipid). PCB 153,138/163, 170, 180 and 187 were the predominant congeners and constituted 71% of total sum PCBs. PBDEs were measurable in all samples, but their concentrations were much lower than for PCBs, with a range from 29-572 ng/g lipid (median 108 ng/g lipid). The most prevalent PBDE congeners in little owl egg samples were BDE 47, 99 and 153. This profile differs from the profile in marine bird species, for which BDE 47 was the dominant congener, indicating that terrestrial birds may be more exposed to higher brominated BDE congeners than marine birds. The fully brominated BDE 209 could be detected in one egg sample (17 ng/g lipid), suggesting that higher brominated BDEs may accumulate in terrestrial food chains. Brominated biphenyl (BB) 153 was determined in all egg samples, with levels ranging from 0.6 to 5.6 ng/g lipid (median 1.3 ng/g lipid). Additionally, hexabromocyclododecane (HBCD) could be identified and quantified in only two eggs at levels of 20 and 50 ng/g lipid. OCPs were present at low concentrations, suggesting a rather low contamination of the sampled environment with OCPs (median concentrations of sum DDTs: 826 ng/g lipid, sum chlordanes: 1,016 ng/g lipid, sum HCHs: 273 ng/g lipid). Hexachlorobenzene (HCB) and octachlorostyrene (OCS) were also found at low median levels of 134 and 3.4 ng/g lipid, respectively. Concentrations of most analytes were significantly higher in eggs collected from deserted nests in comparison to addled (unhatched) eggs, while eggshell thickness did not differ between deserted and addled eggs. No significant correlations were found between eggshell thickness and the analysed organohalogens. - PBDEs are measurable

  3. Current and Potential Future Bromide Loads from Coal-Fired Power Plants in the Allegheny River Basin and Their Effects on Downstream Concentrations.

    Science.gov (United States)

    Good, Kelly D; VanBriesen, Jeanne M

    2016-09-01

    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. PMID:27538590

  4. Analysis of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and its brominated analogues in chlorine-treated water by gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS).

    Science.gov (United States)

    Planas, Carles; Ventura, Francesc; Caixach, Josep; Martín, Jordi; Boleda, M Rosa; Paraira, Miquel

    2015-11-01

    A simple, selective and sensitive method for the analysis of the strong mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and its brominated analogues (BMXs) in chlorine-treated water has been developed. The method is based on gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS), previous liquid-liquid extraction (LLE) of a smaller sample volume compared to other methods and on-line derivatization with a silylation reactive. GC-QqQ-MS/MS has been raised as an alternative easier to perform than gas chromatography coupled to high resolution mass spectrometry (GC-HRMS) for the analysis of MX and BMXs, and it allows to achieve low LODs (0.3 ng/L for MX and 0.4-0.9 ng/L for BMXs). This technique had not been previously described for the analysis of MX and BMXs. Quality parameters were calculated and real samples related to 3 drinking water treatment plants (DWTPs), tap water and both untreated and chlorinated groundwater were analyzed. Concentrations of 0.3-6.6 ng/L for MX and 1.0-7.3 ng/L for BMXs were detected. Results were discussed according to five of the main factors affecting MX and BMXs formation in chlorine-treated water (organic precursors, influence of bromide ions, evolution of MX and BMXs in the drinking water distribution system, groundwater chlorination and infiltration of water coming from chlorination processes in groundwater).

  5. Corrosion Behavior of Austenitic and Duplex Stainless Steels in Lithium Bromide

    Directory of Open Access Journals (Sweden)

    Ayo Samuel AFOLABI

    2009-07-01

    Full Text Available The corrosion behavior of austenitic and duplex stainless steels in various concentrations of lithium, bromide solution was investigated by using the conventional weight loss measurement method. The results obtained show that corrosion of these steels occurred due to the aggressive bromide ion in the medium. Duplex stainless steel shows a greater resistance to corrosion than austenitic stainless steel in the medium. This was attributed to equal volume proportion of ferrite and austenite in the structure of duplex stainless steel coupled with higher content of chromium in its composition. Both steels produced electrochemical noise at increased concentrations of lithium bromide due to continuous film breakdown and repair caused by reduction in medium concentration by the alkaline corrosion product while surface passivity observed in duplex stainless steel is attributed to film stability on this steel.

  6. Chloride/bromide ratios in leachate derived from farm-animal waste

    International Nuclear Information System (INIS)

    Results have important implications for identifying animal sources of contaminated groundwater. - Ratios of conservative chemicals have been used to identify sources of groundwater contamination. While chloride/bromide ratios have been reported for several common sources of groundwater contamination, little work has been done on leachate derived from farm-animal waste. In this study, chloride/bromide ratios were measured in leachate derived from longhorn-cattle, quarter-horse, and pygme-goat waste at a farm in Abilene, Texas, USA. (Minimum, median, and maximum) chloride/bromide ratios of (66.5, 85.6, and 167), (119, 146, and 156), and (35.4, 57.8, and 165) were observed for cattle, horses, and goats, respectively. These ratios are below typical values for domestic wastewater and within the range commonly observed for oilfield brine. Results of this study have important implications for identifying sources of contaminated groundwater in settings with significant livestock and/or oil production

  7. Inhibitory effect of pinaverium bromide on gastrointestinal contractile activity in conscious dogs.

    Science.gov (United States)

    Itoh, Z; Takahashi, I

    1981-01-01

    The inhibitory effect of 4-(6-bromoveratryl)-4-(2-[2-(6,6-dimethyl-2-norpinyl)-ethoxy]-ethyl)-morpholinium hydroxide (pinaverium bromide), a quaternary ammonium derivative, on the contractile activity of the gastrointestinal tract from the stomach to the colon was investigated in six conscious dogs. Gastrointestinal motor activity was monitored by means of chronically implanted force transducers. Pinaverium bromide was continuously administered i.v. for 30 min in doses of 10 and 20 mg/kg/h during both the digestive and interdigestive states. It was found that pinaverium bromide strongly inhibited gastrointestinal contractile activity during both the digestive and interdigestive states; contractions in the stomach were most strongly inhibited; however, those in the small and large bowels were also significantly inhibited. No significant side effects in the circulatory and respiratory systems and the gastrointestinal tract such as nausea, vomiting or diarrhea were observed during and after the infusion of this agent. PMID:7197953

  8. Irradiation as a disinfestation method - update on methyl bromide phase out, regulatory action and emerging opportunities

    International Nuclear Information System (INIS)

    Methyl bromide (MeBr), is the most widely used agricultural fumigant in the world for the control of pests and plant diseases. It is used to control pests and diseases in food, agricultural and forestry commodities after harvest, before or during storage or transportation and/or at time of import to control quarantine or storage pests. Knowing MeBr will be phased out has spurred a search for alternative treatments and products, and has placed pressure on regulatory authorities to approve alternatives. Some of methyl bromide use could be replaced with irradiation. Methyl bromide is also used for soil and structural fumigation, and although there is some use of irradiation for packaged soil or greenhouse products, in general, these uses can not be replaced by irradiation. Some radiation processing facilities have either seen increased business to disinfest commodities, or have experienced more inquiries for service. There are many other processes and products competing for this market and irradiation will not win its share of the business without an improved regulatory picture, improved marketing to methyl bromide users and improved information to answer questions from commodity sectors. The United Nations Environment Program - Methyl Bromide Technical Options Committee (MBTOC) provides a venue for the publication or information about the use and availability of irradiation as an alternative to methyl bromide. It provides the technical base to the Montreal Protocol contributing to the setting of phase out dates; this committee is actively researching and assessing all alternatives and needs information about irradiation. The author is a member of the MBTOC committee

  9. Thermodynamic evaluation of new absorbent mixtures of lithium bromide and organic salts for absorption refrigeration machines

    Energy Technology Data Exchange (ETDEWEB)

    Donate, Marina; Rodriguez, Luis; Lucas, Antonio De; Rodriguez, Juan F. [Department of Chemical Engineering, University of Castilla-La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain)

    2006-01-01

    Mixtures of lithium bromide and organic salts of sodium and potassium (formate, acetate and lactate) have been evaluated as alternative absorbents for absorption refrigeration machines. The main objective is to overpass the limitations of lithium bromide and improve the characteristics and the efficiency of the refrigeration cycle. In order to select the mixture that presents better properties for its employment in absorption refrigeration cycles, a thermodynamic analysis have been done. Density, viscosity, enthalpies of dilution, solubility and vapour pressure data of the proposed mixtures have been measured. A simulation program has been developed to evaluate temperatures, heats exchanged in the different sections and the efficiency of the cycle. (author)

  10. COMPARISON OF ROCURONIUM BROMIDE AND SUCCINYLCHOLINE CHLORIDE FOR USE DURING RAPID SEQUENCE INTUBATION IN ADULTS

    Directory of Open Access Journals (Sweden)

    Ch. Penchalaiah

    2015-08-01

    Full Text Available BACKGROUND AND OBJECTIVE : The goal of rapid sequence intubation is to secure the patients airway smoothly and quickly, minimizing the chances of regurgitation and aspiration of gastric contents. Traditionally succinylcholine chloride has been the neuromuscular blocking drug of choi ce for use in rapid sequence intubation because of its rapid onset of action and profound relaxation. Succinylcholine chloride remains unsurpassed in providing ideal intubating conditions. However the use of succinylcholine chloride is associated with many side effects like muscle pain, bradycardia, hyperkalaemia and rise in intragastric and intraocular pressure. Rocuronium bromide is the only drug currently available which has the rapidity of onset of action like succinylcholine chloride. Hence the present study was undertaken to compare rocuronium bromide with succinylcholine chloride for use during rapid sequence intubation in adult patients. METHODOLOGY : The study population consisted of 90 patients aged between 18 - 60 years posted for various elective su rgeries requiring general anaesthesia . S tudy population was randomly divided into 3 groups with 30 patients in each sub group. 1. Group I : Intubated with 1 mg kg - 1 of succinylcholine chloride (n=30 . 2. Grou p II : Intubated with rocuronium bromide 0.6 mg kg - 1 (n=30 . 3. Group III : Intubated with rocuronium bromide 0.9 mg kg - 1 (n=30 . Intubating conditions were assessed at 60 seconds based on the scale adopted by Toni Magorian et al. 1993. The haemodynamic para meters in the present study were compared using p - value obtained from student t - test . RESULTS : It was noted that succinylcholine chloride 1 mg kg - 1 body weight produced excellent intubating conditions in all patients. Rocuronium bromide 0.6 mg kg - 1 body we ight produced excellent intubating conditions in 53.33% of patients but produced good to excellent intubating conditions in 96.67% of patients. Rocuronium bromide 0.9 mg kg - 1

  11. Cesium Enhances Long-Term Stability of Lead Bromide Perovskite-Based Solar Cells

    OpenAIRE

    Kulbak, Michael; Gupta, Satyajit; Kedem, Nir; Levine, Igal; Bendikov, Tatyana; Hodes, Gary; Cahen, David

    2015-01-01

    Direct comparison between perovskite-structured hybrid organic-inorganic - methyl ammonium lead bromide (MAPbBr3) and all-inorganic cesium lead bromide (CsPbBr3), allows identifying possible fundamental differences in their structural, thermal and electronic characteristics. Both materials possess a similar direct optical band-gap, but CsPbBr3 demonstrates a higher thermal stability than MAPbBr3. In order to compare device properties we fabricated solar cells, with similarly synthesized MAPbB...

  12. Well-Defined Copper(I) Fluoroalkoxide Complexes for Trifluoroethoxylation of Aryl and Heteroaryl Bromides

    KAUST Repository

    Huang, Ronglu

    2015-03-17

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation, and tetrafluoropropoxylation of aryl and heteroaryl bromides were investigated. Efficiency drive: A series of copper(I) fluoroalkoxide complexes bearing N,N ligands have been prepared and structurally characterized. These well-defined complexes serve as efficient reagents for the fluoroalkoxylation of aryl and heteroaryl bromides to produce a wide range of trifluoroethyl, pentafluoropropyl, and tetrafluoropropyl (hetero)aryl ethers in good to excellent yields.

  13. Once-daily glycopyrronium bromide (Seebri Breezhaler(®)) for the treatment of chronic obstructive pulmonary disease (COPD)

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli

    2015-01-01

    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...

  14. Reduced rates and alternatives to methyl bromide for snapdragon production in Florida

    Science.gov (United States)

    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...

  15. Iodine catalyzed and tertiary butyl ammonium bromide promoted p reparation of b enzoxazaphosphininyl phenylboronates

    Directory of Open Access Journals (Sweden)

    K. R. Kishore K. Reddy,

    2009-05-01

    Full Text Available Benzoxazaphosphininyl Phenylboronates were prepared by O-Phosphorylation of potassium salt ofphenylboronic acid with cyclic phosphoromonochloridates in the presence of stoichiometric amount of Iodineand catalytic amount of tertiary butyl ammonium bromide at 50-60 °C in dry toluene.

  16. Palladium-Catalyzed Carbonylation of Aryl Bromides with N-Substituted Cyanamides

    DEFF Research Database (Denmark)

    Lian, Zhong; Friis, Stig D.; Lindhardt, Anders T.;

    2014-01-01

    The palladium(0)-catalyzed three-component coupling reaction of aryl bromides, carbon monoxide, and N-alkyl cyan­amides has been developed employing a two-chamber system with ex situ generation of carbon monoxide from a silacarboxylic acid. The reactions proceeded well and were complete with a...

  17. Mild Pd-catalyzed aminocarbonylation of (hetero)aryl bromides with a palladacycle precatalyst.

    Science.gov (United States)

    Friis, Stig D; Skrydstrup, Troels; Buchwald, Stephen L

    2014-08-15

    A palladacyclic precatalyst is employed to cleanly generate a highly active XantPhos-ligated Pd-catalyst. Its use in low temperature aminocarbonylations of (hetero)aryl bromides provides access to a range of challenging products in good to excellent yields with low catalyst loading and only a slight excess of CO. Some products are unattainable by traditional carbonylative coupling.

  18. Palladium-catalyzed carbonylative sonogashira coupling of aryl bromides using near stoichiometric carbon monoxide

    DEFF Research Database (Denmark)

    Neumann, Karoline T.; Laursen, Simon R.; Lindhardt, Anders T.;

    2014-01-01

    A general procedure for the palladium-catalyzed carbonylative Sonogashira coupling of aryl bromides is reported, using near stoichiometric amounts of carbon monoxide. The method allows a broad substrate scope in moderate to excellent yields. The formed alkynone motive serves as a platform for...

  19. Measurement and Computation of Movement of Bromide Ions and Carbofuran in Ridged HUmic-Sandy Soil

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2010-01-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. R

  20. Methyl Bromide Alternatives Area-Wide Pest Management Project - South Atlantic Progress Report

    Science.gov (United States)

    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...

  1. Strontium and bromide as tracers in X-ray microanalysis of biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Wroblewski, J.; Sagstroem, S.M.; Mulders, H.; Roomans, G.M. (Karolinska Institutet, Stockholm (Sweden))

    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.

  2. Effects of intraoperative magnetic resonance imaging on the neuromuscular blockade of vecuronium bromide in neurosurgery

    International Nuclear Information System (INIS)

    The effects of intraoperative magnetic resonance (iMR) imaging on the neuromuscular blockade of vecuronium bromide were investigated in neurosurgery. Fifty patients with American Society of Anesthesiologists grades I-II scheduled for craniotomy operation were divided into two groups (n=25 each) with no difference in demographic data: the iMR imaging group and control group. Train-of-four (TOF) stimulation through an accelerometer was used to monitor onset, maintenance, and recovery of muscle relaxation caused by vecuronium. Vecuronium bromide was intravenously injected after anesthesia induction. The dosage of vecuronium bromide in the iMR imaging group was larger than in the control group, but not significantly. Duration of vecuronium bromide administration and operation time were significantly longer in the iMR imaging group than in the control group. Time from drug discontinuation to operation termination, and to return to neurosurgery intensive care unit were not different. Time taken by first twitch (T1) in response to TOF stimulation to recover by 25%, and muscle relaxant recovery index were significantly greater in the control group than in the iMR imaging group. The body temperature of the patients increased gradually in the iMR imaging group but decreased in the control group. iMR imaging can prolong the operation time, increase the body temperature of the patient, and remarkably shorten the clinical action time and muscle relaxation recovery index of vecuronium. (author)

  3. Facile Syntheses of N-Substituted Imidazoles and Benzotriazoles from Baylis-Hillman Bromides

    Institute of Scientific and Technical Information of China (English)

    YE Dongyan; LI Jian; LI Chunju; JIA Xueshun

    2009-01-01

    A facile synthesis of N-substituted imidazole and benzotriazole derivatives from Baylis-Hiilman bromides with imidazole and benzotriazole at room temperature was reported. In view of the simple operation, mild reaction con-ditions, good to excellent yields, good regio- and stereoselectivity, the present method exhibited its superiority.

  4. Efficient loading of primary alcohols onto a solid phase using a trityl bromide linker

    DEFF Research Database (Denmark)

    Crestey, François; Ottesen, Lars Korsgaard; Jaroszewski, Jerzy Witold;

    2008-01-01

    The Letter describes an improved, rapid and mild strategy for the loading of primary alcohols onto a polystyrene trityl resin via a highly reactive trityl bromide linker. This protocol facilitates an efficient resin loading even of acid-sensitive or heat-labile alcohols, which otherwise require...

  5. SYNTHESIS AND CATALYTIC PROPERTIES OF CROSS-LINKED HYDROPHOBICALLY ASSOCIATING POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES)

    NARCIS (Netherlands)

    WANG, GJ; ENGBERTS, JBFN

    1994-01-01

    Cross-linked, hydrophobically associating homo- and copolymers were synthesized by free-radical cyclo(co)polymerization of alkylmethyldiallylammonium bromide monomers with a small amount of N,N'-methylenebisacrylamide in aqueous solution using ammonium persulfate as the initiator. The cross-linked h

  6. 76 FR 29238 - Methyl Bromide; Cancellation Order for Registration Amendments To Terminate Certain Soil Uses

    Science.gov (United States)

    2011-05-20

    ... provided, EPA received no comments in response to the February 9, 2011, Federal Register notice (76 FR 7200... AGENCY Methyl Bromide; Cancellation Order for Registration Amendments To Terminate Certain Soil Uses... for the amendments to terminate soil uses, voluntarily requested by the registrants and accepted...

  7. Ozone decomposition under the irradiation of 253.7 nm in the presence of methyl bromide

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper the mechanism and kinetic of ozone decomposition under the irradiation of 253.7 nm UV-light were studied.The quantum yield of the ozone depletion in the presence of methyl bromide is further determined and a reaction model is provided to explain the experimental fact.

  8. COMPARISON OF ONSET TIME, DURATION OF ACTION AND INTUBATING CONDITION SACHIEVED WITH SUXAMETHONIUM AND ROCURONIUM BROMIDE

    OpenAIRE

    Ajit P; Alok P; Devendra Singh

    2013-01-01

    Adverse event profile ofSuxamethonium which is still the relaxant of choice to facilitate tracheal intubation inspired us to conduct a study in which we compared Onset time, Duration of Action and Intubating Conditions Achieved with Suxametho nium and Rocuronium Bromide with the Help of TOF Guard. AIMS : W e compared the onset of relaxation time, intubating condition, and duration of action, the ...

  9. Effect of pinaverium bromide on stress-induced colonic smooth muscle contractility disorder in rats

    OpenAIRE

    Dai, Yun; Liu, Jian-Xiang; Li, Jun-Xia; Xu, Yun-Feng

    2003-01-01

    AIM: To investigate the effect of pinaverium bromide, a L-type calcium channel blocker with selectivity for the gastrointestinal tract on contractile activity of colonic circular smooth muscle in normal or cold-restraint stressed rats and its possible mechanism.

  10. Quantitative gas chromatographic mass spectrometric determination of pinaverium-bromide in human serum.

    Science.gov (United States)

    de Weerdt, G A; Beke, R P; Verdievel, H G; Barbier, F; Jonckheere, J A; de Leenheer, A P

    1983-03-01

    A method has been developed for quantitative determination of pinaverium-bromide, a quaternary ammonium derivative with papaverine-like activity, in human serum. The method involves a chloroform extraction of serum spiked with N-(6,6-dimethyl bicyclo[3.1.1]2-heptenyl-ethoxyethyl) perhydro-1,4-oxazine as internal standard. After evaporation of the solvent, and reduction of the residue with Raney-Nickel, the internal standard and the reduced pinaverium-bromide are re-extracted from the reaction mixture with toluene and analysed isothermally on a fused silica column coated with OV-101. Although chemical ionization with methane revealed intense protonated molecular ions for both pinaverium-bromide and the internal standard, selectivity and sensitivity were significantly lower in comparison with electron impact ionization at 70 e V. Therefore, quantification was performed in the electron impact mode by single ion monitoring of the common fragment ion at m/z 100.2. A linear detector response was observed up to 160 ng ml-1. A within-run assay precision better than 2% CV (n = 5) was found, and a detection limit of 1 ng pinaverium-bromide ml-1 of serum was attained. PMID:6850068

  11. Assessment of PCDD/F and PBDD/F Emissions from Coal-fired Power Plants during Injection of Brominated Activated Carbon for Mercury Control

    Science.gov (United States)

    The effect of the injection of brominated powdered activated carbon (Br-PAC) on the emission of brominated and chlorinated dioxins and furans in coal combustion flue gas has been evaluated. The tests were performed at two U.S. Department of Energy (DOE) demonstration sites where ...

  12. Hyphenation of ultra performance liquid chromatography (UPLC) with inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of bromine containing preservatives

    DEFF Research Database (Denmark)

    Bendahl, Lars; Hansen, Steen Honoré; Gammelgaard, Bente;

    2006-01-01

    Ultra performance liquid chromatography (UPLC) was coupled to inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of three bromine-containing preservatives, monitoring the 79Br and 81Br isotopes simultaneously. Due to the efficiency of the 1.7 microm column packing material...... analysis of bromine-containing preservatives in commercially available cosmetic products....

  13. Molecular simulations and density functional theory calculations of bromine in clathrate hydrate phases

    International Nuclear Information System (INIS)

    Bromine forms a tetragonal clathrate hydrate structure (TS-I) very rarely observed in clathrate hydrates of other guest substances. The detailed structure, energetics, and dynamics of Br2 and Cl2 in TS-I and cubic structure I (CS-I) clathrate hydrates are studied in this work using molecular dynamics and quantum chemical calculations. X-ray diffraction studies show that the halogen-water–oxygen distances in the cages of these structures are shorter than the sum of the van der Waals radii of halogen and oxygen atoms. This suggests that the stabilizing effects of halogen bonding or other non-covalent interactions (NCIs) may contribute to the formation of the unique tetragonal bromine hydrate structure. We performed molecular dynamics simulations of Br2 and Cl2 clathrate hydrates using our previously developed five-site charge models for the dihalogen molecules [Dureckova et al. Can. J. Chem. 93, 864 (2015)] which reproduce the computed electrostatic potentials of the dihalogens and account for the electropositive σ-hole of the halogen bond donor (the dihalogen). Analysis of the radial distribution functions, enthalpies of encapsulation, velocity and orientation autocorrelation functions, and polar angle distributions are carried out for Br2 and Cl2 guests in various cages to contrast the properties of these guests in the TS-I and CS-I phases. Quantum chemical partial geometry optimizations of Br2 and Cl2 guests in the hydrate cages using the M06-2X functional give short halogen-water distances compatible with values observed in X-ray diffraction experiments. NCI plots of guest-cage structures are generated to qualitatively show the relative strength of the non-bonding interactions between dihalogens and water molecules. The differences between behaviors of Br2 and Cl2 guests in the hydrate cages may explain why bromine forms the unique TS-I phase

  14. Effect of brominated furanones on the formation of biofilm by Escherichia coli on polyvinyl chloride materials.

    Science.gov (United States)

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

    2013-01-01

    To study the influence of brominated furanones on the biofilm (BF) formation by Escherichia coli (E. coli) on polyvinyl chloride (PVC) material, and to provide new ways of surface modification of materials to clinically prevent biomaterial centered infection. Three brominated furanones, dissolved in ethanol, furanone-1(3,4-dibromo-5-hydroxyl-furanone), furanone-2(4-bromo-5-(4-methoxypheny)-3-(methylamino)-furanone), and furanone-3(3,4-dibromo-5,5-dimethoxypheny-2(5H)-furanone) with representative chemical structure, were coated on the surfaces of separate PVC materials (1 × 1 cm), respectively. The surface-modified PVC materials were incubated with E. coli and for controls, 75 % ethanol-treated PVC materials were used. This treatment played as control group. The cultivation incubations were for 6, 12, 18, and 24 h. The thickness of bacterial BF and bacterial community quantity unit area on the PVC materials was determined by confocal laser scanning microscopy (CLSM), and the surface structure of bacterial BF formation was examined by scanning electron microscopy (SEM). The results of CLSM indicated the thickness of bacterial BF and bacterial community quantity unit area on PVC materials treated with furanone-3 were significantly lower than that of control at all time points (P 0.05). The results of SEM indicated that after 6 h incubation, the quantity of bacterial attachment to the surface of PVC material treated with furanone-3 was lower than the control group. By 18 h incubation there was completely formed BF structure on the surface of control PVC material. However, there was no significant BF formation on the surface of PVC material treated with furanone-3. The impact of different brominated furanones on SA biofilm formation on the surface of PVC materials are different, furanone-3 can inhibit E. coli biofilm formation on the surface of PVC material.

  15. Ways of reducing the bromine numbers of benzene for nitration with the use of the piperylene additive

    Energy Technology Data Exchange (ETDEWEB)

    Kolyandr, L.Ya.; Litvinenko, A.M.; Mastyukov, V.A.; Potapchenko, A.A.; Savikkova, M.T.; Shoherbakova, T.G.; Shuzhenko, E.A.; Titarenko, V.G.; Tkachenko, L.A.

    1981-01-01

    To study the diminution of the bromine numbers of benzene for nitration, an investigation has been made of the impurities according to the fractions of the tests of benzene production of three coke and chemical works: the works in Makeev-a, ka, Bagleisk and Yenakievo. It has been found that when the piperylene additive is used, the value of the bromine numbers of benzene for nitration is determined, in the main, not by the piperylenes removed during purification. When the intermediate BT fractions are not sufficiently clearly selected, the value of the bromine numbers of benzene is influenced also by the impurities which are concentrated in its terminal fractions. To radically remove piperylenes, it is necessary to improve the contact between the acid and the fraction being purified; this is attained by intensifying mixing and lengthening the purification process.

  16. Reaction modelling of Iron Oxide Bromination in the UT-3 thermochemical cycle for Hydrogen production from water

    International Nuclear Information System (INIS)

    Analysis modelling of the iron oxide bromination had been carried out using experiment data from the iron oxide bromination in the UT-3 thermochemical cycle. Iron oxide in the form of pellets were made of the calcination of the mixture of iron oxide, silica, graphite and cellulose at 1473 K. Thermobalance reactor was used to study the kinetic reactions of the iron oxide bromination at a temperature of 473 K for 2 - 6 hours. The data collected from the experiments were used as input for the common models. However, none of these models could not explain the result of the experiments. A new model, a combination of two kinetic reactions : exposed particle and coated particle was created and worked successfully

  17. 藻有机物在含溴离子条件下氯化消毒HAAs的生成种类%Haloacetic acids species from the chlorination of algal organic matter in the presence of bromide

    Institute of Scientific and Technical Information of China (English)

    魏源源; 刘燕; 刘翔; 代瑞华

    2011-01-01

    藻类污染和溴离子存在是影响沿海地区水库水源消毒副产物形成的重要因素。在和无溴离子存在条件下,以藻细胞模拟生化成分(BSA、鱼油和淀粉),铜绿微囊藻细胞及其胞外有机物为前躯物进行氯化消毒对比实验,从藻细胞生化成分的角度探究藻有机物作为消毒副产物前躯物时,且水中存在溴离子的条件下,氯化消毒形成卤乙酸(HAAs)的种类情况。结果表明,3种模拟生化成分在溴离子存在条件下,形成的溴代HAAs仅为溴氯乙酸或二溴乙酸的1种或2种。与BSA和淀粉为前躯物时形成溴代HAAs的产物种类相比,溴离子对鱼油为前躯物时形成溴代HAAs产物种类的影响更大。模拟生化成分预测NHaAs副产物种类与具体藻种形成的HAAs副产物种类之间具有较好的吻合度。%Bromide and algal pollution are important factors influencing disinfection byproducts (DBPs) formation and speciation in reservoir water in coastal areas. The chlorination of model algal cellular compounds (bovine serum albumin, fish oil and starch), Microcystis aeruginosa and its extra-cellular organic matters (EOMs) were conducted in the absence and presence of bromide. The main aim of the present study is to explore their potential as precursors for haloacetic acids (HAAs) speciation upon chlorination in the presence of bromide. The results showed that bromochloroacetic acid (BCAA) or/and dibromoacetic acid (DBAA) was/were produced as for brominated HAAs (Br-HAAs) from the three model compounds in the presence of bromide. The effect of bromide on Br-HAAs speciation upon fish oil chlorination was more evident than with BSA and starch. There was a good correlation between the species predicted from the model compounds and those obtained from specific algal species.

  18. Reaction of Polymer-supported Selenovinyl Bromide with Grignard Reagents: A Facile Route to the Synthesis of(E)-1, 2-Disubstituted Olefins

    Institute of Scientific and Technical Information of China (English)

    E TANG; Xiang Jin LIN; Lu Ling WU

    2005-01-01

    Polymer-supported selenovinyl bromide, easily prepared from polymer-supported selenenyl bromide with acetylene, reacts with different Grignard reagents using a step-by-step strategy to obtain (E)-1, 2-disubstituted ethenes in good yields.

  19. SYNTHESIS AND GREEN BROMINATION OF SOME CHALCONES AND THEIR ANTIMICROBIAL SCREENING

    Directory of Open Access Journals (Sweden)

    Mayur R. Adokar

    2013-04-01

    Full Text Available Chalcones are the versatile molecules having the structural flexibility which permits structural transformations into flavonoids, flavanones, pyrazoles, oxazoles, pyrimidines etc. Changes in their structure have offered the development of new medicinal agents having improved pharmacological potency. Their derivatives have attracts increasing attention due to numerous pharmacological potential. In the present communication we report the synthesis of chalcones from various acetophenone derivatives with different aromatic aldehydes and green chemistry approach to their bromination with the help of Tetrabutylammonium Tribromide (TBATB. All the synthesized chalcone dibromides were screened for their antimicrobial activity against Aspergillus flavus, Rhizopus sp., Fusarium solani and Aspergillus niger.

  20. Brominated flame retardants in waste electrical and electronic equipment: substance flows in a recycling plant.

    Science.gov (United States)

    Morf, Leo S; Tremp, Josef; Gloor, Rolf; Huber, Yvonne; Stengele, Markus; Zennegg, Markus

    2005-11-15

    Brominated flame retardants (BFRs) are synthetic additives mainly used in electrical and electronic appliances and in construction materials. The properties of some BFRs are typical for persistent organic pollutants, and certain BFRs, in particular some polybrominated diphenyl ether (PBDE) congeners and hexabromocyclododecane (HBCD), are suspected to cause adverse health effects. Global consumption of the most demanded BFRs, i.e., penta-, octa-, and decaBDE, tetrabromobisphenol A (TBBPA), and HBCD, has doubled in the 1990s. Only limited and rather uncertain data are available regarding the occurrence of BFRs in consumer goods and waste fractions as well as regarding emissions during use and disposal. The knowledge of anthropogenic substance flows and stocks is essential for early recognition of environmental impacts and effective chemicals management. In this paper, actual levels of penta-, octa-, and decaBDE, TBBPA, and HBCD in waste electrical and electronic equipment (WEEE) as a major carrier of BFRs are presented. These BFRs have been determined in products of a modern Swiss recycling plant applying gas chromatography/electron capture detection and gas chromatography/mass spectrometry analysis. A substance flow analysis (SFA) technique has been used to characterize the flows of target substances in the recycling process from the bulk WEEE input into the output products. Average concentrations in small size WEEE, representing the relevant electric and electronic appliances in WEEE, sampled in 2003 amounted to 34 mg/kg for pentaBDE, 530 mg/kg for octaBDE, 510 mg/kg for decaBDE, 1420 mg/kg for TBBPA (as an additive), 17 mg/kg for HBCD, 5500 mg/kg for bromine, and 1700 mg/kg for antimony. In comparison to data that have been calculated by SFA for Switzerland from literature for the 1990s, these measured concentrations in small size WEEE were 7 times higher for pentaBDE, unexpectedly about 50% lower for decaBDE, and agreed fairly well for TBBPA (as an additive) and

  1. Antibacterial Activities of a New Brominated Diterpene from Borneon Laurencia spp

    Science.gov (United States)

    Vairappan, Charles Santhanaraju; Ishii, Takahiro; Lee, Tan Kai; Suzuki, Minoru; Zhaoqi, Zhan

    2010-01-01

    In our continuous interest to study the diversity of halogenated metabolites of Malaysian species of the red algal genus Laurencia, we examined the chemical composition of five populations of unrecorded Laurencia sp. A new brominated diterpene, 10-acetoxyangasiol (1), and four other known metabolites, aplysidiol (2), cupalaurenol (3), 1-methyl-2,3,5-tribromoindole (4), and chamigrane epoxide (5), were isolated and identified. Isolated metabolites exhibited potent antibacterial activities against clinical bacteria, Staphylococcus aureus, Staphylococcus sp., Streptococcus pyogenes, Salmonella sp. and Vibrio cholerae. PMID:20631866

  2. Antibacterial Activities of a New Brominated Diterpene from Borneon Laurencia spp.

    Directory of Open Access Journals (Sweden)

    Charles Santhanaraju Vairappan

    2010-05-01

    Full Text Available In our continuous interest to study the diversity of halogenated metabolites of Malaysian species of the red algal genus Laurencia, we examined the chemical composition of five populations of unrecorded Laurencia sp. A new brominated diterpene, 10-acetoxyangasiol (1, and four other known metabolites, aplysidiol (2, cupalaurenol (3, 1-methyl-2,3,5-tribromoindole (4, and chamigrane epoxide (5, were isolated and identified. Isolated metabolites exhibited potent antibacterial activities against clinical bacteria, Staphylococcus aureus, Staphylococcus sp., Streptococcus pyogenes, Salmonella sp. and Vibrio cholerae.

  3. [Effectiveness of pinaverium bromide therapy on colonic motility disorders in irritable bowel syndrome].

    Science.gov (United States)

    Wittmann, T; Fehér, A; Rosztóczy, A; Jánosi, J

    1999-02-28

    The special patterns of the slow wave activity in irrittable bowel syndrome by means of surface electromyography were examined and the effect of pinaverium bromide on the symptoms and on the colonic motility in this disease was estimated. Twenty two patients with irritable bowel syndrome and 7 healthy controls were selected to the study. The clinical symptoms were abdominal pain and bloating in all patients, constipation in 9, and diarrhoea in 6 cases. Surface electromyography was carried out before and on the 14th day of the treatment with pinaverium bromide (50 mg t. i. d). The colonic motility was analysed in a 2 hour fasting and a 2 hour postprandial period following a standard (800 kCal) meal. The slow wave frequency of 0.01-0.04 Hz were selected and analysed. The mean frequency of activity peaks (n/10 min) and power-index (area under curve, microV 10 min) were measured. For statistical analysis Student's t-test was applied. Electromyogram of patients with irritable bowel syndrome showed a significant increase of the measured colonic motility parameters both in fasting and postprandial states. Fourteen days of pinaverium bromide treatment was able to significantly reduce the intensity of the colonic motor activity. Administration of pinaverium bromide completely released in 6 and significantly improved the abdominal pain in other 12 patients, while the bloating disappeared in 12 and was significantly improved in 5 from 22 patients. Pinaverium bromide was able to normalise the stool frequency: the weekly number of stools was decreased from 16 to 7 in the patients complaining diarrhoea ant it was increased from 2 to 6 in the patients with constipation. PMID:10204402

  4. Price Wars and the Stability of Collusion: A Study of the Pre-World War I Bromine Industry

    OpenAIRE

    Margaret Levenstein

    1993-01-01

    Bromine producers colluded to raise prices and profits during most of the period between 1885 and 1914. Collusion was punctuated by price wars in which prices fell sharply. The characteristics of these price wars are compared with those in the Green-Porter and Abreu- Pearce-Stachetti models. Some of the bromine price wars resulted from the imperfect monitoring problems in these models. Those price wars were short and mild. More severe price wars were part of a bargaining process, in which fir...

  5. Synchrotron X-ray fluorescence studies of a bromine-labelled cyclic RGD peptide interacting with individual tumor cells

    International Nuclear Information System (INIS)

    The first example of synchrotron X-ray fluorescence imaging of cultured mammalian cells in cyclic peptide research is reported. The study reports the first quantitative analysis of the incorporation of a bromine-labelled cyclic RGD peptide and its effects on the biodistribution of endogenous elements (for example, K and Cl) within individual tumor cells. The first example of synchrotron X-ray fluorescence imaging of cultured mammalian cells in cyclic peptide research is reported. The study reports the first quantitative analysis of the incorporation of a bromine-labelled cyclic RGD peptide and its effects on the biodistribution of endogenous elements (for example, K and Cl) within individual tumor cells

  6. Analytical approaches for determination of bromine in sediment core samples by X-ray fluorescence spectrometry.

    Science.gov (United States)

    Pashkova, Galina V; Aisueva, Tatyana S; Finkelshtein, Alexander L; Ivanov, Egor V; Shchetnikov, Alexander A

    2016-11-01

    Bromine has been recognized as a valuable indicator for paleoclimatic studies. Wavelength dispersive X-ray fluorescence (WDXRF) and total reflection X-ray fluorescence (TXRF) methods were applied to study the bromine distributions in lake sediment cores. Conventional WDXRF technique usually requires relatively large mass of a sediment sample and a set of calibration samples. Some analytical approaches were developed to apply WDXRF to small sediment core samples in the absence of adequate calibration samples with a known Br content. The mass of a sample to be analyzed was reduced up to 200-300mg and the internal standard method with correction using fundamental parameters was developed for Br quantification. TXRF technique based on the direct analysis of a solid suspension using 20mg of sediment sample by internal standard method was additionally tested. The accuracy of the WDXRF and TXRF techniques was assessed by the comparative analysis of reference materials of sediments, soil and biological samples. In general, good agreement was achieved between the reference values and the measured values. The detection limits of Br were 1mg/kg and 0.4mg/kg for WDXRF and TXRF respectively. The results of the Br determination obtained with different XRF techniques were comparable to each other and used for paleoclimatic reconstructions. PMID:27591627

  7. Synthesis of α-Bromine- Terminated Polystyrene Macroinitiator and Its Initiation of MMA Polymerization by ATRP

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the present paper the synthesis of block copolymers via the transformation from living anionic polymerization (LAP) to atom transfer radical polymerization (ATRP) was described. Α-Bromine-terminated polystyrenes(PStBr) in the LAP step was prepared by using n-BuLi as initiator, tetrahydrofuran (THF) as the activator, α-methylstyrene (α-MeSt) as the capping group and liquid bromine (Br2) as the bromating agent. The effects of reaction conditions such as the amounts of α-MeSt, THF, and Br2 as well as molecular weight of polystyrene on the bromating efficiency (BE) and coupling extent (CE) were examined. The present results show that the yield of PStBr obtained was more than 93.8% and the coupling reaction was substantially absent. PStBr was further used as the macroinitiator in the polymerization of methyl-methacrylate(MMA) in the presence of copper(Ⅰ) halogen and 2,2-bipyridine(bpy) complexes. It was found that the molecular weight of the resulted PSt-b-PMMA increased linearly with the increase of the conversion of MMA and the polydispersity was 1.2-1.6. The structures of PStBr and P(St-b-MMA) were characterized by 1H NMR spectra.

  8. Levelized cost of energy and sensitivity analysis for the hydrogen-bromine flow battery

    Science.gov (United States)

    Singh, Nirala; McFarland, Eric W.

    2015-08-01

    The technoeconomics of the hydrogen-bromine flow battery are investigated. Using existing performance data the operating conditions were optimized to minimize the levelized cost of electricity using individual component costs for the flow battery stack and other system units. Several different configurations were evaluated including use of a bromine complexing agent to reduce membrane requirements. Sensitivity analysis of cost is used to identify the system elements most strongly influencing the economics. The stack lifetime and round-trip efficiency of the cell are identified as major factors on the levelized cost of electricity, along with capital components related to hydrogen storage, the bipolar plate, and the membrane. Assuming that an electrocatalyst and membrane with a lifetime of 2000 cycles can be identified, the lowest cost market entry system capital is 220 kWh-1 for a 4 h discharge system and for a charging energy cost of 0.04 kWh-1 the levelized cost of the electricity delivered is 0.40 kWh-1. With systems manufactured at large scales these costs are expected to be lower.

  9. Hair as an indicator of endogenous tissue levels of brominated flame retardants in mammals.

    Science.gov (United States)

    D'Havé, Helga; Covaci, Adrian; Scheirs, Jan; Schepens, Paul; Verhagen, Ron; De Coen, Wim

    2005-08-15

    Few data are available on brominated flame retardants (BFRs) in terrestrial mammalian wildlife. Moreover, the use of hair in nondestructive monitoring of BFRs in mammals or humans has not been investigated. In the present study, concentrations of polybrominated diphenyl ethers (PBDEs) and brominated biphenyl 153 (BB 153) were analyzed in tissues of the European hedgehog Erinaceus europaeus. Road kills and carcasses from wildlife rescue centers were used to investigate relationships between concentrations of BFRs in hair and internal tissues, BFR tissue distribution (hair, liver, kidney, muscle, and adipose tissue), and PBDE congener tissue pattern dissimilarities. Liver concentrations of PBDEs and BB 153 were in the ranges 1-1178 and 0-2.5 ng/g of liver wet weight, respectively. PBDEs were predominant in adipose tissue and liver, while accumulation of BB 153 was tissue independent. The less persistent compound BDE 99 was more dominant in hair than in internal tissues. We observed positive relationships between BFR levels in hair and internal tissues for sum PBDEs and BDE 47 (0.37 terrestrial mammals which can be used in nondestructive monitoring schemes.

  10. Dissolution of brominated epoxy resins by dimethyl sulfoxide to separate waste printed circuit boards.

    Science.gov (United States)

    Zhu, Ping; Chen, Yan; Wang, Liangyou; Qian, Guangren; Zhang, Wei Jie; Zhou, Ming; Zhou, Jin

    2013-03-19

    Improved methods are required for the recycling of waste printed circuit boards (WPCBs). In this study, WPCBs (1-1.5 cm(2)) were separated into their components using dimethyl sulfoxide (DMSO) at 60 °C for 45 min and a metallographic microscope was used to verify their delamination. An increased incubation time of 210 min yielded a complete separation of WPCBs into their components, and copper foils and glass fibers were obtained. The separation time decreased with increasing temperature. When the WPCB size was increased to 2-3 cm(2), the temperature required for complete separation increased to 90 °C. When the temperature was increased to 135 °C, liquid photo solder resists could be removed from the copper foil surfaces. The DMSO was regenerated by rotary decompression evaporation, and residues were obtained. Fourier transform infrared spectroscopy (FT-IR), thermal analysis, nuclear magnetic resonance, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to verify that these residues were brominated epoxy resins. From FT-IR analysis after the dissolution of brominated epoxy resins in DMSO it was deduced that hydrogen bonding may play an important role in the dissolution mechanism. This novel technology offers a method for separating valuable materials and preventing environmental pollution from WPCBs. PMID:23398278

  11. Biodegradation kinetics of selected brominated flame retardants in aerobic and anaerobic soil

    Energy Technology Data Exchange (ETDEWEB)

    Nyholm, Jenny Rattfelt, E-mail: jenny.rattfelt@chem.umu.s [Department of Chemistry, Umea University, SE-901 87 Umea (Sweden); Lundberg, Charlott; Andersson, Patrik L. [Department of Chemistry, Umea University, SE-901 87 Umea (Sweden)

    2010-06-15

    The purpose of the present study was to investigate the biodegradation kinetics in aerobic and anaerobic soil of the following brominated flame retardants: 2,4,4'-tribromodiphenyl ether (BDE 28), decabromodiphenyl ether (BDE 209), tetrabromobisphenol A (TBBPA), 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), 2,4,6-tribromophenol (246BrPh), and hexabromobenzene (HxBrBz). For comparison, the biodegradation of the chlorinated compounds 2,4,4'-trichlorodiphenyl ether (CDE 28), 2,4,6-trichlorophenol (246ClPh), hexachlorobenzene (HxClBz), and 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) was also assessed. In aerobic soil, BDE 209 showed no significant degradation during the test period, but concentrations of the other BFRs declined, with half-lives decreasing in the following order: BDE 28 > TBBPA > TBECH > HxBrBz > 246BrPh. Declines in almost the same order were observed in anaerobic soil: BDE 28, BDE 209 > TBBPA > HxBrBz > TBECH >246BrPh. - Intra- and extrapolated half-lives in soil of tested brominated flame retardants ranged from 7 days for 2,4,6-tribromorophenol to >400 days for decabromodiphenyl ether.

  12. Novel Spectrophotometric Method for Determination of Macro-paracetamol via Reaction with Bromine

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The reaction between Br2 and paracetamol(p-AAP) leads to the formation of a coloured product, which can be used for spectrophotometric determination of the p-AAP content in its pure form and in different pharmaceutical preparations with p-AAP. The stoichiometric composition of the reaction was found to be n(p-AAP)∶n(bromine)=1∶3. The effects of pH and time on the spectra of p-AAP-bromine redox reaction product were studied. The interference of different additives on the measured spectra of the obtained product was also studied. The results obtained by the present method were compared with those obtained by the standard method. The F- and t- test values were calculated for both of the applied procedures and they met a confidence level of 99%. The proposed procedure actually needs no separation of these drugs from their sources before analysis and was unaffected by interference of other phenolic compounds. The proposed method is simpler and faster than the repoeted ones.

  13. Selected chlorobornanes, polychlorinated naphthalenes and brominated flame retardants in Bjornoya (Bear Island) freshwater biota

    International Nuclear Information System (INIS)

    Levels of selected sparsely investigated persistent organic pollutants (POPs) have been measured in organisms from two Arctic lakes on Bjornoya (Bear Island). Elevated levels of chlorobornanes (CHBs) (up to 46.7 ng/g wet weight=ww), polybrominated diphenyl ethers (PBDEs) (up to 27.2 ng/g ww), polybrominated biphenyls (PBBs) (up to 1.1 ng/g ww) and polychlorinated naphthalenes (PCNs, only 4 congeners) (up to 62.7 pg/g ww), were measured in biota from Lake Ellasjoen. In Lake Oyangen, located only 5 km north of Ellasjoen, levels of these contaminants were significantly lower. δ15N-values were 7-10%o higher in organisms from Ellasjoen as compared to Oyangen. This is attributed to biological inputs related to seabird activities. The present study illustrates that contaminants such as CHBs, brominated flame retardants and PCNs accumulate in the Ellasjoen food web in a manner similar to PCBs and conventional organochlorine pesticides. Transport mechanisms that control PCB and DDT distributions, i.e. atmospheric long-range transport and biotransport by seabirds, are also relevant for the contaminants investigated in the present study. - Elevate levels of chlorobornanes, polychlorinated naphthalenes and brominated flame retardants have been measured in biota from a Norwegian Arctic lake

  14. Development of Zinc/Bromine Batteries for Load-Leveling Applications: Phase 2 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    CLARK,NANCY H.; EIDLER,PHILLIP

    1999-10-01

    This report documents Phase 2 of a project to design, develop, and test a zinc/bromine battery technology for use in utility energy storage applications. The project was co-funded by the U.S. Department of Energy Office of Power Technologies through Sandia National Laboratories. The viability of the zinc/bromine technology was demonstrated in Phase 1. In Phase 2, the technology developed during Phase 1 was scaled up to a size appropriate for the application. Batteries were increased in size from 8-cell, 1170-cm{sup 2} cell stacks (Phase 1) to 8- and then 60-cell, 2500-cm{sup 2} cell stacks in this phase. The 2500-cm{sup 2} series battery stacks were developed as the building block for large utility battery systems. Core technology research on electrolyte and separator materials and on manufacturing techniques, which began in Phase 1, continued to be investigated during Phase 2. Finally, the end product of this project was a 100-kWh prototype battery system to be installed and tested at an electric utility.

  15. Tropospheric Bromine Chemistry: Implications for Present and Pre-industrial Ozone and Mercury

    Science.gov (United States)

    Parella, J. P.; Jacob, D. J.; Liang, Q.; Zhang, Y.; Mickley, L. J.; Miller, B.; Evans, M. J.; Yang, X.; Pyle, J. A.; Theys, N.; VanRoozendael, M.

    2012-01-01

    We present a new model for the global tropospheric chemistry of inorganic bromine (Bry) coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM). Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone mixing ratios by mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  16. Brominated diphenyl ethers in the sediments, porewater, and biota of the Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K.; Klosterhaus, S.; Liebert, D.; Stapleton, H. [Maryland Univ., Solomons, MD (United States)

    2004-09-15

    Levels of brominated diphenyl ethers (BDEs) are rapidly increasing in the environment, and in a short time these chemicals have evolved from 'emerging contaminants' to globally-distributed organic pollutants. Recent research demonstrates BDEs are sufficiently stable to be transported long distances in the environment and to accumulate in higher trophic levels. Photolysis and metabolism appear to be dominant loss processes for the parent compounds, generating a variety of lower brominated diphenyl ethers, hydroxylated metabolites, and other products. BDEs are hydrophobic, and therefore their transport in aquatic systems is likely controlled by sorption to sediments and perhaps exchange across the air-water interface. To date, few studies have examined the geochemistry of BDEs in natural waters. In this paper, we review our recent measurements of BDEs in the Chesapeake Bay, a shallow, productive estuary in eastern North America. We focus on the distribution of BDE congeners sediment, porewater, and in faunal benthos along a contamination gradient downstream from a wastewater treatment plant and on the spatial distribution of BDEs in bottom-feeding and pelagic fish species.

  17. Ultrafast optical limiting properties and transient dynamics of symmetrical phenoxazinium bromine salt

    Science.gov (United States)

    Xiao, Zhengguo; Ge, Jianfeng; Li, Zhongguo; Wu, Xingzhi; Fang, Yu; Shi, Guang; Zhang, Xueru; Wang, Yuxiao; Song, Yinglin

    2015-12-01

    A symmetrical phenoxazinium bromine salt with resonant D-π-D structure was prepared and spectroscopically characterized. The ultrafast nonlinear optical (NLO) response of the compound dissolved in DMF was investigated using open aperture Z-scan method with 190 fs laser pulses at 515 nm. And the photo-physical dynamics of the compound was studied using transient absorption spectra at femtosecond time regime. The titled sample showed strong reverse saturable absorption (RSA) at 515 nm. Transient absorption results demonstrated that the compound exhibited RSA signals at 478-580 nm and SA signals at 600-780 nm. A simplified three-energy-level model was used to determine the photo-physical parameters. And the excited-state lifetime was evaluated to be around one nanosecond. Our results show that the phenoxazinium bromine salt has a large ratio of singlet excited-state absorption cross-section to that of ground state cross-section (18.7), indicating it is a candidate material for future ultrafast optical limiters.

  18. Natural solar photolysis of total organic chlorine, bromine and iodine in water.

    Science.gov (United States)

    Abusallout, Ibrahim; Hua, Guanghui

    2016-04-01

    Municipal wastewater has been increasingly used to augment drinking water supplies due to the growing water scarcity. Wastewater-derived disinfection byproducts (DBPs) may negatively affect the aquatic ecosystems and human health of downstream communities during water reuse. The objective of this research was to determine the degradation kinetics of total organic chlorine (TOCl), bromine (TOBr) and iodine (TOI) in water by natural sunlight irradiation. Outdoor solar photolysis experiments were performed to investigate photolytic degradation of the total organic halogen (TOX) formed by fulvic acid and real water and wastewater samples. The results showed that TOX degradation by sunlight irradiation followed the first-order kinetics with half-lives in the range of 2.6-10.7 h for different TOX compounds produced by fulvic acid. The TOX degradation rates were generally in the order of TOI > TOBr ≅ TOCl(NH2Cl) > TOCl(Cl2). High molecular weight TOX was more susceptible to solar photolysis than corresponding low molecular weight halogenated compounds. The nitrate and sulfite induced indirect TOX photolysis rates were less than 50% of the direct photolysis rates under the conditions of this study. Fulvic acid and turbidity in water reduced TOX photodegradation. These results contribute to a better understanding of the fate of chlorinated, brominated and iodinated DBPs in surface waters.

  19. Selected chlorobornanes, polychlorinated naphthalenes and brominated flame retardants in Bjornoya (Bear Island) freshwater biota

    Energy Technology Data Exchange (ETDEWEB)

    Evenset, Anita [Akvaplan-niva, Polar Environmental Centre, N-9296 Tromso (Norway)]. E-mail: ae@akvaplan.niva.no; Christensen, Guttorm N. [Akvaplan-niva, Polar Environmental Centre, N-9296 Tromso (Norway); Kallenborn, Roland [Norwegian Institute for Air Research, P.O. Box 100, N-2027 Kjeller (Norway)

    2005-08-15

    Levels of selected sparsely investigated persistent organic pollutants (POPs) have been measured in organisms from two Arctic lakes on Bjornoya (Bear Island). Elevated levels of chlorobornanes (CHBs) (up to 46.7 ng/g wet weight=ww), polybrominated diphenyl ethers (PBDEs) (up to 27.2 ng/g ww), polybrominated biphenyls (PBBs) (up to 1.1 ng/g ww) and polychlorinated naphthalenes (PCNs, only 4 congeners) (up to 62.7 pg/g ww), were measured in biota from Lake Ellasjoen. In Lake Oyangen, located only 5 km north of Ellasjoen, levels of these contaminants were significantly lower. {delta}{sup 15}N-values were 7-10%o higher in organisms from Ellasjoen as compared to Oyangen. This is attributed to biological inputs related to seabird activities. The present study illustrates that contaminants such as CHBs, brominated flame retardants and PCNs accumulate in the Ellasjoen food web in a manner similar to PCBs and conventional organochlorine pesticides. Transport mechanisms that control PCB and DDT distributions, i.e. atmospheric long-range transport and biotransport by seabirds, are also relevant for the contaminants investigated in the present study. - Elevate levels of chlorobornanes, polychlorinated naphthalenes and brominated flame retardants have been measured in biota from a Norwegian Arctic lake.

  20. Levels and distribution of brominated flame retardants in the soil of Harbin in China

    Institute of Scientific and Technical Information of China (English)

    WANG Xu; REN Nanqi; QI Hong; MA Wanli; LI Yifan

    2009-01-01

    This study reports the presence of brominated flame retardants in the topsoil in and around Harbin,a city in northeastern China.Samples of soil were collected from 17 locations in 2006,and the levels of 9 polybrominated diphenylethers (PBDEs 17,28,47,66,99,100,153,154,and 183) ranged from 2.45 to 55.9 pg/g dry weight (dw) with a mean of 26.3 pg/g dw.These levels are very low compared with those for some cities in Europe and the USA.BDE 209 and hexabromocyclododecane were the two dominant congeners,with mean concentrations of 520 pg/g dw and 1750 pg/g dw,respectively.The concentrations of the total 9 PBDE congeners clearly decreased from urban areas to background,but the compositions of individual congeners differed.Proportions of heavier congeners decreased while those of lighter congeners increased,along urban-rural-background transect,providing evidence for an urban fractionation effect.Correlation analysis indicated similar sources for PBDEs,hexabromocyclododecane,and 1,2-bis(2,4,6-tribromophenoxy)-ethane from urban areas but pentabromoethylbenzene was probably present due to long-range atmospheric transport.Principal component analysis was used to determine the characteristics of the relationships among these brominated flame retardants in the field.

  1. Nitrogenous disinfection byproducts in English drinking water supply systems: Occurrence, bromine substitution and correlation analysis.

    Science.gov (United States)

    Bond, Tom; Templeton, Michael R; Mokhtar Kamal, Nurul Hana; Graham, Nigel; Kanda, Rakesh

    2015-11-15

    Despite the recent focus on nitrogenous disinfection byproducts in drinking water, there is limited occurrence data available for many species. This paper analyses the occurrence of seven haloacetonitriles, three haloacetamides, eight halonitromethanes and cyanogen chloride in 20 English drinking water supply systems. It is the first survey of its type to compare bromine substitution factors (BSFs) between the haloacetamides and haloacetonitriles. Concentrations of the dihalogenated haloacetonitriles and haloacetamides were well correlated. Although median concentrations of these two groups were lower in chloraminated than chlorinated surface waters, median BSFs for both in chloraminated samples were approximately double those in chlorinated samples, which is significant because of the higher reported toxicity of the brominated species. Furthermore, median BSFs were moderately higher for the dihalogenated haloacetamides than for the haloacetonitriles. This indicates that, while the dihalogenated haloacetamides were primarily generated from hydrolysis of the corresponding haloacetonitriles, secondary formation pathways also contributed. Median halonitromethane concentrations were remarkably unchanging for the different types of disinfectants and source waters: 0.1 μg · mgTOC(-1) in all cases. Cyanogen chloride only occurred in a limited number of samples, yet when present its concentrations were higher than the other N-DBPs. Concentrations of cyanogen chloride and the sum of the halonitromethanes were not correlated with any other DBPs.

  2. Comparative microvascular exchange kinetics of [{sup 77}Br]bromide and {sup 99m}Tc-DTPA in humans

    Energy Technology Data Exchange (ETDEWEB)

    Cousins, Claire [Department of Clinical Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom); Skehan, Stephen J.; Rolph, Susan M.; Flaxman, Mary E.; Ballinger, James R.; Bird, Nicholas J.; Barber, Robert W.; Peters, Michael A. [Department of Nuclear Medicine, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2002-05-01

    The plasma clearance curves of small hydrophilic solutes comprise three exponentials, consistent with a three-compartmental distribution model. A previous comparison between inulin and diethylene triamine penta-acetic acid (DTPA) suggested that these three compartments are in series, the first being plasma and the second and third representing compartments within the extravascular space. Moreover, whilst the total distribution volumes of these two indicators were similar, the volume of the second compartment was higher for DTPA. The purpose of the current study was to investigate whether a solute smaller than DTPA, namely bromide, fits the hypothesis that the second space volume is an inverse function of the size of the solute. Two groups of subjects were studied: group A comprised eight patients undergoing routine diagnostic arteriography and group B, eight patients referred for routine measurement of glomerular filtration rate plus two normal volunteers. {sup 99m}Tc-DTPA and sodium [{sup 77}Br]bromide were intravenously administered simultaneously. In group A, frequent arterial samples were obtained up to 40 min after injection, and antecubital venous samples 30 s after each arterial sample. In group B, frequent venous samples were obtained up to 280 min after injection. Volume measurements based on bromide were corrected for erythrocyte bromide accumulation. In both subject groups, the normalised venous concentration ratio of bromide to DTPA, corrected for red cell bromide uptake, was significantly less than unity in the earliest blood samples, being 0.56 (SD 0.08) at 1 min, consistent with faster diffusion of bromide from plasma to interstitial fluid. Furthermore, the extraction fraction of bromide from plasma to interstitial fluid in the forearm was about 0.6, higher than that of DTPA (about 0.5) in spite of red cell bromide accumulation which equilibrated with plasma bromide within 20 s and resulted in a red cell to plasma concentration ratio of 0.51 (0

  3. Synthesis of polyhydroxylated pyrrolidines from sugar-derived bromonitriles through a cascade addition of allylmagnesium bromide/cyclization/reduction.

    Science.gov (United States)

    Malik, Michał; Jarosz, Sławomir

    2016-02-01

    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.

  4. Prenatal Exposure to Organohalogens, Including Brominated Flame Retardants, Influences Motor, Cognitive, and Behavioral Performance at School Age

    NARCIS (Netherlands)

    Roze, Elise; Meijer, Lisethe; Bakker, Attie; Van Braeckel, Koenraad N. J. A.; Sauer, Pieter J. J.; Bos, Arend F.

    2009-01-01

    BACKGROUND: Organohalogen compounds (OHCs) are known to have neurotoxic effects on the developing brain. OBJECTIVE: We investigated the influence of prenatal exposure to OHCs, including brominated flame retardants, on motor, cognitive, and behavioral outcome in healthy children of school age. METHOD

  5. Corrosion mechanism of 13Cr stainless steel in completion fluid of high temperature and high concentration bromine salt

    International Nuclear Information System (INIS)

    Highlights: • The corrosion behavior of 13Cr steel exposed to bromine salt completion fluid containing high concentration bromine ions was investigated. • There are passive circles around pits on the 13Cr steel surface after 7 d of exposure. • Macroscopic galvanic corrosion formed between the passive halo and the pit. • The mechanism of pitting corrosion on 13Cr stainless steel exposed to heavy bromine brine was established. - Abstract: A series of corrosion tests of 13Cr stainless steel were conducted in a simulated completion fluid environment of high temperature and high concentration bromine salt. Corrosion behavior of specimens and the component of corrosion products were investigated by means of scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The results indicate that 13Cr steel suffers from severe local corrosion and there is always a passive halo around every pit. The formation mechanism of the passive halo is established. OH− ligand generates and adsorbs in a certain scale because of abundant OH− on the surface around the pits. Passive film forms around each pit, which leads to the occurrence of passivation in a certain region. Finally, the dissimilarities in properties and morphologies of regions, namely the pit and its corresponding passive halo, can result in different corrosion sensitivities and may promote the formation of macroscopic galvanic pairs

  6. Exposure to brominated trihalomethanes in water during pregnancy and micronuclei frequency in maternal and cord blood lymphocytes

    DEFF Research Database (Denmark)

    Stayner, Leslie Thomas; Pedersen, Marie; Patelarou, Evridiki;

    2014-01-01

    BACKGROUND: Water disinfection by-products have been associated with an increased cancer risk. Micronuclei (MN) frequency in lymphocytes is a marker of genomic damage and can predict adult cancer risk. OBJECTIVE: We evaluated maternal exposure to drinking water brominated trihalomethanes (BTHM) i...

  7. Accumulation of organochlorines and brominated flame retardants in estuarine and marine food chains: Field measurements and model calculations

    NARCIS (Netherlands)

    Veltman, K.; Hendriks, J.; Huijbregts, M.; Leonards, P.E.G.; Heuvel-Greve, van den M.J.; Vethaak, D.

    2005-01-01

    Food chain accumulation of organochlorines and brominated flame retardants in estuarine and marine environments is compared to model estimations and fresh water field data. The food chain consists of herbivores, detritivores and primary and secondary carnivores i.e. fish, fish-eating birds and marin

  8. Subacute effects of the brominated flame retardants hexabromocyclododecane and tetrabromobisphenol A on hepatic cytochrome P450 levels in rats.

    NARCIS (Netherlands)

    Germer, Silke; Piersma, Aldert H; Ven, Leo T M van der; Kamyschnikow, Andreas; Fery, Yvonne; Schmitz, Hans-Joachim; Schrenk, Dieter

    2006-01-01

    The brominated flame retardants tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are found in the environment, e.g., in sediments and organisms, in food items, human blood samples and mother's milk. In this study, the effects of both compounds on rat hepatic cytochrome P450 (CYP) leve

  9. Corrosion mechanism of 13Cr stainless steel in completion fluid of high temperature and high concentration bromine salt

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Xu, Lining, E-mail: xulining@ustb.edu.cn [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Lu, Minxu [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Meng, Yao [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Zhu, Jinyang; Zhang, Lei [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China)

    2014-09-30

    Highlights: • The corrosion behavior of 13Cr steel exposed to bromine salt completion fluid containing high concentration bromine ions was investigated. • There are passive circles around pits on the 13Cr steel surface after 7 d of exposure. • Macroscopic galvanic corrosion formed between the passive halo and the pit. • The mechanism of pitting corrosion on 13Cr stainless steel exposed to heavy bromine brine was established. - Abstract: A series of corrosion tests of 13Cr stainless steel were conducted in a simulated completion fluid environment of high temperature and high concentration bromine salt. Corrosion behavior of specimens and the component of corrosion products were investigated by means of scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The results indicate that 13Cr steel suffers from severe local corrosion and there is always a passive halo around every pit. The formation mechanism of the passive halo is established. OH{sup −} ligand generates and adsorbs in a certain scale because of abundant OH{sup −} on the surface around the pits. Passive film forms around each pit, which leads to the occurrence of passivation in a certain region. Finally, the dissimilarities in properties and morphologies of regions, namely the pit and its corresponding passive halo, can result in different corrosion sensitivities and may promote the formation of macroscopic galvanic pairs.

  10. A novel model-based approach for dose determination of glycopyrronium bromide in COPD

    Directory of Open Access Journals (Sweden)

    Arievich Helen

    2012-12-01

    Full Text Available Abstract Background Glycopyrronium bromide (NVA237 is an inhaled long-acting muscarinic antagonist in development for treatment of COPD. This study compared the efficacy and safety of once-daily (OD and twice-daily (BID glycopyrronium bromide regimens, using a novel model-based approach, in patients with moderate-to-severe COPD. Methods Double-blind, randomized, dose-finding trial with an eight-treatment, two-period, balanced incomplete block design. Patients (smoking history ≥10 pack-years, post-bronchodilator FEV1 ≥30% and 1/FVC 1 at Day 28. Results 385 patients (mean age 61.2 years; mean post-bronchodilator FEV1 53% predicted were randomized; 88.6% completed. All OD and BID dosing regimens produced dose-dependent bronchodilation; at Day 28, increases in mean trough FEV1 versus placebo were statistically significant for all regimens, ranging from 51 mL (glycopyrronium bromide 12.5 μg OD to 160 mL (glycopyrronium bromide 50 μg BID. Pharmacodynamic steady-state was reached by Day 7. There was a small separation (≤37 mL between BID and OD dose–response curves for mean trough FEV1 at steady-state in favour of BID dosing. Over 24 hours, separation between OD and BID regimens was even smaller (FEV1 AUC0-24h maximum difference for equivalent daily dose regimens: 8 mL. Dose–response results for FEV1 at 12 hours, FEV1 AUC0-12h and FEV1 AUC0-4h at steady-state showed OD regimens provided greater improvement over placebo than BID regimens for total daily doses of 25 μg, 50 μg and 100 μg, while the reverse was true for OD versus BID regimens from 12–24 hours. The 12.5 μg BID dose produced a marginally higher improvement in trough FEV1 versus placebo than 50 μg OD, however, the response at 12 hours over placebo was suboptimal (74 mL. Glycopyrronium bromide was safe and well tolerated at all doses. Conclusions Glycopyrronium bromide 50 μg OD provides significant bronchodilation over a 24 hour period

  11. Facile Synthesis of Heterocycles via 2-Picolinium Bromide and Antimicrobial Activities of the Products

    Directory of Open Access Journals (Sweden)

    Elham S. Darwish

    2008-05-01

    Full Text Available The 2-picolinium N-ylide 4, generated in situ from the N-acylmethyl-2-picolinium bromide 3, underwent cycloaddition to N-phenylmaleimide or carbon disulfideto give the corresponding cycloadducts 6 and 8, respectively similar reactions ofcompound 3 with some electron-deficient alkenes in the presence of MnO2 yielded theproducts 11 and 12. In addition, reaction of 4 with arylidene cyanothioacetamide andmalononitrile derivatives afforded the thiophene and aniline derivatives 15 and 17,respectively. Heating of picolinium bromide 3 with triethylamine in benzene furnished 2-(2-thienylindolizine (18. The structures of the isolated products were confirmed byelemental analysis as well as by 1H- and 13C-NMR, IR, and MS data. Both thestereochemistry and the regioselectivity of the studied reactions are discussed. Thebiological activity of the newly synthesized compounds was examined and showedpromising results.

  12. Indirect complexometric determination of mercury(II) using potassium bromide as selective masking agent

    International Nuclear Information System (INIS)

    A complexometric method for the determination of mercury in presence of other metal ions based on the selective masking ability of potassium bromide towards mercury is described. Mercury(II) present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated against zinc sulfate solution at pH 5-6 using xylenol orange as the indicator. A known excess of 10 % solution of potassium bromide is then added and the EDTA released from Hg-EDTA complex is titrated against standard zinc sulfate solution. Reproducible and accurate results are obtained for 8 mg to 250 mg of mercury(II) with a relative error ±0.28 % and standard deviations /leg 0.5 mg. The interference of various ions is studied. This method was applied to the determination of mercury(II) in its alloys. (author)

  13. Thermodynamic Properties of Hydrogen + Tetra-n-Butyl Ammonium Bromide Semi-Clathrate Hydrate

    Directory of Open Access Journals (Sweden)

    Shunsuke Hashimoto

    2010-01-01

    Full Text Available Thermodynamic stability and hydrogen occupancy on the hydrogen + tetra-n-butyl ammonium bromide semi-clathrate hydrate were investigated by means of Raman spectroscopic and phase equilibrium measurements under the three-phase equilibrium condition. The structure of mixed gas hydrates changes from tetragonal to another structure around 95 MPa and 292 K depending on surrounding hydrogen fugacity. The occupied amount of hydrogen in the semi-clathrate hydrate increases significantly associated with the structural transition. Tetra-n-butyl ammonium bromide semi-clathrate hydrates can absorb hydrogen molecules by a pressure-swing without destroying the hydrogen bonds of hydrate cages at 15 MPa or over.

  14. Effect of pinaverium bromide on jejunal motility and colonic transit time in healthy humans.

    Science.gov (United States)

    Bouchoucha, M; Salles, J P; Fallet, M; Frileux, P; Cugnenc, P H; Barbier, J P

    1992-01-01

    Pinaverium bromide is a specific calcium channel blocker used in the treatment of irritable bowel syndrome (IBS) for its spasmolytic activity. The aim of the present study was to evaluate the effect of orally administered pinaverium bromide on jejunal motility and total and segmental colonic transit time in control subjects. Gastrointestinal studies were performed in 10 healthy volunteers (30 +/- 3 years), before and after a treatment phase of 14 days (150 mg/d). Jejunal motility was measured by prolonged manometry (14 h) and colonic transit time by a multiple ingestion, single marker technique. No significant modification of phase III of the migrating motor complexes was demonstrated. On the contrary, a significant (p < 0.01) but weak decrease of the frequency of contraction was found. Unlike previous studies, no decrease of total or segmental colonic transit time was demonstrated. PMID:1421047

  15. Reaction of bromine and chlorine with phenolic compounds and natural organic matter extracts--Electrophilic aromatic substitution and oxidation.

    Science.gov (United States)

    Criquet, Justine; Rodriguez, Eva M; Allard, Sebastien; Wellauer, Sven; Salhi, Elisabeth; Joll, Cynthia A; von Gunten, Urs

    2015-11-15

    Phenolic compounds are known structural moieties of natural organic matter (NOM), and their reactivity is a key parameter for understanding the reactivity of NOM and the disinfection by-product formation during oxidative water treatment. In this study, species-specific and/or apparent second order rate constants and mechanisms for the reactions of bromine and chlorine have been determined for various phenolic compounds (phenol, resorcinol, catechol, hydroquinone, phloroglucinol, bisphenol A, p-hydroxybenzoic acid, gallic acid, hesperetin and tannic acid) and flavone. The reactivity of bromine with phenolic compounds is very high, with apparent second order rate constants at pH 7 in the range of 10(4) to 10(7) M(-1) s(-1). The highest value was recorded for the reaction between HOBr and the fully deprotonated resorcinol (k = 2.1 × 10(9) M(-1) s(-1)). The reactivity of phenolic compounds is enhanced by the activating character of the phenolic substituents, e.g. further hydroxyl groups. With the data set from this study, the ratio between the species-specific rate constants for the reactions of chlorine versus bromine with phenolic compounds was confirmed to be about 3000. Phenolic compounds react with bromine or chlorine either by oxidation (electron transfer, ET) or electrophilic aromatic substitution (EAS) processes. The dominant process mainly depends on the relative position of the hydroxyl substituents and the possibility of quinone formation. While phenol, p-hydroxybenzoic acid and bisphenol A undergo EAS, hydroquinone, catechol, gallic acid and tannic acid, with hydroxyl substituents in ortho or para positions, react with bromine by ET leading to quantitative formation of the corresponding quinones. Some compounds (e.g. phloroglucinol) show both partial oxidation and partial electrophilic aromatic substitution and the ratio observed for the pathways depends on the pH. For the reaction of six NOM extracts with bromine, electrophilic aromatic substitution

  16. Linear free energy relationship in reactions between diphenyl amine and benzyl bromides

    Indian Academy of Sciences (India)

    S Ranga Reddy; P Manikyamba

    2006-05-01

    Rate of reaction between benzyl bromide and diphenyl amine is retarded by electron-donating groups and enhanced by electron-withdrawing groups present on the benzene ring of the substrate. Hammett's reaction constant of the reaction decreases with increase in temperature according to the equation, \\rho = -11.92 + 3.54/ T. Minimal structural effects observed are attributed to the fact that the isokinetic temperature of the reaction is close to the reaction temperature.

  17. Comparison of injection drotaverine and injection valethamate bromide on duration and course of labor

    OpenAIRE

    Pradnya Rajendra Changede

    2016-01-01

    Background: Numerous drugs have been used to shorten the active phase of labor. How rationale is it to use these drugs to shorten the active phase of labor? Do they really shorten the duration of labor? What adverse effects do they have on the baby and the mother? These questions were the basis to perform the present study of comparing two of such drugs, injection drotaverine and injection Valethamate bromide with control subjects. Methods: This was a prospective study conducted in a terti...

  18. Mechanism of HERG potassium channel inhibition by tetra-n-octylammonium bromide and benzethonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Long, Yan; Lin, Zuoxian [Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China); Xia, Menghang; Zheng, Wei [National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892 (United States); Li, Zhiyuan, E-mail: li_zhiyuan@gibh.ac.cn [Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China)

    2013-03-01

    Tetra-n-octylammonium bromide and benzethonium chloride are synthetic quaternary ammonium salts that are widely used in hospitals and industries for the disinfection and surface treatment and as the preservative agent. Recently, the activities of HERG channel inhibition by these compounds have been found to have potential risks to induce the long QT syndrome and cardiac arrhythmia, although the mechanism of action is still elusive. This study was conducted to investigate the mechanism of HERG channel inhibition by these compounds by using whole-cell patch clamp experiments in a CHO cell line stably expressing HERG channels. Tetra-n-octylammonium bromide and benzethonium chloride exhibited concentration-dependent inhibitions of HERG channel currents with IC{sub 50} values of 4 nM and 17 nM, respectively, which were also voltage-dependent and use-dependent. Both compounds shifted the channel activation I–V curves in a hyperpolarized direction for 10–15 mV and accelerated channel activation and inactivation processes by 2-fold. In addition, tetra-n-octylammonium bromide shifted the inactivation I–V curve in a hyperpolarized direction for 24.4 mV and slowed the rate of channel deactivation by 2-fold, whereas benzethonium chloride did not. The results indicate that tetra-n-octylammonium bromide and benzethonium chloride are open-channel blockers that inhibit HERG channels in the voltage-dependent, use-dependent and state-dependent manners. - Highlights: ► Tetra-n-octylammonium and benzethonium are potent HERG channel inhibitors. ► Channel activation and inactivation processes are accelerated by the two compounds. ► Both compounds are the open-channel blockers to HERG channels. ► HERG channel inhibition by both compounds is use-, voltage- and state dependent. ► The in vivo risk of QT prolongation needs to be studied for the two compounds.

  19. Effect of Impeller Agitation on Preparation of Tetra-n-Butyl Ammonium Bromide Semiclathrate Hydrate Slurries

    OpenAIRE

    Yoshiro Inoue; Kazunari Ohgaki; Shunsuke Hashimoto; Hiroyuki Ito

    2012-01-01

    The slurries-containing tetra-n-butyl ammonium bromide (TBAB) solution and its semiclathrate hydrate have attracted a lot of interest as latent heat transport media. These hydrate slurries contain some microparticles of crystal, and the size and shape of these hydrate particles could affect the mobility of slurries. Hence, it is essential to investigate the efficient hydrate-slurry preparation methods and the effect of hydrate particles on the fluid property of slurries for the application to...

  20. Acute hepatitis after starting pinaverium bromide in a patient taking mirtazapine

    OpenAIRE

    Tak, Sandeep; Tak, Shubhanjali

    2014-01-01

    A 56-year-old man presented with chronic abdominal pain. He had been evaluated extensively in the recent past undergoing upper gastrointestinal endoscopy, colonoscopy and CT scan of the abdomen with normal results. The provisional diagnosis of irritable bowel syndrome was performed and pinaverium bromide was started. The patient had pre-existing hypertension, a major depressive disorder and gastro-oesophageal reflux disease. He had been taking nebivolol and pantoprazole for several years and ...

  1. Role of pinaverium bromide in south Indian patients with irritable bowel syndrome.

    Science.gov (United States)

    Jayanthi, V; Malathi, S; Ramathilakam, B; Dinakaran, N; Balasubramanian, V; Mathew, S

    1998-04-01

    The effect of pinaverium bromide in controlling gastrointestinal symptoms in 61 patients with irritable bowel syndrome was studied, as an open trial. Individually, there was significant relief in abdominal discomfort/pain as well as in bowel symptoms in most of the patients. Abdominal pain was reduced in 49%, stool consistency improved in 74%, straining and urgency decreased in 71% and mucus decreased in 64%. Tolerance to the drug administered was good and side-effects reported were few. PMID:11273320

  2. Tetrabutylammonium Bromide (TBABr)-Based Deep Eutectic Solvents (DESs) and Their Physical Properties

    OpenAIRE

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

    2014-01-01

    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 viscos...

  3. Tiotropium bromide in the routine care of GOLD stage II COPD patients: a pharmaeconomic evaluation

    OpenAIRE

    Orietta Zaniolo; Michela Carsi; Sergio Iannazzo

    2011-01-01

    Background: a secondary pre-specified analysis of the UPLIFT cohort demonstrated that the inclusion of tiotropium bromide in the routine care of GOLD stage II (moderate) chronic obstructive pulmonary disease (COPD) patients is associated with stronger improvements of survival, quality of life, and exacerbation rate than those shown in the total cohort; in this subgroup, tiotropium furthermore induces a significant reduction in the rate of FEV1 decline.Objective: to adapt the Spiriva® model, o...

  4. Flight Experiment to Study Double-Diffusive Instabilities in Silver-Doped Lead Bromide Crystals

    Science.gov (United States)

    Singh, N. B.; Rosch, W. R.; Suhre, D. R.; Coriell, S. R.; Duval, W. M. B.

    1999-01-01

    A detailed study on the effect of convection on crystal quality was carried out by growing lead bromide crystals in transparent Bridgman furnace. Direct observations were made on the solid-liquid interface and a new kind of instability was observed. This could be explained on the basis of toroidal flow in the AgBr-doped lead bromide sample. With the increasing translation velocity, the interface changed from flat to depressed, and then formed a cavity in the center of the growth tube. The crystal grown at the lowest thermal Rayleigh number showed the highest quality and crystal grown at the largest thermal Rayleigh number showed the worst quality. Numerical studies were carried out to provide a framework for interpreting the observed convective and morphological instabilities, and to determine the critical (limiting) concentration of dopant for a particular growth velocity and gravity level. Theoretical instability diagrams were compared with data obtained from the experimental studies. These studies provided basic data on convective behavior in doped lead bromide crystals grown by the commercially important Bridgman process.

  5. A bio-product as alternative to methyl bromide for replant disease control on strawberry

    Institute of Scientific and Technical Information of China (English)

    Yu ZHANG; Tongle HU; Lijing JI; Keqiang CAO

    2008-01-01

    Pre-plant soil fumigation with methyl bromide (MB) is a standard practice for controlling soil-borne diseases especially for strawberry diseases. However, the application of MB will be forbidden in China in the year 2015. For this reason, a bio-product named Kangdi 3 was tested as an alternative to MB in strawberry greenhouses in Mancheng (Hebei Province) and Donggang (Liaoning province), China in 2005 and 2006. Methyl bromide at a normal dosage of 500 kg/hm2 and Kangdi 3 at three dosages of 750, 1500 and 2250 kg/hm2 were tested. Plots without any treatment were used as the control. During the growing stage, assessments were made on fungal communities in rhizosphere, growth status of strawberry, the disease levels on roots as well as the yields. Results showed that Kangdi 3 significantly reduced the quantity of fungi and the disease index, while enhancing strawberry growth and the yields compared with the untreated control. Therefore, Kangdi 3 is a great potential substitute for methyl bromide to control replant diseases in strawberry.

  6. Transport of bromide measured by soil coring, suction plates, and lysimeters under transient flow conditions.

    Science.gov (United States)

    Kasteel, R.; Pütz, Th.; Vereecken, H.

    2003-04-01

    Lysimeter studies are one step within the registration procedure of pesticides. Flow and transport in these free-draining lysimeters do not reflect the field situation mainly because of the occurence of a zone of local saturation at the lower boundary (seepage face). The objective of this study is to evaluate the impact of flow and transport behaviour of bromide detected with different measuring devices (lysimeters, suction plates, and soil coring) by comparing experimental results with numerical simulations in heterogeneous flow domains. We applied bromide as a small pulse to the bare soil surface (Orthic Luvisol) of the three devices and the displacement of bromide was regurlarly sampled for three years under natural wheather conditions. Based on the mean breakthrough curves we observe experimentally that lysimeters have a lower effective pore-water velocity and exhibit more solute spreading resulting in a larger dispersivity than the suction plates. This can be ascribed to the artefact of the lower boundary. We performed numerical transport simulations in 2-D heterogeneous flow fields (scaling approach) choosing appropriate boundary conditions for the various devices. The simulations allow to follow the temporal evolution of flow and transport processes in the various devices and to gain additional process understanding. We conclude that the model is essentially capable to reproduce the main experimental findings only if we account for the spatial correlation structure of the hydraulic properties, i.e. soil heterogeneity.

  7. Recent trends in atmospheric methyl bromide: analysis of post-Montreal Protocol variability

    Directory of Open Access Journals (Sweden)

    S. A. Yvon-Lewis

    2009-03-01

    Full Text Available The atmospheric methyl bromide (CH3Br burden has declined in recent years, in response to the phaseout of agricultural and structural fumigation consumption under the amendments to the Montreal Protocol. The timing and magnitude of this decrease represents an opportunity to examine our current understanding of the CH3Br budget, the phaseout schedule, and recent estimates of interannual variability in biomass burning and global OH. In this study, simulations obtained from a time-dependent global model of atmospheric CH3Br emissions and uptake are compared to observations from the NOAA flask network. The model includes an updated global methyl bromide source inventory that includes biofuel combustion emissions estimated at 6.1±3 Gg yr−1 globally. The phaseout of CH3Br production for agricultural uses began in 1998, concurrent with the pulse in biomass burning associated with the 1998 El Niño. The combined effects of three factors (biomass burning, global OH, and anthropogenic phaseout appear to explain most of the observed atmospheric methyl bromide trend over the 1997–2005 period. The global budget remains imbalanced, with a large missing source. These results suggest that more than 80% of the missing source does not exhibit significant interannual variability during the phaseout period and, therefore, does not result from underestimating agricultural CH3Br emissions.

  8. Replacing methyl bromide in annual strawberry production with glucosinolate-containing green manure crops.

    Science.gov (United States)

    Lazzeri, Luca; Baruzzi, Gianluca; Malaguti, Lorena; Antoniacci, Loredana

    2003-09-01

    The use of biocidal green manure crops is an agronomic technique for amending soil with fresh organic matter containing volatile compounds active in controlling some soil-borne pests and diseases. Two new selections of the Brassicaceae family were cultivated, incorporated before planting strawberries and tested as an alternative to fumigation with methyl bromide. Two biocidal green manure crops (Brassica juncea L sel ISCI20, Eruca sativa Mill cv Nemat) containing glucosinolate-myrosinase systems, a conventional green manure (barley), untreated soil and a fumigated control were evaluated during two seasons. The effect of these soil management systems on subsequent strawberry performance was evaluated by monitoring yield and plant growth parameters. In both years, biocidal plant green manure treatments led to a fruit yield lower than with methyl bromide, but higher than with conventional green manure or untreated soil. These results confirm the good prospects for biocidal green manures, not only as an environmentally friendly alternative to methyl bromide in conventional agriculture, but also in organic agriculture as an alternative to conventional green manure crops.

  9. Effects of oral pinaverium bromide on colonic response to food in irritable bowel syndrome patients.

    Science.gov (United States)

    Bouchoucha, M; Faye, A; Devroede, G; Arsac, M

    2000-08-01

    We have recently developed a simple method to investigate the colonic response to food (CRF). This study describes the modifications of CRF induced by treatment with oral pinaverium bromide in irritable bowel syndrome (IBS) patients. Thirty healthy subjects and 43 patients suffering from IBS were studied. Colonic transit time (CTT) was measured in fasting conditions and after eating a standard test meal. Colonic response to food was quantified by calculating the variation in number of markers in each zone of interest of the large bowel between the X-ray films of the abdomen taken before and after eating. CRF is characterized by caudal propulsion of colonic contents in the two groups. In controls, there is emptying of the caecum-ascending colon region and filling of the rectosigmoid. In IBS patients, only the left transverse colon and the splenic flexure empty. Pinaverium bromide exerts no effect in controls but reverses the CRF of the right colon in IBS patients by inhibiting right colon emptying. These results suggest that the inhibitory action of pinaverium bromide on CRF may support the clinical efficacy of this calcium channel blocker in the treatment of IBS. PMID:10989977

  10. Inhibition of the colonic motor response to eating by pinaverium bromide in irritable bowel syndrome patients.

    Science.gov (United States)

    Fioramonti, J; Frexinos, J; Staumont, G; Bueno, L

    1988-01-01

    The effect of pinaverium bromide on the colonic motor response to eating was investigated in 10 irritable bowel syndrome patients, by means of an intraluminal probe supporting 8 groups of electrodes. At each site examined from transverse to sigmoid colon, the electromyograms exhibited 2 kinds of spike bursts: short spike bursts (SSB) localized at one electrode, and long spike bursts (LSB), isolated, propagated orally or aborally over a few centimeters, or aborally propagated over the whole length of the colon investigated (migrating long spike bursts, MLSB). Recordings were continuously performed over 24 hr. Each patient received at 7.00 p.m. on day 1 and at noon on day 2 an 800-1000 Kcal meal preceded by IV administration of pinaverium bromide (4 mg) or placebo. After placebo administration, the duration of LSB activity and the number of MLSB were significantly increased over 3 postprandial hr by comparison with the 2 hr preceding the meal. After pinaverium injection no significant postprandial change in LSB and MLSB activity was noted. The SSB activity was not modified after the meals preceded by placebo or pinaverium injection. These results suggest that the inhibitory action of pinaverium bromide on postprandial colonic motility may support the clinical efficacy of this agent in the treatment of the irritable bowel syndrome. PMID:3371838

  11. The Effect of Ozonation Process on Bromide-Containing Groundwaters in Bandung Area and Its Surroundings

    Directory of Open Access Journals (Sweden)

    Mindriany Syafila

    2012-11-01

    Full Text Available Disinfection process was applied as the last step of the water treatment to kill pathogenic bacteria in the water. However, according to several studies, the ozonation disinfection process could form undesired by-products. One of the by-products potentially affecting human life is bromate produced from bromide ionic-containing water. This study was carried out to examine the effect of raw water characteristics and pH on bromate formation. Also, the performance of bromate formation for a period of exposure time was analyzed. Raw waters taken from four different areas around Bandung were exposed to ozone introduced to a reactor with a flow rate of 2 L/min. The pH of the raw waters varied from 4, 7 to 10. The results show that there was no evidence of an initial bromide ion concentration, whereas a change in pH value gives a significantly different outcome. In acidic condition (pH of 4 the bromate formation tends to decrease, whereas when the pH value increases to a pH of 10, the bromate formation increases. Therefore, for drinking water with a neutral pH, when bromide ions are detected in the raw water, the drinking water may be toxic due to the presence of bromate.

  12. Detection of water contamination from hydraulic fracturing wastewater: a μPAD for bromide analysis in natural waters.

    Science.gov (United States)

    Loh, Leslie J; Bandara, Gayan C; Weber, Genevieve L; Remcho, Vincent T

    2015-08-21

    Due to the rapid expansion in hydraulic fracturing (fracking), there is a need for robust, portable and specific water analysis techniques. Early detection of contamination is crucial for the prevention of lasting environmental damage. Bromide can potentially function as an early indicator of water contamination by fracking waste, because there is a high concentration of bromide ions in fracking wastewaters. To facilitate this, a microfluidic paper-based analytical device (μPAD) has been developed and optimized for the quantitative colorimetric detection of bromide in water using a smartphone. A paper microfluidic platform offers the advantages of inexpensive fabrication, elimination of unstable wet reagents, portability and high adaptability for widespread distribution. These features make this assay an attractive option for a new field test for on-site determination of bromide. PMID:26161586

  13. Efficient ring-closing metathesis of alkenyl bromides: the importance of protecting the catalyst during the olefin approach.

    Science.gov (United States)

    Gatti, Michele; Drinkel, Emma; Wu, Linglin; Pusterla, Ivano; Gaggia, Fiona; Dorta, Reto

    2010-11-01

    We present the first productive ring-closing metathesis reaction that leads to the construction of cyclic alkenyl bromides. Efficient catalysis employing commercially available Grubbs II catalyst is possible through appropriate modification of the starting bromoalkene moiety.

  14. Investigating the lifetime of bromine-quenched G.M. Counters with temperature

    Science.gov (United States)

    Abilama, Marc; Bates, Mike; Lohstroh, Annika

    2015-09-01

    The amount of halogen quench gas as a percentage of the total fill gas contained within a gas-filled Geiger-Müller detector is directly linked to its operational characteristics. Preserving this halogen gas will help maintain the operating lifetime of the detectors. Such halogen gases are highly corrosive and the small quantities within a gas-filled detector can deplete rapidly via interactions with surrounding materials. The rate of interactions is thought to be proportional to not only temperature, but also to the current initiated by ionisation events associated with the formation of each signal pulse. As all pulses are of similar magnitudes, GM detector operational lifetimes are quantified in accumulated counts rather than a given operating time. We have studied three different types of corrosion-resistant mechanisms to protect the bromine halogen gas from any interactions with 446 stainless steel detector components of ZP1200 Geiger-Müller tubes at temperatures up to 125 °C. Three types of surface treatments for these detectors used were labelled as "raw" using only an oxygen-plasma-bombardment process, "passivated" using a combination of nitric acid passivation followed by an oxygen plasma-bombardment process, and thirdly plating with a few micron thickness of chromium followed by an oxygen plasma-bombardment process. 32 detector samples were irradiated at room temperature with a Caesium-137 source at dose rates of approximately 1.3 mSv/hr up to 5.7×1010 accumulated counts; another 32 detector samples were aged to 3.3×1010 counts at 125 °C. At room temperature, the chromium-plated samples exhibited an initial rise in their starting voltage readings. All other detector performance characteristics, for all detector types, did not change significantly during the ageing process, and the surface morphology of the detector cathodes was unaffected. At 125 °C, the chromium-based plating produced the most stable long-term response. These chromium-plated samples

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

    Directory of Open Access Journals (Sweden)

    S. Coburn

    2015-10-01

    Full Text Available The elevated deposition of atmospheric mercury over the Southeastern United States is currently not well understood. Here we measure partial columns and vertical profiles of bromine monoxide (BrO radicals, a key component of mercury oxidation chemistry, to better understand the processes and altitudes at which mercury is being oxidized in the atmosphere. We use the data from a ground-based MAX-DOAS instrument located at a coastal site ~ 1 km from the Gulf of Mexico in Gulf Breeze, FL, where we had previously detected tropospheric BrO (Coburn et al., 2011. Our profile retrieval assimilates information about stratospheric BrO from the WACCM chemical transport model, and uses only measurements at moderately low solar zenith angles (SZA to estimate the BrO slant column density contained in the reference spectrum (SCDRef. The approach has 2.6 degrees of freedom, and avoids spectroscopic complications that arise at high SZA; knowledge about SCDRef helps to maximize sensitivity in the free troposphere (FT. A cloud-free case study day with low aerosol load (9 April 2010 provided optimal conditions for distinguishing marine boundary layer (MBL: 0–1 km and free tropospheric (FT: 1–15 km BrO from the ground. The average daytime tropospheric BrO vertical column density (VCD of ~ 2.3 × 1013 molec cm−2 (SZA 5 molec cm−2 s−1 for bromine, while contributions from ozone (O3 and chlorine (Cl were 0.9 × 105 and 0.2 × 105 molec cm−2 s−1, respectively. The GOM formation rate is sensitive to recently proposed atmospheric scavenging reactions of the HgBr adduct by nitrogen dioxide (NO2, and to a lesser extent also HO2 radicals. Using a 3-D chemical transport model, we find that surface GOM variations are typical also of other days, and are mainly derived from the free troposphere. Bromine chemistry is active in the FT over Gulf Breeze, where it forms water-soluble GOM that is subsequently available for wet scavenging by thunderstorms or transport to

  16. Bromine release during Plinian eruptions along the Central American Volcanic Arc

    Science.gov (United States)

    Hansteen, T. H.; Kutterolf, S.; Appel, K.; Freundt, A.; Perez-Fernandez, W.; Wehrmann, H.

    2010-12-01

    Volcanoes of the Central American Volcanic Arc (CAVA) have produced at least 72 highly explosive eruptions within the last 200 ka. The eruption columns of all these “Plinian” eruptions reached well into the stratosphere such that their released volatiles may have influenced atmospheric chemistry and climate. While previous research has focussed on the sulfur and chlorine emissions during such large eruptions, we here present measurements of the heavy halogen bromine by means of synchrotron radiation induced micro-XRF microanalysis (SR-XRF) with typical detection limits at 0.3 ppm (in Fe rich standard basalt ML3B glass). Spot analyses of pre-eruptive glass inclusions trapped in minerals formed in magma reservoirs were compared with those in matrix glasses of the tephras, which represent the post-eruptive, degassed concentrations. The concentration difference between inclusions and matrix glasses, multiplied by erupted magma mass determined by extensive field mapping, yields estimates of the degassed mass of bromine. Br is probably hundreds of times more effective in destroying ozone than Cl, and can accumulate in the stratosphere over significant time scales. Melt inclusions representing deposits of 22 large eruptions along the CAVA have Br contents between 0.5 and 13 ppm. Br concentrations in matrix glasses are nearly constant at 0.4 to 1.5 ppm. However, Br concentrations and Cl/Br ratios vary along the CAVA. The highest values of Br contents (>8 ppm) and lowest Cl/Br ratios (170 to 600) in melt inclusions occur across central Nicaragua and southern El Salvador, and correlate with bulk-rock compositions of high Ba/La > 85 as well as low La/Yb discharged 700 kilotons of Br. On average, each of the remaining 21 CAVA eruptions studied have discharged c.100 kilotons of bromine. During the past 200 ka, CAVA volcanoes have emitted a cumulative mass of 3.2 Mt of Br through highly explosive eruptions. There are six periods in the past (c. 2ka, 6ka, 25ka, 40ka, 60ka, 75

  17. Molecular simulations and density functional theory calculations of bromine in clathrate hydrate phases

    Energy Technology Data Exchange (ETDEWEB)

    Dureckova, Hana, E-mail: houci059@uottawa.ca; Woo, Tom K., E-mail: tom.woo@uottawa.ca [Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 5N6 (Canada); Alavi, Saman, E-mail: saman.alavi@nrc-cnrc.gc.ca [Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 5N6 (Canada); National Research Council of Canada, 100 Sussex Dr., Ottawa, Ontario K1N 6N5 (Canada); Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3 (Canada)

    2016-01-28

    Bromine forms a tetragonal clathrate hydrate structure (TS-I) very rarely observed in clathrate hydrates of other guest substances. The detailed structure, energetics, and dynamics of Br{sub 2} and Cl{sub 2} in TS-I and cubic structure I (CS-I) clathrate hydrates are studied in this work using molecular dynamics and quantum chemical calculations. X-ray diffraction studies show that the halogen-water–oxygen distances in the cages of these structures are shorter than the sum of the van der Waals radii of halogen and oxygen atoms. This suggests that the stabilizing effects of halogen bonding or other non-covalent interactions (NCIs) may contribute to the formation of the unique tetragonal bromine hydrate structure. We performed molecular dynamics simulations of Br{sub 2} and Cl{sub 2} clathrate hydrates using our previously developed five-site charge models for the dihalogen molecules [Dureckova et al. Can. J. Chem. 93, 864 (2015)] which reproduce the computed electrostatic potentials of the dihalogens and account for the electropositive σ-hole of the halogen bond donor (the dihalogen). Analysis of the radial distribution functions, enthalpies of encapsulation, velocity and orientation autocorrelation functions, and polar angle distributions are carried out for Br{sub 2} and Cl{sub 2} guests in various cages to contrast the properties of these guests in the TS-I and CS-I phases. Quantum chemical partial geometry optimizations of Br{sub 2} and Cl{sub 2} guests in the hydrate cages using the M06-2X functional give short halogen-water distances compatible with values observed in X-ray diffraction experiments. NCI plots of guest-cage structures are generated to qualitatively show the relative strength of the non-bonding interactions between dihalogens and water molecules. The differences between behaviors of Br{sub 2} and Cl{sub 2} guests in the hydrate cages may explain why bromine forms the unique TS-I phase.

  18. Seasonal variation of bromine monoxide over the Rann of Kutch salt marsh seen from space

    Science.gov (United States)

    Hörmann, Christoph; Beirle, Steffen; Penning de Vries, Marloes; Sihler, Holger; Platt, Ulrich; Wagner, Thomas

    2015-04-01

    Bromine monoxide (BrO) is an important catalyst in the depletion of tropospheric and stratospheric ozone (O3). In the troposphere, reactive bromine can be released from sea ice, volcanoes, sea-salt aerosol or salt lakes. For all of these natural sources enhanced BrO vertical column densities (VCDs) have been successfully observed from ground using Differential Optical Absorption Spectroscopy (DOAS). Until now, satellite observations were only reported for polar regions during springtime and volcanic emissions (mostly for major eruptions). We present the first satellite observations of enhanced monthly mean BrO VCDs over a salt marsh, the Rann of Kutch (India/Pakistan), during 2004-2014 as seen by the Ozone Monitoring Instrument (OMI). The Rann of Kutch is a so-called 'seasonal' salt marsh. During India's summer monsoon (June/July - September/October), the flat desert of salty clay and mudflats, which average 15 meters above sea level, fills with standing rain and sea water. With more than 7500 km2 it is the largest salt desert in the world and additionally one of the hottest areas of India with summer temperatures around 50 ° C and winter temperatures decreasing below 0 ° C. Probably due to these rather extreme conditions, the Rann of Kutch has not been yet investigated for atmospheric composition measurements by ground-based instruments. Satellite observations, however, provide the unique possibility to investigate the entire area remotely over a long-time period. The OMI data reveals recurring maximum BrO VCDs during April/May, but no enhanced column densities during the monsoon season while the area is flooded. In the following months the signal only recovers slowly while the salty surface dries up. We discuss the possible effects of temperature, precipitation and relative humidity on the release of enhanced reactive bromine concentrations. In order to investigate a possible diurnal cycle of the BrO concentration, the OMI results (at a local overflight time

  19. Investigating the lifetime of bromine-quenched G.M. Counters with temperature

    Energy Technology Data Exchange (ETDEWEB)

    Abilama, Marc [Centronic Ltd., Croydon (United Kingdom); University of Surrey, Guildford (United Kingdom); Bates, Mike [Centronic Ltd., Croydon (United Kingdom); Lohstroh, Annika [University of Surrey, Guildford (United Kingdom)

    2015-09-21

    The amount of halogen quench gas as a percentage of the total fill gas contained within a gas-filled Geiger–Müller detector is directly linked to its operational characteristics. Preserving this halogen gas will help maintain the operating lifetime of the detectors. Such halogen gases are highly corrosive and the small quantities within a gas-filled detector can deplete rapidly via interactions with surrounding materials. The rate of interactions is thought to be proportional to not only temperature, but also to the current initiated by ionisation events associated with the formation of each signal pulse. As all pulses are of similar magnitudes, GM detector operational lifetimes are quantified in accumulated counts rather than a given operating time. We have studied three different types of corrosion-resistant mechanisms to protect the bromine halogen gas from any interactions with 446 stainless steel detector components of ZP1200 Geiger–Müller tubes at temperatures up to 125 °C. Three types of surface treatments for these detectors used were labelled as “raw” using only an oxygen-plasma-bombardment process, “passivated” using a combination of nitric acid passivation followed by an oxygen plasma-bombardment process, and thirdly plating with a few micron thickness of chromium followed by an oxygen plasma-bombardment process. 32 detector samples were irradiated at room temperature with a Caesium-137 source at dose rates of approximately 1.3 mSv/hr up to 5.7×10{sup 10} accumulated counts; another 32 detector samples were aged to 3.3×10{sup 10} counts at 125 °C. At room temperature, the chromium-plated samples exhibited an initial rise in their starting voltage readings. All other detector performance characteristics, for all detector types, did not change significantly during the ageing process, and the surface morphology of the detector cathodes was unaffected. At 125 °C, the chromium-based plating produced the most stable long-term response. These

  20. Prostate cancer and toxicity from critical use exemptions of methyl bromide: Environmental protection helps protect against human health risks

    Directory of Open Access Journals (Sweden)

    Budnik Lygia T

    2012-01-01

    Full Text Available Abstract Background Although ozone-depleting methyl bromide was destined for phase-out by 2005, it is still widely applied as a consequence of various critical-use-exemptions and mandatory international regulations aiming to restrict the spread of pests and alien species (e.g. in globalized transport and storage. The withdrawal of methyl bromide because of its environmental risk could fortuitously help in the containment of its human toxicity. Methods We performed a systematic review of the literature, including in vitro toxicological and epidemiological studies of occupational and community exposure to the halogenated hydrocarbon pesticide methyl bromide. We focused on toxic (especially chronic or carcinogenic effects from the use of methyl bromide, on biomonitoring data and reference values. Eligible epidemiological studies were subjected to meta-analysis. Results Out of the 542 peer reviewed publications between 1990-2011, we found only 91 referring to toxicity of methyl bromide and 29 using the term "carcinogenic", "neoplastic" or "mutagenic". Several studies provide new additional data pertaining to the mechanistic aspects of methyl bromide toxicity. Few studies have performed a detailed exposure assessment including biomonitoring. Three evaluated epidemiological studies assessed a possible association between cancer and methyl bromide. Overall, exposure to methyl bromide is associated with an increased risk of prostate cancer OR, 1.21; 95% CI (0,98-1.49, P = 0.076. Two epidemiological studies have analyzed environmental, non-occupational exposure to methyl bromide providing evidence for its health risk to the general public. None of the epidemiological studies addressed its use as a fumigant in freight containers, although recent field and case reports do refer to its toxic effects associated with its use in shipping and storage. Conclusions Both the epidemiological evidence and toxicological data suggest a possible link between methyl

  1. Air-snowpack exchange of bromine, ozone and mercury in the springtime Arctic simulated by the 1-D model PHANTAS - Part 1: In-snow bromine activation and its impact on ozone

    Science.gov (United States)

    Toyota, K.; McConnell, J. C.; Staebler, R. M.; Dastoor, A. P.

    2014-04-01

    To provide a theoretical framework towards a better understanding of ozone depletion events (ODEs) and atmospheric mercury depletion events (AMDEs) in the polar boundary layer, we have developed a one-dimensional model that simulates multiphase chemistry and transport of trace constituents from porous snowpack and through the atmospheric boundary layer (ABL) as a unified system. This paper constitutes Part 1 of the study, describing a general configuration of the model and the results of simulations related to reactive bromine release from the snowpack and ODEs during the Arctic spring. A common set of aqueous-phase reactions describes chemistry both within the liquid-like layer (LLL) on the grain surface of the snowpack and within deliquesced "haze" aerosols mainly composed of sulfate in the atmosphere. Gas-phase reactions are also represented by the same mechanism in the atmosphere and in the snowpack interstitial air (SIA). Consequently, the model attains the capacity of simulating interactions between chemistry and mass transfer that become particularly intricate near the interface between the atmosphere and the snowpack. In the SIA, reactive uptake on LLL-coated snow grains and vertical mass transfer act simultaneously on gaseous HOBr, a fraction of which enters from the atmosphere while another fraction is formed via gas-phase chemistry in the SIA itself. A "bromine explosion", by which HOBr formed in the ambient air is deposited and then converted heterogeneously to Br2, is found to be a dominant process of reactive bromine formation in the top 1 mm layer of the snowpack. Deeper in the snowpack, HOBr formed within the SIA leads to an in-snow bromine explosion, but a significant fraction of Br2 is also produced via aqueous radical chemistry in the LLL on the surface of the snow grains. These top- and deeper-layer productions of Br2 both contribute to the release of Br2 to the atmosphere, but the deeper-layer production is found to be more important for the

  2. Air-snowpack exchange of bromine, ozone and mercury in the springtime Arctic simulated by the 1-D model PHANTAS – Part 1: In-snow bromine activation and its impact on ozone

    Directory of Open Access Journals (Sweden)

    K. Toyota

    2013-08-01

    Full Text Available To provide a theoretical framework towards better understanding of ozone depletion events (ODEs and atmospheric mercury depletion events (AMDEs in the polar boundary layer, we have developed a one-dimensional model that simulates multiphase chemistry and transport of trace constituents from porous snowpack and through the atmospheric boundary layer (ABL as a unified system. In this paper, we describe a general configuration of the model and the results of simulations related to reactive bromine release from the snowpack and ODEs during the Arctic spring. The model employs a chemical mechanism adapted from the one previously used for the simulation of multiphase halogen chemistry involving deliquesced sea-salt aerosols in the marine boundary layer. A common set of aqueous-phase reactions describe chemistry both in the liquid-like (or brine layer on the grain surface of the snowpack and in "haze" aerosols mainly composed of sulfate in the atmosphere. The process of highly soluble/reactive trace gases, whether entering the snowpack from the atmosphere or formed via gas-phase chemistry in the snowpack interstitial air (SIA, is simulated by the uptake on brine-covered snow grains and subsequent reactions in the aqueous phase while being traveled vertically within the SIA. A "bromine explosion", by which, in a conventional definition, HOBr formed in the ambient air is deposited and then converted heterogeneously to Br2, is a dominant process of reactive bromine formation in the top 1 mm (or less layer of the snowpack. Deeper in the snowpack, HOBr formed within the SIA leads to an in-snow bromine explosion, but a significant fraction of Br2 is also produced via aqueous radical chemistry in the brine on the surface of the snow grains. These top- and deeper-layer productions of Br2 both contribute to the Br2 release into the atmosphere, but the deeper-layer production is found to be more important for the net outflux of reactive bromine. Although ozone

  3. Comparison of pinaverium bromide, manganese chloride and D600 effects on electrical and mechanical activities in rat uterine smooth muscle.

    Science.gov (United States)

    Mironneau, J; Lalanne, C; Mironneau, C; Savineau, J P; Lavie, J L

    1984-02-10

    The effects of pinaverium bromide, were compared with those of D600 and manganese chloride (Mn), on membrane potentials, ionic currents and isometric contractions in uterine smooth muscle strips from pregnant rats. Pinaverium bromide (10(-7) - 10(-6) M) depressed twitch contractions and K-contractures within 15-20 min while D600 (2 X 10(-6) M) and Mn (10(-3) M) abolished both contractions. D600 and pinaverium bromide were more potent inhibitors in K-depolarized preparations than in polarized tissues. At a supramaximal dose (10(-5) M), pinaverium bromide decreased the rate of rise, amplitude, and rate of repolarization of the action potential, and prolonged the potential duration. The inward Ca current was depressed and the reduction in Cai was responsible for the decrease in K current. Pinaverium bromide (10(-5) M) depressed the myometrial contractions induced in Ca-free solution by acetylcholine (10(-4) M) and by prolonged membrane depolarizations. Mn (2.5 X 10(-3) M) only reduced the Ach-induced contraction and D600 (10(-5) M) had no effect on intracellular Ca stores. The results indicate that pinaverium bromide has Ca channel blocking properties similar to those of currently used Ca antagonists; it may also exert an effect to depress contractions supported by intracellular Ca release. PMID:6325214

  4. Brominated flame retardants and organochlorine compounds in duplicate diet samples from a Portuguese academic community.

    Science.gov (United States)

    Coelho, Sónia D; Sousa, Ana C A; Isobe, Tomohiko; Kunisue, Tatsuya; Nogueira, António J A; Tanabe, Shinsuke

    2016-10-01

    Concentrations of persistent organic pollutants (POPs), including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), polychlorinated biphenyls (PCBs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), chlordane compounds (CHLs) and dichlorodiphenyltrichloroethane and its metabolites (DDTs), were measured in duplicate diet samples from 21 volunteers at a Portuguese academic community (University of Aveiro). Overall, the levels of the target compounds were low, with detection frequencies varying widely depending on the compounds and with brominated flame retardants (BFRs) registering the lowest detection frequencies. Among PCB congeners, nondioxin-like PCBs were predominant and detected in the majority of the samples. Organochlorine pesticides were also detected in the majority of the samples, with 100% detection for DDTs and HCHs. Estimated daily intakes (EDIs) were calculated using lower and upper bound estimations, and in both cases values were far below the currently established tolerable daily intakes for PCBs and OCs and the reference doses for PBDEs and HBCDDs. PMID:27367176

  5. Kinetics and mechanism of the oxidation of some -hydroxy acids by hexamethylenetetramine-bromine

    Indian Academy of Sciences (India)

    Dimple Garg; Seema Kothari

    2004-11-01

    The oxidation of lactic acid, mandelic acid and ten monosubstituted mandelic acids by hexamethylenetetramine-bromine (HABR) in glacial acetic acid, leads to the formation of the corresponding oxoacid. The reaction is first order with respect to each of the hydroxy acids and HABR. It is proposed that HABR itself is the reactive oxidizing species. The oxidation of -deuteriomandelic acid exhibits the presence of a substantial kinetic isotope effect (/ = 5.91 at 298 K). The rates of oxidation of the substituted mandelic acids show excellent correlation with Brown’s + values. The reaction constants are negative. The oxidation exhibits an extensive cross conjugation between the electron-donating substituent and the reaction centre in the transition state. A mechanism involving transfer of a hydride ion from the acid to the oxidant is postulated.

  6. Short-lived brominated hydrocarbons – observations in the source regions and the tropical tropopause layer

    Directory of Open Access Journals (Sweden)

    S. Brinckmann

    2012-02-01

    Full Text Available We conducted measurements of the five important short-lived organic bromine species in the marine boundary layer (MBL. Measurements were made in the Northern Hemisphere mid-latitudes (Sylt Island, North Sea in June 2009 and in the tropical Western Pacific during the TransBrom ship campaign in October 2009. For the one-week time series on Sylt Island, mean mixing ratios of CHBr3, CH2Br2, CHBr2Cl and CH2BrCl were 2.0, 1.1, 0.2, 0.1 ppt, respectively. We found maxima of 5.8 and 1.6 ppt for the two main components CHBr3 and CH2Br2. Along the cruise track in the Western Pacific (between 41° N and 13° S we measured mean mixing ratios of 0.9, 0.9, 0.2, 0.1 and 0.1 ppt for CHBr3, CH2Br2, CHBrCl2, CHBr2Cl and CH2BrCl. Air samples with coastal influence showed considerably higher mixing ratios than the samples with open ocean origin. Correlation analyses of the two data sets yielded strong linear relationships between the mixing ratios of four of the five species (except for CH2BrCl. Using a combined data set from the two campaigns and a comparison with the results from two former studies, rough estimates of the molar emission ratios between the correlated substances were: 9/1/0.35/0.35 for CHBr3/CH2Br2/CHBrCl2/CHBr2Cl. Additional measurements were made in the tropical tropopause layer (TTL above Teresina (Brazil, 5° S in June 2008, using balloon-borne cryogenic whole air sampling technique. Near the level of zero clear-sky net radiative heating (LZRH at 14.8 km about 2.25 ppt organic bromine was bound to the five short-lived species, making up 13% of total organic bromine (17.82 ppt. CH2Br2 (1.45 ppt and CHBr3 (0.56 ppt accounted for 90% of the budget of short-lived compounds in that region. Near the

  7. Responses of marine unicellular algae to brominated organic compounds in six growth media

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, G.E.; Yoder, M.J.; McLaughlin, L.L.; Lores, E.M.

    1987-12-01

    Marine unicellular algae, Skeletonema costatum, Thalassiosira pseudonana, and Chlorella sp. were exposed to the industrial brominated compounds tetrabromobisphenol A, decabromobiphenyloxide (DBBO), hexabromocyclododecane (HBCD), pentabromomethylbenzene (PBMB), pentabromoethylbenzene (PBEB), and the herbicide bromoxynil (BROM), in six algal growth media. High concentrations of DBBO (1 mg liter-1), PBMB (1 mg liter-1), and PBEB (0.5 mg liter-1) reduced growth by less than 50%. EC50s of the other compounds varied with growth medium, with high EC50/low EC50 ratios between 1.3 and 9.9. Lowest EC50s, 9.3 to 12.0 micrograms liter-1, were obtained with S. costatum and HBCD. It is concluded that responses to toxicants in different media are the results of interactions among algae, growth medium, toxicant, and solvent carrier.

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

    Science.gov (United States)

    Coburn, Sean; Dix, Barbara; Edgerton, Eric; Holmes, Christopher D.; Kinnison, Douglas; Liang, Qing; ter Schure, Arnout; Wang, Siyuan; Volkamer, Rainer

    2016-03-01

    The elevated deposition of atmospheric mercury over the southeastern United States is currently not well understood. Here we measure partial columns and vertical profiles of bromine monoxide (BrO) radicals, a key component of mercury oxidation chemistry, to better understand the processes and altitudes at which mercury is being oxidized in the atmosphere. We use data from a ground-based MAX-DOAS instrument located at a coastal site ˜ 1 km from the Gulf of Mexico in Gulf Breeze, FL, where we had previously detected tropospheric BrO (Coburn et al., 2011). Our profile retrieval assimilates information about stratospheric BrO from the WACCM chemical transport model (CTM), and uses only measurements at moderately low solar zenith angles (SZAs) to estimate the BrO slant column density contained in the reference spectrum (SCDRef). The approach has 2.6 degrees of freedom, and avoids spectroscopic complications that arise at high SZA; knowledge about SCDRef further helps to maximize sensitivity in the free troposphere (FT). A cloud-free case study day with low aerosol load (9 April 2010) provided optimal conditions for distinguishing marine boundary layer (MBL: 0-1 km) and free-tropospheric (FT: 1-15 km) BrO from the ground. The average daytime tropospheric BrO vertical column density (VCD) of ˜ 2.3 × 1013 molec cm-2 (SZA < 70°) is consistent with our earlier reports on other days. The vertical profile locates essentially all tropospheric BrO above 4 km, and shows no evidence for BrO inside the MBL (detection limit < 0.5 pptv). BrO increases to ˜ 3.5 pptv at 10-15 km altitude, consistent with recent aircraft observations. Our case study day is consistent with recent aircraft studies, in that the oxidation of gaseous elemental mercury (GEM) by bromine radicals to form gaseous oxidized mercury (GOM) is the dominant pathway for GEM oxidation throughout the troposphere above Gulf Breeze. The column integral oxidation rates are about 3.6 × 105 molec cm-2 s-1 for bromine

  9. Bioactive brominated diterpenes from the marine red alga Jania Rubens (L.) Lamx.

    Science.gov (United States)

    Awad, Nagwa E

    2004-04-01

    Seven brominated diterpenes of the parguerene and isoparguerene series were isolated for the first time from the red alga Jania rubens (L.) Lamx., collected from the Red Sea coast at Hurghada, Egypt. The diterpenes were identified as isoparguerol (1), isoparguerol-16-acetate (2), isoparguerol-7,16-diacetate (3), parguerol-16-acetate (4), parguerol-7,16-diacetate (5), deoxyparguerol (6) and deoxyparguerol-7-acetate (7). The isolated diterpenes had a marked antitumour activity. Isoparguerol derivatives were slightly more effective than parguerol derivatives. Moreover, the data implied that the cytotoxicity of these compounds were dependent on the number of acetoxy groups. Also, anthelmintic activities of the isolated compounds on earthworms (Allolobophora caliginosa) were studied. PMID:15162360

  10. Thinning of CIGS solar cells: Part I: Chemical processing in acidic bromine solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bouttemy, M.; Tran-Van, P. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Gerard, I., E-mail: gerard@chimie.uvsq.fr [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Hildebrandt, T.; Causier, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Pelouard, J.L.; Dagher, G. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Jehl, Z.; Naghavi, N. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Voorwinden, G.; Dimmler, B. [Wuerth Elektronik Research GmbH, Industriestr. 4, 70565 Stuttgart (Germany); Powalla, M. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW), Industriestr. 6, 70565 Stuttgart (Germany); Guillemoles, J.F. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Lincot, D. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Etcheberry, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France)

    2011-08-31

    CIGSe absorber was etched in HBr/Br{sub 2}/H{sub 2}O to prepare defined thicknesses of CIGSe between 2.7 and 0.5 {mu}m. We established a reproducible method of reducing the absorber thickness via chemical etching. We determine the dissolution kinetics rate of CIGSe using trace analysis by graphite furnace atomic absorption spectrometry of Ga and Cu. The roughness of the etching surface decreases during the first 500 nm of the etching to a steady state value of the root-mean-square roughness near 50 nm. X-ray photoelectron spectroscopy analyses demonstrate an etching process occurring with a constant chemical composition of the treated surface acidic bromine solutions provide a controlled chemical thinning process resulting in an almost flat surface and a very low superficial Se{sup 0} enrichment.

  11. Surface-confined 2D polymerization of a brominated copper-tetraphenylporphyrin on Au(111)

    CERN Document Server

    Smykalla, Lars; Korb, Marcus; Lang, Heinrich; Hietschold, Michael

    2015-01-01

    A coupling-limited approach for the Ullmann reaction-like on-surface synthesis of a two-dimensional covalent organic network starting from a halogenated metallo-porphyrin is demonstrated. Copper-octabromo-tetraphenylporphyrin molecules can diffuse and self-assemble when adsorbed on the inert Au(111) surface. Splitting-off of bromine atoms bonded at the macrocyclic core of the porphyrin starts at room temperature after the deposition and is monitored by X-ray photoelectron spectroscopy for different annealing steps. Direct coupling between the reactive carbon sites of the molecules is, however, hindered by the molecular shape. This leads initially to an ordered non-covalently interconnected supramolecular structure. Further heating to 300{\\deg}C and an additional hydrogen dissociation step is required to link the molecular macrocycles via a phenyl group and form large ordered polymeric networks. This approach leads to a close-packed covalently bonded network of overall good quality. The structures are characte...

  12. Air-snowpack exchange of bromine, ozone and mercury in the springtime Arctic simulated by the 1-D model PHANTAS – Part 2: Mercury and its speciation

    Directory of Open Access Journals (Sweden)

    K. Toyota

    2013-08-01

    not allowing the former reaction to occur in the model. Similarly to ozone (reported in the companion paper, GEM is destroyed via bromine radical chemistry more vigorously in the snowpack interstitial air than in the ambient air. However, the impact of such in-snow sink of GEM is found to be often masked by the re-emissions of GEM from the snow following the photo-reduction of Hg(II deposited from the atmosphere. Gaseous oxidized mercury (GOM formed in the ambient air is found to undergo fast "dry deposition" to the snowpack by being trapped on the snow grains in the top ~ 1 mm layer. We hypothesize that liquid-like layers on the surface of snow grains are connected to create a network throughout the snowpack, thereby facilitating the vertical diffusion of trace constituents trapped on the snow grains at much greater rates than one would expect inside solid ice crystals. Nonetheless, on the timescale of a week simulated in this study, the signal of atmospheric deposition does not extend notably below the top few centimeters of the snowpack. We propose and show that particulate-bound mercury (PBM is produced mainly as HgBr42− by taking up GOM into bromide-enriched aerosols after ozone is significantly depleted in the air mass. In the Arctic, "haze" aerosols may thus retain PBM in ozone-depleted air masses, allowing the airborne transport of oxidized mercury from the area of its production farther than in the form of GOM. Temperature dependence of thermodynamic constants calculated in this study for Henry's law and aqueous-phase halide complex formation of Hg(II species is a critical factor for this proposition, calling for experimental verification. The proposed mechanism may explain a major part of changes in the GOM-PBM partitioning with seasons, air temperature and the concurrent progress of ozone depletion as observed in the high Arctic. The net deposition of mercury to the surface snow is shown to increase with the thickness of the turbulent ABL and to

  13. Associations between brominated flame retardants in house dust and hormone levels in men

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Paula I. [Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Stapleton, Heather M. [Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708 (United States); Mukherjee, Bhramar [Department of Biostatistics, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Hauser, Russ [Department of Environmental Health, Harvard School of Public Health, 677 Huntington Ave., Boston, MA 02115 (United States); Meeker, John D., E-mail: meekerj@umich.edu [Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)

    2013-02-15

    Brominated flame retardants (BFRs) are used in the manufacture of a variety of materials and consumer products in order to meet fire safety standards. BFRs may persist in the environment and have been detected in wildlife, humans and indoor dust and air. Some BFRs have demonstrated endocrine and reproductive effects in animals, but human studies are limited. In this exploratory study, we measured serum hormone levels and flame retardant concentrations [31 polybrominated diphenyl ether (PBDE) congeners and 6 alternate flame retardants] in house dust from men recruited through a US infertility clinic. PBDE congeners in dust were grouped by commercial mixtures (i.e. penta-, octa- and deca-BDE). In multivariable linear regression models adjusted by age and body mass index (BMI), significant positive associations were found between house dust concentrations of pentaBDEs and serum levels of free T4, total T3, estradiol, and sex hormone binding globulin (SHBG), along with an inverse association with follicle stimulating hormone (FSH). There were also positive associations of octaBDE concentrations with serum free T4, thyroid stimulating hormone (TSH), luteinizing hormone (LH) and testosterone and an inverse association of decaBDE concentrations with testosterone. Hexabromocyclododecane (HBCD) was associated with decreased SHBG and increased free androgen index. Dust concentrations of bis-tribromophenoxyethane (BTBPE) and tetrabromo-diethylhexylphthalate (TBPH) were positively associated with total T3. These findings are consistent with our previous report of associations between PBDEs (BDE 47, 99 and 100) in house dust and hormone levels in men, and further suggest that exposure to contaminants in indoor dust may be leading to endocrine disruption in men. - Highlights: ► Brominated flame retardants (BFRs) including PBDEs and alternates were measured. ► Exposure to BFRs is characterized from concentrations in participant vacuum bag dust. ► Exposure to PBDEs and

  14. Determination of chlorine, fluorine, bromine, and iodine in coals with ICP-MS and IC

    Energy Technology Data Exchange (ETDEWEB)

    Bettinelli, M.; Spezia, S.; Minoia, C.; Ronchi, A. [Salvatore Maugeri Foundation, Pavia (Italy)

    2002-07-01

    The combustion process releases many organic and inorganic pollutants into the atmosphere, both in gaseous and solid form. During coal combustion in thermal power plants without pollution control equipment, chlorine, fluorine, bromine, and iodine present in coals are mainly volatilized as gaseous compounds. Limiting pollutant emissions is a precise requirement of the Italian legislation that fixes (in the case of power plants) 100 mg/Nm{sup 3} as the limit value for chlorine, and 5 mg/Nm{sup 3} for fluorine and bromine (expressed as hydrofluoric and hydrobromic acid respectively). No limit for iodine emissions has been established. From this point of view and in order to maintain control of emissions from combustion plants, it is important to monitor the concentration of halogens in fuels. Unfortunately, in literature there are very few data published with regard to the amount of halogens in fossil fuels, which emphasizes the analytical difficulties with regard to the determination of these analytes. In the present paper a, pyrohydrolysis of the sample at 1100{degree}C, followed by the absorption of volatilized compounds in Na{sub 2}CO{sub 3}/NaHCO{sub 3} solution and the final instrumental analysis of Cl, Br, and F with ion chromatography (IC) and Br and I with inductively coupled plasma mass spectrometry (ICP-MS) has been adopted. The accuracy of the method, evaluated by analyzing some certified reference materials, was better than 95% for all analytes and the detection limits adequate to the analytical requirements (0.1 mg/kg for Br and I, 1 mg/kg for F, and 10 mg/kg for C1).

  15. Associations between brominated flame retardants in house dust and hormone levels in men

    International Nuclear Information System (INIS)

    Brominated flame retardants (BFRs) are used in the manufacture of a variety of materials and consumer products in order to meet fire safety standards. BFRs may persist in the environment and have been detected in wildlife, humans and indoor dust and air. Some BFRs have demonstrated endocrine and reproductive effects in animals, but human studies are limited. In this exploratory study, we measured serum hormone levels and flame retardant concentrations [31 polybrominated diphenyl ether (PBDE) congeners and 6 alternate flame retardants] in house dust from men recruited through a US infertility clinic. PBDE congeners in dust were grouped by commercial mixtures (i.e. penta-, octa- and deca-BDE). In multivariable linear regression models adjusted by age and body mass index (BMI), significant positive associations were found between house dust concentrations of pentaBDEs and serum levels of free T4, total T3, estradiol, and sex hormone binding globulin (SHBG), along with an inverse association with follicle stimulating hormone (FSH). There were also positive associations of octaBDE concentrations with serum free T4, thyroid stimulating hormone (TSH), luteinizing hormone (LH) and testosterone and an inverse association of decaBDE concentrations with testosterone. Hexabromocyclododecane (HBCD) was associated with decreased SHBG and increased free androgen index. Dust concentrations of bis-tribromophenoxyethane (BTBPE) and tetrabromo-diethylhexylphthalate (TBPH) were positively associated with total T3. These findings are consistent with our previous report of associations between PBDEs (BDE 47, 99 and 100) in house dust and hormone levels in men, and further suggest that exposure to contaminants in indoor dust may be leading to endocrine disruption in men. - Highlights: ► Brominated flame retardants (BFRs) including PBDEs and alternates were measured. ► Exposure to BFRs is characterized from concentrations in participant vacuum bag dust. ► Exposure to PBDEs and

  16. Scientific Opinion on Emerging and Novel Brominated Flame Retardants (BFRs in Food

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Contaminants in the Food Chain (CONTAM

    2012-10-01

    Full Text Available EFSA was asked to deliver a scientific opinion on brominated flame retardants (BFRs other than PBDEs, PBBs, HBCDDs, TBBPA and brominated phenols and their derivatives. The BFRs that are the subject of the current opinion, were classified in groups termed ‘emerging’ and ‘novel’ BFRs. Information on 17 emerging and 10 novel BFRs was collected. The information varied widely for these BFRs. There is a lack of experimental data on physico-chemical characteristics, stability/reactivity and current use and production volume of all the emerging and novel BFRs. Due to the very limited information on occurrence, exposure and toxicity, the CONTAM Panel could not perform a risk characterisation for any of the BFRs considered. Instead, an attempt was made to identify those BFRs that could be a potential health concern and should be considered first for future investigations. For this purpose the Panel first evaluated the available experimental data on occurrence in food, behaviour in the environment and toxicity. Secondly, a modelling exercise was performed focussing on the potential of the emerging and novel BFRs for persistence in the environment and for their possible bioaccumulation potential. There is convincing evidence that tris(2,3-dibromopropyl phosphate (TDBPP and dibromoneopentyl glycol (DBNPG are genotoxic and carcinogenic, warranting further surveillance of their occurrence in the environment and in food. Based on the limited experimental data on environmental behaviour, 1,2-bis(2,4,6-tribromophenoxyethane (BTBPE and hexabromobenzene (HBB were identified as compounds that could raise a concern for bioaccumulation. For the modelling exercise, the CONTAM Panel selected two environmental characteristics, overall persistence and potential for bioaccumulation, as being most relevant to provide insight into the possibility that emerging or novel BFRs might accumulate in the food chain, and thus might appear in food intended for human

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

    Directory of Open Access Journals (Sweden)

    P. K. Peterson

    2014-09-01

    Full Text Available Multiple axis differential absorption spectroscopy (MAX-DOAS measurements of bromine monoxide (BrO probed the vertical structure of halogen activation events during March–May 2012 at Barrow, Alaska. An analysis of the BrO averaging kernels and degrees of freedom obtained by optimal-estimation-based inversions from raw MAX-DOAS measurements reveals the information is best represented by reducing the retrieved BrO profile to two quantities, the integrated column from the surface through 200 m (VCD200 m, and the lower tropospheric vertical column density (LT-VCD which represents the integrated column of BrO from the surface through 2 km. The percentage of lower-tropospheric BrO in the lowest 200 m was found to be highly variable ranging from shallow layer events, where BrO is present primarily in the lowest 200 m to distributed column events where BrO is observed at higher altitudes. The highest observed LT-VCD events occurred when BrO was distributed throughout the lower troposphere, rather than concentrated near the surface. Atmospheric stability in the lowest 200 m influenced the percentage of LT-VCD that is in the lowest 200 m, with inverted temperature structures having a first-to-third quartile range (Q1–Q3 of VCD200 m/LT-VCD from 15–39% while near neutral temperature structures had a Q1–Q3 range of 7–13%. Data from this campaign show no clear influence of wind speed on either lower-tropospheric bromine activation (LT-VCD or the vertical distribution of BrO, while examination of seasonal trends and the temperature dependence of the vertical distribution supported the conclusion that the atmospheric stability affects the vertical distribution of BrO.

  18. OLGA experiments with {sup 261}104 under chlorinating and brominating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gaeggeler, H.W.; Eichler, B.; Jost, D.T.; Piguet, D.; Tuerler, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Buklanov, G.; Lebedev, V.; Timokhin, S.; Vedeev, M.V.; Yakushev, A.; Zvara, I. [FLNR, Dubna (Russian Federation); Huebener, S. [FZR (Germany)

    1997-09-01

    With the On-Line Gas chemistry Apparatus OLGA III the retention times of element 104 chloride and bromide was measured in a quartz column using the isotope {sup 261}104 with a half-life of 78 s. With HCl as chlorinating agent element 104 was found to quantitatively pass through the column at 150{sup o}C, whereas with HBr this temperature shifted to about 300{sup o}C. Under both halogenating conditions, the homologuous element Hf passed through the column at higher temperatures than element 104, in agreement with expectations. (author) 2 figs., 2 refs.

  19. Synthesis of 1-Bromo-3-methoxy-4-propoxy-5-iodobenzene-A Novel Efficient Process for the Synthesis of Brominated Aromatic Compound

    Institute of Scientific and Technical Information of China (English)

    Hong Xin SHI; Hui LIN; Gérard MANDVILLE

    2004-01-01

    The reaction of aromatic carboxylic acid with oxalyl chloride gives rise to the corres- ponding acid chloride which without purification is treated with the sodium salt of mercapto- pyridine oxide in the presence of 2,2-azo-bisisobutyronitrile (AIBN), radical initiator to give a brominated aromatic compound. After etherification and oxidation, 5-iodovaniline was converted to trisubstituted benzene carboxylic acid which give 1-bromo-3-methoxy-4-propoxy-5-iodo- benzene by this new brominating process with a yield of 74 %.

  20. Measurement and computation of movement of bromide ions and carbofuran in ridged humic-sandy soil.

    Science.gov (United States)

    Leistra, Minze; Boesten, Jos J T I

    2010-07-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. Rainfall was supplemented by sprinkler irrigation. The distribution of the substances in the soil profile of the ridges and furrows was measured on three dates in the potato growing season. Separate ridge and furrow systems were simulated by using the pesticide emission assessment at regional and local scales (PEARL) model for pesticide behavior in soil-plant systems. The substances travelled deeper in the furrow soil than in the ridge soil, because of runoff from the ridges to the furrows. At 19 days after application, the peak of the bromide distribution was measured to be in the 0.1-0.2 m layer of the ridges, while it was in the 0.3-0.5 m layer of the furrows. After 65 days, the peak of the carbofuran distribution in the ridge soil was still in the 0.1 m top layer, while the pesticide was rather evenly distributed in the top 0.6 m of the furrow soil. The wide ranges in concentration measured with depth showed that preferential water flow and substance transport occurred in the sandy soil. Part of the bromide ion distribution was measured to move faster in soil than the computed wave. The runoff of water and pesticide from the ridges to the furrows, and the thinner root zone in the furrows, are expected to increase the risk of leaching to groundwater in ridged fields, in comparison with more level fields.

  1. ACCIDENTAL SUBCUTANEOUS INJECTION OF VECURONIUM BROMIDE IN A PATIENT WITH BURNS

    Directory of Open Access Journals (Sweden)

    Usha Dev

    2014-10-01

    Full Text Available BACKGROUND AND OBJECTIVES: In patients with burn injury drug pharmacology will be altered and this poses special anaesthetic challenge when an subcutaneous injection of a non- depolarizing muscle relaxant occurs in such a patient. Small studies remain an important source of knowledge and hence this study aims to provide information on the anaesthetic management in a case of accidental subcutaneous injection of vecuronium bromide in a burns patient. PRESENTATION, DIAGNOSIS & MANAGEMENT: A 22 year young male with 4 days old hot water induced grade 1 burns involving 45% of body surface area was posted for burns dressing. Anaesthesia was induced with propofol and vecuronium bromide through an external jugular vein to aid tracheal intubation. As the patient was not anaesthetized even after 10 minutes routine check lead to the discovery of fullness at the tip of the intravenous catheter indicating an extravasation of the drugs. Hence the other external jugular vein was cannulated and the patient induced and intubated using propofol, sevoflurane, nitrous oxide and oxygen. The action of vecuronium outlasted the duration of surgery. So the patient continued to receive support of mechanical ventilation with nitrous oxide and oxygen. It took 130 minutes for the clinical signs of recovery from the muscle relaxant to manifest. He was then reversed & extubated with subsequent good recovery. CONCLUSION: Subcutaneous injection of these drugs poses problems of delayed onset of action and prolonged duration of action. In an inadvertent accidental subcutaneous 0.1 mg/kg vecuronium bromide injection in a patient with 4 day old 45% burns showed delayed onset action and prolonged neuromuscular blockade due to subcutaneous deposition of the drug which was managed with mechanical ventilation .The reported resistance to the action of NDMR drugs in patient with burns was not noticed here probably because of the age of the thermal injury.

  2. Efficient SN2 fluorination of primary and secondary alkyl bromides by copper(I) fluoride complexes

    KAUST Repository

    Liu, Yanpin

    2013-11-11

    Copper(I) fluoride complexes ligated by phenanthroline derivatives have been synthesized and structurally characterized by X-ray crystallography. These complexes adopt as either ionic or neutral forms in the solid state, depending on the steric bulkiness of the substituent groups on the phenanthroline ligands. These complexes react with primary and secondary alkyl bromides to produce the corresponding alkyl fluorides in modest to good yields. This new method is compatible with a variety of important functional groups such as ether, thioether, amide, nitrile, methoxyl, hydroxyl, ketone, ester, and heterocycle moieties. © 2013 American Chemical Society.

  3. Radiation Induced Formation of Acrylated Palm Oil Nanoparticles using Cetyltrimethylammonium Bromide Microemulsion System

    International Nuclear Information System (INIS)

    In this study, we report the preparation of Acrylated Palm Oil (APO) nanoparticles using aqueous Cetyltrimethylammonium bromide (CTAB) microemulsion system. This microemulsion system which contains the dispersed APO nano droplets was subjected to the gamma irradiation to induce the formation of the crosslinked APO nanoparticle. After irradiation at higher doses, the size of APO nanoparticles was transformed from a submicron-sized to a nano-sized of the particles. Size decreasing might be due to the intermolecular and the intramolecular crosslinking reactions of the APO nanoparticles during the irradiation process. (author)

  4. Promotion of hexadecyltrimethyleamine bromide to the damage of Alexandrium sp. LC3 by cupric glutamate

    Institute of Scientific and Technical Information of China (English)

    LI Hao; MIAO Jin-lai; CUI Feng-xia; LI Guang-you

    2006-01-01

    The effect of hexadecyltrimethyleamine bromide (HDTMAB) on the removal of A lexandrium sp. LC3 under cupric glutamate stress was investigated. Toxic effect of cupric glutamate on A lexandrium sp. LC3 was significantly promoted in the presence of HDTMAB, especially at 3.0 cmc of HDTMAB. It was found that the sulfhydryl group content of the cell decreased, while the malonaldehyde content and membrane permeability increased when Alexandrium sp. LC3 was treated with HDTMAB and cupric glutamate complex, compared with cupric glutamate alone. The data suggest that HDTMAB might stimulate the damage of A lexandrium sp. LC3 by enhancing the membrane permeability.

  5. Efficient Stille cross-coupling reaction using aryl chlorides or bromides in water.

    Science.gov (United States)

    Wolf, Christian; Lerebours, Rachel

    2003-09-19

    An efficient Stille cross-coupling reaction using a variety of aryl halides in neat water has been developed. Employing palladium-phosphinous acid catalyst [(t-Bu)(2)P(OH)](2)PdCl(2) allows formation of biaryls from aryl chlorides and bromides in good to high yields. Functional groups such as ketones and nitriles are tolerated, and organic cosolvents are not required. The air stability and solubility in water of the palladium complexes used in this study facilitate operation of the coupling reaction and product isolation. The feasibility of catalyst recycling has also been demonstrated. PMID:12968920

  6. Highly stable, luminescent core-shell type methylammonium-octylammonium lead bromide layered perovskite nanoparticles.

    Science.gov (United States)

    Bhaumik, Saikat; Veldhuis, Sjoerd A; Ng, Yan Fong; Li, Mingjie; Muduli, Subas Kumar; Sum, Tze Chien; Damodaran, Bahulayan; Mhaisalkar, Subodh; Mathews, Nripan

    2016-06-01

    A new protocol for the synthesis of a highly stable (over 2 months under ambient conditions) solution-processed core-shell type structure of mixed methylammonium-octylammonium lead bromide perovskite nanoparticles (5-12 nm), having spherical shape, color tunability in the blue to green spectral region (438-521 nm) and a high photoluminescence quantum yield (PLQY) of up to 92% is described. The color tunability, high PLQY and stability are due to the quantum confinement imparted by the crystal engineering associated with core-shell nanoparticle formation during growth. PMID:27165565

  7. Rapid Consumption of Low Concentrations of Methyl Bromide by Soil Bacteria

    OpenAIRE

    Hines, Mark E.; Crill, Patrick M; Varner, Ruth K.; Talbot, Robert W; Shorter, Joanne H.; Kolb, Charles E.; Harriss, Robert C.

    1998-01-01

    A dynamic dilution system for producing low mixing ratios of methyl bromide (MeBr) and a sensitive analytical technique were used to study the uptake of MeBr by various soils. MeBr was removed within minutes from vials incubated with soils and ∼10 parts per billion by volume of MeBr. Killed controls did not consume MeBr, and a mixture of the broad-spectrum antibiotics chloramphenicol and tetracycline inhibited MeBr uptake by 98%, indicating that all of the uptake of MeBr was biological and by...

  8. Nitrate ion photolysis in thin water films in the presence of bromide ions.

    Science.gov (United States)

    Richards, Nicole K; Wingen, Lisa M; Callahan, Karen M; Nishino, Noriko; Kleinman, Michael T; Tobias, Douglas J; Finlayson-Pitts, Barbara J

    2011-06-16

    Nitrate ions commonly coexist with halide ions in aged sea salt particles, as well as in the Arctic snowpack, where NO(3)(-) photochemistry is believed to be an important source of NO(y) (NO + NO(2) + HONO + ...). The effects of bromide ions on nitrate ion photochemistry were investigated at 298 ± 2 K in air using 311 nm photolysis lamps. Reactions were carried out using NaBr/NaNO(3) and KBr/KNO(3) deposited on the walls of a Teflon chamber. Gas phase halogen products and NO(2) were measured as a function of photolysis time using long path FTIR, NO(y) chemiluminescence and atmospheric pressure ionization mass spectrometry (API-MS). Irradiated NaBr/NaNO(3) mixtures show an enhancement in the rates of production of NO(2) and Br(2) as the bromide mole fraction (χ(NaBr)) increased. However, this was not the case for KBr/KNO(3) mixtures where the rates of production of NO(2) and Br(2) remained constant over all values of χ(KBr). Molecular dynamics (MD) simulations show that the presence of bromide in the NaBr solutions pulls sodium toward the solution surface, which in turn attracts nitrate to the interfacial region, allowing for more efficient escape of NO(2) than in the absence of halides. However, in the case of KBr/KNO(3), bromide ions do not appreciably affect the distribution of nitrate ions at the interface. Clustering of Br(-) with NO(3)(-) and H(2)O predicted by MD simulations for sodium salts may facilitate a direct intermolecular reaction, which could also contribute to higher rates of NO(2) production. Enhanced photochemistry in the presence of halide ions may be important for oxides of nitrogen production in field studies such as in polar snowpacks where the use of quantum yields from laboratory studies in the absence of halide ions would lead to a significant underestimate of the photolysis rates of nitrate ions.

  9. Cytotoxicity evaluation of Clinacanthus nutans through dimethylthiazol diphenyltetrazolium bromide and neutral red uptake assays

    OpenAIRE

    Vajrabhaya, La-Ongthong; Korsuwannawong, Suwanna

    2016-01-01

    Objectives: The aim of this study was to compare the results of dimethylthiazol diphenyltetrazolium bromide (MTT) and neutral red uptake (NRU) assays of Clinacanthus nutans cytotoxicity. Materials and Methods: Mouse fibroblast (L929) cells were exposed to 0.01%, 0.1%, 0.25%, and 0.5% (W/V) C. nutans in a 96-cluster-well-culture plate for 24 h. The cell viability after exposure to C. nutans was determined by MTT and NRU assays in separate tissue culture plates. The two assays were compared thr...

  10. Ethidium bromide transport across Mycobacterium smegmatis cell-wall: correlation with antibiotic resistance

    OpenAIRE

    Couto Isabel; Ramos Jorge; Rodrigues Liliana; Amaral Leonard; Viveiros Miguel

    2011-01-01

    Abstract Background Active efflux systems and reduced cell-wall permeability are considered to be the main causes of mycobacterial intrinsic resistance to many antimicrobials. In this study, we have compared the Mycobacterium smegmatis wild-type strain mc2155 with knockout mutants for porins MspA (the main porin of M. smegmatis) and MspC, the efflux pump LfrA (the main efflux pump system of M. smegmatis) and its repressor LfrR for their ability to transport ethidium bromide (EtBr) on a real-t...

  11. Generation, spectroscopy, and structure of cyanoformyl chloride and cyanoformyl bromide, XC(O)CN.

    Science.gov (United States)

    Pasinszki, Tibor; Vass, Gábor; Klapstein, Dieter; Westwood, Nicholas P C

    2012-04-01

    Cyanoformyl chloride and cyanoformyl bromide, XC(O)CN (X = Cl and Br), have been investigated in the gas phase by UV photoelectron and mid-infrared spectroscopies. The ground-state geometries of the neutral molecules have been obtained from quantum-chemical calculations at the B3LYP and CCSD(T) levels using the aug-cc-pVTZ basis set. The individual spectroscopies provide a detailed investigation into the vibrational and electronic character of the molecules and are supported by quantum-chemical calculations. The results are compared to data for structurally and chemically related molecules.

  12. Chemistry of recoil atoms of bromine-82 in neutron-irradiated crystalline perbromates of the alkali metals and ammonium

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, V.V.; Isupov, V.K.; Kirin, I.S.

    1975-01-01

    It was established by ion exchange chromatography that the recoil atoms of bromine-82 in perbromates with thermal neutrons are stabilized in the form of five valence forms: BrO/sub 4//sup -/, BrO/sub 3//sup -/, BrO/sub 2//sup -/, BrO/sup -/, Br/sup -/. The retention of bromine-82 of BrO/sub 4//sup -/ is 2.1 +- 0.4 percent for LiBrO/sub 4/, 2.1 +- 0.4 percent for NaBrO/sub 4/, 2.3 +- 0.4 percent for KBrO/sub 4/, 2.6 +- 0.4 percent for RbBrO/sub 4/, 2.2 +- 0.4 percent for CsBrO/sub 4/, and 1.6 +- 0.4 percent for NH/sub 4/BrO/sub 4/.

  13. Prenatal Exposure to Organohalogens, Including Brominated Flame Retardants, Influences Motor, Cognitive, and Behavioral Performance at School Age

    OpenAIRE

    Roze, Elise; Meijer, Lisethe; Bakker, Attie; Van Braeckel, Koenraad N. J. A.; Sauer, Pieter J. J.; Bos, Arend F

    2009-01-01

    Background Organohalogen compounds (OHCs) are known to have neurotoxic effects on the developing brain. Objective We investigated the influence of prenatal exposure to OHCs, including brominated flame retardants, on motor, cognitive, and behavioral outcome in healthy children of school age. Methods This study was part of the prospective Groningen infant COMPARE (Comparison of Exposure-Effect Pathways to Improve the Assessment of Human Health Risks of Complex Environmental Mixtures of Organoha...

  14. The mercury species and their association with carbonaceous compositions, bromine and iodine in PM2.5 in Shanghai.

    Science.gov (United States)

    Duan, Lian; Xiu, Guangli; Feng, Ling; Cheng, Na; Wang, Chenggang

    2016-03-01

    PM2.5 samples were collected in south Shanghai from November 2013 to October 2014. The species of particulate bounded mercury (PBM), including hydrochloric soluble particle-phase mercury (HPM), element soluble particle-phase mercury (EPM) and residual soluble particle-phase mercury (RPM), were determined in PM2.5. The chemical composition of PM2.5 including organic carbon (OC) and elemental carbon (EC), total bromine and iodine were also analyzed. The results showed that the annual average concentration of PBM was 0.30 ± 0.31 ng m(-3) and 0.34 ± 0.32 ng m(-3) in winter, 0.31 ± 0.19 ng m(-3) in spring, 0.30 ± 0.45 ng m(-3) in fall and 0.28 ± 0.17 ng m(-3) in summer. HPM took the highest fraction 51.2% in PBM, followed by RPM 27.7% and EPM 21.1%. EC positively correlated to particle mercury, especially in winter (r = 0.70), the same for OC in winter (r = 0.72), which indicated that the carbonaceous composition may affect the transformation of Hg in the atmosphere. Mercury species showed different correlations with bromine and iodine in the four seasons. The strongest correlation between bromine, iodine and mercury was found in spring and fall, respectively. Bromine showed the stronger correlation with total mercury and speciated particle mercury than iodine. In addition, the days were classified into haze and non-haze days based on the visibility and relative humidity, while the ratio of HPM in haze days was much higher than that in non-haze days. EC strongly correlated with PBM during haze and non-haze days while OC only positively correlated with PBM in non-haze days, this may indicate that the different carbonaceous part may affect PBM differently.

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

    OpenAIRE

    N. Bobrowski; Giuffrida, G

    2012-01-01

    Over a three year period, from 2006 to 2009, frequent scattered sun light DOAS measurements were conducted at Mt. Etna in a distance of around six kilometres downwind from the summit craters. During the same period and in addition to these measurements, volcanic observations were made by regularly visiting various parts of Mt. Etna.

    Results from these measurements and observations are presented and their relation is discussed. The focus of the investigation is the bromin...

  16. An Empirical Approach to Determining the Boundary Layer Bromine Monoxide (BrO) Abundance from Satellite Total Column Measurements

    Science.gov (United States)

    Simpson, W. R.; Donohoue, D.; Carlson, D. A.

    2009-12-01

    Unique chemistry in the Arctic boundary layer during springtime liberates bromine from sea salt, producing reactive halogen gases (e.g. atomic bromine and bromine monoxide radicals) that then drastically alter atmospheric oxidation pathways. This phenomenon causes ozone depletion events and affects mercury deposition to the snowpack. Satellite remote sensing (e.g. OMI and GOME2 observations) techniques can detect the total column abundance of BrO, which is generally the primary species of the reactive bromine family. However, BrO is also present in the stratosphere, so it is necessary to partition the satellite-observed BrO column abundance into boundary layer and non-boundary layer (primarily stratospheric) partial columns to be able to infer boundary layer abundances and hence chemical affects near the Earth's surface (i.e. ozone and mercury impacts). In this presentation, we describe an empirical method for partitioning the BrO total column and apply it globally during spring 2008. The method indicates that some BrO total column enhancements ("hotspots") are not actually enhancements in the boundary layer BrO abundance but occur aloft. Movies and a statistical analysis of the inferred boundary layer BrO abundance are presented. The method has been tested and performs well at the Barrow field site. However, in areas that lack routine ground truth BrO measurements (e.g. Hudson Bay, Canada), large tropospheric BrO abundances are indicated. It is not clear if these inferred boundary layer BrO events are real or if the simple empirical method described here is failing in those locations. Verification of this method over large spatial regions of the Arctic is needed.

  17. Comparison of Nuclear Activation Methods for Bromine. Instrumental Analyses of Pesticides in Plant Materials Close to the Limit of Sensitivity

    International Nuclear Information System (INIS)

    There has been worldwide interest in pesticide residue analysis for control and ecological purposes. Although several agricultural research establishments have in the past developed suitable radioisotope tracer techniques to detect and remove organic pesticides from food, suitable micro-analytical techniques for the measurement of traces of toxic elements present in these materials have not been available. In cooperation with the United States Department of Agriculture, Plant Pest Control Laboratory, an investigation has been conducted on the use of neutron activation techniques for determining bromine, arsenic and mercury residues in soils, foliage, fruit, and vegetable materials. This paper discusses the various instrumental and data reduction techniques which were developed to measure traces of bromine by neutron activation methods, especially those employed in the limit of sensitivity range wherein special statistical methods are necessary. A large number of samples of soils, foliage, orange and vegetable materials, activated in the Texas A and M Research Reactor were counted at appropriate times after activation using three different counting systems: firstly, an automated system with an Nal (Tl) spectrometer; secondly, a 2 cm3 Ge(Li) solid-state detector connected to a Victoreen 3200-channel analyzer; and thirdly a slow γ-γ coincidence unit. The spectral data from the automated system were reduced by the AA-6 least squares method, and alternatively by means of computer spectrum stripping and peak area computation methods. The photopeak activities from the solid-state detector spectra were measured by the peak area method. The results obtained from the three counting systems using different data reduction techniques were compared to determine the best for the measurement of bromine concentration in the limit-of-sensitivity range. The γ-γ coincidence counting technique appears to have advantages in measuring the bromine content even in the ppm range in

  18. [Formation of disinfection by-products by Microcystis aeruginosa intracellular organic matter: comparison between chlorination and bromination].

    Science.gov (United States)

    Tian, Chuan; Guo, Ting-Ting; Liu, Rui-Ping; Jefferson, William; Liu, Hui-Juan; Qu, Jiu-Hui

    2013-11-01

    In order to illustrate the effects of released algal organic matter in cyanobacteria blooms on raw water quality and water treatment process, intracellular organic matter (IOM) of Microcystis aeruginosa, which is the dominant species in cyanobacteria blooms, was chosen as a precursor and characterized. In addition, the transformation of IOM and the formation of disinfection byproducts were evaluated at different pH of 6.5, 7.1 and 8.4 after chlorination or bromination, with subsequent correlation analysis. The results indicated that IOM was primarily composed of macromolecular matter, i. e. , the species with relative molecular weight of > 30 x 10(3), constituting 68.8% of dissolved organic carbon (DOC). Fluorescence excitation-emission matrix indicated that IOM was mainly composed of aromatic protein-like matter with an intensity of 92.6 AU x L x mg(-1). After reaction with chlorine or bromine, the intensity of aromatic protein-like peaks decreased sharply by 76.6% - 93.3%, and its reduction correlated well with the formation of trihalomethane (THMs, R2 = 0.81) and haloacetic acid (HAAs, R2 = 0.77). The formation of THMs and HAAs increased with the increase in pH. Compared with chlorine, bromine formed more THMs and HAAs, and tended to form highly halogenated HAAs. However, with increasing pH, the reactivity with IOM between chlorine and bromine was closer, i.e, k(OBr-IOM)/k(OCl-(IOM) < k(HOBr-IOM/k(HOCl-IOM).

  19. Occurrence of brominated flame retardants in black thermo cups and selected kitchen utensils purchased on the European market.

    Science.gov (United States)

    Samsonek, J; Puype, F

    2013-01-01

    In order to screen for the presence of a recycled polymer waste stream from waste electric and electronic equipment (WEEE), a market survey was conducted on black plastic food-contact articles (FCA). An analytical method was applied combining X-ray fluorescence spectrometry (XRF) with thermal desorption gas chromatography coupled with mass spectrometry (thermal desorption GC-MS). Firstly, XRF spectrometry was applied to distinguish bromine-positive samples. Secondly, bromine-positive samples were submitted for identification by thermal desorption GC-MS. Generally, the bromine-positive samples contained mainly technical decabromodiphenyl ether (decaBDE). Newer types of BFRs such as tetrabromobisphenol A (TBBPA), tetrabromobisphenol A bis(2,3-dibromopropyl), ether (TBBPA-BDBPE) and decabromodiphenylethane (DBDPE), replacing the polybrominated diphenyleters (PBDEs) and polybrominated diphenyls (PBBs), were also identified. In none of the tested samples were PBBs or hexabromocyclododecane (HBCD) found. Polymer identification was carried out using Fourier-transformed infrared spectroscopy measurement (FTIR) on all samples. The results indicate that polypropylene-polyethylene copolymers (PP-PE) and mainly styrene-based food-contact materials, such as acrylonitrile-butadiene-styrene (ABS) have the highest risk of containing BFRs. PMID:24040839

  20. Bromination of Graphene: A New Route to Making High Performance Transparent Conducting Electrodes with Low Optical Losses

    KAUST Repository

    Mansour, Ahmed E.

    2015-07-22

    The unique optical and electrical properties of graphene have triggered great interest in its application as a transparent conducting electrode material and significant effort has been invested in achieving high conductivity while maintaining transparency. Doping of graphene has been a popular route for reducing its sheet resistance, but this has typically come at a significant cost in optical transmission. We demonstrate doping of few layers graphene with bromine as a means of enhancing the conductivity via intercalation without major optical losses. Our results demonstrate the encapsulation of bromine leads to air-stable transparent conducting electrodes with five-fold improvement of sheet resistance reaching at the cost of only 2-3% loss of optical transmission. The remarkably low tradeoff in optical transparency leads to the highest enhancements in the figure of merit reported thus far for FLG. Furthermore, we tune the workfunction by up to 0.3 eV by tuning the bromine content. These results should help pave the way for further development of graphene as a potential substitute to transparent conducting polymers and metal oxides used in optoelectronics, photovoltaics and beyond.

  1. Occurrence of PBDEs and other alternative brominated flame retardants in sludge from wastewater treatment plants in Korea.

    Science.gov (United States)

    Lee, Sunggyu; Song, Geum-Ju; Kannan, Kurunthachalam; Moon, Hyo-Bang

    2014-02-01

    Studies on the occurrence of polybrominated diphenyl ethers (PBDEs) and other alternative brominated flame retardants in the environment are scarce. In this study, PBDEs and non-PBDE brominated flame retardants (NBFRs), including decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), were measured in sludge collected from three types of wastewater treatment plants (WWTPs) in Korea. Total concentrations of PBDEs (∑PBDE) in sludge ranged from 298 to 48,000 (mean: 3240) ng/g dry weight. Among 10 NBFRs analyzed, DBDPE and BTBPE were the only ones detected in sludge samples. Concentrations of DBDPE and BTBPE ranged from parametric multidimensional scaling ordination showed that congener profiles of PBDEs in sludge are dependent on the types of WWTPs. Almost all sludge samples contained a low ratio (mean: 0.18) of DBDPE/BDE 209, indicating an on-going contamination by PBDEs in Korea. However, the high ratios (>1) of DBDPE/BDE 209 were found in sludge from I-WWTPs, reflecting a shift in the usage pattern of BFRs by the Korean industry. The nationwide annual emission fluxes of ∑PBDE, DBDPE and BTBPE via WWTPs to the environment were estimated to be 7400, 480, and 3.7 kg/year, respectively. This is the first study on the occurrence of alternative brominated flame retardants in sludge from Korea. PMID:23993837

  2. Brominated flame retardants in the surrounding soil of two manufacturing plants in China: Occurrence, composition profiles and spatial distribution.

    Science.gov (United States)

    Li, Wen-Long; Liu, Li-Yan; Zhang, Zi-Feng; Song, Wei-Wei; Huo, Chun-Yan; Qiao, Li-Na; Ma, Wan-Li; Li, Yi-Fan

    2016-06-01

    Surface soil samples were collected surrounding two brominated flame retardants (BFRs) manufacturing plants in China in August 2014 and analyzed for 23 polybrominated diphenyl ethers (PBDEs) and 8 novel brominated flame retardants (NBFRs). BDE209 and decabromodiphenylethane (DBDPE) were the predominant compounds in soil with the median levels of 1600 and 560 ng/g dw, respectively. The PBDEs profiles in soil samples were consistent with that of commercial product (comDecaBDE). The percentage contributions to total PBDEs decreased from higher to lower brominated homologues. Lower concentrations of NBFRs (excluding DBDPE) were detected in soil surrounding the two plants, suggesting they are byproducts or degradation products of the manufacturing activities. The concentrations of most BFRs dropped exponentially within 3-5 km of the manufacturing plants, suggesting recent deposition of these compounds to the soil. Directional distribution indicated that PBDEs and DBDPE concentrations were highest in the north direction of Plants 1. Three-day air parcel forward trajectories confirmed that the air parcel was responsible for the higher concentration of BFRs in the soil of north direction of the plant.

  3. Investigation of the Stratospheric Bromine Chemistry by Balloon-Borne Spectroscopic Observations and Photochemical Modelling: A Case Study of J(BrONO2) / k[BrO][NO2

    OpenAIRE

    Kreycy, Sebastian

    2013-01-01

    Besides chlorine, bromine is the second most important halogen when it comes to the destruction of ozone in the stratosphere. Although 150 times more chlorine than bromine is transported into the stratosphere, the higher ozone-depleting efficiency of bromine (by a factor of 45) makes it very important for catalytic cycles. In this study, balloon-borne DOAS (Differential Optical Absorption Spectroscopy) measurements of direct sunlight and limb measurements of scattered skylight, recorded...

  4. Theoretical study of the reaction kinetics of atomic bromine with tetrahydropyran

    KAUST Repository

    Giri, Binod

    2015-02-12

    A detailed theoretical analysis of the reaction of atomic bromine with tetrahydropyran (THP, C5H10O) was performed using several ab initio methods and statistical rate theory calculations. Initial geometries of all species involved in the potential energy surface of the title reaction were obtained at the B3LYP/cc-pVTZ level of theory. These molecular geometries were reoptimized using three different meta-generalized gradient approximation (meta-GGA) functionals. Single-point energies of the stationary points were obtained by employing the coupled-cluster with single and double excitations (CCSD) and fourth-order Møller-Plesset (MP4 SDQ) levels of theory. The computed CCSD and MP4(SDQ) energies for optimized structures at various DFT functionals were found to be consistent within 2 kJ mol-1. For a more accurate energetic description, single-point calculations at the CCSD(T)/CBS level of theory were performed for the minimum structures and transition states optimized at the B3LYP/cc-pVTZ level of theory. Similar to other ether + Br reactions, it was found that the tetrahydropyran + Br reaction proceeds in an overall endothermic addition-elimination mechanism via a number of intermediates. However, the reactivity of various ethers with atomic bromine was found to vary substantially. In contrast with the 1,4-dioxane + Br reaction, the chair form of the addition complex (c-C5H10O-Br) for THP + Br does not need to undergo ring inversion to form a boat conformer (b-C4H8O2-Br) before the intramolecular H-shift can occur to eventually release HBr. Instead, a direct, yet more favorable route was mapped out on the potential energy surface of the THP + Br reaction. The rate coefficients for all relevant steps involved in the reaction mechanism were computed using the energetics of coupled cluster calculations. On the basis of the results of the CCSD(T)/CBS//B3LYP/cc-pVTZ level of theory, the calculated overall rate coefficients can be expressed as kov.,calc.(T) = 4.60 × 10

  5. Development of Zinc/Bromine Batteries for Load-Leveling Applications: Phase 1 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Eidler, Phillip

    1999-07-01

    The Zinc/Bromine Load-Leveling Battery Development contract (No. 40-8965) was partitioned at the outset into two phases of equal length. Phase 1 started in September 1990 and continued through December 1991. In Phase 1, zinc/bromine battery technology was to be advanced to the point that it would be clear that the technology was viable and would be an appropriate choice for electric utilities wishing to establish stationary energy-storage facilities. Criteria were established that addressed most of the concerns that had been observed in the previous development efforts. The performances of 8-cell and 100-cell laboratory batteries demonstrated that the criteria were met or exceeded. In Phase 2, 100-kWh batteries will be built and demonstrated, and a conceptual design for a load-leveling plant will be presented. At the same time, work will continue to identify improved assembly techniques and operating conditions. This report details the results of the efforts carried out in Phase 1. The highlights are: (1) Four 1-kWh stacks achieved over 100 cycles, One l-kWh stack achieved over 200 cycles, One 1-kWh stack achieved over 300 cycles; (2) Less than 10% degradation in performance occurred in the four stacks that achieved over 100 cycles; (3) The battery used for the zinc loading investigation exhibited virtually no loss in performance for loadings up to 130 mAh/cm{sup 2}; (4) Charge-current densities of 50 ma/cm{sup 2} have been achieved in minicells; (5) Fourteen consecutive no-strip cycles have been conducted on the stack with 300+ cycles; (6) A mass and energy balance spreadsheet that describes battery operation was completed; (7) Materials research has continued to provide improvements in the electrode, activation layer, and separator; and (8) A battery made of two 50-cell stacks (15 kWh) was produced and delivered to Sandia National Laboratories (SNL) for testing. The most critical development was the ability to assemble a battery stack that remained leak free. The

  6. Modelling the impact of chlorine and bromine emissions from large Plinian eruptions on ozone

    Science.gov (United States)

    Brenna, Hans; Krüger, Kirstin; Kutterolf, Steffen

    2016-04-01

    Large Plinian volcanic eruptions inject large amounts of atmosphere-relevant gases (e.g. S, Cl, Br) and materials into the stratosphere. If the eruption occurs in the tropics, it can have a global impact due to the dispersal through the large scale meridional overturning circulation. Most climate model studies concentrate on the sulfate aerosol effects on climate. In contrast, ozone-depletion initiated by volcanic halogens from tropical eruptions was believed to play an insignificant role for the global atmosphere, based on observations from the recent El Chichon and Pinatubo eruptions. New results regarding the halogen release by Plinian eruptions, as well as recent volcanic plume observations and model simulations facilitate now our investigation into what effect the combined chlorine and bromine emissions from large tropical eruptions have on ozone and the atmosphere in general. A complete halogen data set for the last 200 ka (Kutterolf et al., 2015), derived by the petrological method from paleo-eruptions of the Central American Volcanic Arc (CAVA), are used to force simulations with the advanced chemistry climate model WACCM (Whole Atmosphere Community Climate Model). The goal is to quantify the impact of volcanic halogens on the preindustrial atmosphere when the background chlorine levels were low compared to the present day with the main focus on stratospheric ozone. We carried out 5 model simulations assuming that 10% of the Cl and Br (9.51e+6 kg Br and 2.93e+9 kg Cl) emitted from the average CAVA eruption is injected into the tropical stratosphere during January. The model response reveals a global impact on the ozone layer affecting via radiation also atmospheric dynamics for more than 5 years. Given the current decline in anthropogenic chlorine, the results will become relevant for future halogen-rich explosive eruptions in the tropics. References: Kutterolf, S., T. Hansteen, A. Freundt, H. Wehrmann, K. Appel, K. Krüger, and W. Pérez (2015), Bromine

  7. Brominated flame retardants in the Arctic. An overview of spatial and temporal trends

    Energy Technology Data Exchange (ETDEWEB)

    Wit, C. de [Institute of Applied Environmental Research, Stockholm (Sweden); Alaee, M.; Muir, D. [National Water Research Institute, Burlington, MA (United States)

    2004-09-15

    The Stockholm Convention on Persistent Organic Pollutants (POPs), which entered into force on May 17, 2004, includes wording that chemicals with the characteristics of POPs are those found in locations ''distant from sources'' and those for which ''monitoring data showing that long-range environmental transport of the chemical may have occurred''. Thus, the Arctic has become an important indicator region for assessment of persistence and bioaccumulation. The Arctic environment is well suited as a region in which to evaluate POPs. Some regions of thee Arctic, particularly the Barents Sea area north of Norway and western Russia are relatively close to source regions of POPs. Cold conditions favor persistence of POPs relative to temperate or tropical environments. The presence of fourth level carnivores (e.g. polar bears and seabirds), and storage of lipid as an energy source, make Arctic food webs vulnerable to bioaccumulative chemicals. Indigenous people in the Arctic utilizing a traditional diet, which is high in nutritionally beneficial fat, results in their elevated exposure to some POPs. The first indication that brominated flame retardants (BFRs) were reaching the Arctic was the detection by Jansson et al. of lower molecular weight polybrominated diphenyl ethers (PBDEs) in Svalbard Brunnichfs guillemots (130 ng/g lipid weight) and ringed seals (40 ng/g lw) collected in 1981. Whitefish collected from Lake Storvindeln in 1986, a pristine mountain lake in the Swedish mountains near Ammarnas, had {sigma}PBDE levels of 26 ng/g lw. Despite these early findings, only recently have the spatial and temporal trends of BFRs been studied in detail in the Arctic. The purpose of this paper is to review the new data on BFRs in the Arctic and assess whether this information supports the view that PBDEs and other BFRs of similar molecular weight are POPs and potential global pollutants. This review is based on a recent assessment of POPs

  8. Using prechloramination to control trihalomethanes formation in River Huang water with high bromide

    Institute of Scientific and Technical Information of China (English)

    TAO Hui; CHEN Wei; LIN Tao; LIU Cheng; CHEN Jie; LI Gui-bai

    2008-01-01

    An effective technology in controlling trihalomethanes (THMs)formation in the case of large amounts of bromide presenting wag proposed,and the water of River Huang seriously polluted by bromide in winter in Tianjin City wag studied.The THMs formation characteristics during prechloramination using preformed chloramines and convened chloramines were studied through jar tests.Results show that,in prechloramination process,the formation of THMs by preformed chloramines is very few,while that by converted chloramines is a little higher.And the formation of THMs,especially Br-substituted THMs,increases with tIle increase of time and Cl2:N ratio as well as the decrease of pH.The result obtained in a pilot plant shows that compared with preehlorination,the prechlommination process can efficiendy control the formation of THMs,especially the Br-substituted species.With equal chlorine dosage.the prechloramination can maintain a hrser chlorine residue which offers a larger CT value than prechlorination.

  9. Moving away from methyl bromide: political economy of pesticide transition for California strawberries since 2004.

    Science.gov (United States)

    Mayfield, Erin N; Norman, Catherine Shelley

    2012-09-15

    We examine the progress of the phaseout of the use of the pesticide methyl bromide in the production of California field strawberries. This phaseout is required under the Montreal Protocol and has been contentious in this sector, which receives exemptions from the schedule initially agreed under the treaty, and in international negotiations over the future of the Protocol. We examine the various ex-ante predictions of the impacts on growers, consumers and trade patterns in light of several years of declining allocations under the Critical Use provisions of the Protocol and the 2010 approval of iodomethane for use in California and subsequent 2012 withdrawal of this alternative from the US market. We find that, contrary to ex-ante industry claims, the years of declining methyl bromide use have been years of rising yields, acreage, exports, revenues and market share for California growers, even when faced with a global recession and increased imports from Mexican growers who retain the right to use the chemical under the Protocol. This has implications for the Protocol as a whole and for the remainder of the US phaseout of this chemical in particular. PMID:22575205

  10. Model prediction uncertainty of bromide and pesticides transport in laboratory column

    Science.gov (United States)

    Dusek, Jaromir; Dohnal, Michal; Snehota, Michal; Sobotkova, Martina; Ray, Chittaranjan; Vogel, Tomas

    2016-04-01

    Knowledge of transport parameters of reactive solutes such as pesticides is a prerequisite for reliable predictions of their fate and transport in soil porous systems. Water flow and transport of bromide tracer and five pesticides (atrazine, imazaquin, sulfometuron methyl, S-metolachlor, and imidacloprid) through an undisturbed soil column of tropical Oxisol were analyzed using a one-dimensional numerical model. Laboratory column leaching experiment with three flow interruptions was conducted. The applied numerical model is based on Richards' equation for solving water flow and the advection-dispersion equation for solving solute transport. A global optimization method was used to evaluate the model's sensitivity to transport parameters and the uncertainty of model predictions. Within the Monte Carlo modeling framework, multiple forward simulations searching through the parametric space, were executed to describe the observed breakthrough curves. All pesticides were found to be relatively mobile. Experimental data indicated significant non-conservative behavior of bromide tracer. All pesticides, with the exception of imidacloprid, were found less persistent. Three of the five pesticides (atrazine, sulfometuron methyl, and S-metolachlor) were better described by the linear kinetic sorption model, while the breakthrough curves of imazaquin and imidacloprid were more appropriately approximated using nonlinear instantaneous sorption. Sensitivity analysis suggested that the model is most sensitive to sorption distribution coefficient. The prediction limits contained most of the measured points of the experimental breakthrough curves, indicating adequate model concept and model structure for the description of transport processes in the soil column under study.

  11. Recent trends in atmospheric methyl bromide: analysis of post-Montreal Protocol variability

    Directory of Open Access Journals (Sweden)

    S. A. Yvon-Lewis

    2009-08-01

    Full Text Available The atmospheric methyl bromide (CH3Br burden has declined in recent years, in response to the phaseout of agricultural and structural fumigation consumption under the amendments to the Montreal Protocol. The timing and magnitude of this decrease represents an opportunity to examine our current understanding of atmospheric CH3Br and its budget, response to the phaseout, and response to interannual variability in biomass burning and global OH. In this study, simulations obtained from a time-dependent global model of atmospheric CH3Br emissions and uptake are compared to observations from the NOAA flask network. The model includes a detailed gridded ocean model coupled to a time-dependant atmospheric 2-box model. The phaseout of CH3Br production for agricultural uses began in 1998, concurrent with the pulse in biomass burning associated with the 1998 El Niño. The combined effects of three factors (biomass burning, global OH, and anthropogenic phaseout appear to explain most of the observed atmospheric methyl bromide variability over the 1997–2008 period. The global budget remains imbalanced, with a large missing source indicated. The missing source does not exhibit a systematic decline during the phaseout period, and therefore, is not the result of significantly underestimating non-QPS agricultural CH3Br emissions. The model results suggest that the oceans should be less undersaturated than before the phaseout began.

  12. Thermodynamics of micellization of hexadecyltrimethylammonium bromide in propylene glycol-water mixture: A conductivity study

    Directory of Open Access Journals (Sweden)

    Janošević-Ležaić Aleksandra M.

    2014-01-01

    Full Text Available Micellization of hexadecyltrimethylammonium bromide (syn. cetyltrimethylammonium bromide, CTAB in propylene glycol-water (30% v/v binary mixture, as well as the thermodynamic properties of the resulting micelles, were investigated by electrical conductivity measurements. The conductivity data were used to determine both the critical micellar concentration (CMC and the micellar ionization degree (α of CTin the temperature range 298.2-310.2 K. The equilibrium model of micelle formation was applied in order to obtain the thermodynamic parameters (the standard molar Gibbs free energy, ΔGm0, enthalpy, ΔHm0 and entropy, ΔSm0 of the micellization process. The values of DGm0 and DHm0 were found to be negative at all investigated temperatures, while the values of ΔSm0 were positive and became more positive as temperature increased. A linear dependence between ΔSm0 and ΔHm0, i.e. an enthalpy-entropy compensation effect, was observed. [Projekat Ministarstva nauke Republike Srbije, br. 172015

  13. Modelling of a Tracer experiment (Bromide) at the lysimeter Wagna/Austria with MIKE-SHE

    Science.gov (United States)

    Reszler, Christian; Fank, Johann

    2015-04-01

    Data of a tracer experiment with Bromide at one of the three lysimeters in Wagna/Austria are used to test the unsaturated zone solute transport model in MIKE-SHE. On April 4th, 2005 50 mg/l of Bromide were applied on the lysimeter operated with conventional farming. At this time the lysimeter was covered with bare soil until the start of the cultivation of pumpkin one month later. Concentrations at the lysimeter bottom (180 cm depth) were measured and, after break-through, plant uptake was measured to quantify mass recovery. The model using the Richards-Van Genuchten-Mualem approach is setup by comprehensive data of vegetation and soil hydraulic properties available at the lysimeter. Water movement simulation in the unsaturated zone is tested against measured seepage rates at the lysimeter bottom and soil water contents in different soil depths in a period of five years. A sensitivity study shows that, particularly in the quaternary gravel zone two different parameter sets are necessary to represent the different dynamics of water content and seepage. With both two sets the general dynamics of the tracer experiment are simulated well. However, the early rapid rise of the measured concentrations could not be represented by either parameter set, which indicates a complex pore system consisting of different flow paths in the gravel zone, e.g., a system of matrix flow and macro-pore flow.

  14. Modeling Water Flow and Bromide Transport in a Two-Scale-Structured Lignitic Mine Soil

    Science.gov (United States)

    Dusek, J.; Gerke, H. H.; Vogel, T.; Maurer, T.; Buczko, U.

    2008-12-01

    Two-dimensional single- and dual-permeability simulations are used to analyze water and solute fluxes in heterogeneous lignitic mine soil at a forest-reclaimed mine spoil heap. The soil heterogeneity on this experimental site "Barenbrucker Hohe" resulted from inclined dumping structures and sediment mixtures that consist of sand with lignitic dust and embedded lignitic fragments. Observations on undisturbed field suction- cell lysimeters including tracer experiments revealed funneling-type preferential flow with lateral water and bromide movement along inclined sediment structures. The spatial distribution of soil structures and fragment distributions was acquired by a digital camera and identified by a supervised classification of the digital profile image. First, a classical single-domain modeling approach was proposed with spatially variable scaling factors inferred from image analyses. In the next step, a two-continuum scenario was constructed to examine additional effects of nonequilibrium on the flow regime. The scaling factors used for the preferential flow domain are here obtained from the gradient of the grayscale images. So far, the single domain scenarios failed to predict the bromide leaching patterns although water effluent could be described. Dual-permeability model allows the incorporation of structural effects and can be used as a tool to further testing other approaches that account for structure effects. The numerical study suggests that additional experiments are required to obtain better understanding of the highly complex transport processes on this experimental site.

  15. Pressure-Induced Structural and Optical Properties of Organometal Halide Perovskite-Based Formamidinium Lead Bromide.

    Science.gov (United States)

    Wang, Lingrui; Wang, Kai; Zou, Bo

    2016-07-01

    Organometal halide perovskites (OMHPs) are attracting an ever-growing scientific interest as photovoltaic materials with moderate cost and compelling properties. In this Letter, pressure-induced optical and structural changes of OMHP-based formamidinium lead bromide (FAPbBr3) were systematically investigated. We studied the pressure dependence of optical absorption and photoluminescence, both of which showed piezochromism. Synchrotron X-ray diffraction indicated that FAPbBr3 underwent two phase transitions and subsequent amorphization, leading directly to the bandgap evolution with redshift followed by blueshift during compression. Raman experiments illustrated the high pressure behavior of organic cation and the surrounding inorganic octahedra. Additionally, the effect of cation size and the different intermolecular interactions between organic cation and inorganic octahedra result in the fact that FAPbBr3 is less compressible than the reported methylammonium lead bromide (MAPbBr3). High pressure studies of the structural evolution and optical properties of OMHPs provide important clues in optimizing photovoltaic performance and help to design novel OMHPs with higher stimuli-resistant ability. PMID:27321024

  16. Acute hepatitis after starting pinaverium bromide in a patient taking mirtazapine.

    Science.gov (United States)

    Tak, Sandeep; Tak, Shubhanjali

    2014-01-01

    A 56-year-old man presented with chronic abdominal pain. He had been evaluated extensively in the recent past undergoing upper gastrointestinal endoscopy, colonoscopy and CT scan of the abdomen with normal results. The provisional diagnosis of irritable bowel syndrome was performed and pinaverium bromide was started. The patient had pre-existing hypertension, a major depressive disorder and gastro-oesophageal reflux disease. He had been taking nebivolol and pantoprazole for several years and mirtazapine for the last 1 year. The patient developed nausea, vomiting and anorexia after 5 days of starting pinaverium bromide. Investigations revealed marked elevation of liver enzymes and bilirubin. He was negative for HIV, HBSAg, anti-hepatitis C virus, IgM for hepatitis A virus, hepatitis E virus, antinuclear antibody and antimitochondrial antibody. An ultrasound showed mild hepatomegaly with hypoechoic echo texture; the rest of scan was normal. Pinaverium and mirtazapine were stopped immediately. The patient was treated symptomatically and his liver profile returned to normal after 4 weeks. PMID:25015163

  17. Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers; Bromid als Tracer zur Untersuchung der Wasserbewegung und der Nitratverlagerung in Boeden: Vergleich mit stabilisotopen Tracern

    Energy Technology Data Exchange (ETDEWEB)

    Russow, R.; Knappe, S. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Bad Lauchstaedt (Germany). Sektion Bodenforschung

    1999-02-01

    Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and {sup 15}N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D{sub 2}O, bromide and [{sup 15}N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers. [Deutsch] Fuer die Untersuchung der Wasserbewegung sowie der daran gekoppelten Nitrat-Verlagerung ist der Einsatz von Tracern das Mittel der Wahl. Dabei wird Bromid als Tracer haeufig bevorzugt, da es allgemein als ein repraesentativer Tracer fuer Wasser und als konservativer Tracer (nicht involviert in chemische und biologische Bodenprozesse) zur Untersuchung des Anionentransportes in Boeden angesehen wird und es gegenueber den stabilen Isotopen Deuterium und {sup 15}N billiger und einfacher zu bestimmen ist. Gegenueber den radioaktiven Tracern (z.B. Tritium), die zwar sehr empfindlich und einfach messbar sind, besteht der grosse Vorteil, dass, wie bei den stabilen Isotopen, keine Strahlenschutzmassnahmen ergriffen werden muessen. Es gibt jedoch auch einschraenkende Hinweise fuer die Verwendung von Bromid als Tracer im System Boden

  18. The Research on Programmable Control System of Lithium-Bromide Absorption Refrigerating Air Conditioner Based on the Network

    Directory of Open Access Journals (Sweden)

    Sun Lunan

    2016-01-01

    Full Text Available This article regard the solar lithium-bromide absorption refrigerating air conditioning system as the research object, and it was conducting adequate research of the working principle of lithium bromide absorption refrigerating machine, also it was analyzing the requirements of control system about solar energy air conditioning. Then the solar energy air conditioning control system was designed based on PLC, this system was given priority to field bus control system, and the remote monitoring is complementary, which was combining the network remote monitoring technology. So that it realized the automatic control and intelligent control of new lithium bromide absorption refrigerating air conditioning system with solar energy, also, it ensured the control system can automatically detect and adjust when the external conditions was random changing, to make air conditioning work effectively and steadily, ultimately ,it has great research significance to research the air conditioning control system with solar energy.

  19. Combination of ozonation and photocatalysis for purification of aqueous effluents containing formic acid as probe pollutant and bromide ion.

    Science.gov (United States)

    Parrino, F; Camera-Roda, G; Loddo, V; Palmisano, G; Augugliaro, V

    2014-03-01

    The treatment by advanced oxidation processes (AOPs) of waters contaminated by organic pollutants and containing also innocuous bromide ions may generate bromate ions as a co-product. In the present work heterogeneous photocatalysis and ozonation have individually been applied and in combination (integrated process) to degrade the organic compounds in water containing also bromide anions. The results show that: i) the sole photocatalysis does not produce bromate ions and in the case of its presence, it is able to reduce bromate to innocuous bromide ions; ii) the integration of photocatalysis and ozonation synergistically enhances the oxidation capabilities; and iii) in the integrated process bromate ions are not produced as long as some oxidizable organics are present.

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

    Directory of Open Access Journals (Sweden)

    N. Bobrowski

    2012-03-01

    Full Text Available Over a three year period, from 2006 to 2009, frequent scattered sun light DOAS measurements were conducted at Mt. Etna in a distance of around six kilometres downwind from the summit craters. During the same period and in addition to these measurements, volcanic observations were made by regularly visiting various parts of Mt. Etna.

    Results from these measurements and observations are presented and their relation is discussed. The focus of the investigation is the bromine monoxide/sulphur dioxide (BrO/SO2 ratio, and its variability in relation to volcanic processes.

    That the halogen/sulphur ratio can serve as a precursor or indicator for the onset of eruptive activity was already proposed by earlier works (e.g. Noguchi and Kamiya, 1963; Menyailov, 1975; Pennisi and Cloarec, 1998; Aiuppa, 2002. However, there is still a limited understanding today because of the complexity with which halogens are released, depending on magma composition and degassing conditions. Our understanding of these processes is far from complete, for example of the rate and mechanism of bubble nucleation, growth and ascent in silicate melts (Carroll and Holloway, 1994, the halogen vapour-melt partitioning and the volatile diffusivity in the melt (Aiuppa et al., 2009.

    With this study we aim to add one more piece to the puzzle of what halogen/sulphur ratios might tell about volcanic activities. Our data set shows an increase of the BrO/SO2 ratio several weeks prior to an eruption, followed by a decline before and during the initial phase of eruptive activities. Towards the end of activity or short afterwards, the ratio increases to baseline values again and remains more or less constant during quiet phases. To explain the observed evolution of the BrO/SO2 ratio, a first empirical model is proposed. This model suggests that bromine, unlike chlorine and fluorine, is less soluble in the magmatic melt than sulphur