Science.gov

Sample records for 1-4-hydroxyiminomethylpyridinium-4-4-carbamoylpyridinium butane dibromide

  1. A comparison of the ability of a new bispyridinium oxime--1-(4-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium)butane dibromide and currently used oximes to reactivate nerve agent-inhibited rat brain acetylcholinesterase by in vitro methods.

    PubMed

    Kuca, K; Kassa, J

    2003-12-01

    The efficacy of a new bispyridinium oxime 1-(4-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium)butane dibromide, called K048, and currently used oximes (pralidoxime, obidoxime, the oxime HI-6) to reactivate acetylcholinesterase inhibited by various nerve agents (sarin, tabun, cyclosarin, VX) was tested by in vitro methods. The new oxime K048 was found to be a more efficacious reactivator of nerve agent-inhibited acetylcholinesterase than pralidoxime (in the case of VX, tabun and cyclosarin), obidoxime (cyclosarin and tabun) and HI-6 (tabun) but it did not reach the efficacy of currently used oximes for the reactivation of acetylcholinesterase inhibited by sarin. Thus, the oxime K048 seems to be a relatively efficacious broad spectrum acetylcholinesterase reactivator and, therefore, it could be useful for the treatment of a nerve agent-exposed population if information about detection of the type of nerve agent is not available.

  2. Pretreatment with pyridinium oximes improves antidotal therapy against tabun poisoning.

    PubMed

    Lucić Vrdoljak, Ana; Calić, Maja; Radić, Bozica; Berend, Suzana; Jun, Daniel; Kuca, Kamil; Kovarik, Zrinka

    2006-11-10

    Oximes K033 [1,4-bis(2-hydroxyiminomethylpyridinium) butane dibromide] and K048 [1-(4-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium) butane dibromide] were tested as pretreatment drugs in tabun-poisoned mice followed by treatment with atropine plus K033, K048, K027 [1-(4-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium) propane dibromide], TMB-4 [1,3-bis(4-hydroxyiminomethylpyridinium) propane dibromide] and HI-6 [(1-(2-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium)-2-oxapropane dichloride)]. Oxime doses of 25% or 5% of its LD(50) were used for pretreatment 15 min before tabun-poisoning and for treatment 1 min after tabun administration to mice. The best therapeutic effect was obtained when oxime K048 (25% of its LD(50)) was used in both pretreatment and treatment with atropine. This regiment insured survival of all tested animals after the application of 10 LD(50) of tabun. In addition, since butyrylcholinesterase (BChE; EC 3.1.1.8) is considered an endogenous bioscavenger of anticholinesterase compounds and its interactions with oximes could be masked by AChE interactions, we evaluated kinetic parameters for interactions of tested oximes with native and tabun-inhibited human plasma BChE and compared them with results obtained previously for human erythrocyte acetylcholinesterase (AChE; EC 3.1.1.7). Progressive inhibition of BChE by tabun was slightly faster than that of AChE. The reactivation of tabun-inhibited BChE by oximes was very slow, and BChE binding affinity for oximes was lower than AChE's. Therefore, BChE could scavenge tabun prior to AChE inhibition, but fast oxime-assisted reactivation of tabun-inhibited AChE or protection of AChE by oxime against inhibition with tabun would not be obstructed by interaction between BChE and oximes.

  3. In vitro and in vivo evaluation of pyridinium oximes: mode of interaction with acetylcholinesterase, effect on tabun- and soman-poisoned mice and their cytotoxicity.

    PubMed

    Calić, Maja; Vrdoljak, Ana Lucić; Radić, Bozica; Jelić, Dubravko; Jun, Daniel; Kuca, Kamil; Kovarik, Zrinka

    2006-02-15

    The increased concern about terrorist use of nerve agents prompted us to search for new more effective oximes against tabun and soman poisoning. We investigated the interactions of five bispyridinium oximes: K027 [1-(4-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium) propane dibromide], K048 [1-(4-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium) butane dibromide], K033 [1,4-bis(2-hydroxyiminomethylpyridinium) butane dibromide], TMB-4 [1,3-bis(4-hydroxyiminomethylpyridinium) propane dibromide] and HI-6 [(1-(2-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium)-2-oxapropane dichloride)] with human erythrocyte acetylcholinesterase (AChE; E.C. 3.1.1.7) and their effects on tabun- and soman-poisoned mice. All the oximes reversibly inhibited AChE, and the enzyme-oxime dissociation constants were between 17 and 180 microM. Tabun-inhibited AChE was completely reactivated by TMB-4, K027 and K048, with the overall reactivation rate constants of 306, 376 and 673 min(-1)M(-1), respectively. The reactivation of tabun-inhibited AChE by K033 reached 50% after 24h, while HI-6 failed to reactivate any AChE at all. Soman-inhibited AChE was resistant to reactivation by 1mM oximes. All studied oximes protected AChE from phosphorylation with both soman and tabun. In vivo experiments showed that the studied oximes were relatively toxic to mice; K033 was the most toxic (LD50=33.4 mg/kg), while K027 was the least toxic (LD50=672.8 mg/kg). The best antidotal efficacy was obtained with K048, K027 and TMB-4 for tabun poisoning, and HI-6 for soman poisoning. Moreover, all tested oximes showed no cytotoxic effect on several cell lines in concentrations up to 0.8mM. The potency of the oximes K048 and K027 to protect mice from five-fold LD50 of tabun and their low toxicity make these compounds leading in the therapy of tabun poisoning. The combination of HI-6 and atropine is the therapy of choice for soman poisoning.

  4. Volatilization of ethylene dibromide from water

    USGS Publications Warehouse

    Rathbun, R.E.; Tai, D.Y.

    1987-01-01

    Overall mass-transfer coefficients for the volatilization of ethylene dibromide from water were measured simultaneously with the oxygen absorption coefficient in a laboratory stirred tank. Coefficients were measured as a function of mixing conditions in the water for two windspeeds. The ethylene dibromide mass-transfer coefficient depended on windspeed; the ethylene dibromide liquid-film coefficient did not, in agreement with theory. A constant relation existed between the liquid-film coefficients for ethylene dibromide and oxygen.

  5. 75 FR 74714 - DCNA (dicloran), Ziram, Diquat Dibromide, and Chloropicrin; Notice of Receipt of Requests to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-01

    ... dibromide use on soybean and sorghum, and chloropicrin use on mushroom casing, potting soil, and small area.......... Sorghum and soybean. Herbicide. 2749-530 Diquat dibromide 37.3% Diquat Dibromide....... Sorghum and soybean (seed SL AG. crop only). 2749-531 Diquat Manufacturing Diquat Dibromide....... Sorghum and...

  6. 76 FR 27317 - Ziram, Diquat Dibromide, and Chloropicrin; Order for Amendments To Terminate Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-11

    ......... Sorghum and soybean. Herbicide. 2749-530 Diquat Dibromide 37.3% Diquat Dibromide...... Sorghum and soybean (seed SL AG. crop only). 2749-531 Diquat Manufacturing Diquat Dibromide...... Sorghum and soybean (seed......... Sorghum and soybean (seed Desiccant. crop only). 82633-2 Sharda Diquat Diquat Dibromide...... Sorghum...

  7. 21 CFR 184.1165 - n-Butane and iso-butane.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false n-Butane and iso-butane. 184.1165 Section 184.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT... GRAS § 184.1165 n-Butane and iso-butane. (a) n-Butane and iso-butane (empirical formula C4H10, CAS...

  8. 21 CFR 184.1165 - n-Butane and iso-butane.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false n-Butane and iso-butane. 184.1165 Section 184.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1165 n-Butane and iso-butane. (a) n-Butane and...

  9. 21 CFR 184.1165 - n-Butane and iso-butane.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false n-Butane and iso-butane. 184.1165 Section 184.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1165 n-Butane and iso-butane. (a) n-Butane and...

  10. 21 CFR 184.1165 - n-Butane and iso-butane.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true n-Butane and iso-butane. 184.1165 Section 184.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1165 n-Butane and iso-butane. (a) n-Butane and...

  11. 21 CFR 184.1165 - n-Butane and iso-butane.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false n-Butane and iso-butane. 184.1165 Section 184.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1165 n-Butane and iso-butane. (a) n-Butane and...

  12. 40 CFR 80.82 - Butane blending.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF...; and (ii) The frequency of sampling and testing for the butane received from each butane supplier must... reformulated gasoline that has been downgraded to conventional gasoline, provided that the equivalent...

  13. Ignition properties of n-butane and iso-butane in a rapid compression machine

    SciTech Connect

    Gersen, S.; Darmeveil, J.H.; Mokhov, A.V.; Levinsky, H.B.

    2010-02-15

    Autoignition delay times of n-butane and iso-butane have been measured in a Rapid Compression Machine in the temperature range 660-1010 K, at pressures varying from 14 to 36 bar and at equivalence ratios {phi} = 1.0 and {phi} = 0.5. Both butane isomers exhibit a negative-temperature-coefficient (NTC) region and, at low temperatures, two-stage ignition. At temperatures below {proportional_to}900 K, the delay times for iso-butane are longer than those for the normal isomer, while above this temperature both butanes give essentially the same results. At temperatures above {proportional_to}720 K the delay times of the lean mixtures are twice those for stoichiometric compositions; at T < 720 K, the equivalence ratio is seen to have little influence on the ignition behavior. Increasing the pressure from 15 bar to 30 bar decreases the amplitude of the NTC region, and reduces the ignition delay time for both isomers by roughly a factor of 3. In the region in which two-stage ignition is observed, 680-825 K, the duration of the first ignition stage decreases sharply in the range 680-770 K, but is essentially flat above 770 K. Good quantitative agreement is found between the measurements and calculations for n-butane using a comprehensive model for butane ignition, including both delay times in the two-stage region, with substantial differences being observed for iso-butane, particularly in the NTC region. (author)

  14. Microbiology: Deep-sea secrets of butane metabolism

    NASA Astrophysics Data System (ADS)

    Ragsdale, Stephen W.

    2016-11-01

    Anaerobic microbes have been found to break down the hydrocarbon butane by a pathway with some similarities to anaerobic methane breakdown. Harnessing the butane pathway might enable biofuel generation. See Article p.396

  15. 21 CFR 582.1165 - Butane.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... used in accordance with good manufacturing or feeding practice. ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Butane. 582.1165 Section 582.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS,...

  16. Dose-response studies with ethylene dibromide. [Hydra oligactis

    SciTech Connect

    Adams, J.A.

    1987-04-01

    This study represents the first of a series of Descriptive-Reproductive-Toxicology Studies currently underway in the authors laboratory. Ethylene Dibromide (EDB) is suspected of causing infertility (especially in males), carcinogenesis, mutagenesis, and possibly teratogenesis. Coupling the suspected undesirable effects of EDB exposure with the fact that the chemical has broad utility (soil fumigant, fruit and grain fumigant, gasoline additive, etc.), EDB is an important agricultural and industrial toxin. In this study Hydra oligactis are exposed to EDB in an attempt to determine the acute toxicity of the chemical. Since Hydra is organized at the tissue level only, the toxin can be applied as a component of an artificial pond water (APW) medium. The EDB stock solution is 19:1 Acetone (emulsifier): EDB. Direct dilutions are made and exposures are continuous. The medium is exchanged daily after feeding. The LC50 at 48 hours incubation with EDb is 70 mgL . Compared to the LC50's for two common commercial PCB mixtures, Aroclors 1254 and 1016, EDb is shown to be a highly toxic chemical. The respective LC50's for the PCB's are 20 mgL (Aroclor 1254) and 5 mgL (Aroclor 1016) at 72 hrs. Sublethal EDB toxicity is currently being studied.

  17. Semen study of papaya workers exposed to ethylene dibromide

    SciTech Connect

    Ratcliffe, J.M.; Schrader, S.M.; Steenland, K.; Clapp, D.; Turner, T.

    1984-01-01

    A cross sectional semen and cytogenetic study was performed on male workers exposed to ethylene-dibromide (EDB) in the papaya fumigation industry in Hawaii. Semen analyses were conducted on 46 men in six fumigation facilities with an average length of employment of 5 years and airborne exposures to EDB ranging from 16 to 213 parts per billion. Statistically significant decreases in sperm count per ejaculate and the percentage of viable and motile sperm and increases in the proportion of specific morphological abnormalities were observed among exposed men when compared with controls. Semen volume and sperm concentration were also lower in the exposed group. No effect of exposure to EDB on sperm velocity, the overall proportion of sperm with normal morphology or YFF bodies was noted. The authors conclude that based on the decreases in sperm count, viability and motility and increases in certain types of morphological abnormalities among workers exposed to EDB, EDB may increase the risk of reproductive impairment in workers at exposure levels near the NIOSH recommended limit of 45 parts per billion and far below the current OSHA standard of 20 parts per million.

  18. 75 FR 6658 - Malathion, Diquat Dibromide, Metam-potassium and Metam-sodium; Notice of Receipt of Requests to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ... AGENCY Malathion, Diquat Dibromide, Metam-potassium and Metam-sodium; Notice of Receipt of Requests to... registrations containing the pesticides malathion, diquat dibromide, metam-potassium, and metam-sodium. The... would terminate metam-sodium and metam- potassium soil fumigant uses (agricultural application)...

  19. Differentiation of diastereotopic bromine atoms in SN2 reactions of gem-dibromides.

    PubMed

    Münster, Niels; Harms, Klaus; Koert, Ulrich

    2012-02-11

    A novel directed S(N)2 reaction of conformationally biased gem-dibromides and an arenesulfinate anion is described. The reaction results in the diastereoselective formation of α-bromosulfones. The selectivity originates from pre-coordination of the nucleophile to a free hydroxyl group in the γ-position.

  20. Synthesis of an Advanced Intermediate of the Jatrophane Diterpene Pl-4: A Dibromide Coupling Approach

    PubMed Central

    2013-01-01

    The preparation of an advanced intermediate toward the synthesis of the jatrophane diterpene Pl-4 is described. The key step is a regioselective chelation-controlled lithiation of the (Z)-configured bromide in the corresponding vinyl dibromide precursor. The method outlined within this Article is suitable for the facile access of sterically hindered internal vinyl halides for further coupling reactions. PMID:23895274

  1. Phosphorus-Containing Bis-allenes: Synthesis and Heterocyclization Reactions Mediated by Iodine or Copper Dibromide.

    PubMed

    Essid, I; Laborde, C; Legros, F; Sevrain, N; Touil, S; Rolland, M; Ayad, T; Volle, J-N; Pirat, J-L; Virieux, D

    2017-03-30

    Bisphosphorylallenes were easily obtained in multigram scale from the Wittig-type rearrangement of bispropargyl alcohols. Unlike other conjugated bis-allenes, these reagents underwent a double cyclization mediated by iodine or copper dibromide leading to the formation of bis-1,2-oxaphospholenes.

  2. Anaerobic Biodegradation of Ethylene Dibromide and 1,2-Dichloroethane in the Presence of Fuel Hydrocarbons

    EPA Science Inventory

    Field evidence from underground storage tank sites where leaded gasoline leaked indicates the lead scavengers 1,2- dibromoethane (ethylene dibromide, or EDB) and 1,2- dichloroethane (1,2-DCA) may be present in groundwater at levels that pose unacceptable risk. These compounds are...

  3. Exploring Butane Hash Oil Use: A Research Note.

    PubMed

    Miller, Bryan Lee; Stogner, John M; Miller, J Mitchell

    2016-01-01

    The practice of "dabbing" has seen an apparent upswing in popularity in recent months within American drug subcultures. "Dabbing" refers to the use of butane-extracted marijuana products that offer users much higher tetrahydrocannabinol content than flower cannabis through a single dosage process. Though considerably more potent than most marijuana strains in their traditional form, these butane hash oil products and the practice of dabbing are underexplored in the empirical literature, especially in prohibition states. A mixed-methods evaluation of a federally funded treatment program for drug-involved offenders identified a small sample (n = 6) of butane hash oil users and generated focus group interview data on the nature of butane hash oil, the practice of dabbing, and its effects. Findings inform discussion of additional research needed on butane hash oil and its implications for the ongoing marijuana legalization debate, including the diversity of users, routes of administration, and differences between retail/medical and prohibition states.

  4. Food contamination with styrene dibromide via packaging migration of leachate from polystyrene cold-storage insulation.

    PubMed

    Bendall, Justin G

    2007-04-01

    During distribution through an offshore transportation and cold-storage network, a multitonne consignment of cheese became contaminated, as apparent by a surface taint on some of the cheese blocks. Analysis of the volatile aroma compounds revealed that the taint was caused by styrene dibromide, estimated to be present in the tainted cheese at less than nanogram per gram concentrations. Condensed water, which had accumulated within the polystyrene insulation over a period of years, had been released by physical damage to the walls of an old cold store, and organic contaminants from the leached water had migrated through the packaging material of the cheese bags. Because styrene dibromide is toxic and mutagenic, its presence was intolerable in food intended for human consumption, and the consignment of cheese was ordered to be destroyed.

  5. Gas-film coefficients for the volatilization of ethylene dibromide from water

    USGS Publications Warehouse

    Rathbun, R.E.; Tal, D.Y.

    1986-01-01

    Gas-film coefficients for the volatilization of ethylene dibromide (EDB) and water were determined in the laboratory as a function of wind speed and temperature. The ratio of the coefficients was independent of wind speed and increased slightly with temperature. Use of this ratio with an environmentally determined gas-film coefficient for the evaporation of water permits determination of the gas-film coefficient for the volatilization of EDB from environmental waters.

  6. Study on propane-butane gas storage by hydrate technology

    NASA Astrophysics Data System (ADS)

    Hamidi, Nurkholis; Wijayanti, Widya; Widhiyanuriyawan, Denny

    2016-03-01

    Different technology has been applied to store and transport gas fuel. In this work the storage of gas mixture of propane-butane by hydrate technology was studied. The investigation was done on the effect of crystallizer rotation speed on the formation of propane-butane hydrate. The hydrates were formed using crystallizer with rotation speed of 100, 200, and 300 rpm. The formation of gas hydrates was done at initial pressure of 3 bar and temperature of 274K. The results indicated that the higher rotation speed was found to increase the formation rate of propane-butane hydrate and improve the hydrates stability.

  7. Biofiltration control of VOC emissions: Butane and benzene

    SciTech Connect

    Allen, E.R.

    1995-12-31

    Laboratory studies were conducted on the biological elimination of n-butane and benzene from air streams using activated sludge-treated compost biofilters. Four types of experimental biofilter systems were developed: a bench scale packed tower system used primarily for kinetic studies; a small scale column system used to study the effects of different filter media on n-butane removal; a three stage system used to study benzene elimination; and a static batch biofilter system used to study the effects of temperature, compost water content, compost pH, and initial benzene concentrations on benzene elimination. Removal efficiencies greater than 90% were obtained for n-butane. Removal followed first order kinetics at inlet concentrations less than 25 ppM n-butane and zero order kinetics above 100 ppM n-butane. Removal of benzene followed fractional order kinetics for inlet concentrations from 15 to 200 ppM benzene. Thus, the removal of benzene is both mass transfer and bioreaction limited for the concentration range studied. The removal efficiency of benzene was found to be highly dependent on compost water content, compost pH, and temperature. Compost showed a low capacity for benzene removal, which suggested that degradation of these hydrocarbons required different species of microorganisms.

  8. Explicit photochemical mechanism for atmospheric oxidation of n-butane

    SciTech Connect

    Wen, L.

    1992-01-01

    Alkanes, being an important component of atmosphere, serve as precursors to ozone formation in urban and rural air masses. An explicit photochemical oxidation mechanism for n-butane, which is the major hydrocarbon component of automobile exhaust, is created in this work. The yields of organic nitrates from n-butane, n-pentane, and methyl ethyl ketone photooxidations were studied in Teflon bag and smog chamber experiments. Comparing with the expression currently using the most atmospheric model studies, the total butyl nitrates yield obtained in this work is about 36% lower, and the ratio of primary to secondary butyl nitrates is slightly higher. It is shown in this work that the yields of hydroxyl and carbonyl butyl nitrates are very low, and can be ignored in the explicit photochemical mechanisms. The explicit photochemical oxidation mechanism for methyl ethyl ketone (MEK) was created first because it is the major product from photooxidation of n-butane. The explicit photochemical oxidation mechanism for n-butane, created later, draws on the MEK mechanism. The mechanisms were tested by comparing model predictions with experimental observations from smog chamber experiments. The comparisons were conducted for species which had experimental observation data, such as O[sub 3], NO, and NO[sub 2], n-butane, MEK, organic nitrates, and aldehydes species. The sixteen smog chamber experiments, used in model simulations, were conducted during 1978 to 1992. The mechanisms are mainly based on the available kinetic data in literature and the experimental result in this work. The rate constants for some reactions in the mechanisms were adjusted to make a better fit with the experimental observations. These reactions were: reaction of OH and n-butane to form secondary butyl peroxy radical, decomposition of secondary butoxy radical, and reaction of OH and MEK.

  9. Induction of delayed mutations by benzene and ethylene dibromide in drosophila

    SciTech Connect

    Kale, P.; Kale, R.

    1995-08-01

    Two carcinogens, ethylene dibromide and benzene, were used to induce delayed (germinal mosaic) sex-linked recessive lethal mutations in spermatozoa and spermatids of adult Drosophila males. Significant numbers of delayed mutations (in F{sub 3}) were scored in absence of conventional (in F{sub 2}) mutations. A large proportion of nonlethal F{sub 2} cultures carried delayed mutations, so much so that, in some cultures, all F{sub 2} females were carriers of mutations. The mechanism through which single strand damage to treated X chromosomes can result in such delayed lethals is discussed. These observations indicate that the delayed mutation test should be used for testing the mutagenicity of environmental compounds, especially carcinogens, which tested negative in the conventional sex-linked recessive lethal mutation test. The data will support the relationship between mutagenesis and carcinogenesis and, also will further enhance the sensitivity of the Drosophila mutation assay. 12 refs., 4 tabs.

  10. A critical analysis on the rotation barriers in butane.

    PubMed

    Mo, Yirong

    2010-04-16

    As a textbook prototype for the introduction of steric hindrance in organic chemistry, the elucidation of the butane rotation barriers is fundamental for structural theory, and requires a consistent theoretical model to differentiate the steric and electronic effects. Here we employed the BLW method to probe the electronic (hyperconjugative) interactions. Results show that although there are stronger hyperconjugative interactions in the staggered anti and gauche conformers than the eclipsed structures, the energy curve and barriers are dominated by the steric repulsion.

  11. Thermophilic archaea activate butane via alkyl-coenzyme M formation.

    PubMed

    Laso-Pérez, Rafael; Wegener, Gunter; Knittel, Katrin; Widdel, Friedrich; Harding, Katie J; Krukenberg, Viola; Meier, Dimitri V; Richter, Michael; Tegetmeyer, Halina E; Riedel, Dietmar; Richnow, Hans-Hermann; Adrian, Lorenz; Reemtsma, Thorsten; Lechtenfeld, Oliver J; Musat, Florin

    2016-11-17

    The anaerobic formation and oxidation of methane involve unique enzymatic mechanisms and cofactors, all of which are believed to be specific for C1-compounds. Here we show that an anaerobic thermophilic enrichment culture composed of dense consortia of archaea and bacteria apparently uses partly similar pathways to oxidize the C4 hydrocarbon butane. The archaea, proposed genus 'Candidatus Syntrophoarchaeum', show the characteristic autofluorescence of methanogens, and contain highly expressed genes encoding enzymes similar to methyl-coenzyme M reductase. We detect butyl-coenzyme M, indicating archaeal butane activation analogous to the first step in anaerobic methane oxidation. In addition, Ca. Syntrophoarchaeum expresses the genes encoding β-oxidation enzymes, carbon monoxide dehydrogenase and reversible C1 methanogenesis enzymes. This allows for the complete oxidation of butane. Reducing equivalents are seemingly channelled to HotSeep-1, a thermophilic sulfate-reducing partner bacterium known from the anaerobic oxidation of methane. Genes encoding 16S rRNA and methyl-coenzyme M reductase similar to those identifying Ca. Syntrophoarchaeum were repeatedly retrieved from marine subsurface sediments, suggesting that the presented activation mechanism is naturally widespread in the anaerobic oxidation of short-chain hydrocarbons.

  12. [Cardiac arrest and hypothermia caused by suicidal intoxication with butane: a case report].

    PubMed

    Jansen, Gerrit; Mertzlufft, Fritz; Kirchhoff, Carsten; Bach, Friedhelm

    2012-02-01

    In the emergency medicine field cases of intoxication by sniffing agents do not occur very often. Nevertheless, considering the easy availability of butane the option of abuse especially by adolescent persons cannot be ignored. Although many cases of accidental death caused by malignant arrhythmia are described ("Sudden sniffing death syndrome"), suicide attempts using butane are a rarity. In this case the emergency treatment has to allow for special pathophysiological changes explained by physicochemical characteristics of butane. The following case report describes the symptomatology and pre-hospital treatment of an intoxication by butane with a suicidal intention.

  13. Effects of ethylene dibromide on hydra oligactis: parent and offspring toxicity study

    SciTech Connect

    Wilson, B.A.; Adams, J.A.

    1988-04-01

    Ethylene Dibromide (EDB) has become increasingly prevalent in the environment due to its uses as soil, fruit, and grain fumigants, lead scavengers in petrol, and industrial solvent. Because of its increasing environmental prevalence and its proposed toxic effects of EDB on Hydras, parents (P1) which have been pre-exposed to an established sublethal concentration for 14 days. The effect of nonexposed offspring (F1/P2) taken from pre-exposed parents (P1) versus their untreated offspring (F2) will also be evaluated. This mortality study revealed that the LC50 of both parents and F1's shifted from 50 mg/L, to 106.25 mg/L and 118.75 mg/L respectively, which suggest that exposed Hydras possibly become more tolerant to EDB. In the F2 generation, after 48 and 72 hrs 10% mortality was observed in the 200 mg/L group, 30% at 250 mg/L and 20% at 300 mg/L which indicated that the resistance to EDB toxicity is inheritable. There is also a strong dose-response correlation between EDB concentration and mortality.

  14. Semen quality in papaya workers with long term exposure to ethylene dibromide.

    PubMed Central

    Ratcliffe, J M; Schrader, S M; Steenland, K; Clapp, D E; Turner, T; Hornung, R W

    1987-01-01

    To examine whether long term occupational exposure to ethylene dibromide (EDB) affects semen quality a cross sectional study of semen quality was conducted among 46 men employed in the papaya fumigation industry in Hawaii, with an average duration of exposure of five years and a geometric mean breathing zone exposure to airborne EDB of 88 ppb (eight hour time weighted average) and peak exposures of up to 262 ppb. The comparison group consisted of 43 unexposed men from a nearby sugar refinery. Statistically significant decreases in sperm count per ejaculate, the percentage of viable and motile sperm, and increases in the proportion of sperm with specific morphological abnormalities (tapered heads, absent heads, and abnormal tails) were observed among exposed men by comparison with controls after consideration of smoking, caffeine and alcohol consumption, subject's age, abstinence, history of urogenital disorders, and other potentially confounding variables. No effect of exposure to EDB on sperm velocity, the overall proportion of sperm with normal morphology, or YFF bodies was observed. These data strongly suggest that EDB may increase the risk of reproductive impairment in workers at exposure levels near the National Institute for Occupational Safety and Health recommended limit of 45 ppb (as an eight hour time weighted average) and far below the current standard of the Occupational Safety and Health Administration of 20 ppm. PMID:3297130

  15. Dual Carbon-Bromine Stable Isotope Analysis Allows Distinguishing Transformation Pathways of Ethylene Dibromide.

    PubMed

    Kuntze, Kevin; Kozell, Anna; Richnow, Hans H; Halicz, Ludwik; Nijenhuis, Ivonne; Gelman, Faina

    2016-09-20

    The present study investigated dual carbon-bromine isotope fractionation of the common groundwater contaminant ethylene dibromide (EDB) during chemical and biological transformations, including aerobic and anaerobic biodegradation, alkaline hydrolysis, Fenton-like degradation, debromination by Zn(0) and reduced corrinoids. Significantly different correlation of carbon and bromine isotope fractionation (ΛC/Br) was observed not only for the processes following different transformation pathways, but also for abiotic and biotic processes with, the presumed, same formal chemical degradation mechanism. The studied processes resulted in a wide range of ΛC/Br values: ΛC/Br = 30.1 was observed for hydrolysis of EDB in alkaline solution; ΛC/Br between 4.2 and 5.3 were determined for dibromoelimination pathway with reduced corrinoids and Zn(0) particles; EDB biodegradation by Ancylobacter aquaticus and Sulfurospirillum multivorans resulted in ΛC/Br = 10.7 and 2.4, respectively; Fenton-like degradation resulted in carbon isotope fractionation only, leading to ΛC/Br ∞. Calculated carbon apparent kinetic isotope effects ((13)C-AKIE) fell with 1.005 to 1.035 within expected ranges according to the theoretical KIE, however, biotic transformations resulted in weaker carbon isotope effects than respective abiotic transformations. Relatively large bromine isotope effects with (81)Br-AKIE of 1.0012-1.002 and 1.0021-1.004 were observed for nucleophilic substitution and dibromoelimination, respectively, and reveal so far underestimated strong bromine isotope effects.

  16. Cost effective propulsion systems for small satellites using butane propellant

    NASA Astrophysics Data System (ADS)

    Gibbon, D.; Underwood, C.; Sweeting, M.; Amri, R.

    2002-07-01

    This paper will describe the work performed at the Surrey Space Centre to produce cost effective propulsion systems for small spacecraft with relatively low deltaV (ΔV) requirements. Traditionally, cold gas nitrogen systems have been used for this type of application, however they have high storage volume requirements. This can be a problem on small spacecraft, which are typically volume limited. An alternative solution is to use liquefied gases, which store as liquids, hence have reasonable density levels, and can be used in a cold gas thruster. At the Surrey Space Centre, butane has been selected as the propellant of choice. Although it has slightly lower specific impulse performance than nitrogen, it has a significantly higher storage density and it stores at a very low pressure, hence no regulation system is required. On 28 th June 2000 Surrey Satellite Technology Ltd (SSTL) launched it first nanosatellite SNAP-1. This 6.5kg spacecraft was equipped with a small cold gas propulsion system utilising 32.6 grams of butane propellant. During the propulsion system operation phase the spacecraft's semi major axis was raised by nearly 4 kilometers using the propulsion system. The design of the propulsion system will be described and the low cost features highlighted. Telemetry data will be used to describe the propulsion operations and an overall mission specific impulse will be derived. SSTL are currently under contract to build three Earth observation spacecraft for a Disaster Monitoring Constellation (DMC). Each spacecraft will weigh approx 100 kg and have a ΔV requirement of 10 m/sec. A butane system has been designed and manufactured to meet the requirements of these spacecraft. The system is based very much on the flight heritage of the SNAP-1 system, with the addition of greater propellant storage capacity. The lessons learnt from the SNAP-1 operation will be reviewed and the resulting design improvements on the DMC propulsion systems will be detailed.

  17. Butane Hash Oil Burns Associated with Marijuana Liberalization in Colorado.

    PubMed

    Bell, Cameron; Slim, Jessica; Flaten, Hanna K; Lindberg, Gordon; Arek, Wiktor; Monte, Andrew A

    2015-12-01

    Butane hash oil (BHO), also known as "amber," "dab," "glass," "honey," "shatter," or "wax," is a potent marijuana concentrate, containing up to 90 % tetrahydrocannabinol (THC). BHO is easily manufactured using highly volatile butane as a solvent. Our objective was to characterize hydrocarbon burns associated with BHO manufacture in Colorado. This was a cross-sectional study utilizing the National Burn Repository to capture all hydrocarbon burns reported to the local burn center from January 1st, 2008, through August 31st, 2014. We abstracted demographic and clinical variables from medical records for patients admitted for hydrocarbon burns associated with butane hash oil extraction. Twenty-nine cases of BHO burns were admitted to the local burn center during the study period. Zero cases presented prior to medical liberalization, 19 (61.3 %) during medical liberalization (Oct 2009-Dec 2013), and 12 (38.7 %) in 2014 since legalization. The majority of cases were Caucasian (72.4 %) males (89.7 %). Median age was 26 (range 15-58). The median total-body-surface-area (TBSA) burn size was 10 % (TBSA range 1-90 %). Median length of hospital admission was 10 days. Six required intubation for airway protection (21 %). Nineteen required skin grafting, eight wound care only, one required surgical fracture repair, and one required surgical debridement. Hydrocarbon burns associated with hash oil production have increased since the liberalization of marijuana policy in Colorado. A combination of public health messaging, standardization of manufacturing processes, and worker safety regulations are needed to decrease the risks associated with BHO production.

  18. Structure, spectroscopy and DFT calculations of 1,2-di(3-hydroxymethylpyridinium)ethane dibromide

    NASA Astrophysics Data System (ADS)

    Komasa, Anna; Barczyński, Piotr; Ratajczak-Sitarz, Małgorzata; Katrusiak, Andrzej; Dega-Szafran, Zofia; Szafran, Mirosław

    2016-09-01

    The molecular structure of 1,2-di(3-hydroxymethylpyridinium)ethane dibromide (1) has been characterized by X-ray diffraction, B3LYP/6-311++G(d,p) calculations, FTIR, Raman and NMR spectra. The crystals are monoclinic, space group C2/c. 1,2-Di(3-hydroxymethylpyridinium)ethane dication and hydrogen-bonded bromide anions in crystals are located at the inversion center. The both CH2OH groups are engaged in two equal length hydrogen bonds with bromide anions. Two structures (2) and (3) were optimized at the B3LYP/6-311++G(d,p) level of theory. The optimized complex (2) resembles the crystal structure, while complex (3) is preferred energetically. The O⋯Br- hydrogen bonds distances are: 3.289(2) Å in crystals (1), but in the optimized structures (2) and (3) they are 3.303 Å and 3.461 Å, respectively. The investigated complex is additionally stabilized by the N+⋯Br- electrostatic attractions. The potential energy distributions (PED) were used for the assignments of IR and Raman frequencies in the experimental and calculated spectra of the title compound. The FTIR spectrum of (1) is consistent with the X-ray results. Interpretation of the 1H and 13C NMR spectra in DMSO-d6 has been based on 2D experiments. The calculated GIAO/B3LYP/6-311++G(d,p) magnetic shielding constants have been used to predict 1H and 13C chemical shifts for the optimized structures of (2) and (3).

  19. Movement and fate of ethylene dibromide (EDB) in ground water in Seminole County, Georgia

    USGS Publications Warehouse

    McConnell, J.B.

    1987-01-01

    An investigation to assess the movement and fate of ethylene dibromide (EDB) in the Upper Floridan aquifer (formerly the principal artesian aquifer) was conducted, because a previous investigation conducted in August 1983, had found EDB contamination of the aquifer in about a 4 sq mi area in central Seminole County, Georgia. Analyses of water from wells resampled in June 1985 indicate that EDB was present in the groundwater 2 yr after last being applied as a soil fumigant. The investigation revealed that groundwater recharge and irrigation pumping between August 1983 and June 1985 did not substantially change the areal extent of EDB in the Upper Floridan aquifer but concentrations of EDB seem to be declining. The highest concentrations again were found in two irrigation wells near Buck Hole, a sinkhole in a swampy depression in central Seminole County. EDB concentrations in these two wells ranged from 1.5 to 13 micrograms/L. Samples from two of three wells in the residuum near Buck Hole also had detectable concentrations of EDB. The presence of EDB in water samples from wells tapping the residuum and wells tapping the Upper Floridan aquifer indicates that agriculturally applied EDB has moved downward from the surface soils through the residuum and into the aquifer. Results of aquifer tests conducted in a similar geohydrologic setting suggest that local pumping from the highly transmissive aquifer may accelerate downward movement of water and EDB. Potentiometric surface maps of the Upper Floridan aquifer indicate that east of Fishpond Drain, where the highest concentrations of EDB were detected, the direction of groundwater flow and the direction of potential EDB transport generally is south-southeasterly. However, the movement of an EDB plume from the area of relatively high concentrations near Buck Hole along inferred groundwater flow lines was not detected. (Author 's abstract)

  20. Experimental and DFT studies of initiation processes for butane isomerization over sulfated-zirconia catalysts

    SciTech Connect

    Hong, Z.; Watwe, R.M.; Natal-Santiago, M.A.; Hill, J.M.; Dumesic, J.A.; Fogash, K.B.; Kim, B.; Masqueda-Jimenez, B.I.

    1998-09-10

    Reaction kinetics studies were conducted of isobutane and n-butane isomerization at 423 K over sulfated-zirconia, with the butane feeds purified of olefins. Dihydrogen evolution was observed during butane isomerization over fresh catalysts, as well as over catalysts selectively poisoned by preadsorbed ammonia. Butane isomerization over sulfated-zirconia can be viewed as a surface chain reaction comprised of initiation, propagation, and termination steps. The primary initiation step in the absence of feed olefins is considered to be the dehydrogenation of butane over sulfated-zirconia, generating butenes which adsorb onto acid sites to form protonated olefinic species associated with the conjugate base form of the acid sites. Quantum-chemical calculations, employing density-functional theory, suggest that the dissociative adsorption of dihydrogen, isobutylene hydrogenation, and dissociative adsorption of isobutane are feasible over the sulfated-zirconia cluster, and these reactions take place over Zr-O sites.

  1. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with argon

    SciTech Connect

    Malinina, A. A. Malinin, A. N.

    2015-03-15

    Results are presented from studies of the optical characteristics and parameters of the plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with argon—the working medium of an exciplex gas-discharge emitter. It is established that the partial pressures of mercury dibromide vapor and argon at which the average and pulsed emission intensities in the blue—green spectral region (λ{sub max} = 502 nm) reach their maximum values are 0.6 and 114.4 kPa, respectively. The electron energy distribution function, the transport characteristics, the specific power spent on the processes involving electrons, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering from the molecules and atoms of the working mixture are determined by numerical simulation, and their dependences on the reduced electric field strength are analyzed. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules for a reduced electric field of E/N = 20 Td, at which the maximum emission intensity in the blue—green spectral region was observed in this experiment, is found to be 8.1 × 10{sup −15} m{sup 3}/s.

  2. [Case report of butane intoxication with fatal outcome].

    PubMed

    Kirichek, A V; Rassinskaia, L A; Shirokova, L V; Simonov, E A

    2009-01-01

    Forensic medical examiners know numerous cases of non-occupational intoxication (e.g. suicide, drug intoxication, household poisoning) but rarely encounter cases of occupational poisoning with household gases. Collection of forensic chemical facts testifying to the presence of saturated hydrocarbons in blood and other tissues is a challenging task. It hampers evaluation of their toxic effect on human brain for the purpose of forensic medical examination. A method is proposed for the analysis of biological materials allowing for the detection of natural alkanes, such as butane, along with recommendations on taking samples for chemical analysis in suspected cases of poisoning with household gases. The method is designed to be employed in combination with up-to-date analytical techniques, such as capillary gas chromatography and mass spectrometry.

  3. A fatal case of n-butane poisoning after inhaling anti-perspiration aerosol deodorant.

    PubMed

    Ago, Mihoko; Ago, Kazutoshi; Ogata, Mamoru

    2002-06-01

    We report a case of sudden death due to n-butane poisoning after the inhalation of anti-perspiration aerosol deodorant. The deceased was a 15-year-old boy who was found unresponsive on the road, and was pronounced dead after 1.25h. A spray can of anti-perspiration deodorant and vinyl bags were found in a thicket near the scene. An autopsy revealed pulmonary edema, cerebral edema and congestion of the organs. Using qualitative gas chromatography/mass spectrometry, the existence of n-butane was ascertained. The concentration of n-butane (in microl/ml or microl/g) was estimated to be 15.3 in the blood, 13.3 in the brain, 26.6 in the liver, 7.5 in the lung, and 13.6 in the kidney. These n-butane levels in the blood and in the tissues were higher than those of previous reports of death associated with n-butane inhalation. We concluded that the cause of death was n-butane poisoning and presumed that n-butane in the can of anti-perspiration aerosol deodorant induced fatal cardiac arrhythmia.

  4. Forestomach lesions induced by butylated hydroxyanisole and ethylene dibromide: a scientific and regulatory perspective.

    PubMed

    Moch, R W

    1988-01-01

    Selected pathology lesions from 9 studies, 5 with butylated hydroxyanisole (BHA) and 4 with ethylene dibromide (EDB) are reviewed and their relative importance in regulatory evaluation is discussed. When Fischer 344 (F344) rats were fed BHA at 0.5% and 2.0% of the diet for 2 years, an increased number of rats of both sexes had epithelial hyperplasia of the forestomach at both treatment levels, compared to controls. At the 2.0% level, an increased number of rats had forestomach papilloma or forestomach squamous cell carcinoma. In a second study, in which F344 rats were fed BHA at 1.0% and 2.0% of the diet for 2 years, increased numbers of rats in both treatment groups were reported to have hyperplasia or papilloma of the forestomach. At the 2.0% level, increased numbers of rats developed squamous cell carcinoma of the forestomach. More Syrian golden hamsters fed BHA at 1.0% and 2.0% of the diet for 2 years reportedly had hyperplasia, papilloma or squamous cell carcinoma of the forestomach than did nontreated animals. Ingestion of BHA at 0.5% and 1.0% of the diet by B6C3F1 mice for 2 years was reported to produce an increase of animals with hyperplasia or papilloma of the forestomach at both dosage levels, compared to nontreated mice. When beagle dogs were fed BHA at 1.0% and 1.3% of the diet for 180 days, no lesions/tumors of the distal esophagus or stomach were identified at gross necropsy or by light or electron microscopy. When EDB was administered by gavage to Osborne-Mendel rats and B6C3F1 mice under conditions of the National Toxicology Bioassay Program, more rats and mice, both male and female, developed squamous cell carcinoma of the forestomach than did nontreated groups. EDB administered via inhalation to F344 rats and B6C3F1 mice did not cause squamous cell carcinoma of the forestomach; however, other neoplasms occurred which were considered to be treatment-related. Information gleaned from the BHA and EDB studies with multiple animal species facilitated

  5. Investigation of ethylene dibromide (EDB) in ground water in Seminole County, Georgia

    USGS Publications Warehouse

    McConnell, James B.; Hicks, D.W.; Lowe, L. E.; Cohen, S.Z.; Jovanovich, A.P.

    1984-01-01

    An investigation of ground water in Seminole County, Georgia, for ethylene dibromide (EDB) was conducted in August 1983 by the U.S. Geological Survey in cooperation with the Exposure Assessment Branch of the U.S. Environmental Protection Agency. The purpose of the investigation was to determine whether EDB, which was previously detected in ground-water samples from four neighboring wells, was localized in the vicinity of the wells or was more widespread in the ground-water system. EDB was detected in 6 of 19 wells sampled. Concentrations ranged from 0.03 to 11.8 micrograms per liter. Five of the six samples that contained EDB were collected from irrigation wells, and one was collected from a domestic well. Concentrations of 4.5 and 11.8 micrograms per liter were found in two irrigation wells located near Buck Hole, a sinkhole in a swampy depression in central Seminole County. EDB was not detected in samples from the remaining 10 irrigation and 3 domestic wells and the surface-water site (detection level less than 0.01 microgram per liter). Nine core samples were collected from a borehole near one of the irrigation wells that had high EDB concentrations. EDB was found in a core sample near the surface and in samples from depths of 24 to 25, 34 to 35, and 39 to 40 feet in the residuum. EDB concentrations in the core samples ranged from 0.06 to 2.4 micrograms per kilogram. EDB in the aquifer was found in a 4-square-mile area of the county in the vicinity of Buck Hole. EDB application information and the local hydrogeology indicate that EDB contamination in ground water in Seminole County probably is due to soil fumigation with EDB. Apparently, EDB moves downward through the residuum and, through undetermined pathways, enters the aquifer. However, because the high concentration of EDB in the aquifer seems to be localized in the Buck Hole area, the possibility of contamination from an EDB fumigant spill cannot be disregarded at this time.

  6. Acute Intramuscular Toxicity (LD50) of 1,1’-Methylenebis (4- (Hydroxyimino) Methyl) Pyridinium Dibromide, (MMB-4) in Male Mice

    DTIC Science & Technology

    1983-04-01

    METHODS Test Substance Chemical name: 1,1 ’-Methylenebis[4-[(hydroxyimino) methyl] pyridinium] dibromide, (01MB-4) (TAO03) Chemical Abstract Service...name: 1,1 ’-Methylenebis[4-[(hydroxyimino)methyl] pyridiniumldibromide, (CMIB-1 𔃾 Chemical Abstract Service Registry Number: None Molecular formula

  7. Catalytic reactive distillation process development for 1,1 diethoxy butane production from renewable sources.

    PubMed

    Agirre, I; Barrio, V L; Güemez, B; Cambra, J F; Arias, P L

    2011-01-01

    Some acetals can be produced from renewable resources (bioalcohols) and seem to be good candidates for different applications such as oxygenated diesel additives. In the present case the production of 1,1 diethoxy butane from bioethanol and butanal is presented. Butanal can be obtained from biobutanol following a partial oxidation or a dehydrogenation process. In this paper innovative process development about the synthesis of the mentioned acetal including catalytic reactive distillation experimental and simulation results will be presented and discussed. Katapak SP modules containing Amberlyst 47 resin were used as structured catalytic packings. This reactive system allowed reaching higher conversions than the equilibrium ones at the same temperatures. All the experimental data gathered allowed to tune a simulation model for the reactive distillation operation which showed a fairly good behavior in order to perform initial 1,1 diethoxy butane production process design studies.

  8. PHYSICAL PROPERTIES OF FLUORINATED PROPANE AND BUTANE DERIVATIVES AS ALTERNATIVE REFRIGERANTS

    EPA Science Inventory

    Physical property measurements are presented for 24 fluorinated propane and butane derivatives and one fluorinated ether. These measurements include melting point, boiling point, vapor pressure below the boiling point, heat of vaporization at the boiling point, critical propertie...

  9. Surface diffusion and desorption kinetics for perfluoro-n-butane on Ru(001)

    NASA Astrophysics Data System (ADS)

    Arena, M. V.; Westre, E. D.; George, S. M.

    1991-03-01

    The surface diffusion and desorption kinetics for perfluoro-n-butane on Ru(001) were examined using laser-induced thermal desorption (LITD) and temperature programmed desorption (TPD) techniques. The surface diffusion displayed Arrhenius behavior and was coverage independent. The surface diffusion parameters for perfluoro-n-butane on Ru(001) were Edif=2.9±0.3 kcal/mol and D0=5.9×10-2±0.2 cm2/s. The desorption parameters for perfluoro-n-butane on Ru(001) were Edes=13.8±0.6 kcal/mol and νdes=2.8×1021±0.1 s-1. In comparison, the surface diffusion parameters for n-butane on Ru(001) were Edif=3.5±0.2 kcal/mol and D0=1.4×10-1±0.2 cm2/s. The desorption parameters for n-butane on Ru(001) were Edes=11.9±0.5 kcal/mol and νdes=3.6×1015±0.1 s-1. The corrugation ratio, defined as Ω≡Edif/Edes, was determined to be Ω=0.21 for perfluoro-n-butane on Ru(001). This corrugation ratio was substantially different than the corrugation ratio of Ω≊0.30 measured for n-butane and various other n-alkanes, cycloalkanes and branched alkanes on Ru(001). The comparison between perfluoro-n-butane and the other alkanes indicates that fluorination lowers the surface corrugation ratio on Ru(001). Likewise, fluorination significantly increases the preexponential for desorption from Ru(001). This study illustrates the magnitude of substituent effects on surface diffusion and desorption kinetics for a physisorbed molecule on a single-crystal metal surface.

  10. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with neon

    SciTech Connect

    Malinina, A. A. Malinin, A. N.

    2013-12-15

    Results are presented from studies of the optical characteristics and parameters of plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with neon—the working medium of a non-coaxial exciplex gas-discharge emitter. The electron energy distribution function, the transport characteristics, the specific power losses for electron processes, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering by the working mixture components are determined as functions of the reduced electric field. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules is found to be 1.6 × 10{sup −14} m{sup 3}/s for a reduced electric field of E/N = 15 Td, at which the maximum emission intensity in the blue-green spectral region (λ{sub max} = 502 nm) was observed in this experiment.

  11. Industrial-hygiene report, walk-through survey, papaya packing/shipping facilities, Hilo, Hawaii, July 1983. [Ethylene dibromide exposure

    SciTech Connect

    Clapp, D.

    1983-07-01

    Worker exposure to ethylene dibromide (EDB) was investigated at three papaya packing and shipping facilities in Hilo, Hawaii. Breathing-zone samples were collected in the three facilities over a three day period. Blind spikes were submitted as a control on time and temperature effects. Blank samples were also prepared. Spike results reflected the effects of time and temperature in shipment from Hawaii to Massachusetts. All spikes were roughly comparable and showed a recovery of about 68%. Overnight laboratory results were adjusted upward by 72% and NIOSH laboratory results by 68%. Six out of 38 samples exceeded the NIOSH recommended amount of 130 ppb. The author concludes that there is a chronic, low-concentration exposure to EDB for all workers in the papaya industry in Hilo. An epidemiological study of reproductive and cytogenetic effects of EDB exposure on these workers is recommended.

  12. Spectral characteristics of a broadband exciplex spontaneous emission source upon mixtures of the cadmium dibromide vapor with gases

    NASA Astrophysics Data System (ADS)

    Guivan, M. M.; Malinin, A. N.

    2007-03-01

    The spectral characteristics of radiation from atmospheric-pressure gas-discharge plasma in mixtures of cadmium dibromide vapor with gases (Ne, Ar, Kr, Xe, and N2), as well as the temporal characteristics of the voltage and current, have been investigated. A barrier discharge at the repetition frequency of sine voltage pulses up to 140 kHz has been used to create the gas-discharge plasma and excite the components of the working mixture. The discharge radiation has been analyzed in the spectral range 200-900 nm with a high resolution (0.05 nm). In the spectra, we have revealed radiation from exciplex molecules CdBr( B → X) and CdBr( C → X), atomic lines of cadmium and inert gases, and, in mixtures with xenon, radiation of exciplex molecules XeBr( B → X, B → A). The XeBr( B → X) radiation prevailed in the spectra at mixture temperatures up to 200°C. The further increase of the temperature resulted in the prevalence of the CdBr( B → X) radiation. The most intense CdBr( B → X) radiation was observed in mixtures of CdBr2/Xe. When the temperature of the mixture was higher than 250°C, the discharge radiation had a silvery-white color. Regularities in the spectral characteristics of the radiation from the gas-discharge plasma are discussed. The high-frequency atmospheric-pressure barrier discharge in mixtures of cadmium dibromide with gases, excited by sine voltage pulses, can be used in multiwave and broadband excilamps, operating in the UV and visible regions.

  13. Dexamethasone inhibits induction of liver tumor necrosis factor-alpha mRNA and liver growth induced by lead nitrate and ethylene dibromide.

    PubMed Central

    Ledda-Columbano, G. M.; Columbano, A.; Cannas, A.; Simbula, G.; Okita, K.; Kayano, K.; Kubo, Y.; Katyal, S. L.; Shinozuka, H.

    1994-01-01

    We have recently demonstrated that a single injection of the mitogen lead nitrate to rats induced a rapid increase of tumor necrosis factor-alpha (TNF-alpha) mRNA in the liver and suggested that this cytokine may be involved in triggering hepatocyte proliferation in this model of direct hyperplasia. In this study, we examined whether a similar induction of liver TNF-alpha mRNA could be observed preceding the onset of hepatocyte proliferation induced by ethylene dibromide, another hepatocyte mitogen. In addition, we used dexamethasone, a well known inhibitor of TNF-alpha production, to determine whether its administration could suppress hepatocyte proliferation induced by lead nitrate and ethylene dibromide. A single intragastric administration of ethylene dibromide (100 mg/kg) to male Wistar rats enhanced liver TNF-alpha mRNA after 4 and 7 hours, which then returned to control levels by 24 hours. TNF-alpha mRNA was detectable only in a nonparenchymal cell fraction of the liver. Pretreatment of rats with a single dose of dexamethasone (2 mg/kg) 60 minutes before lead nitrate (100 mumol/kg) or ethylene dibromide completely abolished the increased levels of liver TNF-alpha mRNA induced by these agents. Inhibition by dexamethasone of TNF-alpha mRNA was associated with an inhibition of liver cell proliferation induced by these mitogens, as measured by [3H]thymidine incorporation into hepatic DNA, mitotic index, and DNA content. These results further support the hypothesis that TNF-alpha may be involved in triggering hepatocyte proliferation induced by primary mitogens. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:7943184

  14. Easy to Use Plastic Optical Fiber-Based Biosensor for Detection of Butanal

    PubMed Central

    Varriale, Antonio; Staiano, Maria; Di Pietrantonio, Fabio; Notargiacomo, Andrea; Zeni, Luigi; D’Auria, Sabato

    2015-01-01

    The final goal of this work is to achieve a selective detection of butanal by the realization of a simple, small-size and low cost experimental approach. To this end, a porcine odorant-binding protein was used in connection with surface plasmon resonance transduction in a plastic optical fiber tool for the selective detection of butanal by a competitive assay. This allows to reduce the cost and the size of the sensing device and it offers the possibility to design a “Lab-on-a-chip” platform. The obtained results showed that this system approach is able to selectively detect the presence of butanal in the concentration range from 20 μM to 1000 μM. PMID:25789470

  15. Monte Carlo simulation of n-butane in water. Conformational evidence for the hydrophobic effecta)

    NASA Astrophysics Data System (ADS)

    Jorgensen, William L.

    1982-12-01

    Monte Carlo statistical mechanics simulations have been carried out for a dilute solution of n-butane in water at 25 °C and 1 atm. The intermolecular interactions were described by Coulomb and Lennard-Jones terms in the TIPS format including the TIPS2 parameters for water. The internal rotation about the central CC bond in n-butane was included using a rotational potential based on molecular mechanics (MM2) calculations. The precision of the simulation results was enhanced by preferential sampling and by umbrella sampling for the internal rotation over chopped barriers. Conformational results are also reported from a long Monte Carlo run for pure liquid n-butane using umbrella sampling. Although no condensed phase effect is found on the conformational equilibrium in pure liquid n-butane, there is a pronounced increase in the gauche population of n-butane upon transfer from the gas phase to aqueous solution. The latter finding is in near quantitative accord with the shift predicted by Pratt and Chandler from their theoretical model. It is also consistent with the basic tenet of the hydrophobic effect regarding the folding of natural and synthetic polymers in water. In addition, detailed structural results for the system are reported. Notably, the water molecules in the first shell around n-butane have normal bonding energies and hydrogen bonding profiles for bulk water. However, since their coordination numbers are low, this situation can only be achieved by greater ordering which is entropically costly. The validity of the observations is supported by the computed heat and volume of solution which are in accord with experimental data.

  16. [Clinical study of butane gas abuse: in comparison with toluene-based solvent and marihuana].

    PubMed

    Tohhara, S; Tani, N; Nakajima, T; Tsuda, E

    1989-12-01

    We reported 2 cases of patients who abused butane gas, toluene-based solvent and marihuana. They showed different signs in the each substance, respectively. Butane gas was easier to make visual hallucinations and distorted perception of body form, and was less potent and addictive than toluene-based solvent. Spontaneous laughter and the most amotivational state were characterized by marihuana intoxication. Alteration of auditory perception that simple music sounded wonderful was also experienced. Furthermore, the above symptoms were thought to change by the order of taking the substance. Therefore, it is needed to examine the order of the use of drugs and clarify differences of symptoms in abuse among drugs, respectively.

  17. Laboratory, Field, and Modeling Studies of Aerobic Cometabolism of CAHs by Butane-Utilizing Microorganisms

    NASA Astrophysics Data System (ADS)

    Mathias, M.; Semprini, L.; Dolan, M. E.; McCarty, P. L.; Hopkins, G. D.

    2002-12-01

    The ability of butane-utilizing microorganisms to aerobically cometabolize a mixture of chlorinated aliphatic hydrocarbons (CAHs) in laboratory microcosms and in an in-situ field demonstration was modeled using parameter values measured in laboratory experiments. The butane grown culture was inoculated into soil and groundwater microcosms and exposed to butane with several repeated additions of 1,1,1-trichloroethane (TCA), 1,1-dichloroethylene (1,1-DCE), and 1,1-dichloroethane (1,1-DCA) at aqueous concentrations of 200 μg/L, 100 μg/L, and 200 μg/L, respectively. The utilization of butane and the transformation of the CAH mixture in the batch microcosms were simulated using differential equations accounting for Michaelis-Menten kinetics with cell growth and decay, substrate utilization, transformation product toxicity, and substrate inhibition of CAH transformation. Both competitive inhibition kinetics and mixed inhibition kinetics, determined in prior laboratory studies, were included in the model construct. The equations were solved simultaneously using fourth-order Runge-Kutta numerical integration. The batch microcosm experimental results were simulated well with parameter values determined independently in culture kinetic studies, with some minor adjustments. Having adequately defined the parameter values from laboratory studies, the biotransformation model was combined with 1-D advective-dispersive transport to simulate the results of in-situ bioremediation tests conducted at the Moffett Field Test Facility in CA. The butane-utilizing culture was injected into a 7 m subsurface test site and exposed to alternating pulses of oxygen and butane, along with TCA (150 μg/L), 1,1-DCE (50 μg/L) and 1,1-DCA (150 μg/L). The model simulated well the transient transformation of the CAHs in response to different butane and oxygen pulse cycles and injection concentrations. Model simulations correlated well with field results and indicated that better remediation

  18. Ethylene dibromide and disulfiram: studies in vivo and in vitro on the mechanism of the observed synergistic carcinogenic response.

    PubMed

    Elliott, B M; Ashby, J

    1980-01-01

    Two possible mechanisms for the reported carcinogenic synergism between ethylene dibromide (EDB) and disulfiram have been investigated in vivo and in vitro, the first involving increased production of an EDB-derived glutathione mustard and the second increased production of bromoacetaldehyde. Consistent with both of these suggested mechanisms, repeated administrations of disulfiram to rats inreased liver glutathione-S-transferase activity and decreased liver low Km aldehyde dehydrogenase activity. However, when added to a rat liver S-9 fraction in vitro, disulfiram decreased transferase activity and only depressed the dehydrogenase activity after a period of preincubation. Although the mutagenic potency of EDB to Salmonella typhimurium was slightly enhanced in vitro by the addition of a rat liver S-9 fraction, the further addition of disulfiram to the assay medium produced no additional change. Similarly, the addition of a range of S-9 and S-0.5 liver fractions derived from disulfiram-treated rats also failed to enhance significantly its mutagenic potency over the normal S-9 fraction. The general implications of these findings are discussed.

  19. Trichloroethylene aerobic cometabolism by suspended and immobilized butane-growing microbial consortia: a kinetic study.

    PubMed

    Frascari, Dario; Zanaroli, Giulio; Bucchi, Giacomo; Rosato, Antonella; Tavanaie, Nasrin; Fraraccio, Serena; Pinelli, Davide; Fava, Fabio

    2013-09-01

    A kinetic study of butane uptake and trichloroethylene (TCE) aerobic cometabolism was conducted by two suspended-cell (15 and 30°C) and two attached-cell (15 and 30°C) consortia obtained from the indigenous biomass of a TCE-contaminated aquifer. The shift from suspended to attached cells resulted in an increase of butane (15 and 30°C) and TCE (15°C) biodegradation rates, and a significant decrease of butane inhibition on TCE biodegradation. The TCE 15°C maximum specific biodegradation rate was equal to 0.011 mg(TCE ) mg(protein)(-1) d(-1) with suspended cells and 0.021 mg(TCE) mg(protein)(-1) d(-1) with attached cells. The type of mutual butane/TCE inhibition depended on temperature and biomass conditions. On the basis of a continuous-flow simulation, a packed-bed PFR inoculated with the 15 or 30°C attached-cell consortium could attain a 99.96% conversion of the studied site's average TCE concentration with a 0.4-0.5-day hydraulic residence time, with a low effect of temperature on the TCE degradation performances.

  20. Biooxidation of n-butane to 1-butanol by engineered P450 monooxygenase under increased pressure.

    PubMed

    Nebel, Bernd A; Scheps, Daniel; Honda Malca, Sumire; Nestl, Bettina M; Breuer, Michael; Wagner, Hans-Günter; Breitscheidel, Boris; Kratz, Detlef; Hauer, Bernhard

    2014-12-10

    In addition to the traditional 1-butanol production by hydroformylation of gaseous propene and by fermentation of biomass, the cytochrome P450-catalyzed direct terminal oxidation of n-butane into the primary alcohol 1-butanol constitutes an alternative route to provide the high demand of this basic chemical. Moreover the use of n-butane offers an unexploited ubiquitous feed stock available in large quantities. Based on protein engineering of CYP153A from Polaromonas sp. JS666 and the improvement of the native redox system, a highly ω-regioselective (>96%) fusion protein variant (CYP153AP.sp.(G254A)-CPRBM3) for the conversion of n-butane into 1-butanol was developed. Maximum yield of 3.12g/L butanol, of which 2.99g/L comprise for 1-butanol, has been obtained after 20h reaction time. Due to the poor solubility of n-butane in an aqueous system, a high pressure reaction assembly was applied to increase the conversion. After optimization a maximum product content of 4.35g/L 1-butanol from a total amount of 4.53g/L butanol catalyzed by the self-sufficient fusion monooxygenase has been obtained at 15bar pressure. In comparison to the CYP153A wild type the 1-butanol concentration was enhanced fivefold using the engineered monooxygenase whole cell system by using the high-pressure reaction assembly.

  1. AROMATIC AND POLYCYCLIC AROMATIC HYDROCARBON FORMATION IN A LAMINAR PREMIXED N-BUTANE FLAME. (R825412)

    EPA Science Inventory

    Abstract

    Experimental and detailed chemical kinetic modeling work has been performed to investigate aromatic and polycyclic aromatic hydrocarbon (PAH) formation pathways in a premixed, rich, sooting, n-butane¯oxygen¯argon burner s...

  2. THE HEAT CAPACITY OF FLUORINATED PROPANE AND BUTANE DERIVATIVES BY DIFFERENTIAL SCANNING CALORIMETRY

    EPA Science Inventory

    The paper gives results of the measurement (to 3% accuracy) of the constant-pressure liquid-phase heat capacities of 21 hydrogen-containing fluorinated propane and butane derivatives and one fluorinated ether (CF3OCF2H) with boiling points ranging from -34.6 to 76.7 C, using diff...

  3. Enantioselective dehydration of butan-2-ol using zeolite Y modified with dithiane oxides

    SciTech Connect

    Feast, S.; Siddiqui, H.; Bethell, D.

    1997-04-15

    Modification of zeolite H-Y by dithiane oxides (2-R-1,3-dithiane 1-oxide; R = H, CH{sub 3}, C{sub 6}H{sub 5}) is shown to enhance significantly its activity for the acid catalyzed gas phase dehydration of butan-2-ol. The rate enhancement is observed for catalysts that are prepared by adding the dithiane oxide to the zeolite synthesis gel or by adsorption of the dithiane oxide onto commercial samples of zeolite H-Y. The origin of the rate enhancement is considered to result from a specific interaction between the dithiane oxide modifier with both the extra-framework and framework aluminum in the zeolite. Modification of zeolite H-Y with (R)-1,3-dithiane 1-oxide enhances the conversion of (S)-butan-2-ol compared to (R)-butan-2-ol in the temperature range 110-150{degrees}C when the two enantiomers are reacted separately. Modification with (S)-2-phenyl-1,3-dithiane 1-oxide gives a catalyst for which (R)-butan-2-ol is the most reactive of the two enantiomers. Reaction of racemic butan-2-ol over these chirally modified H-Y zeolites demonstrates that this modification procedure makes the zeolite enantiomerically discriminating and one enantiomer preferentially reacts, although both are present in the micropores under the reaction conditions. This effect is considered to be due to enantioselective rate enhancement, since, although the rate of dehydration of both enantiomers is enhanced in the chiral environment, the dehydration rate of one enantiomer is accelerated relative to the other. It is suggested that the effect is due to preferential adsorption at the chiral active site. 34 refs., 7 figs., 6 tabs.

  4. Ethylene dibromide (EDB) trends in the upper Floridan Aquifer, Seminole County, Georgia, October 1981 to November 1987

    USGS Publications Warehouse

    McConnell, J.B.

    1988-01-01

    Results of an investigation to assess the persistence and trends of ethylene dibromide (EDB) in the Upper Floridan aquifer, in Georgia indicate that in November 1987, EDB was present in the groundwater 4 years after it was last applied as a soil fumigant in the intensively farmed area of central Seminole County. At that time, EDB was detected in water samples from one domestic well and four irrigation wells. Concentrations ranged from less than 0.01 micrograms/L to 3.3 micrograms/L. The investigation in November 1987 revealed the groundwater contamination was limited to the 4-sq-mi area in the vicinity of Buck Hole, a sinkhole in a swampy depression in the central part of the County. In three of the five wells in which EDB was detected, concentrations have not changed significantly since August 1983. However, in one irrigation well near Buck Hole, the concentration decreased from 110 to 0.7 microgram/L since October 1981. In another irrigation well near Buck Hole, the concentration decreased from 26 to about 2.5 microgram/L during that period. The groundwater level data indicate that from Buck Hole, the hydraulic gradient in the Upper Floridan aquifer is about 2.8 ft/mi toward the east. However, the movement of EDB from the area of relatively high concentration near Buck Hole in the direction of inferred flow lines is not apparent. Although concentration gradients were not detected along flow lines, the movement of water induced by pumping wells W4 and W5 produced short-term decreasing and increasing trends in EDB Concentrations in wells W4 and W5, respectively. (USGS)

  5. Undetected Groundwater Contamination at Underground Storage Tank Sites by the Gasoline Lead Scavengers Ethylene Dibromide and 1,2-Dichloroethane

    NASA Astrophysics Data System (ADS)

    Falta, R. W.

    2004-05-01

    Ethylene dibromide (EDB) is a synthetic organic chemical that was produced in large amounts for use as a leaded gasoline additive and pesticide. The chlorinated solvent 1,2-dichlorethane (1,2-DCA) is widely used in the chemical industry, and was also added to leaded gasoline. EDB and 1,2-DCA are classified as probable human carcinogens by the United States Environmental Protection Agency (EPA), and EDB's use as a pesticide was suspended in 1984. The current EPA maximum contaminant level (MCL) for EDB in drinking water is 0.05 ug/l, and the MCL for 1,2-DCA is 5 ug/l. EDB has proven to be both mobile and persistent in groundwater, and contamination of groundwater by EDB was documented in several states beginning in the early 1980s. The majority of this contamination is attributed to agricultural uses of EDB, however approximately 90 percent of the EDB produced was used as a leaded gasoline additive, and it was present in virtually all leaded gasoline sold in the US. 1,2-DCA is commonly found as a groundwater contaminant, and it is both mobile and persistent. Past site investigations and remediation efforts at underground storage tank sites contaminated by leaded gasoline have rarely addressed the potential for EDB or 1,2-DCA contamination. However, the concentrations of EDB and 1,2-DCA in leaded gasoline were high enough to produce groundwater concentrations of thousands of ug/l. For this reason, there is a substantial likelihood that undetected EDB and 1,2-DCA plumes above the MCL may exist at many sites where leaded gasoline leaked or spilled. An initial review of field data from underground storage tank sites in two states suggests that this problem is widespread.

  6. Optical characterizations of ZnO, SnO2, and TiO2 thin films for butane detection.

    PubMed

    Mazingue, Thomas; Escoubas, Ludovic; Spalluto, Lorenzo; Flory, François; Jacquouton, Patrick; Perrone, Alessio; Kaminska, Eliana; Piotrowska, Anna; Mihailescu, Ion; Atanasov, Peter

    2006-03-01

    The optogeometric properties of various sensitive thin films involved in gas sensing applications are investigated by using the m-line technique and atomic force microscopy. Variations of these optical properties are studied under butane and ozone exposure.

  7. Dynamics of Exchange at Gas-Zeolite Interfaces 1: Pure Component n-Butane and Isobutane

    SciTech Connect

    CHANDROSS,MICHAEL E.; WEBB III,EDMUND B.; GREST,GARY S.; MARTIN,MARCUS G.; THOMPSON,AIDAN P.; ROTH,M.W.

    2000-07-13

    The authors present the results of molecular dynamics simulations of n-butane and isobutane in silicalite. They begin with a comparison of the bulk adsorption and diffusion properties for two different parameterizations of the interaction potential between the hydrocarbon species, both of which have been shown to reproduce experimental gas-liquid coexistence curves. They examine diffusion as a function of the loading of the zeolite, as well as the temperature dependence of the diffusion constant at loading and for infinite dilution. They continue with simulations in which interfaces are formed between single component gases and the zeolite. After reaching equilibrium, they examine the dynamics of exchange between the bulk gas and the zeolite. Finally, they calculate the permeability of the zeolite for n-butane and isobutane as a function of pressure. Their simulations are performed for a number of different gas temperatures and pressures, covering a wide range of state points.

  8. Development of a large-entrainment-ratio axisymmetric supersonic ejector for micro butane combustor

    NASA Astrophysics Data System (ADS)

    Fan, Yong; Suzuki, Yuji; Kasagi, Nobuhide

    2006-09-01

    A large-entrainment-ratio micro ejector has been developed to supply fuel-air mixture for a micro butane combustor. As a key component of the ejector, an axisymmetric convergent-divergent supersonic nozzle having a throat diameter of 42 µm is fabricated with high-precision electro-discharge machining. Operating conditions and geometric parameters of the ejector are systematically changed, and their effects on volume-flow-rate ratio are investigated in a series of experiments. Experimental data are compared with analytic solutions and CFD results. It is found that the present micro ejector achieves a maximum air-to-butane volume-flow-rate ratio of 43 when the back pressure is 11.6 Pa. It is also found that the present ejector can produce larger volume-flow-rate ratio than the previous MEMS 2D ejector at small back pressure.

  9. [Myocardial infarction after butane inhalation in a 14-year-old boy].

    PubMed

    Godlewski, Krzysztof; Werner, Bozena; Sterliński, Maciej; Pytkowski, Mariusz; Szwed, Hanna; Domagała, Marek; Koc, Lucyna

    2006-03-01

    Myocardial infarction is a rare disease in children. Among many reasons the toxic damage of myocardium should be taken into consideration. The authors present the case of a 14-year-old boy with sudden cardiac arrest due to ventricular fibrillation and myocardial infarction as a result of butane gas inhalation. Coronary angiography revealed normal coronary arteries. Cardioverter-defibrillator was implanted as a secondary prophylaxis of sudden cardiac death.

  10. Biofiltration control of VOC and air toxic emissions: n-Butane and benzene

    SciTech Connect

    Allen, E.R.

    1996-12-31

    n-Butane and benzene vapors are routinely observed in urban atmospheres. Their presence in urban airsheds is of concern because of their ozone production potential as volatile organic compounds (VOCs) and/or potential toxicity. Also, these saturated hydrocarbons are representative of airborne aliphatic and aromatic compounds. Separate laboratory studies have been conducted on the biological elimination of n-butane (n-C{sub 4}H{sub 10}) and benzene (C{sub 6}H{sub 6}) from airstreams using treated compost biofilters. The removal efficiencies were found to exceed 90% for a conditioned biofilter medium and pollutant low concentrations (< 25 ppm) and zeroth order kinetics at higher concentrations (> 100 ppm), whereas benzene vapor elimination followed zeroth order kinetics at concentrations up to 200 ppm. The maximum n-butane and benzene elimination capacities observed for the compost biofilters and conditions employed were 25 and 70 g pollutant m{sup -3} h{sup -1}, respectively. 13 refs., 6 figs., 2 tabs.

  11. Sulfated nanozirconia: an investigation on acid-base properties and n-butane isomerization activity.

    PubMed

    Mishra, H K; Dalai, A K; Das, D D; Parida, K M; Pradhan, N C

    2004-04-15

    Hydrated zirconia was synthesized by an organo-inorganic route employing surfactant and was sulfated using aqueous ammonium persulfate, followed by drying at 110 degrees C. The sample thus obtained was calcined at 600 degrees C to obtain sulfated zirconia and was characterized by several physicochemical methods. Crystallite sizes of sulfated zirconia were calculated from X-ray line broadening using the Debye-Scherer equation and were found to be in the range of 25 nm. When pretreated in air, the catalyst was found to exhibit butane isomerization activity at a temperature as low as 35 degrees C under atmospheric pressure. It showed conversion as high as 37% at 100 degrees C under normal pressure when pretreated in air, whereas nitrogen-pretreated catalyst showed zero activity under similar conditions. NH(3) and CO(2) temperature-programmed desorption studies on air- and helium-pretreated samples indicated that the catalyst surface changes appreciably during air pretreatment. Results on butane isomerization in conjunction with TPD studies suggest that zirconium-oxy sites play an important role in butane activation during the reaction.

  12. Sorption of methane, ethane, propane, butane, carbon dioxide, and nitrogen on kerogen

    NASA Astrophysics Data System (ADS)

    Pribylov, A. A.; Skibitskaya, N. A.; Zekel', L. A.

    2014-06-01

    Sorption isotherms of nitrogen, methane (in the pressure range of 0.1-40 MPa), ethane (0.1-3.7MPa), propane (0.01-1 MPa), butane (0.01-0.2 MPa), and carbon dioxide (0.1-6 MPa) are measured on two adsorbents with kerogen contents of 16 and 75% at temperatures of 303, 323, 343 K. Adsorption volumes are calculated for all adsorption systems using two independent methods. The BET technique is used to determine the surface area values of the two adsorbents on the basis of sorption data for ethane, propane, butane, and carbon dioxide. The initial and isosteric adheat of sorption values are calculated on the basis of sorption isotherms of ethane, propane, butane, carbon dioxide measured at three temperatures. It is found from comparing the dependences of isosteric heat of sorption on the two adsorbents that molecules of the above gases diffuse into its bulk (adsorbent 2) in addition to sorbing on the outside surface formed by kerogen molecules, while sorption of the same gases on the rock (adsorbent 1) is similar to sorption on a smooth hard adsorbent surface.

  13. Ring-strain-enabled reaction discovery: new heterocycles from bicyclo[1.1.0]butanes.

    PubMed

    Walczak, Maciej A A; Krainz, Tanja; Wipf, Peter

    2015-04-21

    Mechanistically as well as synthetically, bicyclo[1.1.0]butanes represent one of the most fascinating classes of organic compounds. They offer a unique blend of compact size (four carbon atoms), high reactivity (strain energy of 66 kcal/mol), and mechanistic pathway diversity that can be harvested for the rapid assembly of complex scaffolds. The C(1)-C(3) bond combines the electronic features of both σ and π bonds with facile homolytic and heterolytic bond dissociation properties and thereby readily engages pericyclic, transition-metal-mediated, nucleophilic, and electrophilic pathways as well as radical acceptor and donor substrates. Despite this multifaceted reaction profile and recent advances in the preparation of bicylo[1.1.0]butanes, the current portfolio of synthetic applications is still limited compared with those of cyclopropanes and cyclobutanes. In this Account, we describe our work over the past decade on the exploration of substituent effects on the ring strain and the reactivity of bicyclo[1.1.0]butanes, particularly in the context of metal-mediated processes. We first describe Rh(I)-catalyzed cycloisomerization reactions of N-allyl amines to give pyrrolidine and azepine heterocycles. The regioselectivity of the C,C-bond insertion/ring-opening step in these reactions is controlled by the phosphine ligand. After metal carbene formation, an intramolecular cyclopropanation adds a second fused ring system. A proposed mechanism rationalizes why rhodium(I) complexes with monodentate ligands favor five-membered heterocycles, as opposed to Rh(I)-bidentate ligand catalysts, which rearrange N-allyl amines to seven-membered heterocycles. The scope of Rh(I)-catalyzed cycloisomerization reactions was extended to allyl ethers, which provide a mixture of five- and seven-membered cyclic ethers regardless of the nature of the phosphine additive and Rh(I) precatalyst. The chemical diversity of these cycloisomerization products was further expanded by a consecutive

  14. Combination of best promoter and micellar catalyst for chromic acid oxidation of 1-butanol to 1-butanal in aqueous media at room temperature.

    PubMed

    Saha, Rumpa; Ghosh, Aniruddha; Saha, Bidyut

    2014-04-24

    In aqueous acidic media, picolinic acid, 2,2'-bipyridine and 1,10-phenanthroline promoted Cr(VI) oxidation of 1-butanol produces 1-butanal. 1-butanal is separated from mixture by fractional distillation. The anionic surfactant (SDS) and neutral surfactant (TX-100) accelerate the process while the cationic surfactant (CPC) retards the reaction. Combination of bipy and SDS is the best choice for chromic acid oxidation of 1-butanol to 1-butanal in aqueous media.

  15. Gas carburizing of steel with furnace atmospheres formed in situ from methane and air and from butane and air

    NASA Astrophysics Data System (ADS)

    Stickels, C. A.; Mack, C. M.; Pieprzak, J. A.

    1992-01-01

    Carburizing experiments were conducted at 927 °C (1700 °F) and 843 °C (1550 °F) using furnace atmospheres formed from methane and air and from butane and air introduced directly into the carburizing furnace. Gas flow rates were low to promote equilibration of the reaction products within the furnace. The air flow rate was held constant while the methane or butane flow was automatically regulated to maintain a constant oxygen potential, as measured by a zirconia oxygen sensor, within the furnace. In comparing the results of these experiments with earlier results obtained using propane and air, several differences were noted: (a) The methane content of the furnace atmosphere, measured by infrared analysis, was about twice as great when methane was the feed gas rather than propane or butane. This was true despite the fact that the mean residence time of the gas within the furnace was greater in the methane experiments. Methane appears to be less effective than propane or butane in reducing the CO2 and H2O contents to the levels required for carburizing. (b) There was a greater tendency for the CO content of the furnace atmosphere to decrease at high carbon potentials when methane is used instead of propane or butane. The decrease in CO content is due to hydrogen dilution caused by sooting in the furnace vestibule. These differences in behavior make propane or butane better suited than methane for in situ generation of carburizing atmospheres. However, there is no difference in the amount of carburizing occurring at a specified carbon potential when methane, propane, or butane are used as the feed gas in this process.

  16. Discovery of a novel nicotinic receptor antagonist for the treatment of nicotine addiction: 1-(3-Picolinium)-12-triethylammonium-dodecane dibromide (TMPD).

    PubMed

    Dwoskin, Linda P; Joyce, B Matthew; Zheng, Guangrong; Neugebauer, Nichole M; Manda, Vamshi K; Lockman, Paul; Papke, Roger L; Bardo, Michael T; Crooks, Peter A

    2007-10-15

    Limitations in efficacy and high relapse rates of currently available smoking cessation agents reveal the need for more efficacious pharmacotherapies. One strategy is to develop subtype-selective nicotinic receptor (nAChR) antagonists that inhibit nicotine-evoked dopamine (DA) release, the primary neurotransmitter involved in nicotine reward. Simple alkylation of the pyridino N-atom converts nicotine from a potent agonist into a potent antagonist. The classical antagonists, hexamethonium and decamethonium, differentiate between peripheral nAChR subtypes. Using a similar approach, we interconnected varying quaternary ammonium moieties with a lipophilic linker to provide N,N'-bis-nicotinium analogs, affording a lead compound, N,N'-dodecyl-1,12-diyl-bis-3-picolinium dibromide (bPiDDB), which inhibited nicotine-evoked DA release and decreased nicotine self-administration. The current work describes a novel compound, 1-(3-picolinium)-12-triethylammonium-dodecane dibromide (TMPD), a hybrid of bPiDDB and decamethonium. TMPD completely inhibited (IC(50)=500 nM) nicotine-evoked DA release from superfused rat striatal slices, suggesting that TMPD acts as a nAChR antagonist at more than one subtype. TMPD (1 microM) inhibited the response to acetylcholine at alpha3beta4, alpha4beta4, alpha4beta2, and alpha1beta1varepsilondelta receptors expressed in Xenopus oocytes. TMPD had a 2-fold higher affinity than choline for the blood-brain barrier choline transporter, suggesting brain bioavailability. TMPD did not inhibit hyperactivity in nicotine sensitized rats, but significantly and specifically decreased nicotine self-administration. Together, the results suggest that TMPD may have the ability to reduce the rewarding effect of nicotine with minimal side effects, a pharmacological profile indicative of potential clinical utility for the treatment of tobacco dependence.

  17. Pressure and concentration dependences of the autoignition temperature for normal butane + air mixtures in a closed vessel

    SciTech Connect

    Chandraratna, M.R.; Griffiths, J.F. . School of Chemistry)

    1994-12-01

    The condition at which autoignition occurs in lean premixed n-butane + air mixtures over the composition range 0.2%--2.5% n-butane by volume (0.06 < [phi] < 0.66) were investigated experimentally. Total reactant pressure from 0.1 to 0.6 MPa (1--6 atm) were studied in a spherical, stainless-steel, closed vessel (0.5 dm[sup 3]). There is a critical transition from nonignition to ignition, at pressures above 0.1 MPa, as the mixture is enriched in the vicinity of 1% fuel vapor by volume. There is also a region of multiplicity, which exhibits three critical temperatures at a given composition. Chemical analyses show that partially oxygenated components,including many o-heterocyclic compounds, are important products of the lean combustion of butane at temperatures up to 800 K. The critical conditions for autoignition are discussed with regard to industrial ignition hazards, especially in the context of the autoignition temperature of alkanes given by ASTM or BS tests. The differences between the behavior of n-butane and the higher n-alkanes are explained. The experimental results are also used as a basis for testing a reduced kinetic model to represent the oxidation and autoignition of n-butane or other alkanes.

  18. Butane-2,3-dione: the key contributor to axillary and foot odor associated with an acidic note.

    PubMed

    Hara, Takeshi; Kyuka, Ayumi; Shimizu, Hironori

    2015-02-01

    Human body odor, which contains several volatile organic compounds, possesses various odor qualities. To identify key volatile compounds responsible for the common unpleasant odors derived from human axillae and feet, the odor quality and intensity of 118 human axillae and feet were directly evaluated by sniffing, and odor compounds obtained from the subjects were identified. Furthermore, the sensory differences in odor intensity and quality with and without addition of butane-2,3-dione were evaluated by using the visual analog scale (VAS). An acidic odor was a common unpleasant note in human axillae and feet. Butane-2,3-dione was identified as a key compound associated with this odor. Strong positive correlations between the amount of butane-2,3-dione, and the odor intensities of axillae and feet were observed, and the addition of butane-2,3-dione solution to blended short-chain fatty-acid solutions caused significantly increased VAS values of axillary-like odor, unpleasantness, and odor intensity compared to those of each solution without added butane-2,3-dione.

  19. Adsorption of butane, 2-methylpropane, and 1-butene on activated carbon

    SciTech Connect

    Olivier, M.G.; Berlier, K.; Jadot, R. . Service de Thermodynamique)

    1994-10-01

    Four adsorption isotherms at 278, 288, 293, and 303 K of butane, 2-methylpropane, and 1-butene are obtained on activated carbon. The results at pressures up to 0.8P/P[sub s] are measured on an automated apparatus and correlated by the vacancy solution model of Cochran and Danner. This work aims at determining the influence of a double bond and a branched structure on the adsorption capacity. For their industrial separation by an adsorption process, it is important to have equilibrium data on the same adsorbent and at different temperatures.

  20. Kinetics of Methyl t-Butyl Ether Cometabolism at Low Concentrations by Pure Cultures of Butane-Degrading Bacteria

    PubMed Central

    Liu, Catherine Y.; Speitel, Gerald E.; Georgiou, George

    2001-01-01

    Butane-oxidizing Arthrobacter (ATCC 27778) bacteria were shown to degrade low concentrations of methyl t-butyl ether (MTBE; range, 100 to 800 μg/liter) with an apparent half-saturation concentration (Ks) of 2.14 mg/liter and a maximum substrate utilization rate (kc) of 0.43 mg/mg of total suspended solids per day. Arthrobacter bacteria demonstrated MTBE degradation activity when grown on butane but not when grown on glucose, butanol, or tryptose phosphate broth. The presence of butane, tert-butyl alcohol, or acetylene had a negative impact on the MTBE degradation rate. Neither Methylosinus trichosporium OB3b nor Streptomyces griseus was able to cometabolize MTBE. PMID:11319100

  1. Low-temperature superacid catalysis: Reactions of n - butane and propane catalyzed by iron- and manganese-promoted sulfated zirconia

    SciTech Connect

    Tsz-Keung, Cheung; d`Itri, J.L.; Lange, F.C.; Gates, B.C.

    1995-12-31

    The primary goal of this project is to evaluate the potential value of solid superacid catalysts of the sulfated zirconia type for light hydrocarbon conversion. The key experiments catalytic testing of the performance of such catalysts in a flow reactor fed with streams containing, for example, n-butane or propane. Fe- and Mn-promoted sulfated zirconia was used to catalyze the conversion of n-butane at atmospheric pressure, 225-450{degrees}C, and n-butane partial pressures in the range of 0.0025-0.01 atm. At temperatures <225{degrees}C, these reactions were accompanied by cracking; at temperatures >350{degrees}C, cracking and isomerization occurred. Catalyst deactivation, resulting at least in part from coke formation, was rapid. The primary cracking products were methane, ethane, ethylene, and propylene. The observation of these products along with an ethane/ethylene molar ratio of nearly 1 at 450{degrees}C is consistent with cracking occurring, at least in part, by the Haag-Dessau mechanism, whereby the strongly acidic catalyst protonates n-butane to give carbonium ions. The rate of methane formation from n-butane cracking catalyzed by Fe- and Mn-promoted sulfated zirconia at 450{degrees}C was about 3 x 10{sup -8} mol/(g of catalyst {center_dot}s). The observation of butanes, pentanes, and methane as products is consistent with Olah superacid chemistry, whereby propane is first protonated by a very strong acid to form a carbonium ion. The carbonium ion then decomposes into methane and an ethyl cation which undergoes oligocondensation reactions with propane to form higher molecular weight alkanes. The results are consistent with the identification of iron- and manganese-promoted sulfated zirconia as a superacid.

  2. The oxidation of n-butane and n-heptane in a CFR engine; Isomerization reactions and delay of autoignition

    SciTech Connect

    Sahetchian, K.A.; Blin, N.; Rigny, R.; Seydi, A. ); Murat, M. )

    1990-03-01

    During the oxidation of {ital n}-butane in a flow system and also in a motored CFR engine (600 rpm) hydrogen peroxide, primary and secondary butylhydroperoxides, and peracetic acid are formed. In the CFR engine these peroxides appear only when the compression ratio is larger than 10:1 ({ital T}{sub max} = 650 K). No autoignition has been observed. A comparison of {ital n}-butane and {ital n}-heptane oxidation is presented. Isomerization reactions,which are correlated with the alkane structure and the octane number, account for the differences in the experimental results.

  3. Detailed product analysis during the low temperature oxidation of n-butane

    PubMed Central

    Herbinet, Olivier; Battin-Leclerc, Frédérique; Bax, Sarah; Le Gall, Hervé; Glaude, Pierre-Alexandre; Fournet, René; Zhou, Zhongyue; Deng, Liulin; Guo, Huijun; Xie, Mingfeng; Qi, Fei

    2013-01-01

    The products obtained from the low-temperature oxidation of n-butane in a jet-stirred reactor (JSR) have been analysed using two methods: gas chromatography analysis of the outlet gas and reflectron time-of-flight mass spectrometry. The mass spectrometer was combined with tunable synchrotron vacuum ultraviolet photoionization and coupled with a JSR via a molecular-beam sampling system. Experiments were performed under quasi-atmospheric pressure, for temperatures between 550 and 800 K, at a mean residence time of 6s and with a stoichiometric n-butane/oxygen/argon mixture (composition = 4/26/70 in mol %). 36 reaction products have been quantified, including addition to the usual oxidation products, acetic acid, hydrogen peroxide, C1, C2 and C4 alkylhydroperoxides and C4 ketohydroperoxides. Evidence of the possible formation of products (dihydrofuranes, furanones) derived from cyclic ethers has also been found. The performance of a detailed kinetic model of the literature has been assessed with the simulation of the formation of this extended range of species. These simulations have also allowed the analysis of possible pathways for the formation of some obtained products. PMID:21031192

  4. Metabolism of acetoin in mammalian liver slices and extracts. Interconversion with butane-2,3-diol and biacetyl.

    PubMed

    Gabriel, M A; Jabara, H; al-Khalidi, U A

    1971-10-01

    1. [(14)C]Acetoin was enzymically synthesized from [(14)C]pyruvate with a pyruvate decarboxylase preparation. Its optical activity was [alpha](20) (d)-78 degrees . 2. Large amounts (1000-fold higher than physiological concentrations) of acetoin were incubated with rat liver mince. Acetoin disappeared but very little (14)CO(2) was evolved. A compound accumulated, which was purified and identified as butane-2,3-diol. Chromatography on borate-impregnated paper indicated the presence of both the erythro and threo forms. 3. Liver extracts capable of interconverting biacetyl, acetoin and butane-2,3-diol were obtained. These interconversions were catalysed by two different enzymes: acetoin dehydrogenase (EC 1.1.1.5) and butane-2,3-diol dehydrogenase (EC 1.1.1.4), previously identified in bacteria. Both required NAD(+) or NADP(+) as cofactors and were different from alcohol dehydrogenase. The equilibrium in both cases favoured the more reduced compound. 4. The activity of butane-2,3-diol dehydrogenase was decreased by dialysis against EDTA: the addition of Co(2+), Cu(2+), Zn(2+) and other bivalent metal ions restored activity. 5. Biacetyl reductase was resolved into multiple forms by CM-Sephadex chromatography and electrophoresis.

  5. Anaerobic degradation of propane and butane by sulfate-reducing bacteria enriched from marine hydrocarbon cold seeps

    PubMed Central

    Jaekel, Ulrike; Musat, Niculina; Adam, Birgit; Kuypers, Marcel; Grundmann, Olav; Musat, Florin

    2013-01-01

    The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes. They were cold-adapted, showing highest sulfate-reduction rates between 16 and 20 °C. Analysis of 16S rRNA gene libraries, followed by whole-cell hybridizations with sequence-specific oligonucleotide probes showed that each enrichment culture was dominated by a unique phylotype affiliated with the Desulfosarcina-Desulfococcus cluster within the Deltaproteobacteria. These phylotypes formed a distinct phylogenetic cluster of propane and butane degraders, including sequences from environments associated with hydrocarbon seeps. Incubations with 13C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in 13C, demonstrating that they were directly involved in hydrocarbon degradation. Furthermore, using the nanoSIMS data, carbon assimilation rates were calculated for the dominant cells in each enrichment culture. PMID:23254512

  6. Support shape effect in metal oxide catalysis: ceria nanoshapes supported vanadia catalysts for oxidative dehydrogenation of iso-butane

    SciTech Connect

    Wu, Zili; Schwartz, Viviane; Li, Meijun; Rondinone, Adam Justin; Overbury, Steven {Steve} H

    2012-01-01

    The activation energy of VOx/CeO2 catalysts in oxidative dehydrogenation of iso-butane was found dependent on the shape of ceria support: rods < octahedra, closely related to the surface oxygen vacancy formation energy and defects amount of the two ceria supports with different crystallographic surface planes.

  7. Reference Equations of State for the Thermodynamic Properties of Fluid Phase n-Butane and Isobutane

    NASA Astrophysics Data System (ADS)

    Bücker, D.; Wagner, W.

    2006-06-01

    New formulations for the thermodynamic properties of fluid phase n-butane and isobutane in the form of fundamental equations explicit in the Helmholtz energy are presented. The functional form of the correlation equations for the residual parts was developed simultaneously for both substances considering data for the thermodynamic properties of ethane, propane, n-butane, and isobutane. Each contains 25 coefficients which were fitted to selected data for the thermal and caloric properties of the respective fluid both in the single-phase region and on the vapor-liquid phase boundary. This work provides information on the available experimental data for the thermodynamic properties of n- and isobutane, and presents all details of the new formulations. The new equations of state describe the pρT surfaces with uncertainties in density of 0.02% (coverage factor k=2 corresponding to a confidence level of about 95%) from the melting line up to temperatures of 340 K and pressures of 12 MPa. The available reliable data sets in other regions are represented within their experimental uncertainties. The primary data, to which the equation for n-butane was fitted, cover the fluid region from the melting line to temperatures of 575 K and pressures of 69 MPa. The equation for isobutane was fitted to primary data that cover the fluid region from the melting line to temperatures of 575 K and pressures of 35 MPa. Beyond the range described by experimental data, the equations yield reasonable extrapolation behavior up to very high temperatures and pressures. In addition to the equations of state, independent equations for the vapor pressures, the saturated-liquid and saturated-vapor densities, and the melting pressures are given. Tables of thermodynamic properties calculated from the new formulations are listed in Appendix 2. Additionally, a preliminary equation of state for propane is presented that was developed in the course of the simultaneous optimization. This equation has the

  8. Kinetic characterization of the soluble butane monooxygenase from Thauera butanivorans, formerly 'Pseudomonas butanovora'.

    PubMed

    Cooley, Richard B; Dubbels, Bradley L; Sayavedra-Soto, Luis A; Bottomley, Peter J; Arp, Daniel J

    2009-06-01

    Soluble butane monooxygenase (sBMO), a three-component di-iron monooxygenase complex expressed by the C(2)-C(9) alkane-utilizing bacterium Thauera butanivorans, was kinetically characterized by measuring substrate specificities for C(1)-C(5) alkanes and product inhibition profiles. sBMO has high sequence homology with soluble methane monooxygenase (sMMO) and shares a similar substrate range, including gaseous and liquid alkanes, aromatics, alkenes and halogenated xenobiotics. Results indicated that butane was the preferred substrate (defined by k(cat) : K(m) ratios). Relative rates of oxidation for C(1)-C(5) alkanes differed minimally, implying that substrate specificity is heavily influenced by differences in substrate K(m) values. The low micromolar K(m) for linear C(2)-C(5) alkanes and the millimolar K(m) for methane demonstrate that sBMO is two to three orders of magnitude more specific for physiologically relevant substrates of T. butanivorans. Methanol, the product of methane oxidation and also a substrate itself, was found to have similar K(m) and k(cat) values to those of methane. This inability to kinetically discriminate between the C(1) alkane and C(1) alcohol is observed as a steady-state concentration of methanol during the two-step oxidation of methane to formaldehyde by sBMO. Unlike methanol, alcohols with chain length C(2)-C(5) do not compete effectively with their respective alkane substrates. Results from product inhibition experiments suggest that the geometry of the active site is optimized for linear molecules four to five carbons in length and is influenced by the regulatory protein component B (butane monooxygenase regulatory component; BMOB). The data suggest that alkane oxidation by sBMO is highly specialized for the turnover of C(3)-C(5) alkanes and the release of their respective alcohol products. Additionally, sBMO is particularly efficient at preventing methane oxidation during growth on linear alkanes > or =C(2,) despite its high

  9. Bis(butane-1,4-diammonium) di-μ-oxido-bis[trifluoridooxidomolybdate(V)] monohydrate

    PubMed Central

    Lhoste, J.; Hemon-Ribaud, A.; Maisonneuve, V.; Jobic, S.; Bujoli-Doeuff, M.

    2012-01-01

    The title compound, (C4H14N2)2[Mo2O4F6]·H2O, was obtained by solvothermal reaction at 443 K for 72 h from a mixture of MoO3, HF, 1,4-diamino­butane (dab), water and ethyl­ene glycol. The structure consists of [Mo2O4F6]4− anionic dimers containing strongly distorted MoO3F3 octa­hedra (with twofold symmetry), diprotonated dab cations and water mol­ecules (twofold symmetry) in the ratio 1:2:1. The cohesion of the three-dimensional structure is ensured through N—H⋯O, N—H⋯F and O—H⋯F inter­actions. PMID:23468731

  10. Thermochemistry of radicals formed by hydrogen abstraction from 1-butanol, 2-methyl-1-propanol, and butanal.

    PubMed

    Papajak, Ewa; Seal, Prasenjit; Xu, Xuefei; Truhlar, Donald G

    2012-09-14

    We calculate the standard state entropy, heat capacity, enthalpy, and Gibbs free energy for 13 radicals important for the combustion chemistry of biofuels. These thermochemical quantities are calculated from recently proposed methods for calculating partition functions of complex molecules by taking into account their multiple conformational structures and torsional anharmonicity. The radicals considered in this study are those obtained by hydrogen abstraction from 1-butanol, 2-methyl-1-propanol, and butanal. Electronic structure calculations for all conformers of the radicals were carried out using both density functional theory and explicitly correlated coupled cluster theory with quasipertubative inclusion of connected triple excitations. The heat capacity and entropy results are compared with sparsely available group additivity data, and trends in enthalpy and free energy as a function of radical center are discussed for the isomeric radicals.

  11. Thermochemistry of radicals formed by hydrogen abstraction from 1-butanol, 2-methyl-1-propanol, and butanal

    NASA Astrophysics Data System (ADS)

    Papajak, Ewa; Seal, Prasenjit; Xu, Xuefei; Truhlar, Donald G.

    2012-09-01

    We calculate the standard state entropy, heat capacity, enthalpy, and Gibbs free energy for 13 radicals important for the combustion chemistry of biofuels. These thermochemical quantities are calculated from recently proposed methods for calculating partition functions of complex molecules by taking into account their multiple conformational structures and torsional anharmonicity. The radicals considered in this study are those obtained by hydrogen abstraction from 1-butanol, 2-methyl-1-propanol, and butanal. Electronic structure calculations for all conformers of the radicals were carried out using both density functional theory and explicitly correlated coupled cluster theory with quasipertubative inclusion of connected triple excitations. The heat capacity and entropy results are compared with sparsely available group additivity data, and trends in enthalpy and free energy as a function of radical center are discussed for the isomeric radicals.

  12. Thermophysical properties of normal butane from 135 to 700 K at pressures to 70 MPa

    SciTech Connect

    Haynes, W.M.; Goodwin, R.D.

    1982-04-01

    Using a modified version of the nonanalytic equation of state, thermophysical properties of normal butane are derived from physical properties data and are tabulated at integral temperatures from 135 to 700 K along isobars at pressures to 70 MPa. These isobar tables, along with a table for the saturated liquid, give values for densities, compressibility factors, internal energies, enthalpies, entropies, heat capacities, fugacities, sound velocities, dielectric constants, and isochore and isotherm derivatives. Equations, whose coefficients are determined from a least squares fit to selected experimental data, are also presented for vapor pressures, orthobaric liquid and vapor densities, ideal gas properties, second virial coefficients, dielectric constants, heats of vaporization, melting pressures, and orthobaric liquid specific heats, enthalpies, and entropies. Comparisons between experimental and calculated values for all properties considered here are reported in detail.

  13. Butane Hash Oil Burns: A 7-Year Perspective on a Growing Problem.

    PubMed

    Romanowski, Kathleen S; Barsun, Alura; Kwan, Peter; Teo, Esther H; Palmieri, Tina L; Sen, Soman; Maguina, Pirko; Greenhalgh, David G

    With the legalization of marijuana in four states, and decriminalization in many others, marijuana is becoming easier to obtain. The authors have experienced an increase in burn injuries related to the production of butane hash oil (BHO; a concentrated tetrahydrocannabinol product produced by the distillation of marijuana plant products with pressurized butane). This article updates our experience and highlights the increasing public health problem associated with these burns. Charts of patients who presented to the burn center with suspicion of BHO-related injuries between January 2007 and December 2014 were examined. Data collected included demographics, injury characteristics, treatment utilized, and outcomes. Charts of 101 patients were identified as having BHO-related burn injury. The mean age of these patients was 30.5 ± 10.6 years (mean ± standard deviation, range: 2-55 years) and 93.1% were male. Patients sustained a mean of 26.8 ± 24.1% TBSA burn with 14.3 ± 25.1% third degree burns. Three patients died as the result of their injuries. Patients required a mean of 12 ± 48.4 ventilator days, and 27.1 ± 59.4 days in the hospital. The number of patients presenting with these burns increased over the past 7 years. BHO burns occur most commonly in February (12 patients), on Wednesday (19 patients), and between 18:00 and 06:00 (58 patients). There has been a sharp increase in the number of patients presenting with burn-associated BHO production in the region over the past 7 years. The authors as burn care providers need to increase public awareness of this issue and aid in the development of legislation to help prevent these burns before it becomes a public health crisis.

  14. 1,2 Dibromo-3-chloropropane (DBCP) and ethylene dibromide (EDB) in well water in the Fresno/Clovis metropolitan area, California.

    PubMed

    Kloos, H

    1996-01-01

    Ground-water contamination with the pesticides 1,2 dibromo-3-chloropropane (DBCP) and ethylene dibromide (EDB) affects Fresno/Clovis city in California. The spatial and temporal distribution of DBCP and EDB in public wells in Fresno/Clovis was examined, using mapping and time-series analyses of chemical test results, during the time periods 1979-1980 and 1992-1993. Health risks were estimated from mean concentrations, lifetime cancer risks were estimated, and monitoring and control programs were reviewed. Mean DBCP concentrations in selected wells declined from 0.56 ppb in 1979-1980 to 0.18 ppb in 1992-1993. Closure of wells and wellhead filtration caused levels to be reduced further (i.e., to 0.06 ppb). Mean EDB concentrations declined from 0.25 ppb to 0.15 ppb during the same time periods. The estimated lifetime cancer risk for DBCP was 1 excess death per 125 000 population in 1992-1993, but this risk varied within the city. The risk for EDB was 1 excess death per 2.2 million. Recommendations were made for the modeling of pesticide movement in ground water and for epidemiological studies.

  15. Improving the understanding of DNA-propanediyl-1,3-bis(dodecyldimethylammonium) dibromide interaction using thermodynamic, structural and kinetic approaches.

    PubMed

    Grueso, Elia; Kuliszewska, Edyta; Prado-Gotor, Rafael; Perez-Tejeda, Pilar; Roldan, Emilio

    2013-12-14

    A kinetic, thermodynamic and structural study of the interaction of the gemini surfactant propanediyl-1,3-bis(dimethyldodecylammonium dibromide) (12-3-12.2Br) with calf thymus DNA was carried out at several ionic strengths (NaCl) in aqueous solutions. A new 12-3-12(2+)-selective membrane was prepared in order to gain insight into the factors that control the binding of 12-3-12.2Br to DNA. We used ethidium bromide (EB) as a fluorescence probe to follow the kinetics of the interaction by using the stopped-flow fluorescence technique. The results can be explained in terms of a reaction mechanism involving two consecutive reversible (fast and slow) steps. The fast step was attributed to the union/separation of the surfactant with/from the DNA polynucleotide. Changes in the kinetic constants in the forward and backward directions were discussed in terms of the Brönsted-Pitzer equation and of the increase in hydrophobic interactions of the surfactant tails as a consequence of salting-out effects, respectively. The slow step corresponds to a conformational change of the surfactant-DNA complex to a more compacted form. The equilibrium constant, calculated from the forward and reverse rate constants of these steps, agrees with the results obtained from potentiometric titration using a 12-3-12-(2+) selective electrode.

  16. Use of new field methods of semen analysis in the study of occupational hazards to reproduction: the example of ethylene dibromide

    SciTech Connect

    Schrader, S.M.; Ratcliffe, J.M.; Turner, T.W.; Hornung, R.W.

    1987-12-01

    Increasing attention has been paid to the use of semen analysis as an indicator of exposure to potential mutagenic and reproductive hazards. In the infertility clinic setting, semen evaluations include the measurement of sperm concentration, volume, pH, motility, velocity and morphology, the analysis of seminal plasma to evaluate accessory sex gland function and, in some cases, the in vitro evaluation of fertilization capacity and sperm-cervical mucus interaction. To date, however, the study of semen characteristics of occupationally exposed populations has been confined principally to the measurement of sperm concentration and sperm morphology. This has been largely due to the unavailability of portable equipment suitable for the measurement of other semen characteristics and the difficulty of obtaining fresh semen samples in the field setting. National Institute for Occupational Safety and Health researchers have developed mobile laboratory facilities which enable us to evaluate fresh samples, in the field, for semen characteristics in addition to concentration and morphology. This paper describes the application of these methods using the example of our recent cross-sectional study of workers occupationally exposed to ethylene dibromide in the papaya fumigation industry. We discuss our findings in the context of the usefulness of semen analysis as an indicator of occupational hazards to male reproduction.

  17. Implications of sterically constrained n-butane oxidation reactions on the reaction mechanism and selectivity to 1-butanol

    NASA Astrophysics Data System (ADS)

    Dix, Sean T.; Gómez-Gualdrón, Diego A.; Getman, Rachel B.

    2016-11-01

    Density functional theory (DFT) is used to analyze the reaction network in n-butane oxidation to 1-butanol over a Ag/Pd alloy catalyst under steric constraints, and the implications on the ability to produce 1-butanol selectively using MOF-encapsulated catalysts are discussed. MOFs are porous crystalline solids comprised of metal nodes linked by organic molecules. Recently, they have been successfully grown around metal nanoparticle catalysts. The resulting porous networks have been shown to promote regioselective chemistry, i.e., hydrogenation of trans-1,3-hexadiene to 3-hexene, presumably by forcing the linear alkene to stand "upright" on the catalyst surface and allowing only the terminal C-H bonds to be activated. In this work, we extend this concept to alkane oxidation. Our goal is to determine if a MOF-encapsulated catalyst could be used to selectively produce 1-butanol. Reaction energies and activation barriers are presented for more than 40 reactions in the pathway for n-butane oxidation. We find that C-H bond activation proceeds through an oxygen-assisted pathway and that butanal and 1-butanol are some of the possible products.

  18. 4-(Phenylsulfanyl)butan-2-One Suppresses Melanin Synthesis and Melanosome Maturation In Vitro and In Vivo

    PubMed Central

    Wu, Shing-Yi Sean; Wang, Hui-Min David; Wen, Yi-Shan; Liu, Wangta; Li, Pin-Hui; Chiu, Chien-Chih; Chen, Pei-Chin; Huang, Chiung-Yao; Sheu, Jyh-Horng; Wen, Zhi-Hong

    2015-01-01

    In this study, we screened compounds with skin whitening properties and favorable safety profiles from a series of marine related natural products, which were isolated from Formosan soft coral Cladiella australis. Our results indicated that 4-(phenylsulfanyl)butan-2-one could successfully inhibit pigment generation processes in mushroom tyrosinase platform assay, probably through the suppression of tyrosinase activity to be a non-competitive inhibitor of tyrosinase. In cell-based viability examinations, it demonstrated low cytotoxicity on melanoma cells and other normal human cells. It exhibited stronger inhibitions of melanin production and tyrosinase activity than arbutin or 1-phenyl-2-thiourea (PTU). Also, we discovered that 4-(phenylsulfanyl)butan-2-one reduces the protein expressions of melanin synthesis-related proteins, including the microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (Trp-1), dopachrome tautomerase (DCT, Trp-2), and glycoprotein 100 (GP100). In an in vivo zebrafish model, it presented a remarkable suppression in melanogenesis after 48 h. In summary, our in vitro and in vivo biological assays showed that 4-(phenylsulfanyl)butan-2-one possesses anti-melanogenic properties that are significant in medical cosmetology. PMID:26343635

  19. Enthalpy difference between conformations of normal alkanes: Raman spectroscopy study of n-pentane and n-butane.

    PubMed

    Balabin, Roman M

    2009-02-12

    Conformation equilibrium in normal pentane (C(5)H(12)) was studied by the low-temperature gas-phase Raman spectroscopy method. A special retroreflecting multipass cell was constructed. Gas-phase (vapor) spectra were recorded in the temperature region of -130.3 to -23.1 degrees C and in the spectral range below 500 cm(-1). The peaks of trans-trans (399.0 cm(-1)), trans-gauche (328.9 cm(-1)), and gauche(+)-gauche(+) (267.1 cm(-1)) conformers (rotamers) of n-pentane were assigned using quantum chemistry data (MP2 and B3LYP methods with aug-cc-pVTZ basis set). The contour of each line was deconvoluted using ab initio data to obtain precise total integral intensity. The intensities at different temperatures were used to evaluate the enthalpy (energy) difference between trans-gauche and trans-trans (DeltaH(tg) = 618 +/- 6 cal/mol), and gauche(+)-gauche(+) and trans-trans (DeltaH(g+g+) = 940 +/- 20 cal/mol) conformers. Normal butane (n-butane) measurements under similar experimental conditions have been taken to understand the chain length influence. The C(4)H(10) enthalpy difference value has been evaluated (DeltaH(g) = 660 +/- 22 cal/mol). The results are compared with published experimental and theoretical data. The data presented here can be used as a reference for quantum chemistry calculations of conformation equilibrium in n-butane and n-pentane.

  20. Statistical thermodynamics of 1-butanol, 2-methyl-1-propanol, and butanal.

    PubMed

    Seal, Prasenjit; Papajak, Ewa; Yu, Tao; Truhlar, Donald G

    2012-01-21

    The purpose of the present investigation is to calculate partition functions and thermodynamic quantities, viz., entropy, enthalpy, heat capacity, and Gibbs free energies, for 1-butanol, 2-methyl-1-propanol, and butanal in the vapor phase. We employed the multi-structural (MS) anharmonicity method and electronic structure calculations including both explicitly correlated coupled cluster theory and density functional theory. The calculations are performed using all structures for each molecule and employing both the local harmonic approximation (MS-LH) and the inclusion of torsional anharmonicity (MS-T). The results obtained from the MS-T calculations are in excellent agreement with experimental data taken from the Thermodynamics Research Center data series and the CRC Handbook of Chemistry and Physics, where available. They are also compared with Benson's empirical group additivity values, where available; in most cases, the present results are more accurate than the group additivity values. In other cases, where experimental data (but not group additivity values) are available, we also obtain good agreement with experiment. This validates the accuracy of the electronic structure calculations when combined with the MS-T method for estimating the thermodynamic properties of systems with multiple torsions, and it increases our confidence in the predictions made with this method for molecules and temperatures where experimental or empirical data are not available.

  1. Statistical thermodynamics of 1-butanol, 2-methyl-1-propanol, and butanal

    NASA Astrophysics Data System (ADS)

    Seal, Prasenjit; Papajak, Ewa; Yu, Tao; Truhlar, Donald G.

    2012-01-01

    The purpose of the present investigation is to calculate partition functions and thermodynamic quantities, viz., entropy, enthalpy, heat capacity, and Gibbs free energies, for 1-butanol, 2-methyl-1-propanol, and butanal in the vapor phase. We employed the multi-structural (MS) anharmonicity method and electronic structure calculations including both explicitly correlated coupled cluster theory and density functional theory. The calculations are performed using all structures for each molecule and employing both the local harmonic approximation (MS-LH) and the inclusion of torsional anharmonicity (MS-T). The results obtained from the MS-T calculations are in excellent agreement with experimental data taken from the Thermodynamics Research Center data series and the CRC Handbook of Chemistry and Physics, where available. They are also compared with Benson's empirical group additivity values, where available; in most cases, the present results are more accurate than the group additivity values. In other cases, where experimental data (but not group additivity values) are available, we also obtain good agreement with experiment. This validates the accuracy of the electronic structure calculations when combined with the MS-T method for estimating the thermodynamic properties of systems with multiple torsions, and it increases our confidence in the predictions made with this method for molecules and temperatures where experimental or empirical data are not available.

  2. Measurement of impinging butane flame using combined optical system with digital speckle tomography

    NASA Astrophysics Data System (ADS)

    Ko, Han Seo; Ahn, Seong Soo; Kim, Hyun Jung

    2011-11-01

    Three-dimensional density distributions of an impinging and eccentric flame were measured experimentally using a combined optical system with digital speckle tomography. In addition, a three-dimensional temperature distribution of the flame was reconstructed from an ideal gas equation based on the reconstructed density data. The flame was formed by the ignition of premixed butane/air from air holes and impinged upward against a plate located 24 mm distance from the burner nozzle. In order to verify the reconstruction process for the experimental measurements, numerically synthesized phantoms of impinging and eccentric flames were derived and reconstructed using a developed three-dimensional multiplicative algebraic reconstruction technique (MART). A new scanning technique was developed for the accurate analysis of speckle displacements necessary for investigating the wall jet regions of the impinging flame at which a sharp variation of the flow direction and pressure gradient occur. The reconstructed temperatures by the digital speckle tomography were applied to the boundary condition for numerical analysis of a flame impinged plate. Then, the numerically calculated temperature distribution of the upper side of the flame impinged plate was compared to temperature data taken by an infrared camera. The absolute average uncertainty between the numerical and infrared camera data was 3.7%.

  3. Subcritical Butane Extraction of Wheat Germ Oil and Its Deacidification by Molecular Distillation.

    PubMed

    Li, Jinwei; Sun, Dewei; Qian, Lige; Liu, Yuanfa

    2016-12-07

    Extraction and deacidification are important stages for wheat germ oil (WGO) production. Crude WGO was extracted using subcritical butane extraction (SBE) and compared with traditional solvent extraction (SE) and supercritical carbon dioxide extraction (SCE) based on the yield, chemical index and fatty acid profile. Furthermore, the effects of the molecular distillation temperature on the quality of WGO were also investigated in this study. Results indicated that WGO extracted by SBE has a higher yield of 9.10% and better quality; at the same time, its fatty acid composition has no significant difference compared with that of SE and SCE. The molecular distillation experiment showed that the acid value, peroxide value and p-anisidine value of WGO were reduced with the increase of the evaporation temperatures, and the contents of the active constituents of tocopherol, polyphenols and phytosterols are simultaneously decreased. Generally, the distillation temperature of 150 °C is an appropriate condition for WGO deacidification with the higher deacidification efficiency of 77.78% and the higher retention rate of active constituents.

  4. Recreational inhalation of butane and propane in adolescents: Two forensic cases of accidental death.

    PubMed

    Sironi, Luca; Amadasi, Alberto; Zoja, Riccardo

    2016-09-01

    The recreational use of inhalants is a fairly widespread habit among adolescents because of the ease of availability and methods of assumption. Their use is however not free of risks, both for direct toxicity on several target organs and for a mechanism of gas replacement with lack of oxygen. The first case concerns a 12-year-old boy who died suddenly after sniffing a mix of butane and propane contained in a can of air freshener. The second case concerns a 14-year-old boy who died by acute poisoning by the same mixture contained in a refill for lighters. High concentrations of the compounds were found in the tissues by analysis with gas chromatography-mass spectrometry. The compounds found in tissues and biological fluids were perfectly compatible with those contained in the containers used for the inhalation. The mechanisms of death were therefore assessed in a combination of the direct toxicity of the compound and oxygen replacement, thus highlighting the crucial help that toxicological analyses can provide in such cases.

  5. bdGas carburizing of steel with furnace atmospheres formed in situ from methane and air and from butane and air

    NASA Astrophysics Data System (ADS)

    Stickels, C. A.; Mack, C. M.; Pieprzak, J. A.

    1982-12-01

    Carburizing experiments were conducted at 927°C (1700°F) and 843°C (1550°F) using furnace atmospheres formed from methane and air and from butane and air introduced directly into the carburizing furnace. Gas flow rates were low to promote equilibration of the reaction products within the furnace. The air flow rate was held constant while the methane or butane flow was automatically regulated to maintain a constant oxygen potential, as measured by a zirconia oxygen sensor, within the furnace. In comparing the results of these experiments with earlier results obtained using propane and air, several differences were noted: (a) The methane content of the furnace atmosphere, measured by infrared analysis, was about twice as great when methane was the feed gas rather than propane or butane. This was true despite the fact that the mean residence time of the gas within the furnace was greater in the methane experiments. Methane appears to be less effective than propane or butane in reducing the CO2 and H2O contents to the levels required for carburizing. (b) There was a greater tendency for the CO content of the furnace atmosphere to decrease at high carbon potentials when methane is used instead of propane or butane. The decrease in CO content is due to hydrogen dilution caused by sooting in the furnace vestibule. These differences in behavior make propane or butane better suited than methane for in situ generation of carburizing atmospheres. However, there is no difference in the amount of carburizing occurring at a specified carbon potential when methane, propane, or butane are used as the feed gas in this process.

  6. The effects of ethylene dibromide on semen quality and fertility in the rabbit: evaluation of a model for human seminal characteristics.

    PubMed

    Williams, J; Gladen, B C; Turner, T W; Schrader, S M; Chapin, R E

    1991-05-01

    Mature (12 months old) male New Zealand White rabbits (8-10/group) were dosed subcutaneously with ethylene dibromide (EDB) in corn oil (untreated and vehicle controls, 15, 30, or 45 mg/kg body wt/day for 5 days). Weekly semen samples (for 6 weeks preexposure, during treatment, and 12 weeks postdosing [pd]) were analyzed for sperm concentration, number, morphology, viability, and motion parameters (velocity, linearity, beat cross-frequency, amplitude of lateral head displacement (ALH), and circularity), and semen pH, osmolality, volume, fructose, citric acid, carnitine, protein, and acid phosphatase (AP). Male fertility was assessed preexposure and at 4 and 12 weeks pd by artificial insemination of three females/male/time point with one million motile sperm. The percentage pregnant females, litter size, fetal body weights, and structural development were assessed. In the 45 mg/kg dose group of males there was 30% mortality and liver damage in 43% of the survivors as evidenced by increased levels of serum enzymes. Also in this group, EDB produced significant decreases in sperm velocity, percentage motility, and ALH (up to 25% at various times pd). There were also dose-related decreases in semen pH (up to 2%) and total ejaculate volume (up to 23%, 15 and 30 mg/kg dose groups only). AP activities were significantly elevated (up to 116%) 2 weeks pd in the 45 mg/kg dose group. All other semen parameters evaluated were unaffected. Male fertility and fetal structural development were also unaffected. Of the seven semen parameters perturbed by EDB in humans (Schrader et al., 1988), four were also affected in the rabbit (sperm velocity, percentage motility, pH, and volume), whereas sperm number, viability, and morphology were not. Thus, some of the male reproductive effects of EDB in the human have been modelled in the rabbit, although the rabbit appears not to be as sensitive, since semen parameters were affected only at doses close to the LD50 (55 mg/kg). The present study

  7. Positive and Negative Contributions in the Solvation Enthalpy due to Specific Interactions in Binary Mixtures of C1-C4 n-Alkanols and Chloroform with Butan-2-one.

    PubMed

    Varfolomeev, Mikhail A; Rakipov, Ilnaz T; Solomonov, Boris N; Lodowski, Piotr; Marczak, Wojciech

    2015-06-25

    In the paper, results of calorimetric measurements, IR spectra, and calculated ab initio stabilization energies of dimers are reported for binary systems butan-2-one + (methanol, ethanol, propan-1-ol, butan-1-ol, and chloroform). Changes in the total enthalpy of specific interactions due to dissolution of butan-2-one in the alcohols, calculated using equations derived in previous works, are positive. That results from the endothermic breaking of the O-H···O-H bonds not completely compensated by the exothermic effects of formation of the O-H···O═C ones. Moreover, the concentration of nonbonded molecules of butan-2-one is significant even in dilute solutions, as is evidenced by the shape of the C═O stretching vibrations band in the IR spectra. Apart from that, the spectra do not confirm 1:2 complexes in spite of two lone electron pairs in the carbonyl group of butan-2-one capable of forming the hydrogen bonds. The changes in enthalpy of specific interactions are negative for dilute solutions of alcohols and chloroform in butan-2-one and of butan-2-one in chloroform, because no hydrogen bonds occur in pure butan-2-one. The experimental results are positively correlated with the enthalpies estimated from the ab initio energies using a simple "chemical reaction" approach.

  8. [Atypical case of teenager fatal poisoning by butane as a result of gas for lighters inhalation against his will].

    PubMed

    Celiński, Rafał; Skowronek, Rafał; Uttecht-Pudełko, Anna

    2013-01-01

    Inhalatomania with volatile organic compounds is a still present phenomenon among Polish young adolescents. Conscious, voluntary exposition on such substances may result in serious health consequences, including sudden death in the course of acute intoxication. In this paper, atypical case of death of 16-year-old teenager as a result of complications of physically forced inhalation of gas for lighters is presented. According to testimonies of witnesses, the container was placed in the mouth of victim and the gas was introduced directly to his throat. Autopsy revealed small damage of tooth with corresponding bruising of lower lip; brain and lung oedma; single bruisings in the upper respiratory tract and subpleural. Chemical-toxicological analysis of blood, brain and lung samples taken during autopsy revealed in all of them the presence of n-butan--a component of gas for lighters (the greatest in brain and lung tissues). Additionally, in blood the presence of carboxyhemoglobin (COHb) in concentration 7% was confirmed. Based on the results of analyses, acute intoxication with n-butan was estimated as a cause of death; however the key role played the information obtained during the investigation. This case shows, that deaths resulting from gas for lighters inhalation may be a consequence of forced exposition--against victim's will. So medical staff should always check, if on the body of patient there are any signs of physical constraint (the presence of bruisings in the area of viscerocranium and oral cavity, teeth damages, etc.).

  9. Filtrates and Residues: Measuring the Atomic or Molecular Mass of a Gas with a Tire Gauge and a Butane Lighter Fluid Can.

    ERIC Educational Resources Information Center

    Bodner, George M.; Magginnis, Lenard J.

    1985-01-01

    Describes the use of an inexpensive apparatus (based on a butane lighter fluid can and a standard tire pressure gauge) in measuring the atomic/molecular mass of an unknown gas and in demonstrating the mass of air or the dependence of pressure on the mass of a gas. (JN)

  10. Michael, Michael-aldol and Michael-Michael reactions of enolate equivalents of butane-2,3-diacetal protected glycolic acid derivatives.

    PubMed

    Ley, Steven V; Dixon, Darren J; Guy, Richard T; Rodríguez, Félix; Sheppard, Tom D

    2005-11-21

    Consecutive coupling reactions of butane-2,3-diacetal protected glycolic acid derivatives with Michael acceptors and aldehydes are reported. An enantiopure sample of this building block was used to kinetically resolve a chiral Michael acceptor present as a racemic mixture of enantiomers.

  11. Enthalpy difference between conformations of normal alkanes: Intramolecular basis set superposition error (BSSE) in the case of n-butane and n-hexane

    NASA Astrophysics Data System (ADS)

    Balabin, Roman M.

    2008-10-01

    In this paper, an extra error source for high-quality ab initio calculation of conformation equilibrium in normal alkanes—intramolecular basis set superposition error (BSSE)—is discussed. Normal butane (n-butane) and normal hexane (n-hexane) are used as representative examples. Single-point energy difference and BSSE values of trans and gauche conformations for n-butane (and trans-trans-trans and gauche-gauche-gauche conformations for n-hexane) were calculated using popular electron correlation methods: The second-order Moller-Plesset (MP2), the fourth-order Moller-Plesset (MP4), and coupled cluster with single and double substitutions with noniterative triple excitation [CCSD(T)] levels of theory. Extrapolation to the complete basis set is applied. The difference between BSSE-corrected and uncorrected relative energy values ranges from ˜100 cal/mol (in case of n-butane) to more than 1000 cal/mol (in case of n-hexane). The influence of basis set type (Pople or Dunning) and size [up to 6-311G(3df,3pd) and aug-cc-pVQZ] is discussed.

  12. Activation and isomerization of n-butane on sulfated zirconia model systems--an integrated study across the materials and pressure gaps.

    PubMed

    Breitkopf, C; Papp, H; Li, X; Olindo, R; Lercher, J A; Lloyd, R; Wrabetz, S; Jentoft, F C; Meinel, K; Förster, S; Schindler, K-M; Neddermeyer, H; Widdra, W; Hofmann, A; Sauer, J

    2007-07-21

    Butane activation has been studied using three types of sulfated zirconia materials, single crystalline epitaxial films, nanocrystalline films, and powders. A surface phase diagram of zirconia in interaction with SO(3) and water was established by DFT calculations, which was verified by LEED investigations on single-crystalline films and by IR spectroscopy on powders. At high sulfate surface densities a pyrosulfate species is the prevailing structure in the dehydrated state; if such species are absent, the materials are inactive. Theory and experiment show that the pyrosulfate can react with butane to give butene, H(2)O and SO(2), hence butane can be activated via oxidative dehydrogenation. This reaction occurred on all investigated materials; however, isomerization could only be proven for powders. Transient and equilibrium adsorption measurements in a wide pressure and temperature range (isobars measured via UPS on nanocrystalline films, microcalorimetry and temporal analysis of products measurements on powders) show weak and reversible interaction of butane with a majority of sites but reactive interaction with <5 micromol g(-1) sites. Consistently, the catalysts could be poisoned by adding sodium to the surface in a ratio S/Na = 35. Future research will have to clarify what distinguishes these few sites.

  13. Bimetallic catalysts. V. Kinetics of the hydrogenolysis of butane over Pt-Mo/SiO[sub 2] catalysts

    SciTech Connect

    Leclercq, G.; Gharbi, A.El.; Pietrzyk, S. )

    1993-11-01

    The kinetics of the hydrogenolysis of butane on various Pt-Mo catalysts deposited on silica with the same metal content but with various Mo/(Mo + Pt) ratios has been studied. The hydrogenolysis of the two different kinds of C-C bonds has been distinguished. It is shown that the addition of Mo to Pt drastically changes the selectivity of the reaction, but that this selectivity is approximately the same for all the bimetallic Pt-Mo catalysts. Using a rate equation that had already been used for the hydrogenolysis of alkanes (Maurel, R., Leclercq, G., and Leclercq, L., J. Catal. 44, 68 (1975)), calculation has been made of the values of the equilibrium adsorption constants ([lambda]) and those of the rate constants of the C-C bond splitting steps (k) for the hydrogenolysis of the terminal C-C bonds ([lambda][sub 1] and k[sub 1]) and of the middle C-C bond ([lambda][sub 2] and k[sub 2]). In this way it has been shown that only Pt alone, two different intermediaries with high [lambda] values are formed in which the C-C bonds will be broken further with different selectivities but with low rate constants. On the contrary, on all Pt-Mo catalysts, butane is adsorbed as a single intermediate adsorbed species with a much lower adsorption equilibrium constant than on Pt alone, but this adsorbed species is much more reactive (k[sub 1] and k[sub 2]). The adsorption equilibrium constants are the same for all Pt-Mo taking into account the margin of error, which shows that, on all Pt-Mo, butane is adsorbed on the same mixed Pt-Mo site of constant composition whatever the catalyst's composition. The number of these active sites (proportional to k[sub 1] and k[sub 2]) increases as Mo/(Mo + Pt) increases up to 25-30%, then it decreases. 38 refs., 3 figs., 5 tabs.

  14. A novel predictive model for formation enthalpies of Si and Ge hydrides with propane- and butane-like structures.

    PubMed

    Weng, C; Kouvetakis, J; Chizmeshya, A V G

    2011-04-15

    Butane- and propane-like silicon-germanium hydrides and chlorinated derivatives represent a new class of precursors for the fabrication of novel metastable materials at low-temperature regimes compatible with selective growth and commensurate with the emerging demand for the reduced thermal budgets of complementary metal oxide semiconductor integration. However, predictive simulation studies of the growth process and reaction mechanisms of these new compounds, needed to accelerate their deployment and fine-tune the unprecedented low-temperature and low-pressure synthesis protocols, require experimental thermodynamic data, which are currently unavailable. Furthermore, traditional quantum chemistry approaches lack the accuracy needed to treat large molecules containing third-row elements such as Ge. Accordingly, here we develop a method to accurately predict the formation enthalpy of these compounds using atom-wise corrections for Si, Ge, Cl, and H. For a test set of 15 well-known hydrides of Si and Ge and their chlorides, such as Si(3)H(8), Ge(2)H(6), SiGeH(6), SiHCl(3), and GeCl(4), our approach reduces the deviations between the experimental and predicted formation enthalpies obtained from complete basis set (CBS-QB3), G2, and B3LPY thermochemistry to levels of 1-3 kcal/mol, or a factor of ∼5 over the corresponding uncorrected values. We show that our approach yields results comparable or better than those obtained using homodesmic reactions while circumventing the need for thermochemical data of the associated reaction species. Optimized atom-wise corrections are then used to generate accurate enthalpies of formation for 39 pure Si-Ge hydrides and a selected group of 20 chlorinated analogs, of which some have recently been synthesized for the first time. Our corrected enthalpies perfectly reproduce the experimental stability trends of heavy butane-like compounds containing Ge. This is in contrast to the direct application of the CBS-QB3 method, which yields

  15. Photochemistry and photophysics of n-butanal, 3-methylbutanal, and 3,3-dimethylbutanal: experimental and theoretical study.

    PubMed

    Tadić, Jovan M; Moortgat, Geert K; Bera, Partha P; Loewenstein, Max; Yates, Emma L; Lee, Timothy J

    2012-06-21

    Dilute mixtures of n-butanal, 3-methylbutanal, and 3,3-dimethylbutanal in synthetic air, different N(2)/O(2) mixtures, and pure nitrogen (up to 100 ppm) were photolyzed with fluorescent UV lamps (275-380 nm) at 298 K. The main photooxidation products were ethene (n-butanal), propene (3-methylbutanal) or i-butene (3,3-dimethylbutanal), CO, vinylalcohol, and ethanal. The photolysis rates and the absolute quantum yields were found to be dependent on the total pressure of synthetic air but not of nitrogen. At 100 Torr, the total quantum yield Φ(100) = 0.45 ± 0.01 and 0.49 ± 0.07, whereas at 700 Torr, Φ(700) = 0.31 ± 0.01 and 0.36 ± 0.03 for 3-methylbutanal and 3,3-dimethybutanal, respectively. Quantum yield values for n-butanal were reported earlier by Tadić et al. (J. Photochem. Photobiol. A2001143, 169-179) to be Φ(100) = 0.48 ± 0.02 and Φ(700) = 0.32 ± 0.01. Two decomposition channels were identified: the radical channel RCHO → R + HCO (Norrish type I) and the molecular channel CH(3)CH(CH(3))CH(2)CHO → CH(2)CHCH(3) + CH(2)═CHOH or CH(3)C(CH(3))(2)CH(2)CHO → CHC(CH(3))CH(3) + CH(2)═CHOH, (Norrish type II) having the absolute quantum yields of 0.123 and 0.119 for 3-methybutanal and 0.071 and 0.199 for 3,3-dimethylbutanal at 700 Torr of synthetic air. The product ethenol CH(2)═CHOH tautomerizes to ethanal. We have performed ab initio and density functional quantum (DFT) chemical computations of both type I and type II processes starting from the singlet and triplet excited states. We conclude that the Norrish type I dissociation produces radicals from both singlet and triplet excited states, while Norrish type II dissociation is a two-step process starting from the triplet excited state, but is a concerted process from the singlet state.

  16. Solubility of n-butane and 2-methylpropane (isobutane) in 1-alkyl-3-methylimidazolium-based ionic liquids with linear and branched alkyl side-chains.

    PubMed

    Pison, Laure; Shimizu, Karina; Tamas, George; Lopes, José Nuno Canongia; Quitevis, Edward L; Gomes, Margarida F Costa

    2015-11-11

    The solubility of n-butane and 2-methylpropane (isobutane) in three ionic liquids - 1-(2-methylpropyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [(2mC3)C1im][Ntf2], 1-(3-methylbutyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [(3mC4)C1im][Ntf2] and 1-methyl-3-pentylimidazolium bis(trifluoromethylsulfonyl)imide [C5C1im][Ntf2] - has been measured at atmospheric pressure from 303 to 343 K. Isobutane is less soluble than n-butane in all the ionic liquids. Henry's constant values range from 13.8 × 10(5) Pa for n-butane in [C5C1im][Ntf2] at 303 K to 64.5 × 10(5) Pa for isobutane in [(2mC3)C1im][Ntf2] at 343 K. The difference in solubility between the two gases can be explained by a more negative enthalpy of solvation for n-butane. A structural analysis of the pure solvents and of the solutions of the gases, probed by molecular dynamics simulations, could explain the differences found in the systems: (i) the nonpolar domains of the ionic liquids accommodate better the long and more flexible n-butane solute; (ii) the small differences in solubility of each gas in the ionic liquids with the same number of carbon atoms in the alkyl side-chains are explained by the absence of large structural differences in the pure solvents. In all cases, the structural analysis of the four ionic liquids confirms that the studied gases can act as probes of the molecular structure of the ionic liquids, the simulations being always compatible with the experimental solubility data.

  17. Performance and efficiency evaluations of new fluorinated ethers, propanes, and butanes. Report for January-April 1993

    SciTech Connect

    Gage, C.L.; Kazachki, G.S.

    1993-01-01

    The paper gives results of a thermodynamic evaluation that investigates the performance of 15 new chemicals as refrigerants, the impact of the new chemicals on compressor size and operating characteristics, and the efficiency of the refrigerants in vapor compression cycles. Their efficiency in the basic vapor compression cycle is low, but improves substantially in a cycle with internal heat exchange. Several alternatives are identified as promising replacements. As a step in evaluating the potential performance of the 15 compounds, the evaluation using limited property data was performed on the chemicals for use as refrigerants in supermarket, chiller, refrigerator/freezer, heat pump, and air conditioning applications. The 15 chemicals included 10 fluorinated propanes, 3 fluorinated butanes, and 2 fluorinated ethers which are potential chlorofluorocarbon (CFC) and hydrochlorofluorocarbon replacements.

  18. Use of butane-isobutane refrigerant spray in the management of a mucocoele in a visually impaired child.

    PubMed

    Birapu, Uday Chowdary; Puppala, Ravindar; Kethineni, Balaji; Banavath, Sunitha

    2016-01-28

    Mucocoeles are commonly observed lesions in children and young adults. Conventional management using a scalpel aims at enucleation, requiring psychological preparation of the parent as well as the child because of inherent fear and apprehension towards surgery. This is still more complex in children with visual impairment. The other management techniques are laser, cryotherapy and micromarsupialisation, management strategies that, being painless and tolerable, reduce the anxiety of the child and are therefore more acceptable. The basic technique of cryotherapy stresses on rapid cooling, gradual thawing and repeated freezing to ensure tissue destruction. We report a case of a 13-year-old boy with visual impairment, presenting with a mucocoele on the lower lip, which was managed using butane-isobutane refrigerant spray, which is otherwise routinely employed for pulp vitality testing. A single, 2 min freeze/thaw cycle was used. The healing was uneventful.

  19. L'engelure causée par le butane commercial au cours d’un accident industriel

    PubMed Central

    Assi-Dje Bi Dje, V.; Abhe, C.M.; Sie-Essoh, J.B.; Kouamé, K.; Vilasco, B.

    2014-01-01

    Summary Les engelures sont encore exceptionnelles en Afrique sub-saharienne, mais l’essor des industries pétrochimiques en rapport avec la promotion d’une large utilisation du gaz domestique (butane commercial) expose au risque de survenue de ce type de brûlures abusivement dites gelures. Nous rapportons un cas de brûlures au froid par gaz de pétrole liquéfié (GPL) en milieu professionnel dont le diagnostic de gravité et la prise en charge tardifs ont défavorisé l’évolution locale. Le respect des mesures de sécurité au sein des usines reste néanmoins le principal moyen de prévention de ce type de brûlures méconnues. PMID:26170791

  20. The substrate binding cavity of particulate methane monooxygenase from Methylosinus trichosporium OB3b expresses high enantioselectivity for n-butane and n-pentane oxidation to 2-alcohol.

    PubMed

    Miyaji, Akimitsu; Miyoshi, Teppei; Motokura, Ken; Baba, Toshihide

    2011-11-01

    The particulate methane monooxygenase (pMMO) of Methylosinus trichosporium OB3b oxidized n-butane and n-pentane and mainly produced (R)-2-butanol and (R)-2-pentanol that comprised 78 and 89% of the product, respectively, indicating that the pro-R hydrogen of the 2-position carbon of n-butane and n-pentane is oriented toward a catalytic site within the substrate binding site of pMMO. The protein cavity adjacent to the catalytic center for pMMO has optimum volume for recognizing n-butane and n-pentane for enantioselective hydroxylation.

  1. Poly[diammonium [(μ4-butane-1,2,3,4-tetra­carboxyl­ato)zincate] tetra­hydrate

    PubMed Central

    Jin, Shouwen; Huang, Yanfei; Wei, Shuaishuai; Zhou, Yong; Zhou, Yingping

    2012-01-01

    In the title compound, {(NH4)2[Zn(C8H6O8)]·4H2O}n, the asymmetric unit contains one ammonium cation, half of a butane-1,2,3,4-tetra­carboxyl­ate anion, one Zn2+ cation and two water mol­ecules. The butane-1,2,3,4-tetra­carboxyl­ate ligand is located about an inversion centre at the mid-point of the central C—C bond. The Zn2+ cation is situated on a twofold rotation axis and is surrounded by four O atoms from four symmetry-related butane-1,2,3,4-tetra­carboxyl­ate anions in a distorted tetra­hedral environment. In turn, each anion coordinates to four Zn2+ cations. The bridging mode of the anions leads to a three-dimensional framework structure with channels extending along [110] and [010] in which the ammonium cations and the water mol­ecules are located. N—H⋯O and O—H⋯O hydrogen bonding between the cations and water mol­ecules and the uncoordinating O atoms of the carboxyl­ate groups consolidates the crystal packing. PMID:23125594

  2. Three products are better than two: entropic advantages in the competing dissociation reactions of ionized azo-t-butane.

    PubMed

    Rabaev, Madlena; Boulanger, Anne-Marie; Holland, David M P; Shaw, David A; Mayer, Paul M

    2009-02-26

    Ionized azo-t-butane (m/z 142) undergoes three dissociation reactions: competitive cleavage of the N-C bond to form (1) the t-butyl cation ((CH(3))(3)C(+), m/z 57) plus a neutral that is nominally (CH(3))(3)CN(2)(*) (85 Da); (2) m/z 85 cation, (CH(3))(3)CN(2)(+), plus the neutral t-butyl radical; and (3) a minor rearrangement reaction leading to ionized butene. The competition between channels (1) and (2) is governed by both energetic and entropic considerations as the 85 Da neutral lies in a 1 kJ mol(-1) potential energy well and when formed dissociates into the t-butyl radical and N(2). This gives channel 1 an entropic advantage over channel 2, as long as the transition states for these processes reside close to products, a conclusion supported by threshold photoelectron photoion coincidence spectroscopy, tandem mass spectrometry, and ab initio calculations.

  3. Autoignited laminar lifted flames of methane, ethylene, ethane, and n-butane jets in coflow air with elevated temperature

    SciTech Connect

    Choi, B.C.; Chung, S.H.

    2010-12-15

    The autoignition characteristics of laminar lifted flames of methane, ethylene, ethane, and n-butane fuels have been investigated experimentally in coflow air with elevated temperature over 800 K. The lifted flames were categorized into three regimes depending on the initial temperature and fuel mole fraction: (1) non-autoignited lifted flame, (2) autoignited lifted flame with tribrachial (or triple) edge, and (3) autoignited lifted flame with mild combustion. For the non-autoignited lifted flames at relatively low temperature, the existence of lifted flame depended on the Schmidt number of fuel, such that only the fuels with Sc > 1 exhibited stationary lifted flames. The balance mechanism between the propagation speed of tribrachial flame and local flow velocity stabilized the lifted flames. At relatively high initial temperatures, either autoignited lifted flames having tribrachial edge or autoignited lifted flames with mild combustion existed regardless of the Schmidt number of fuel. The adiabatic ignition delay time played a crucial role for the stabilization of autoignited flames. Especially, heat loss during the ignition process should be accounted for, such that the characteristic convection time, defined by the autoignition height divided by jet velocity was correlated well with the square of the adiabatic ignition delay time for the critical autoignition conditions. The liftoff height was also correlated well with the square of the adiabatic ignition delay time. (author)

  4. Dry Reforming of Ethane and Butane with CO2 over PtNi/CeO2 Bimetallic Catalysts

    DOE PAGES

    Yan, Binhang; Yang, Xiaofang; Yao, Siyu; ...

    2016-09-21

    Dry reforming is a potential process to convert CO2 and light alkanes into syngas (H2 and CO), which can be subsequently transformed to chemicals and fuels. Here in this work, PtNi bimetallic catalysts have been investigated for dry reforming of ethane and butane using both model surfaces and supported powder catalysts. The PtNi bimetallic catalyst shows an improvement in both activity and stability as compared to the corresponding monometallic catalysts. The formation of PtNi alloy and the partial reduction of Ce4+ to Ce3+ under reaction conditions are demonstrated by in-situ Ambient Pressure X-ray Photoemission Spectroscopy (AP-XPS), X-ray Diffraction (XRD) andmore » X-ray Absorption Fine Structure (XAFS) measurements. A Pt-rich bimetallic surface is revealed by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) following CO adsorption. Combined in-situ experimental results and Density Functional Theory (DFT) calculations suggest that the Pt-rich PtNi bimetallic surface structure would weaken the binding of surface oxygenates/carbon species and reduce the activation energy for C-C bond scission, leading to an enhanced dry reforming activity.« less

  5. Bioaugmentation with butane-utilizing microorganisms to promote in situ cometabolic treatment of 1,1,1-trichloroethane and 1,1-dichloroethene

    NASA Astrophysics Data System (ADS)

    Semprini, Lewis; Dolan, Mark E.; Hopkins, Gary D.; McCarty, Perry L.

    2009-01-01

    A field study was performed to evaluate the potential for in-situ aerobic cometabolism of 1,1,1-trichloroethane (1,1,1-TCA) through bioaugmentation with a butane enrichment culture containing predominantly two Rhodococcus sp. strains named 179BP and 183BP that could cometabolize 1,1,1-TCA and 1,1-dicholoroethene (1,1-DCE). Batch tests indicated that 1,1-DCE was more rapidly transformed than 1,1,1-TCA by both strains with 183BP being the most effective organism. This second in a series of bioaugmentation field studies was conducted in the saturated zone at the Moffett Field In Situ Test Facility in California. In the previous test, bioaugmentation with an enrichment culture containing the 183BP strain achieved short term in situ treatment of 1,1-DCE, 1,1,1-TCA, and 1,1-dichloroethane (1,1-DCA). However, transformation activity towards 1,1,1-TCA was lost over the course of the study. The goal of this second study was to determine if more effective and long-term treatment of 1,1,1-TCA could be achieved through bioaugmentation with a highly enriched culture containing 179BP and 183BP strains. Upon bioaugmentation and continuous addition of butane and dissolved oxygen and or hydrogen peroxide as sources of dissolved oxygen, about 70% removal of 1,1,1-TCA was initially achieved. 1,1-DCE that was present as a trace contaminant was also effectively removed (˜ 80%). No removal of 1,1,1-TCA resulted in a control test leg that was not bioaugmented, although butane and oxygen consumption by the indigenous populations was similar to that in the bioaugmented test leg. However, with prolonged treatment, removal of 1,1,1-TCA in the bioaugmented leg decreased to about 50 to 60%. Hydrogen pexoxide (H 2O 2) injection increased dissolved oxygen concentration, thus permitting more butane addition into the test zone, but more effective 1,1,1-TCA treatment did not result. The results showed bioaugmentation with the enrichment cultures was effective in enhancing the cometabolic treatment

  6. Effects of Zeolite Structural Confinement on Adsorption Thermodynamics and Reaction Kinetics for Monomolecular Cracking and Dehydrogenation of n-Butane.

    PubMed

    Janda, Amber; Vlaisavljevich, Bess; Lin, Li-Chiang; Smit, Berend; Bell, Alexis T

    2016-04-13

    The effects of zeolite structure on the kinetics of n-butane monomolecular cracking and dehydrogenation are investigated for eight zeolites differing in the topology of channels and cages. Monte Carlo simulations are used to calculate enthalpy and entropy changes for adsorption (ΔHads-H+ and ΔSads-H+) of gas-phase alkanes onto Brønsted protons. These parameters are used to extract intrinsic activation enthalpies (ΔHint‡), entropies (ΔSint‡), and rate coefficients (kint) from measured data. As ΔSads-H+ decreases (i.e., as confinement increases), ΔHint‡ and ΔSint‡ for terminal cracking and dehydrogenation decrease for a given channel topology. These results, together with positive values observed for ΔSint‡, indicate that the transition states for these reactions resemble products. For central cracking (an earlier transition state), ΔHint‡ is relatively constant, while ΔSint‡ increases as ΔSads-H+ decreases because less entropy is lost upon protonation of the alkane. Concurrently, selectivities to terminal cracking and dehydrogenation decrease relative to central cracking because ΔSint‡ decreases for the former reactions. Depending on channel topology, changes in the measured rate coefficients (kapp) with confinement are driven by changes in kint or by changes in the adsorption equilibrium constant (Kads-H+). Values of ΔSint‡ and ΔHint‡ are positively correlated, consistent with weaker interactions between the zeolite and transition state and with the greater freedom of movement of product fragments within more spacious pores. These results differ from earlier reports that ΔHint‡ and ΔSint‡ are structure-insensitive and that kapp is dominated by Kads-H+. They also suggest that ΔSads-H+ is a meaningful descriptor of confinement for zeolites having similar channel topologies.

  7. Comparison of two-body and three-body decomposition of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene

    NASA Astrophysics Data System (ADS)

    Chin, Chih-Hao; Lee, Shih-Huang

    2012-01-01

    We investigated two-body (binary) and three-body (triple) dissociations of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene on the ground potential-energy surfaces using quantum-chemical and Rice-Ramsperger-Kassel-Marcus calculations; most attention is paid on the triple dissociation mechanisms. The triple dissociation includes elimination of a hydrogen molecule from a combination of two separate terminal hydrogen atoms; meanwhile, the rest part simultaneously decomposes to two stable fragments, e.g., C2H4, C2H2, or CO. Transition structures corresponding to the concerted triple dissociation were identified using the B3LYP/6-311G(d,p) level of theory and total energies were computed using the method CCSD(T)/6-311+G(3df, 2p). The forward barrier height of triple dissociation has a trend of ethanedial < propanal < propenal < n-butane < 1-butene < 1,3-butadiene, pertaining to the reaction enthalpy. Ratios of translational energies of three separate fragments could be estimated from the transition structure of triple dissociation. The synchronous concerted dissociation of propanal, propenal, and 1-butene leading to three different types of molecular fragments by breaking nonequivalent chemical bonds is rare. The triple dissociation of propanal, n-butane, 1-butene, and 1,3-butadiene were investigated for the first time. To outline a whole picture of dissociation mechanisms, some significant two-body dissociation channels were investigated for the calculations of product branching ratios. The triple dissociation plays an important role in the three carbonyl compounds, but plays a minor or negligible role in the three hydrocarbons.

  8. Comparison of two-body and three-body decomposition of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene.

    PubMed

    Chin, Chih-Hao; Lee, Shih-Huang

    2012-01-14

    We investigated two-body (binary) and three-body (triple) dissociations of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene on the ground potential-energy surfaces using quantum-chemical and Rice-Ramsperger-Kassel-Marcus calculations; most attention is paid on the triple dissociation mechanisms. The triple dissociation includes elimination of a hydrogen molecule from a combination of two separate terminal hydrogen atoms; meanwhile, the rest part simultaneously decomposes to two stable fragments, e.g., C(2)H(4), C(2)H(2), or CO. Transition structures corresponding to the concerted triple dissociation were identified using the B3LYP/6-311G(d,p) level of theory and total energies were computed using the method CCSD(T)/6-311+G(3df, 2p). The forward barrier height of triple dissociation has a trend of ethanedial < propanal < propenal < n-butane < 1-butene < 1,3-butadiene, pertaining to the reaction enthalpy. Ratios of translational energies of three separate fragments could be estimated from the transition structure of triple dissociation. The synchronous concerted dissociation of propanal, propenal, and 1-butene leading to three different types of molecular fragments by breaking nonequivalent chemical bonds is rare. The triple dissociation of propanal, n-butane, 1-butene, and 1,3-butadiene were investigated for the first time. To outline a whole picture of dissociation mechanisms, some significant two-body dissociation channels were investigated for the calculations of product branching ratios. The triple dissociation plays an important role in the three carbonyl compounds, but plays a minor or negligible role in the three hydrocarbons.

  9. Densities and vapor-liquid equilibria in binary mixtures formed by propyl methanoate + ethanol, + propan-1-ol, and + butan-1-ol at 160.0 kPa

    SciTech Connect

    Falcon, J.; Ortega, J.; Gonzalez, E.

    1996-07-01

    Densities and excess volumes were determined at 298.15 K for propyl methanoate + ethanol, + propan-1-ol, and + butan-1-ol. The results of those quantities were then correlated to get the concentrations of vapor-liquid equilibrium obtained isobarically at 160 kPa for the same mixtures. Two mixtures show azeotropes: for propyl methanoate (1) + ethanol (2), x{sub 1} = 0.443 at T = 358.7 K; and for propyl methanoate (1) + propan-1-ol (2), x{sub 1} = 0.762 at T = 368.2 K. The mixtures are thermodynamically consistent, and the predictions made using several group-contribution models are satisfactory.

  10. The Power of Biocatalysis: A One‐Pot Total Synthesis of Rhamnolipids from Butane as the Sole Carbon and Energy Source

    PubMed Central

    Gehring, Christian; Wessel, Mirja; Schaffer, Steffen

    2016-01-01

    Abstract Microbially derived surfactants, so‐called biosurfactants, have drawn much attention in recent years and are expected to replace current petrochemical surfactants, owing to their environmental and toxicological benefits. One strategy to support that goal is to reduce production costs by replacing relatively expensive sugars with cheaper raw materials, such as short‐chain alkanes. Herein, we report the successful one‐pot total synthesis of rhamnolipids, a class of biosurfactants with 12 stereocenters, from butane as sole carbon and energy source through the design of a tailored whole‐cell biocatalyst. PMID:28032017

  11. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Butan-1-ol (VMSD1511, LB5192_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Butan-1-ol (VMSD1511, LB5192_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  12. Volumetric Properties of the Mixture Methyl ethanoate C3H6O2 + C4H10O Butan-1-ol (VMSD1511, LB4029_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Methyl ethanoate C3H6O2 + C4H10O Butan-1-ol (VMSD1511, LB4029_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  13. Volumetric Properties of the Mixture Butan-1-ol C4H10O + C8H8 Vinylbenzene (VMSD1511, LB4664_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-1-ol C4H10O + C8H8 Vinylbenzene (VMSD1511, LB4664_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  14. Volumetric Properties of the Mixture Butan-1-ol C4H10O + C7H8O Methyl phenyl ether (VMSD1511, LB4559_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-1-ol C4H10O + C7H8O Methyl phenyl ether (VMSD1511, LB4559_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  15. Volumetric Properties of the Mixture Trichloroethene C2HCl3 + C4H10O Butan-1-ol (VMSD1511, LB4850_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloroethene C2HCl3 + C4H10O Butan-1-ol (VMSD1511, LB4850_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  16. Volumetric Properties of the Mixture Butan-1-ol C4H10O + C7H8O Methyl phenyl ether (VMSD1412, LB4565_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-1-ol C4H10O + C7H8O Methyl phenyl ether (VMSD1412, LB4565_V)' providing data by calculation of isentropic compressibility from low-pressure density and thermodynamic speed of sound data at variable mole fraction and constant temperature, in the single-phase region(s).

  17. Volumetric Properties of the Mixture Oxolan-2-one C4H6O2 + C4H10O Butan-1-ol (VMSD1511, LB4906_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Oxolan-2-one C4H6O2 + C4H10O Butan-1-ol (VMSD1511, LB4906_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  18. Volumetric Properties of the Mixture Trichloroethene C2HCl3 + C4H10O Butan-1-ol (VMSD1412, LB4856_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloroethene C2HCl3 + C4H10O Butan-1-ol (VMSD1412, LB4856_V)' providing data by calculation of isentropic compressibility from low-pressure density and thermodynamic speed of sound data at variable mole fraction and constant temperature, in the single-phase region(s).

  19. Volumetric Properties of the Mixture Propenenitrile C3H3N + C4H10O Butan-1-ol (VMSD1511, LB4927_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Propenenitrile C3H3N + C4H10O Butan-1-ol (VMSD1511, LB4927_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  20. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Butan-1-ol (VMSD1412, LB5194_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Butan-1-ol (VMSD1412, LB5194_V)' providing data by calculation of isentropic compressibility from low-pressure density and thermodynamic speed of sound data at variable mole fraction and constant temperature, in the single-phase region(s).

  1. Carbon nanotube-induced preparation of vanadium oxide nanorods: Application as a catalyst for the partial oxidation of n-butane

    SciTech Connect

    Chen Xiaowei; Zhu Zhenping; Haevecker, Michael; Su Dangsheng . E-mail: dangsheng@fhi-berlin.mpg.de; Schloegl, Robert

    2007-02-15

    A vanadium oxide-carbon nanotube composite was prepared by solution-based hydrolysis of NH{sub 4}VO{sub 3} in the presence of carbon nanotubes. The carbon nanotubes induce the nucleation of the 1D vanadium oxide nanostructures, with the nuclei growing into long freestanding nanorods. The vanadium oxide nanorods with the lengths up to 20 {mu}m and the widths of 5-15 nm exhibit a well-ordered crystalline structure. Catalytic tests show that the composite with nanostructured vanadium oxide is active for the partial oxidation of n-butane to maleic anhydride at 300 deg. C.

  2. Determination of nickel in biological materials after microwave dissolution using inductively coupled plasma atomic emission spectrometry with prior extraction into butan-1-ol.

    PubMed

    Vereda Alonso, E; García de Torres, A; Cano Pavón, J M

    1992-07-01

    A sensitive procedure has been developed for the determination of ultratrace amounts of nickel in biological materials by inductively coupled plasma atomic emission spectrometry after extraction of the nickel ion into butan-1-ol by using 1,5-bis(di-2-pyridylmethylene)thiocarbonohydrazide as the extracting reagent. Fast, efficient and complete sample digestion is achieved by an HNO3-HCl poly(tetrafluoroethylene) bomb dissolution technique using microwave heating. Results obtained for eleven certified reference materials agreed with the certified values.

  3. Evidence for Involvement of Copper Ions and Redox State in Regulation of Butane Monooxygenase in Pseudomonas butanovora▿

    PubMed Central

    Doughty, D. M.; Kurth, E. G.; Sayavedra-Soto, L. A.; Arp, D. J.; Bottomley, P. J.

    2008-01-01

    Pseudomonas butanovora possesses an alcohol-inducible alkane monooxygenase, butane monooxygenase (BMO), that initiates growth on C2-C9 alkanes. A lacZ transcriptional reporter strain, P. butanovora bmoX::lacZ, in which the BMO promoter controls the expression of β-galactosidase activity, was used to show that 1-butanol induced the BMO promoter in the presence or absence of O2 when lactate-grown, BMO-repressed cells were washed free of lactate and incubated in NH4Cl-KNa phosphate buffer. In contrast, when lactate-grown cells of the reporter strain were incubated in phosphate buffer containing the mineral salts of standard growth medium, 1-butanol-dependent induction was significantly repressed at low O2 (1 to 2% [vol/vol]) and totally repressed under anoxic conditions. The repressive effect of the mineral salts was traced to its copper content. In cells exposed to 1% (vol/vol) O2, CuSO4 (0.5 μM) repressed 1-butanol-dependent induction of β-galactosidase activity. Under oxic conditions (20% O2 [vol/vol]), significantly higher concentrations of CuSO4 (2 μM) were required for almost complete repression of induction in lactate-grown cells. A combination of the Cu2+ reducing agent Na ascorbate (100 μM) and CuSO4 (0.5 μM) repressed the induction of β-galactosidase activity under oxic conditions to the same extent that 0.5 μM CuSO4 alone repressed it under anoxic conditions. Under oxic conditions, 2 μM CuSO4 repressed induction of the BMO promoter less effectively in butyrate-grown cells of the bmoX::lacZ strain and of an R8-bmoX::lacZ mutant reporter strain with a putative BMO regulator, BmoR, inactivated. Under anoxic conditions, CuSO4 repression remained highly effective, regardless of the growth substrate, in both BmoR-positive and -negative reporter strains. PMID:18281403

  4. Unusual Butane- and Pentanetriol-Based Tetraether Lipids in Methanomassiliicoccus luminyensis, a Representative of the Seventh Order of Methanogens

    PubMed Central

    Elling, Felix J.; Yoshinaga, Marcos Y.; Söllinger, Andrea; Urich, Tim; Hinrichs, Kai-Uwe

    2016-01-01

    ABSTRACT A new clade of archaea has recently been proposed to constitute the seventh methanogenic order, the Methanomassiliicoccales, which is related to the Thermoplasmatales and the uncultivated archaeal clades deep-sea hydrothermal vent Euryarchaeota group 2 and marine group II Euryarchaeota but only distantly related to other methanogens. In this study, we investigated the membrane lipid composition of Methanomassiliicoccus luminyensis, the sole cultured representative of this seventh order. The lipid inventory of M. luminyensis comprises a unique assemblage of novel lipids as well as lipids otherwise typical for thermophilic, methanogenic, or halophilic archaea. For instance, glycerol sesterpanyl-phytanyl diether core lipids found mainly in halophilic archaea were detected, and so were compounds bearing either heptose or methoxylated glycosidic head groups, neither of which have been reported so far for other archaea. The absence of quinones or methanophenazines is consistent with a biochemistry of methanogenesis different from that of the methanophenazine-containing methylotrophic methanogens. The most distinctive characteristic of the membrane lipid composition of M. luminyensis, however, is the presence of tetraether lipids in which one glycerol backbone is replaced by either butane- or pentanetriol, i.e., lipids recently discovered in marine sediments. Butanetriol dibiphytanyl glycerol tetraether (BDGT) constitutes the most abundant core lipid type (>50% relative abundance) in M. luminyensis. We have thus identified a source for these unusual orphan lipids. The complementary analysis of diverse marine sediment samples showed that BDGTs are widespread in anoxic layers, suggesting an environmental significance of Methanomassiliicoccales and/or related BDGT producers beyond gastrointestinal tracts. IMPORTANCE Cellular membranes of members of all three domains of life, Archaea, Bacteria, and Eukarya, are largely formed by lipids in which glycerol serves as

  5. Physical properties of fluorinated propane and butane derivatives and the vapor pressure of R-245ca/338mccq mixtures as R-11 alternatives

    SciTech Connect

    Beyerlein, A.L.; DesMarteau, D.D.; Xie, Y.; Naik, K.N.

    1996-11-01

    Two new fluorinated propane derivatives, six new fluorinated butane derivatives,and the R-245ca(HCF{sub 2}CF{sub 2}CH{sub 2}F)/338mccq(CF{sub 3}CF{sub 2}CH{sub 2}CH{sub 2}F) mixtures are investigated as R-11 alternatives. The investigations on the pure chemicals included measurements of the melting point, boiling point, vapor pressure below the boiling point, heat of vaporization at the boiling point, saturated liquid density, and critical properties (temperature and density). Four of the butane derivatives--R-338mcfm, R-356mffm, R-356mecs, and R-356mms--have boiling points comparable to that of R-11 and have potential as far-term R-11 alternatives. The vapor pressures of the R-245ca/338mccq mixtures were measured over the entire concentration range for temperatures ranging from 25 C (77 F) to 135 C (275 F). The mixtures form an azeotrope at 0.64 R-245ca mole fraction with a normal boiling point of 22.6 C (72.7 F).

  6. PM, NOx and butane emissions from on-road vehicle fleets in Hong Kong and their implications on emission control policy

    NASA Astrophysics Data System (ADS)

    Ning, Zhi; Wubulihairen, Maimaitireyimu; Yang, Fenhuan

    2012-12-01

    Vehicular emissions are the major sources of air pollution in urban areas. For metropolitan cities with large population working and living in environments with direct traffic impact, emission control is of great significance to protect public health. Implementation of more stringent emission standards, retrofitting fleet with emission control devices and switching to clearer fuel has been commonly practiced in different cities including Hong Kong. The present study employed a new plume chasing method for effective and quick evaluation of on-road fleet emission factors of particulate matter (PM), nitrogen oxides (NOx), and butane from heavy duty diesel trucks, diesel buses and liquefied petroleum gas (LPG) vehicles. The results showed distinct profiles of the emissions from different fleets with excessive butane emissions from LPG fleet and contrasting PM and NOx emissions from diesel trucks and buses fleets. A cross comparison was also made with emission data from other cities and from historic local studies. The implications of the observed difference on the effectiveness of emission control measures and policy are discussed with recommendations of direction for future research and policy making.

  7. Synthesis, Crystal Structure and Interaction With DNA of N,N′-(Butane-1,4-Diyl)Bis(Guanidinium) Tetrachloroplatinate (II)

    PubMed Central

    Viossat, Bernard; Labouze, Xavier; Morgant, Georges; Saturnino, Carmella; Lancelot, Jean Charles; Robba, Max; Dung, Nguyen Huy

    1998-01-01

    The design, synthesis, crystal structure and interaction with DNA of the N,N′-(butane-1,4-diyl)bis(guanidinium) tetrachloroplatinate(ll) are described. Crystal data: a = 8.152(1), b = 8.889(4), c = 10.700(3) Å , α = 81.59(3), β = 87.99(5), γ = 78.48(6)°, V = 752(1) Å3, Z = 2 , space group P-1. The structure was refined to R = 0.039 and Rw = 0.046 from 1853 reflections (I > 3σ(I)). This compound, named PtC4Gua, does not exhibit a center of symmetry and the center linker chain C(2) - C(3) - C(4) - C(5) is in gauche conformation. The cation is bisprotonated with the H+ attached to the imine group of each terminal guanidinium function. The presence of the platinum moiety reinforces the binding of the butane(bis)guanidinium structure with double stranded DNA as judged from thermal denaturation studies and DNA unwinding experiments. PMID:18475859

  8. Evidence for Modified Mechanisms of Chloroethene Oxidation in Pseudomonas butanovora Mutants Containing Single Amino Acid Substitutions in the Hydroxylase α-Subunit of Butane Monooxygenase▿

    PubMed Central

    Halsey, Kimberly H.; Doughty, David M.; Sayavedra-Soto, Luis A.; Bottomley, Peter J.; Arp, Daniel J.

    2007-01-01

    The properties of oxidation of dichloroethene (DCE) and trichloroethylene (TCE) by three mutant strains of Pseudomonas butanovora containing single amino acid substitutions in the α-subunit of butane monooxygenase hydroxylase (BMOH-α) were compared to the properties of the wild-type strain (Rev WT). The rates of oxidation of three chloroethenes (CEs) were reduced in mutant strain G113N and corresponded with a lower maximum rate of butane oxidation. The rate of TCE degradation was reduced by one-half in mutant strain L279F, whereas the rates of DCE oxidation were the same as those in Rev WT. Evidence was obtained that the composition of products of CE oxidation differed between Rev WT and some of the mutant strains. For example, while Rev WT released nearly all available chlorine stoichiometrically during CE oxidation, strain F321Y released about 40% of the chlorine during 1,2-cis-DCE and TCE oxidation, and strain G113N released between 14 and 25% of the available chlorine during oxidation of DCE and 56% of the available chlorine during oxidation of TCE. Whereas Rev WT, strain L279F, and strain F321Y formed stoichiometric amounts of 1,2-cis-DCE epoxide during oxidation of 1,2-cis-DCE, only about 50% of the 1,2-cis-DCE oxidized by strain G113N was detected as the epoxide. Evidence was obtained that 1,2-cis-DCE epoxide was a substrate for butane monooxygenase (BMO) that was oxidized after the parent compound was consumed. Yet all of the mutant strains released less than 40% of the available 1,2-cis-DCE chlorine, suggesting that they have altered activity towards the epoxide. In addition, strain G113N was unable to degrade the epoxide. TCE epoxide was detected during exposure of Rev WT and strain F321Y to TCE but was not detected with strains L279F and G113N. Lactate-dependent O2 uptake rates were differentially affected by DCE degradation in the mutant strains, providing evidence that some products released by the altered BMOs reduced the impact of CE on cellular

  9. Host cells and methods for producing 3-methyl-2-buten-1-ol, 3-methyl-3-buten-1-ol, and 3-methyl-butan-1-ol

    DOEpatents

    Chou, Howard H.; Keasling, Jay D.

    2011-07-26

    The invention provides for a method for producing a 5-carbon alcohol in a genetically modified host cell. In one embodiment, the method comprises culturing a genetically modified host cell which expresses a first enzyme capable of catalyzing the dephosphorylation of an isopentenyl pyrophosphate (IPP) or dimethylallyl diphosphate (DMAPP), such as a Bacillus subtilis phosphatase (YhfR), under a suitable condition so that 5-carbon alcohol is 3-methyl-2-buten-1-ol and/or 3-methyl-3-buten-1-ol is produced. Optionally, the host cell may further comprise a second enzyme capable of reducing a 3-methyl-2-buten-1-ol to 3-methyl-butan-1-ol, such as a reductase.

  10. Numerical Analysis of Autoignition and Combustion of n-Butane and Air Mixture in Homogeneous-Charge Compression-Ignition Engine Using Elementary Reactions

    NASA Astrophysics Data System (ADS)

    Yamasaki, Yudai; Iida, Norimasa

    The present study focuses on clarifying the combustion mechanism of the homogeneous-charge compression-ignition (HCCI) engine in order to control ignition and combustion as well as to reduce HC and CO emissions and to maintain high combustion efficiency by calculating the chemical kinetics of elementary reactions. For the calculations, n-butane was selected as fuel since it is a fuel with the smallest carbon number in the alkane family that shows two-stage autoignition (heat release with low-temperature reaction (LTR) and with high-temperature reaction (HTR)) similarly to higher hydrocarbons such as gasoline. The CHEMKIN code was used for the calculations assuming zero dimensions in the combustion chamber and adiabatic change. The results reveal the heat release mechanism of the LTR and HTR, the control factor of ignition timing and combustion speed, and the condition need to reduce HC and CO emissions and to maintain high combustion efficiency.

  11. Oxidative dehydrogenation of n-butane over magnesium vanadate nano-catalysts supported on magnesia-zirconia: effect of vanadium content.

    PubMed

    Lee, Jong Kwon; Hong, Ung Gi; Yoo, Yeonshick; Cho, Young-Jin; Lee, Jinsuk; Chang, Hosik; Song, In Kyu

    2013-12-01

    Magnesia-zirconia (MgO-ZrO2) support was prepared by a sol-gel method, and magnesium vanadate nano-catalysts supported on magnesia-zirconia (X-Mg3(VO4)2/MgO-ZrO2) were then prepared by a wet impregnation method with a variation of vanadium content (X = 6.6, 9.9, 12.8, 15.2, and 19.1 wt%). X-Mg3(VO4)2/MgO-ZrO2 nano-catalysts were applied to the oxidative dehydrogenation of n-butane to n-butene and 1,3-butadiene. The formation of X-Mg3(VO4)2/MgO-ZrO2 nano-catalysts was well confirmed by XRD, XPS, and ICP-AES analyses. 15.2-Mg3(VO4)2/MgO-ZrO2 and 19.1-Mg3(VO4)2/MgO-ZrO2 catalysts experienced a catalyst deactivation, while the other Mg3(VO4)2/MgO-ZrO2 catalysts showed a stable catalytic performance during the whole reaction time. The effect of oxygen property of X-Mg3(VO4)2/MgO-ZrO2 nano-catalysts on the catalytic performance in the oxidative dehydrogenation of n-butane was investigated. Experimental results revealed that oxygen capacity of the catalyst was closely related to the catalytic performance, while oxygen mobility of the catalyst played an important role in the catalyst stability. Among the catalysts tested, 12.8-Mg3(VO4)2/MgO-ZrO2 catalyst showed the best catalytic performance in terms of yield for TDP (total dehydrogenation products).

  12. Evaluated Kinetics of the Reactions of H and CH3 with n-Alkanes: Experiments with n-Butane and a Combustion Model Reaction Network Analysis.

    PubMed

    Manion, Jeffrey A; Sheen, David A; Awan, Iftikhar A

    2015-07-16

    Presented is a combined experimental and modeling study of the kinetics of the reactions of H and CH3 with n-butane, a representative aliphatic fuel. Abstraction of H from n-alkane fuels creates alkyl radicals that rapidly decompose at high temperatures to alkenes and daughter radicals. In combustion and pyrolysis, the branching ratio for attack on primary and secondary hydrogens is a key determinant of the initial olefin and radical pool, and results propagate through the chemistry of ignition, combustion, and byproduct formation. Experiments to determine relative and absolute rate constants for attack of H and CH3 have been carried out in a shock tube between 859 and 1136 K for methyl radicals and 890 to 1146 K for H atoms. Pressures ranged from 140 to 410 kPa. Appropriate precursors are used to thermally generate H and CH3 in separate experiments under dilute and well-defined conditions. A mathematical design algorithm has been applied to select the optimum experimental conditions. In conjunction with postshock product analyses, a network analysis based on the detailed chemical kinetic combustion model JetSurf 2 has been applied. Polynomial chaos expansion techniques and Monte Carlo methods are used to analyze the data and assess uncertainties. The present results provide the first experimental measurements of the branching ratios for attack of H and CH3 on primary and secondary hydrogens at temperatures near 1000 K. Results from the literature are reviewed and combined with the present data to generate evaluated rate expressions for attack on n-butane covering 300 to 2000 K for H atoms and 400 to 2000 K for methyl radicals. Values for generic n-alkanes and related hydrocarbons are also recommended. The present experiments and network analysis further demonstrate that the C-H bond scission channels in butyl radicals are an order of magnitude less important than currently indicated by JetSurf 2. Updated rate expressions for butyl radical fragmentation reactions

  13. Mg3(VO4)2-MgO-ZrO2 nano-catalysts for oxidative dehydrogenation of n-butane.

    PubMed

    Lee, Jong Kwon; Seo, Hyun; Hong, Ung Gi; Yoo, Yeonshick; Cho, Young-Jin; Lee, Jinsuk; Park, Gle; Chang, Hosik; Song, In Kyu

    2014-11-01

    A series of X-Mg3(VO4)2-MgO-ZrO2 nano-catalysts with different vanadium content (X = 3.3, 5.3, 7.0, 10.2, and 13.4) were prepared by a single-step citric acid-derived sol-gel method for use in the oxidative dehydrogenation of n-butane to n-butene and 1,3-butadiene. The effect of vanadium content of X-Mg3(VO4)2-MgO-ZrO2 nano-catalysts on their physicochemical properties and catalytic activities in the oxidative dehydrogenation of n-butane was investigated. Successful formation of X-Mg3(VO4)2-MgO-ZrO2 nano-catalysts was confirmed by XRD, Raman spectroscopy, and ICP-AES analyses. The catalytic performance of X-Mg3(VO4)2-MgO-ZrO2 nano-catalysts strongly depended on vanadium content. All the X-Mg3(VO4)2-MgO-ZrO2 nano-catalysts showed a stable catalytic performance without catalyst deactivation during the reaction. Among the catalysts tested, 7.0-Mg3(VO4)2-MgO-ZrO2 nano-catalyst showed the best catalytic performance in terms of yield for total dehydrogenation products (TDP, n-butene and 1,3-butadiene). TPRO (temperature-programmed reoxidation) experiments were carried out to measure the oxygen capacity of the catalyst. Experimental results revealed that oxygen capacity of the catalyst was closely related to the catalytic performance. Yield for TDP increased with increasing oxygen capacity of the catalyst.

  14. 75 FR 29435 - Diquat Dibromide; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... the following activities: Crop production (NAICS code 111). Animal production (NAICS code 112). Food... evidence of increased quantitative or qualitative susceptibility of in utero animals or of offspring in...) occurred at a higher dose than the dose causing effects in maternal animals (decreased body-weight...

  15. THE CRYSTAL STRUCTURE OF DIPHENYLTELLURIUM DIBROMIDE,

    DTIC Science & Technology

    TELLURIUM COMPOUNDS, *ORGANOMETALLIC COMPOUNDS, CRYSTAL STRUCTURE , CRYSTAL STRUCTURE , BROMIDES, SYMMETRY(CRYSTALLOGRAPHY), X RAY DIFFRACTION, FOURIER ANALYSIS, LEAST SQUARES METHOD, MOLECULAR STRUCTURE, CHEMICAL BONDS.

  16. (η5-Penta­methyl­cyclo­penta­dien­yl)(η6-4-phenyl­butan-2-one)ruthenium(II) tetra­phenyl­borate

    PubMed Central

    Loughrey, Bradley T.; Williams, Michael L.; Healy, Peter C.

    2010-01-01

    The title compound, [Ru(C10H15)(C10H12O)][B(C6H5)4], crystallizes as discrete (η5-penta­methyl­cyclo­penta­dien­yl)Ru(η6-4-phenyl­butan-2-one)]+ cations and [BPh4]− anions. In the cation, the non-H atoms of the butan-2-one group are approximately planar (r.m.s. deviation = 0.056 Å) and lie nearly perpendicular to the plane of the phenyl ring with a dihedral angle between the two planes of 69.3 (1)°. No significant C—H⋯O inter­actions are observed between the methyl and phenyl H atoms and the carbonyl O atom. PMID:21589253

  17. Effect of modification methods on the surface properties and n-butane isomerization performance of La/Ni-promoted SO42-/ZrO2-Al2O3

    NASA Astrophysics Data System (ADS)

    Wang, Pengzhao; Zhang, Jiaoyu; Han, Chaoyi; Yang, Chaohe; Li, Chunyi

    2016-08-01

    The La and/or Ni was introduced into alumina-promoted sulfated zirconia by impregnation and co-precipitation to improve the catalytic property of n-butane isomerization. Catalysts characterization shows that the addition of La/Ni has a remarkable influence on the surface and textual properties depending on the modification method. The impregnation of La/Ni facilitates the transformation of a small amount of tetragonal zirconia into monoclinic phase, while the co-precipitation improves the stability of tetragonal ZrO2. H2-TPR indicates that the addition of La/Ni changes the interaction between SO42- and supports, which affects the acidity on the surface. Specifically, the Lewis acidity is significantly enhanced by either modification method. The co-precipitation reserves almost all of the Brønsted acid sites, while the impregnation causes a remarkable decrease of Brønsted acid sites. Reaction results demonstrate that the co-precipitation exhibits a significant advantage over impregnation that the higher conversion of n-butane and selectivity to isobutane are obtained on the catalyst prepared by co-precipitation. The increase of catalytic activity is ascribed to the accelerated activation rate of n-butane molecules by hydride subtraction on the Lewis acid sites at higher reaction temperature. Furthermore, the addition of La/Ni improves the selectivity to isobutane by inhibiting the bimolecular reaction.

  18. Synthesis and structural characterization of five new copper (I) complexes with 1,10-phenanthroline and 1,4-bis(diphenylphosphino)butane(dppb)

    NASA Astrophysics Data System (ADS)

    Li, Jian-Bao; Fan, Wei-Wei; Min-Liu; Xiao, Ye-Lan; Jin, Qiong-Hua; Li, Zhong-Feng

    2015-04-01

    The mixture of copper(I) salts CuX (X = Cl, Br, SCN, CN, SO3CF3) and 1,10-phenanthroline (phen) reacts with 1,4-bis(diphenylphosphino)butane (dppb) to give dinuclear complexes [Cu2(dppb)(phen)2Cl2]ṡ4DMF (1), [Cu2(dppb)(phen)2Br2]ṡDMF (2), [Cu2(dppb)(phen)2(SCN)2] (3) and two 1D chain complexes {[Cu2(dppb)(phen)2(CN)2(H2O)]}nṡnH2O (4) and {[Cu2(dppb)(phen)2](SO3CF3)2}n (5), respectively. The structures of these compounds were investigated by elemental analysis, single-crystal X-ray diffraction, electronic absorption spectroscopy, fluorescence spectroscopy, 1H NMR and 31P NMR spectroscopy. Each Cu atom adopts a distorted tetrahedral configuration, and all the complexes are considerably air-stable in solid state and in solution. Detailed NMR studies have been performed to disclose the behavior of the prepared copper(I) complexes in solution. All the five complexes are bright green and cyan luminophores in a solid state at room temperature. This makes them potential candidates as cheap emitting materials for electroluminescent devices.

  19. Synthesis, characterization and testing of a new V2O5/Al2O3-MgO catalyst for butane dehydrogenation and limonene oxidation.

    PubMed

    Strassberger, Zea; Ramos-Fernandez, Enrique V; Boonstra, Agnes; Jorna, Remy; Tanase, Stefania; Rothenberg, Gadi

    2013-04-21

    We report the synthesis and characterization of new V2O5/Al2O3-MgO catalysts and their application in oxidative dehydrogenation and epoxidation reactions. The materials were prepared by wet impregnation under excess acid conditions. Anchoring of the desired species on the support occurs via an exchange reaction between the vanadium complex and surface hydroxyl groups. The IR and UV-Vis spectra of these catalysts indicate the presence of monomeric vanadium species at 5 wt% V2O5 loading, along with small amounts of polymeric species at 5 and 10 wt% V2O5 loadings. Electron paramagnetic resonance (EPR) spectroscopy reveals the presence of ferromagnetic VO(2+) dimers following calcination at 773 K. The catalysts were then tested in two reactions, namely the gas phase oxidative dehydrogenation of n-butane under flow conditions at 773 K and the liquid phase epoxidation of limonene with H2O2. The dehydrogenation reaction gave butenes and 1,3-butadiene in moderate selectivity at 8-10% conversion. The epoxidation of limonene was less successful, giving 50-70% selectivity to the 1,2-epoxide at 10-20% conversion.

  20. A novel radial anode layer ion source for inner wall pipe coating and materials modification—Hydrogenated diamond-like carbon coatings from butane gas

    NASA Astrophysics Data System (ADS)

    Murmu, Peter P.; Markwitz, Andreas; Suschke, Konrad; Futter, John

    2014-08-01

    We report a new ion source development for inner wall pipe coating and materials modification. The ion source deposits coatings simultaneously in a 360° radial geometry and can be used to coat inner walls of pipelines by simply moving the ion source in the pipe. Rotating parts are not required, making the source ideal for rough environments and minimizing maintenance and replacements of parts. First results are reported for diamond-like carbon (DLC) coatings on Si and stainless steel substrates deposited using a novel 360° ion source design. The ion source operates with permanent magnets and uses a single power supply for the anode voltage and ion acceleration up to 10 kV. Butane (C4H10) gas is used to coat the inner wall of pipes with smooth and homogeneous DLC coatings with thicknesses up to 5 μm in a short time using a deposition rate of 70 ± 10 nm min-1. Rutherford backscattering spectrometry results showed that DLC coatings contain hydrogen up to 30 ± 3% indicating deposition of hydrogenated DLC (a-C:H) coatings. Coatings with good adhesion are achieved when using a multiple energy implantation regime. Raman spectroscopy results suggest slightly larger disordered DLC layers when using low ion energy, indicating higher sp3 bonds in DLC coatings. The results show that commercially interesting coatings can be achieved in short time.

  1. A novel radial anode layer ion source for inner wall pipe coating and materials modification--hydrogenated diamond-like carbon coatings from butane gas.

    PubMed

    Murmu, Peter P; Markwitz, Andreas; Suschke, Konrad; Futter, John

    2014-08-01

    We report a new ion source development for inner wall pipe coating and materials modification. The ion source deposits coatings simultaneously in a 360° radial geometry and can be used to coat inner walls of pipelines by simply moving the ion source in the pipe. Rotating parts are not required, making the source ideal for rough environments and minimizing maintenance and replacements of parts. First results are reported for diamond-like carbon (DLC) coatings on Si and stainless steel substrates deposited using a novel 360° ion source design. The ion source operates with permanent magnets and uses a single power supply for the anode voltage and ion acceleration up to 10 kV. Butane (C4H10) gas is used to coat the inner wall of pipes with smooth and homogeneous DLC coatings with thicknesses up to 5 μm in a short time using a deposition rate of 70 ± 10 nm min(-1). Rutherford backscattering spectrometry results showed that DLC coatings contain hydrogen up to 30 ± 3% indicating deposition of hydrogenated DLC (a-C:H) coatings. Coatings with good adhesion are achieved when using a multiple energy implantation regime. Raman spectroscopy results suggest slightly larger disordered DLC layers when using low ion energy, indicating higher sp(3) bonds in DLC coatings. The results show that commercially interesting coatings can be achieved in short time.

  2. Dry Reforming of Ethane and Butane with CO2 over PtNi/CeO2 Bimetallic Catalysts

    SciTech Connect

    Yan, Binhang; Yang, Xiaofang; Yao, Siyu; Wan, Jie; Myint, MyatNoeZin; Gomez, Elaine; Xie, Zhenhua; Kattel, Shyam; Xu, Wenqian; Chen, Jingguang G.

    2016-09-21

    Dry reforming is a potential process to convert CO2 and light alkanes into syngas (H2 and CO), which can be subsequently transformed to chemicals and fuels. Here in this work, PtNi bimetallic catalysts have been investigated for dry reforming of ethane and butane using both model surfaces and supported powder catalysts. The PtNi bimetallic catalyst shows an improvement in both activity and stability as compared to the corresponding monometallic catalysts. The formation of PtNi alloy and the partial reduction of Ce4+ to Ce3+ under reaction conditions are demonstrated by in-situ Ambient Pressure X-ray Photoemission Spectroscopy (AP-XPS), X-ray Diffraction (XRD) and X-ray Absorption Fine Structure (XAFS) measurements. A Pt-rich bimetallic surface is revealed by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) following CO adsorption. Combined in-situ experimental results and Density Functional Theory (DFT) calculations suggest that the Pt-rich PtNi bimetallic surface structure would weaken the binding of surface oxygenates/carbon species and reduce the activation energy for C-C bond scission, leading to an enhanced dry reforming activity.

  3. Luminescent dinuclear copper(I) complexes bearing 1,4-bis(diphenylphosphino)butane and functionalized 3-(2'-pyridyl)pyrazole mixed ligands.

    PubMed

    Chen, Jing-Lin; Guo, Zong-Hao; Yu, Hua-Guang; He, Li-Hua; Liu, Sui-Jun; Wen, He-Rui; Wang, Jin-Yun

    2016-01-14

    A family of new dinuclear Cu(i) complexes with 1,4-bis(diphenylphosphino)butane (dppb) and functionalized 3-(2'-pyridyl)pyrazole mixed ligands has been synthesized and characterized. It is revealed that all these Cu(i) complexes include a [Cu2(dppb)2](2+) framework with the two Cu(i) atoms doubly bridged by a pair of dppb to generate a fourteen-membered Cu2P4C8 ring, and functionalized 3-(2'-pyridyl)pyrazole adopts a neutral chelating coordination mode without the N-H bond cleavage of the pyrazolyl ring. All these dinuclear Cu(i) complexes display a relatively weak low-energy absorption in CH2Cl2 solution, which is closely related to the variation of the Cu-N and Cu-P bonds caused by the substituent on the pyrazolyl ring. These dinuclear Cu(i) complexes are all emissive in solution and solid states at ambient temperature, which can be well modulated through structural modification of 3-(2'-pyridyl)pyrazole. It is shown that introduction of the trifluoromethyl group into the pyrazolyl ring is helpful for enhancing the luminescence properties of Cu(i) pyrazole phosphine complexes.

  4. The role of hydroxyl group acidity on the activity of silica-supported secondary amines for the self-condensation of n-butanal.

    PubMed

    Shylesh, Sankaranarayanapillai; Hanna, David; Gomes, Joseph; Canlas, Christian G; Head-Gordon, Martin; Bell, Alexis T

    2015-02-01

    The catalytic activity of secondary amines supported on mesoporous silica for the self-condensation of n-butanal to 2-ethylhexenal can be altered significantly by controlling the Brønsted acidity of M--OH species present on the surface of the support. In this study, M--OH (M=Sn, Zr, Ti, and Al) groups were doped onto the surface of SBA-15, a mesoporous silica, prior to grafting secondary propyl amine groups on to the support surface. The catalytic activity was found to depend critically on the synthesis procedure, the nature and amount of metal species introduced and the spatial separation between the acidic sites and amine groups. DFT analysis of the reaction pathway indicates that, for weak Brønsted acid groups, such as Si--OH, the rate-limiting step is C--C bond formation, whereas for stronger Brønsted acid groups, such as Ti and Al, hydrolysis of iminium species produced upon C--C bond formation is the rate-limiting step. Theoretical analysis shows further that the apparent activation energy decreases with increasing Brønsted acidity of the M--OH groups, consistent with experimental observation.

  5. NTP technical report on the toxicity studies of Butanal oxime (CAS No. 110-69-0) administered in drinking water and by gavage to F344/N rats and B6C3F1 mice.

    PubMed

    Burka, Leo T

    2004-01-01

    Butanal oxime is used as a volatile antiskinning agent in paints, inks, and similar products. Butanal oxime was chosen for toxicology testing as a representative of the aldoxime class. Male and female F344/N rats and B6C3F1 mice received butanal oxime (99 percent pure) in drinking water for 15 days or by gavage in 0.5 percent methylcellulose for 14 weeks. Animals were evaluated for clinical pathology, reproductive system effects, and histopathology. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, and mouse peripheral blood erythrocytes. In the 15-day studies, groups of five male and five female rats and mice received 0, 312, 625, 1,250, 2,500, or 5,000 ppm butanal oxime in drinking water, resulting in average daily doses of approximately 40, 70, or 100 mg butanal oxime/kg body weight to male and female rats; 45, 90, 130, 200, or 300 mg/kg to male mice; and 45, 85, 100, 130, or 170 mg/kg to female mice. Due to body weight loss and lack of water consumption, all male and female rats receiving 2,500 or 5,000 ppm were removed from the study on day 9; average daily doses were not calculated for these groups. All other rats and mice survived until the end of the studies. Mean body weights of 1,250 ppm male and female rats and 2,500 and 5,000 ppm male and female mice were significantly less than those of the controls. Male mice receiving 5,000 ppm and females receiving 2,500 or 5,000 ppm lost weight during the study. Water consumption by rats and mice receiving 1,250 ppm or greater was less than that by the controls. Thinness in 2,500 and 5,000 ppm rats and mice was the only clinical finding of toxicity. Spleen weights were significantly decreased in 2,500 and 5,000 ppm female mice. No chemical-related lesions were observed grossly; histologic examinations were not performed. In the 14-week studies, groups of 10 male and 10 female rats and mice received butanal oxime by gavage at doses of 0, 25, 50, 100, 200, or

  6. Interactions of butane, but-2-ene or xylene-like linked bispyridinium para-aldoximes with native and tabun-inhibited human cholinesterases.

    PubMed

    Calić, Maja; Bosak, Anita; Kuca, Kamil; Kovarik, Zrinka

    2008-09-25

    Kinetic parameters were evaluated for inhibition of native and reactivation of tabun-inhibited human erythrocyte acetylcholinesterase (AChE, EC 3.1.1.7) and human plasma butyrylcholinesterase (BChE, EC 3.1.1.8) by three bispyridinium para-aldoximes with butane (K074), but-2-ene (K075) or xylene-like linker (K114). Tested aldoximes reversibly inhibited both cholinesterases with the preference for binding to the native AChE. Both cholinesterases showed the highest affinity for K114 (K(i) was 0.01 mM for AChE and 0.06 mM for BChE). The reactivation of tabun-inhibited AChE was efficient by K074 and K075. Their overall reactivation rate constants were around 2000 min(-1)M(-1), which is seven times higher than for the classical bispyridinium para-aldoxime TMB-4. The reactivation of tabun-inhibited AChE assisted by K114 was slow and reached 90% after 20 h. Since the aldoxime binding affinity of tabun-inhibited AChE was similar for all tested aldoximes (and corresponded to their K(i)), the rate of the nucleophilic displacement of the phosphoryl-moiety from the active site serine was the limiting factor for AChE reactivation. On the other hand, none of the aldoximes displayed a significant reactivation of tabun-inhibited BChE. Even after 20 h, the reactivation maximum was 60% for 1 mM K074 and K075, and only 20% for 1 mM K114. However, lower BChE affinities for K074 and K075 compared to AChE suggest that the fast tabun-inhibited AChE reactivation by these compounds would not be obstructed by their interactions with BChE in vivo.

  7. Performance studies of copper-iron/ceria-yttria stabilized zirconia anode for electro-oxidation of butane in solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Kaur, Gurpreet; Basu, Suddhasatwa

    2013-11-01

    Addition of second metal to Cu is useful for electro-oxidation of hydrocarbons in solid oxide fuel cells (SOFC). In this work, electro-catalysts based on Cu-Fe bimetallic anode for use of both H2 and n-C4H10 in SOFC is prepared by wet impregnation method into a porous CeO2-YSZ matrix. The prepared Cu-Fe/CeO2-YSZ anodes are then characterized by thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), elemental dispersive X-ray (EDX) and scanning electron microscopy (SEM). Carbonaceous deposits formed on Cu-Fe/CeO2-YSZ anodes after exposure to n-C4H10 are studied using a combination of i-V characteristics and TGA measurements. It is observed that the addition of Fe to Cu in CeO2-YSZ cermet anode enhance the performance in H2 and n-C4H10 fuels. The performance of cell having molar ratio of Cu-Fe of 1:1 in Cu-Fe/CeO2-YSZ anode shows power density of 240 mW cm-2 and 260 mW cm-2 in n-C4H10 and in H2 after n-C4H10 flow at 800 °C. The i-V curve shows that the conductivity of the anode improves after exposure to n-C4H10. No apparent degradation in performance is observed after n-C4H10 flow except for carbon fibre formation indicating Cu-Fe bimetallic is worth considering as an anode for direct butane SOFC.

  8. Crystal structure of olanzapine and its solvates. Part 3. Two and three-component solvates with water, ethanol, butan-2-ol and dichloromethane

    NASA Astrophysics Data System (ADS)

    Wawrzycka-Gorczyca, Irena; Borowski, Piotr; Osypiuk-Tomasik, Joanna; Mazur, Liliana; Koziol, Anna E.

    2007-03-01

    Crystalline solvates of olanzapine ( 1), 2-methyl-4-(4-methyl-1-piperazinyl)-10 H-thieno[2,3- b][1,5]benzodiazepine, have been characterized by an X-ray analysis and thermal (DSC) data. Crystallization of 1 from ethanol gives a solid containing both water and ethanol molecules; the solvate 1 · H 2O · EtOH (2:2:1) is monoclinic with the space group P2 1/ c and the unit-cell volume V = 3752.8(12) Å 3. Butan-2-ol forms with 1 solvate which is also a three-component phase, 1 · H 2O · BuOH, but its stoichiometry is different (1:1:1). The space group for this crystal is P2 1/ c and the unit-cell volume V = 2216.5(7) Å 3. Crystalline olanzapine dichloromethane solvate (2:1), 1 · CH 2Cl 2, is triclinic with the space group P1¯. The characteristic feature of all crystal structures is presence of a pair of olanzapine molecules which form dimer stabilized by multiple weak C-H⋯π interactions between the N-methylpiperazine fragment and the phenyl / thiophene systems. Theoretical calculations have been performed indicating that the total C-H⋯π binding energy is about 8 kcal mol -1. In the crystal structure, the self-assembled olanzapine molecular dimers are arranged into parallel crystal planes. Packing of the layers proceeds in two ways in which structural motives are replicated by (i) perpendicular translation forming columns, and (ii) rotation around the twofold screw axis (parallel to the layer).

  9. Syngas generation from n-butane with an integrated MEMS assembly for gas processing in micro-solid oxide fuel cell systems.

    PubMed

    Bieberle-Hütter, A; Santis-Alvarez, A J; Jiang, B; Heeb, P; Maeder, T; Nabavi, M; Poulikakos, D; Niedermann, P; Dommann, A; Muralt, P; Bernard, A; Gauckler, L J

    2012-11-21

    An integrated system of a microreformer and a carrier allowing for syngas generation from liquefied petroleum gas (LPG) for micro-SOFC application is discussed. The microreformer with an overall size of 12.7 mm × 12.7 mm × 1.9 mm is fabricated with micro-electro-mechanical system (MEMS) technologies. As a catalyst, a special foam-like material made from ceria-zirconia nanoparticles doped with rhodium is used to fill the reformer cavity of 58.5 mm(3). The microreformer is fixed onto a microfabricated structure with built-in fluidic channels and integrated heaters, the so-called functional carrier. It allows for thermal decoupling of the cold inlet gas and the hot fuel processing zone. Two methods for heating the microreformer are compared in this study: a) heating in an external furnace and b) heating with the two built-in heaters on the functional carrier. With both methods, high butane conversion rates of 74%-85% are obtained at around 550 °C. In addition, high hydrogen and carbon monoxide yields and selectivities are achieved. The results confirm those from classical lab reformers built without MEMS technology (N. Hotz et al., Chem. Eng. Sci., 2008, 63, 5193; N. Hotz et al., Appl. Catal., B, 2007, 73, 336). The material combinations and processing techniques enable syngas production with the present MEMS based microreformer with high performance for temperatures up to 700 °C. The functional carrier is the basis for a new platform, which can integrate the micro-SOFC membranes and the gas processing unit as subsystem of an entire micro-SOFC system.

  10. Volumetric Properties of the Mixture Butan-2-ol C4H10O + C10H16 6,6-Dimethyl-2-methylenebicyclo[3.1.1]heptane (VMSD1412, LB3746_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-2-ol C4H10O + C10H16 6,6-Dimethyl-2-methylenebicyclo[3.1.1]heptane (VMSD1412, LB3746_V)' providing data by calculation of isentropic compressibility from low-pressure density and thermodynamic speed of sound data at variable mole fraction and constant temperature, in the single-phase region(s).

  11. Volumetric Properties of the Mixture Butan-2-ol C4H10O + C10H16 6,6-Dimethyl-2-methylenebicyclo[3.1.1]heptane (VMSD1511, LB3744_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-2-ol C4H10O + C10H16 6,6-Dimethyl-2-methylenebicyclo[3.1.1]heptane (VMSD1511, LB3744_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  12. Experimental and theoretical charge-density analysis of 1,4-bis(5-hexyl-2-thienyl)butane-1,4-dione: applications of a virtual-atom model.

    PubMed

    Ahmed, Maqsood; Nassour, Ayoub; Noureen, Sajida; Lecomte, Claude; Jelsch, Christian

    2016-02-01

    The experimental and theoretical charge densities of 1,4-bis(5-hexyl-2-thienyl)butane-1,4-dione, a precursor in the synthesis of thiophene-based semiconductors and organic solar cells, are presented. A dummy bond charges spherical atom model is applied besides the multipolar atom model. The results show that the dummy bond charges model is accurate enough to calculate electrostatic-derived properties which are comparable with those obtained by the multipolar atom model. The refinement statistics and the residual electron density values are found to be intermediate between the independent atom and the multipolar formalisms.

  13. catena-Poly[{μ(3)-4,4',6,6'-tetra-chloro-2,2'-[butane-1,4-diylbis(nitrilo-methanyl-yl-idene)]diphenolato}{μ(2)-4,4',6,6'-tetra-chloro-2,2'-[butane-1,4-diylbis(nitrilo-methanylyl-idene)]diphenolato}dicopper(II)].

    PubMed

    Kia, Reza; Kargar, Hadi; Adabi Ardakani, Amir; Tahir, Muhammad Nawaz

    2012-07-01

    The asymmetric unit of the title compound, [Cu(2)(C(18)H(14)Cl(4)N(2)O(2))(2)](n), contains two independent Cu(II) ions which are bridged by a pair of 4,4',6,6'-tetra-chloro-2,2'-[butane-1,4-diylbis(nitrilo-methanylyl-idene)]diphenolate ligands, forming a dinuclear unit. One of the Cu(II) ions is coordinated in a distorted square-planar environment and the other is coordinated in a distorted square-pyramidal environment. The long apical Cu-O bond of the square-pyramidal coordinated Cu(II) ion is formed by a symmetry-related O atom, creating a one-dimensional polymer along [010]. In addition, short inter-molecular Cl⋯Cl distances [3.444 (2) Å] and weak π-π inter-actions [centroid-centroid distances = 3.736 (2)-3.875 (3) Å] are observed. The crystal studied was an inversion twin with a refined twin component ratio of 0.60 (1):0.40 (1).

  14. Development of a pre-concentration system and auto-analyzer for dissolved methane, ethane, propane, and butane concentration measurements with a GC-FID

    NASA Astrophysics Data System (ADS)

    Chepigin, A.; Leonte, M.; Colombo, F.; Kessler, J. D.

    2014-12-01

    Dissolved methane, ethane, propane, and butane concentrations in natural waters are traditionally measured using a headspace equilibration technique and gas chromatograph with flame ionization detector (GC-FID). While a relatively simple technique, headspace equilibration suffers from slow equilibration times and loss of sensitivity due to concentration dilution with the pure gas headspace. Here we present a newly developed pre-concentration system and auto-analyzer for use with a GC-FID. This system decreases the time required for each analysis by eliminating the headspace equilibration time, increases the sensitivity and precision with a rapid pre-concentration step, and minimized operator time with an autoanalyzer. In this method, samples are collected from Niskin bottles in newly developed 1 L plastic sample bags rather than glass vials. Immediately following sample collection, the sample bags are placed in an incubator and individually connected to a multiport sampling valve. Water is pumped automatically from the desired sample bag through a small (6.5 mL) Liqui-Cel® membrane contactor where the dissolved gas is vacuum extracted and directly flushed into the GC sample loop. The gases of interest are preferentially extracted with the Liqui-Cel and thus a natural pre-concentration effect is obtained. Daily method calibration is achieved in the field with a five-point calibration curve that is created by analyzing gas standard-spiked water stored in 5 L gas-impermeable bags. Our system has been shown to substantially pre-concentrate the dissolved gases of interest and produce a highly linear response of peak areas to dissolved gas concentration. The system retains the high accuracy, precision, and wide range of measurable concentrations of the headspace equilibration method while simultaneously increasing the sensitivity due to the pre-concentration step. The time and labor involved in the headspace equilibration method is eliminated and replaced with the

  15. Mise en évidence d'états excités dans les spectres de photoionisation du cyclohexane et du diméthyl 2-2-butane liquides

    NASA Astrophysics Data System (ADS)

    Casanovas, J.; Guelfucci, J. P.; Caselles, O.

    1991-07-01

    Excited states are probably occurring, at an intermediate stage, in the VUV photoionization process of liquid hydrocarbons, as suggested by a Stern-Volmer behaviour when interacting with electron quenchers. They are here detected in the VUV photoionization spectrum of cyclohexane and dimethyl-2-2-butane in liquid phase. Some of the discernable peaks can be assigned as valence and Rydberg states, yet observed in gas phase. Supplementary peaks are observed, the existence of which is to be interpretated. L'existence d'états excités dans le processus de photoionisation VUV des hydrocarbures en phase liquide - précédemment suggérée par l'observation de la loi de Stern-Volmer lors de l'interaction avec des capteurs d'électrons - est ici détectée en traçant le spectre de photoionisation VUV du cyclohexane et du diméthyl-2-2-butane purs en phase liquide. Certains des pics observés coïncident avec les états de valence et de Rydberg de ces mêmes corps en phase gaz. Il apparaît des pics supplémentaires dont la nature doit être précisée.

  16. Maleic anhydride from normal butane

    SciTech Connect

    Cooley, S.D.; Doshi, B.

    1987-01-01

    Worldwide about one billion pounds of maleic anhydride is used annually in the manufacture of a number of commercially valuable products, including unsaturated polyester resins, agricultural chemicals, and lubricating oil additives. Maleic anhydride is not found in nature. It was first prepared in 1834 by heating malic acid (hydroxy-succinic acid, a compound found in apples and many other fruits). Maleic anhydride was not available commercially until ca. 1930 when the catalytic air oxidation of benzene was begun by National Aniline and Chemical on an industrial scale. The estimated worldwide production in 1985 was 1023 million pounds coming from more than 35 plants varying in capacity from 6 million pounds to 170 million pounds annually.

  17. Oxidative dehydrogenation of n-butane over vanadium magnesium oxide catalysts supported on nano-structured MgO and ZrO2: effect of oxygen capacity of the catalyst.

    PubMed

    Lee, Howon; Lee, Jong Kwon; Hong, Ung Gi; Song, In Kyu; Yoo, Yeonshick; Cho, Young-Jin; Lee, Jinsuk; Chang, Hosik; Jung, Ji Chul

    2012-07-01

    Vanadium-magnesium oxide catalysts supported on nano-structured MgO and ZrO2 (Mg3(VO4)2/MgO/ZrO2) were prepared by a wet impregnation method with a variation of Mg:Zr ratio (8:1, 4:1, 2:1, and 1:1). For comparison, Mg3(VO4)2/MgO and Mg3(VO4)2/ZrO2 catalysts were also prepared by a wet impregnation method. The prepared catalysts were applied to the oxidative dehydrogenation of n-butane in a continuous flow fixed-bed reactor. Mg3(VO4)2/MgO/ZrO2 (Mg:Zr = 4:1, 2:1, and 1:1) and Mg3(VO4)2/ZrO2 catalysts showed a stable catalytic activity during the whole reaction time, while Mg3(VO4)2/MgO/ZrO2 (8:1) and Mg3(VO4)2/MgO catalysts experienced a severe catalyst deactivation. Deactivation of Mg3(VO4)2/MgO/ZrO2 (8:1) and Mg3(VO4)2/MgO catalysts was due to their low oxygen mobility. Effect of oxygen capacity (the amount of oxygen in the catalyst involved in the reaction) of the supported Mg3(V04)2 catalysts on the catalytic performance in the oxidative dehydrogenation of n-butane was investigated. Experimental results revealed that oxygen capacity of the catalyst was closely related to the catalytic activity in the oxidative dehydrogenation of n-butane. A large oxygen capacity of the catalyst was favorable for obtaining a high catalytic activity in this reaction. Among the catalysts tested, Mg3(VO4)2/MgO/ZrO2 (4:1) catalyst with the largest oxygen capacity showed the best catalytic performance.

  18. Role of the reaction intermediates in determining PHIP (parahydrogen induced polarization) effect in the hydrogenation of acetylene dicarboxylic acid with the complex [Rh (dppb)]{sup +} (dppb: 1,4-bis(diphenylphosphino)butane)

    SciTech Connect

    Reineri, F.; Aime, S.; Gobetto, R.; Nervi, C.

    2014-03-07

    This study deals with the parahydrogenation of the symmetric substrate acetylene dicarboxylic acid catalyzed by a Rh(I) complex bearing the chelating diphosphine dppb (1,4-bis(diphenylphosphino)butane). The two magnetically equivalent protons of the product yield a hyperpolarized emission signal in the {sup 1}H-NMR spectrum. Their polarization intensity varies upon changing the reaction solvent from methanol to acetone. A detailed analysis of the hydrogenation pathway is carried out by means of density functional theory calculations to assess the structure of hydrogenation intermediates and their stability in the two solvents. The observed polarization effects have been accounted on the basis of the obtained structures. Insights into the lifetime of a short-lived reaction intermediate are also obtained.

  19. Role of the reaction intermediates in determining PHIP (parahydrogen induced polarization) effect in the hydrogenation of acetylene dicarboxylic acid with the complex [Rh (dppb)]+ (dppb: 1,4-bis(diphenylphosphino)butane).

    PubMed

    Reineri, F; Aime, S; Gobetto, R; Nervi, C

    2014-03-07

    This study deals with the parahydrogenation of the symmetric substrate acetylene dicarboxylic acid catalyzed by a Rh(I) complex bearing the chelating diphosphine dppb (1,4-bis(diphenylphosphino)butane). The two magnetically equivalent protons of the product yield a hyperpolarized emission signal in the (1)H-NMR spectrum. Their polarization intensity varies upon changing the reaction solvent from methanol to acetone. A detailed analysis of the hydrogenation pathway is carried out by means of density functional theory calculations to assess the structure of hydrogenation intermediates and their stability in the two solvents. The observed polarization effects have been accounted on the basis of the obtained structures. Insights into the lifetime of a short-lived reaction intermediate are also obtained.

  20. Pt3Ru6 clusters supported on gamma-Al2O3: synthesis from Pt3Ru6(CO)21(mu3-H)(mu-H)3, structural characterization, and catalysis of ethylene hydrogenation and n-butane hydrogenolysis.

    PubMed

    Chotisuwan, Saowapa; Wittayakun, Jatuporn; Gates, Bruce C

    2006-06-29

    The supported clusters Pt-Ru/gamma-Al2O3 were prepared by adsorption of the bimetallic precursor Pt3Ru6(CO)21(mu3-H)(mu-H)3 from CH2Cl2 solution onto gamma-Al2O3 followed by decarbonylation in He at 300 degrees C. The resultant supported clusters were characterized by infrared (IR) and extended X-ray absorption fine structure (EXAFS) spectroscopies and as catalysts for ethylene hydrogenation and n-butane hydrogenolysis. After adsorption, the nu(CO) peaks characterizing the precursor shifted to lower wavenumbers, and some of the hydroxyl bands of the support disappeared or changed, indicating that the CO ligands of the precursor interacted with support hydroxyl groups. The EXAFS results show that the metal core of the precursor remained essentially unchanged upon adsorption, but there were distortions of the metal core indicated by changes in the metal-metal distances. After decarbonylation of the supported clusters, the EXAFS data indicated that Pt and Ru atoms interacted with support oxygen atoms and that about half of the Pt-Ru bonds were maintained, with the composition of the metal frame remaining almost unchanged. The decarbonylated supported bimetallic clusters reported here are the first having essentially the same metal core composition as that of a precursor metal carbonyl, and they appear to be the best-defined supported bimetallic clusters. The material was found to be an active catalyst for ethylene hydrogenation and n-butane hydrogenolysis under conditions mild enough to prevent substantial cluster disruption.

  1. Crystal structure of (μ-1,4-di-carb-oxy-butane-1,4-di-carboxyl-ato)bis-[bis-(tri-phenyl-phosphane)silver(I)] di-chloro-methane tris-olvate.

    PubMed

    Frenzel, Peter; Korb, Marcus; Lang, Heinrich

    2016-02-01

    The mol-ecular structure of the tetra-kis(tri-phenyl-phosphan-yl)disilver salt of butane-1,1,4,4-tetra-carb-oxy-lic acid, [Ag2(C8H8O8)(C18H15P)4]·3CH2Cl2, crystallizes with one and a half mol-ecules of di-chloro-methane in the asymmetric unit. The coordination complex exhibits an inversion centre through the central CH2-CH2 bond. The Ag(I) atom has a distorted trigonal-planar P2O coordination environment. The packing is characterized by inter-molecular T-shaped π-π inter-actions between the phenyl rings of the PPh3 substituents in neighbouring mol-ecules, forming a ladder-type superstructure parallel to [010]. These ladders are arranged in layers parallel to (101). Intra-molecular hydrogen bonds between the OH group and one O atom of the Ag-bonded carboxyl-ate group results in an asymmetric bidendate coordination of the carboxyl-ate moiety to the Ag(I) ion.

  2. Crystal structure of (E)-2-[4-(4-hy­droxy­phen­yl)butan-2-yl­idene]hydrazine-1-carbo­thio­amide

    PubMed Central

    de Oliveira, Adriano Bof; Beck, Johannes; Landvogt, Christian; Feitosa, Bárbara Regina Santos; Rocha, Fillipe Vieira

    2015-01-01

    The title compound, C11H15N3OS, is a thio­semicarbazone derivative of the raspberry ketone rheosmin [systematic name: 4-(4-hy­droxy­phen­yl)butane-2-one]. The mol­ecule deviates from planarity, with the bridging C—C—C=N torsion angle equal to −101.3 (2)°. The maximum deviation from the mean plane of the non-H atoms of the thio­semicarbazone fragment [C=N—N—C(= S)—N] is 0.085 (5) Å for the Schiff base N atom, and the dihedral angle between this mean plane and the aromatic ring is 50.31 (8)°. In the crystal, mol­ecules are linked by N—H⋯O, N—H⋯S and O—H⋯S hydrogen bonds, forming a three-dimensional structure, with the mol­ecules stacked along [011]. PMID:25705493

  3. Rhenium Complexes and Clusters Supported on c-Al2O3: Effects of Rhenium Oxidation State and Rhenium Cluster Size on Catalytic Activity for n-butane Hydrogenolysis

    SciTech Connect

    Lobo Lapidus, R.; Gates, B

    2009-01-01

    Supported metals prepared from H{sub 3}Re{sub 3}(CO){sub 12} on {gamma}-Al{sub 2}O{sub 3} were treated under conditions that led to various rhenium structures on the support and were tested as catalysts for n-butane conversion in the presence of H{sub 2} in a flow reactor at 533 K and 1 atm. After use, two samples were characterized by X-ray absorption edge positions of approximately 5.6 eV (relative to rhenium metal), indicating that the rhenium was cationic and essentially in the same average oxidation state in each. But the Re-Re coordination numbers found by extended X-ray absorption fine structure spectroscopy (2.2 and 5.1) show that the clusters in the two samples were significantly different in average nuclearity despite their indistinguishable rhenium oxidation states. Spectra of a third sample after catalysis indicate approximately Re{sub 3} clusters, on average, and an edge position of 4.5 eV. Thus, two samples contained clusters approximated as Re{sub 3} (on the basis of the Re-Re coordination number), on average, with different average rhenium oxidation states. The data allow resolution of the effects of rhenium oxidation state and cluster size, both of which affect the catalytic activity; larger clusters and a greater degree of reduction lead to increased activity.

  4. New Antimony Lanthanide Disulfide Dibromides LnSbS

    SciTech Connect

    Gout, D.; Jobic, S.; Evain, M.; Brec, R.

    2001-05-01

    CeSbS{sub 2}Br{sub 2} (I), Ce{sub 1/2}La{sub 1/2}SbS{sub 2}Br{sub 2} (II), and LaSbS{sub 2}Br{sub 2} (III) have been synthesized at 700 C from a mixture of LnBr{sub 3}, Ln{sub 2}S{sub 3}, Sb, and S and characterized by single-crystal X-ray diffraction. The three phases are isostructural (space group P2{sub 1}/c, Z=4) and crystallize in a novel, dense, bidimensional structure with cell parameters a=8.709(3) {angstrom}, b=9.187(2) {angstrom}, c=17.397(5) {angstrom} {beta}=104.26(3) for I, a=8.739(7) {angstrom}, b=9.219(7) {angstrom}, c=17.41(2) {angstrom}, =104.3(1) for II, and a=8.785(1) {angstrom}, b=9.236(2) {angstrom}, c=17.372(3) {angstrom}, {beta}=104.09(2) for III. In these compounds, [Ln S{sub 5}Br{sub 4}] and [Ln S{sub 3}Br{sub 6}] (Ln=Ce, La) distorted tricapped trigonal prisms define infinite {sub {infinity}}{sup 2}[LnS{sub 2}Br{sub 2}] layers counterbalanced and capped by antimony cations. In good accordance with the structural features, the charge balance in these materials is to be written Ln{sup III}Sb{sup III}S{sup -II}{sub 2}Br{sup -I}{sub 2}. These compounds exhibit a yellow hue with a measured absorption threshold of 2.42(1), 2.55(1), and 2.72(1) eV for I, II, and III, respectively. In the two cerium containing bromothioantimonates I and II, the origin of the color is assigned to a Ce-4f{yields}Ce-5d electronic transition, which shifts to higher energy from I to II due either to a matrix effect (increase of the mean Ln-S distances under the substitution of Ce for La) or to an atomic ordering between Ce and La cations on the Ln(1) and Ln(2) crystallographic sites. In contrast, the electronic transition at play in III involves a charge transfer from the bromine and sulfur ions to the antimony ions, the latter contributing substantially to the lowermost levels of the conduction band.

  5. Synthesis, characterization and biological study on Cr 3+, ZrO 2+, HfO 2+ and UO 22+ complexes of oxalohydrazide and bis(3-hydroxyimino)butan-2-ylidene)-oxalohydrazide

    NASA Astrophysics Data System (ADS)

    El-Asmy, A. A.; El-Gammal, O. A.; Radwan, H. A.

    2010-09-01

    Cr 3+, ZrO 2+, HfO 2+ and UO 22+ complexes of oxalohydrazide (H 2L 1) and oxalyl bis(diacetylmonoxime hydrazone) [its IUPAC name is oxalyl bis(3-hydroxyimino)butan-2-ylidene)oxalohydrazide] (H 4L 2) have been synthesized and characterized by partial elemental analysis, spectral (IR; electronic), thermal and magnetic measurements. [Cr(L 1)(H 2O) 3(Cl)]·H 2O, [ZrO(HL 1) 2]·C 2H 5OH, [UO 2(L 1)(H 2O) 2] [ZrO(H 3L 2)(Cl)] 2·2H 2O, [HfO(H 3L 2)(Cl)] 2·2H 2O and [UO 2(H 2L 2)]·2H 2O have been suggested. H 2L 1 behaves as a monobasic or dibasic bidentate ligand while H 4L 2 acts as a tetrabasic octadentate with the two metal centers. The molecular modeling of the two ligands have been drawn and their molecular parameters were calculated. Examination of the DNA degradation of H 2L 1 and H 4L 2 as well as their complexes revealed that direct contact of [ZrO(H 3L 2)(Cl)] 2·2H 2O or [HfO(H 3L 2)(Cl)] 2·2H 2O degrading the DNA of Eukaryotic subject. The ligands and their metal complexes were tested against Gram's positive Bacillus thuringiensis (BT) and Gram's negative ( Escherichia coli) bacteria. All compounds have small inhibitory effects.

  6. Preparation of USY zeolite VOx supported catalysts from V(AcAc)3 and NH4VO3. Catalytic properties for the dehydrogenation of n-butane in oxygen-free atmosphere.

    PubMed

    Garcia, Elba M; Sanchez, Miguel D; Tonetto, Gabriela; Volpe, María A

    2005-12-01

    The preparation of different samples of vanadia supported on ultrastable zeolite (VO(x)/USY) is discussed. The samples were prepared in order to obtain highly dispersed V-species, avoiding the formation of crystalline vanadia and the destruction of the zeolite framework. Two methods were employed for preparing VO(x)/USY samples: an organic route using V(AcAc)3 and an inorganic route using NH4VO3. The characterization of the samples was performed with XRD, TPR, NH3-TPD, and N2 isotherms. From these results it is concluded that when VO(x) is supported on the surface of USY from acidic aqueous solution of ammonium metavanadate, the destruction of the zeolite framework is accomplished. For higher pH values in the impregnating solution, undesired V2O5 is formed on the USY surface. On the other hand, VO(x)/USY prepared from the organic precursor shows no destruction of the USY structure. In addition, highly dispersed VO(x) are formed, though for relatively high V loadings (6%) an obstruction of the zeolite windows takes place. The samples are tested as catalysts for gas phase dehydrogenation of n-butane to olefins. The catalysts prepared from NH4VO3 are almost inactive for the reaction. On the other hand, both samples prepared from V(AcAc)3 present initial conversion levels in the 8-12% range. However, the selectivity depends on the V loading, the catalysts with 6% loading being the most selective (75%). The catalytic patterns of the samples (activity and selectivity) are in agreement with the physicochemical features of the VO(x)/USY surface.

  7. In vitro and in vivo antitumor activity of a novel carbonyl ruthenium compound, the ct-[RuCl(CO)(dppb)(bipy)]PF-6[dppb=1,4-bis(diphenylphosphine)butane and bipy=2,2'-bipyridine].

    PubMed

    Carnizello, Andréa P; Barbosa, Marília I F; Martins, Monize; Ferreira, Natália H; Oliveira, Pollyanna F; Magalhães, Geórgia M; Batista, Alzir A; Tavares, Denise C

    2016-11-01

    This study performed in vitro and in vivo biological assays of the ruthenium (II) compound ct-[RuCl(CO)(dppb)(bipy)]PF6 (where, dppb=1,4-bis(diphenylphosphine)butane and bipy=2,2'-bipyridine). The cytotoxic activity of this compound was evaluated against different tumor cell lines (HeLa, human cervical adenocarcinoma; MCF7, human breast adenocarcinoma; MO59J, human glioblastoma; HepG2, hepatocellular carcinoma and B16F10, murine melanoma) and healthy cell line (V79, Chinese hamster lung fibroblasts), by XTT (sodium 2,3'-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)-carbonyl]-3,4-tetrazolium-bis(4-methoxy-6-nitro)benzene-sulfonic acid hydrate) method. A syngeneic murine melanoma tumor model (B16F10) was used to evaluate its antitumor activity. Additionally, experiments were performed to assess the interactions with ctDNA (calf thymus DNA) and BSA (bovine serum albumin). The results showed that ct-[RuCl(CO)(dppb)(bipy)]PF6 was cytotoxic against all tumor cell lines tested. Furthermore, the compound was more effective against tumor cells compared to the normal cell line, indicating selectivity, especially in B16F10 cells. Significant tumor growth reduction was observed in animals treated with the compound compared to the untreated control. Histopathological analysis of tumor tissue revealed a significant reduction of mitosis in animals treated with the compound compared to the untreated control. In the ctDNA and BSA interaction experiments, the compound in study showed weak interactions with ctDNA and hydrophobic interactions with BSA. The ruthenium compound investigated showed promising results in in vitro and in vivo biological assays.

  8. (2R)-4-Oxo-4[3-(Trifluoromethyl)-5,6-diihydro:1,2,4}triazolo[4,3-a}pyrazin-7(8H)-y1]-1-(2,4,5-trifluorophenyl)butan-2-amine: A Potent, Orally Active Dipeptidyl Peptidase IV Inhibitor for the Treatment of Type 2 Diabetes

    SciTech Connect

    Kim, D.; Wang, L.; Beconi, M.; Eiermann, G.; Fisher, M.; He, H.; Hickey, G.; Kowalchick, Jennifer; Leiting, Barbara; Lyons, K.; Marsilio, F.; McCann, F.; Patel, R.; Petrov, A.; Scapin, G.; Patel, S.; Roy, R.; Wu, J.; Wyvratt, M.; Zhang, B.; Zhu, L.; Thornberry, N.; Weber, A.

    2010-11-10

    A novel series of {beta}-amino amides incorporating fused heterocycles, i.e., triazolopiperazines, were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. (2R)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (1) is a potent, orally active DPP-IV inhibitor (IC{sub 50} = 18 nM) with excellent selectivity over other proline-selective peptidases, oral bioavailability in preclinical species, and in vivo efficacy in animal models. MK-0431, the phosphate salt of compound 1, was selected for development as a potential new treatment for type 2 diabetes.

  9. Crystal structure of (μ-1,4-di­carb­oxy­butane-1,4-di­carboxyl­ato)bis­[bis­(tri­phenyl­phosphane)silver(I)] di­chloro­methane tris­olvate

    PubMed Central

    Frenzel, Peter; Korb, Marcus; Lang, Heinrich

    2016-01-01

    The mol­ecular structure of the tetra­kis(tri­phenyl­phosphan­yl)disilver salt of butane-1,1,4,4-tetra­carb­oxy­lic acid, [Ag2(C8H8O8)(C18H15P)4]·3CH2Cl2, crystallizes with one and a half mol­ecules of di­chloro­methane in the asymmetric unit. The coordination complex exhibits an inversion centre through the central CH2—CH2 bond. The AgI atom has a distorted trigonal–planar P2O coordination environment. The packing is characterized by inter­molecular T-shaped π–π inter­actions between the phenyl rings of the PPh3 substituents in neighbouring mol­ecules, forming a ladder-type superstructure parallel to [010]. These ladders are arranged in layers parallel to (101). Intra­molecular hydrogen bonds between the OH group and one O atom of the Ag-bonded carboxyl­ate group results in an asymmetric bidendate coordination of the carboxyl­ate moiety to the AgI ion. PMID:26958391

  10. Crystal structure of a Cu(II) complex with a bridging ligand: poly[[penta-kis-[μ2-1,1'-(butane-1,4-di-yl)bis-(1H-imidazole)-κ(2) N (3):N (3')]dicopper(II)] tetranitrate tetra-hydrate].

    PubMed

    Wu, Fayuan; Shang, Mengxiang; Li, Shihua; Zhao, Yu

    2014-12-01

    A novel two-dimensional→three-dimensional Cu(II) coordination polymer, {[Cu2(C10H14N4)5](NO3)4·4H2O} n , based on the 1,1'-(butane-1,4-di-yl)bis-(1H-imidazole) (biim) ligand and containing one crystallographically unique Cu(II) atom, has been synthesized under hydro-thermal conditions. The Cu(II) atom is coordinated by five N atoms from biim ligands, one of which has crystallographically imposed inversion symmetry, giving rise to a slightly distorted CuN5 square-pyramidal geometry. The Cu(II) cations are linked by biim ligands to give a 4(4) layer; the layers are further bridged by biim ligands, generating a double sheet with a thickness of 14.61 Å. The sheet features rhombic Cu4(biim)4 windows built up from four Cu(II) centers and four biim ligands with dimensions of 14.11 × 14.07 Å(2). Each window of a layer is penetrated directly by the biim ligand of the adjacent net, giving a two-dimensional→three-dimensional entangled framework.

  11. Crystal structure of bis­[μ-1,4-bis­(di­phenyl­phos­phan­yl)butane-κ2 P:P′]bis­[(3,4,7,8-tetra­methyl-1,10-phenanthroline-κ2 N,N′)copper(I)] bis­(hexa­fluorido­phosphate) di­chloro­methane disolvate

    PubMed Central

    Nishikawa, Michihiro; Mutsuura, Kotaro; Tsubomura, Taro

    2016-01-01

    The dication of the title compound, [Cu2(C28H28P2)2(C16H16N2)2](PF6)2·2CH2Cl2, has crystallographically imposed inversion symmetry. The copper(I) cation is coordinated in a distorted tetra­hedral geometry by two N atoms of a chelating 3,4,7,8-tetra­methyl-1,10-phenanthroline ligand and two P atoms of two bridging 1,4-bis­(di­phenyl­phosphan­yl)butane ligands, forming a 14-membered ring. An intra­molecular π–π inter­action stabilizes the conformation of the dication. In the crystal, dications are linked by π–π inter­actions involving adjacent phenanthroline rings, forming chains running parallel to [111]. Weak C—H⋯F hydrogen inter­actions are also observed. PMID:27840706

  12. 75 FR 17712 - Malathion and Diquat Dibromide; Cancellation Order for Amendments to Terminate Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-07

    ... Herbicide only) Soybean (seed crop only) 4787-46 Atrapa 8E Malathion Animal premise and barns used for dairy and livestock 67760-40 Fyfanon 57% EC Malathion Animal premise and barns used for dairy and...

  13. Structure and physical properties of [micro-tris(1,4-bis(tetrazol-1-yl)butane-N4,N4')iron(II)] bis(hexafluorophosphate), a new Fe(II) spin-crossover compound with a three-dimensional threefold interlocked crystal lattice.

    PubMed

    Grunert, C Matthias; Schweifer, Johannes; Weinberger, Peter; Linert, Wolfgang; Mereiter, Kurt; Hilscher, Gerfried; Müller, Martin; Wiesinger, Günter; van Koningsbruggen, Petra J

    2004-01-12

    [micro-Tris(1,4-bis(tetrazol-1-yl)butane-N4,N4')iron(II)] bis(hexafluorophosphate), [Fe(btzb)(3)](PF(6))(2), crystallizes in a three-dimensional 3-fold interlocked structure featuring a sharp two-step spin-crossover behavior. The spin conversion takes place between 164 and 182 K showing a discontinuity at about T(1/2) = 174 K and a hysteresis of about 4 K between T(1/2) and the low-spin state. The spin transition has been independently followed by magnetic susceptibility measurements, (57)Fe-Mössbauer spectroscopy, and variable temperature far and midrange FTIR spectroscopy. The title compound crystallizes in the trigonal space group P3 (No. 147) with a unit cell content of one formula unit plus a small amount of disordered solvent. The lattice parameters were determined by X-ray diffraction at several temperatures between 100 and 300 K. Complete crystal structures were resolved for 9 of these temperatures between 100 (only low spin, LS) and 300 K (only high spin, HS), Z = 1 [Fe(btzb)(3)](PF(6))(2): 300 K (HS), a = 11.258(6) A, c = 8.948(6) A, V = 982.2(10) A(3); 100 K (LS), a = 10.989(3) A, c = 8.702(2) A, V = 910.1(4) A(3). The molecular structure consists of octahedral coordinated iron(II) centers bridged by six N4,N4' coordinating bis(tetrazole) ligands to form three 3-dimensional networks. Each of these three networks is symmetry related and interpenetrates each other within a unit cell to form the interlocked structure. The Fe-N bond lengths change between 1.993(1) A at 100 K in the LS state and 2.193(2) A at 300 K in the HS state. The nearest Fe separation is along the c-axis and identical with the lattice parameter c.

  14. Economic evaluation of the acetone-butane fermentation

    SciTech Connect

    Lenz, T.G.; Moreira, A.R.

    1980-01-01

    The economics of producing acetone as 1-butanol via fermentation have been examined for a 45 x 1 kg of solvents/year plant. For a molasses substrate the total annual production costs were approximately $39 million vs. a total annual income of $36 million, with approximatley $20 million total required capital. Molasses cost of approximately $24.4 million/year was critical to these economics. Liquid whey was next evaluated as an alternative feed. Whey feed saved approximately 11 million dollars annually in feed costs and yielded approximately 8 million net additional annual revenues from protein sale. The primary differences gave an annual gross profit of approximately $15 million for the whey case and resulted in a discounted cash flow rate return of 29%. Waste-based acetone-butanol production via fermentation deserves further attention in view of the attractive whey-based economics and the excellent potential of butanol as a fuel extender, especially for diesohol blending.

  15. LIQUID BUTANE FILLED LOAD FOR A LINER DRIVEN PEGASUS EXPERIMENT

    SciTech Connect

    M.A. SALAZAR; W. ANDERSON; ET AL

    2001-06-01

    A hydrogen rich, low density liquid, contained within the internal volume of a cylindrical liner, was requested of the Polymers and Coatings Group (MST-7) of the Los Alamos Materials Science Division for one of the last liner driven experiments conducted on the Los Alamos Pegasus facility. The experiment was a continuation of the Raleigh-Taylor hydrodynamics series of experiments and associated liners that have been described previously [1,2].

  16. Liquid butane filled load for a liner driven Pegasus experiment.

    SciTech Connect

    Salazar, M. A.; Armijo, E. V.; Anderson, W. E.; Atchison, W. L.; Bartos, J. J.; Garcia, F.; Randolph, B.; Sheppard, M. G.; Stokes, J. L.

    2001-01-01

    A hydrogen rich, low density liquid, contained within the internal volume of a cylindrical liner, was requested of the Polymers and Coatings Group (MST-7) of the Los Alamos Materials Science Division for one of the last liner driven experiments conducted on the Los Alamos Pegasus facility. The experiment (Fig.1) was a continuation of the Raleigh-Taylor hydrodynamics series of experiments and associated liners that have been described previously.

  17. 3,3'-Di-n-propyl-1,1'-[p-phenyl-enebis(methyl-ene)]diimidazolium dibromide.

    PubMed

    Haque, Rosenani A; Nasri, S Fatimah; Hemamalini, Madhukar; Fun, Hoong-Kun

    2011-08-01

    The asymmetric unit of the title compound, C(20)H(28)N(4) (2+)·2Br(-), consists of half a 3,3'-di-n-propyl-1,1'-[p-phenyl-enenis(methyl-ene)]diimidazolium cation and a bromide anion. The cation is located on an inversion center and adopts an ⋯AAA⋯ trans conformation. In the crystal, the cation is linked to the anions via weak C-H⋯Br hydrogen bonds.

  18. Biological and Abiotic Transformations of Ethylene Dibromide and 1,2-Dichloroethane in Ground Water at Leaded Gasoline Spill Sites

    EPA Science Inventory

    Tetra-ethyl lead was widely used in leaded automobile gasoline from 1923 until 1987. To prevent lead deposits from fouling the engine, 1,2-dibromoethane (EDB) and 1,2-dichloroethane (1,2-DCA) were added to the gasoline to act as lead scavengers. The Maximum Contaminant Levels...

  19. The influence of antidotal treatment of low-level tabun exposure on cognitive functions in rats using a water maze.

    PubMed

    Kassa, J; Kunesova, G

    2006-01-01

    In this study, the influence of antidotal treatment of tabun poisoning on cognitive function, in the case of low-level tabun exposure, was studied. The impairment of cognitive function was evaluated by the measurement of spatial learning and memory in rats poisoned with a sublethal dose of tabun and treated with atropine alone or in combination with newly developed oximes {K027 [1-(4-hydroxyiminomethyl- pyridinium)-3-(4-carbamoylpyridinium) propane dibromide] and K048 [1-(4-hydroxyimino- methylpyridinium)-3-(4-carbamoylpyridinium) butane dibromide]} or currently available oxime (trimedoxime), using the Morris water maze. While atropine alone caused an impairment of studied cognitive functions, the addition of an oxime to atropine contributes to the improvement of cognitive performance of treated tabun-poisoned rats regardless of the type of oxime. The differences in the ameliorative effects of oximes on atropine-induced mnemonic deficits were not significant. Therefore, each low-level nerve agent exposure should be treated by complex antidotal treatment consisting of anticholinergic drug and oxime.

  20. Simulated consumer exposure to dimethyl ether and propane/butane in hairsprays.

    PubMed

    Hartop, P J; Cook, T L; Adams, M G

    1991-08-01

    Synopsis The potential human exposures from use of dimethyl ether (DME) and 'liquefied petroleum gas'(LPG) arising from use in hairsprays have been assessed. DME and LPG concentrations were measured in the 'breathing zone' of an experimental manikin and an 'accompanying child' designed to simulate human use of hairsprays in a domestic situation and in the breathing zone of a 'stylist' and 'customer' under salon conditions. Results were expressed as the 10 min time weighted average in the air (TWA10) and as the peak concentration in the breathing zone of the 'user'. Following a 10s use of hairspray containing 50% DME or 26% LPG, TWA10 values for an adult user in a closed room (volume 21 m(3)) were on average 114 ppm and 73 ppm respectively. The child TWA10 values were 89 ppm (DME) and 80 ppm (LPG). Leaving the door open during spraying did not significantly alter these values. The peak concentrations measured in the user breathing zone were 1577 ppm of DME and 671 ppm of LPG. Simulated salon use of a hairspray gave a calculated value of 55 ppm DME and 88 ppm LPG for the stylist over an 8 h working period.

  1. Resonance Raman Spectroscopy of 0-A12O3- Supported Vanadium Oxide Catalysts for Butane Dehydrogenation

    SciTech Connect

    Wu, Zili; Kim, Hack-Sung; Stair, Peter

    2008-01-01

    This chapter contains sections titled: Introduction; Structure of Al{sub 2}O{sub 3}-Supported Vanadia Catalysts; Quantification of Surface VOx Species on Supported Vanadia Catalysts; Conclusion; Acknowledgements; and References.

  2. A 10-watt CW photodissociation laser with IODO perfluoro-tert-butane

    NASA Technical Reports Server (NTRS)

    Tabibi, Bagher; Venable, Demetrius D.

    1989-01-01

    NASA has been investigating the feasibility of direct solar-pumped laser systems for power beaming in space. Among the various gas, liquid, and solid laser systems being proposed as candidates for solar-pumped lasers, the iodine photodissociation gas laser has demonstrated its potential for space application. Of immediate attention is the determination of system requirements and the choice of lasants to improve the system efficiency. The development of an efficient iodine laser depends on the availability of a suitable iodide which has favorable laser kinetics, chemically reversibility, and solar energy utilization. Among the various alkyliodide lasants comparatively tested in a long-pulse system, perfluoro- tert-butyl iodide, T-C4F9I, was found to be the best. However, the operating conditions for the laser medium in a continuously pumped and continuous-flow iodine laser differ considerably from those in the pulsed regime. The results of the continuous wave (CW)) laser performance from t-C4F9I are reported. Perfluoro- n-propyl iodide, n-C3F7I is used for comparison because of its universal use in photodissociation iodine lasers.

  3. Performance of Commercially Available Flame Arrestors for Butane/Air and Gasoline/Air Mixtures

    DTIC Science & Technology

    1978-09-01

    Model TBA16-3-O-3, 465 SCFM, 16 oz. capacity) by way of a 4-inch diameter by 4-feet long pipe which incorporates a Meriam Model 50MY15-4 Laminar...fuel supply tank incorporated a Meriam Model 50W20 1F LFE flowmeter, a Jenkins manual throttling valve, a manual shut-off cock, an ASCO 8210854 solenoid... Meriam Model A-844 manometer used to measure the pressure drop. Air temperature was measured using a Grounded sheath type thermocouple (Omega Type CAIN

  4. An acridine derivative, [4,5-bis{(N-carboxy methyl imidazolium)methyl}acridine] dibromide, shows anti-TDP-43 aggregation effect in ALS disease models

    PubMed Central

    Prasad, Archana; Raju, Gembali; Sivalingam, Vishwanath; Girdhar, Amandeep; Verma, Meenakshi; Vats, Abhishek; Taneja, Vibha; Prabusankar, Ganesan; Patel, Basant K.

    2016-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with aggregation of TAR DNA-binding protein-43 (TDP-43) in neuronal cells and manifests as motor neuron dysfunction & muscle atrophy. The carboxyl-terminal prion-like domain of TDP-43 can aggregate in vitro into toxic β-sheet rich amyloid-like structures. So far, treatment options for ALS are very limited and Riluzole, which targets glutamate receptors, is the only but highly ineffective drug. Therefore, great interest exists in developing molecules for ALS treatment. Here, we have examined certain derivatives of acridine containing same side chains at position 4 & 5, for inhibitory potential against TDP-43 aggregation. Among several acridine derivatives examined, AIM4, which contains polar carboxyl groups in the side arms, significantly reduces TDP-43-YFP aggregation in the powerful yeast model cell and also abolishes in vitro amyloid-like aggregation of carboxyl terminal domain of TDP-43, as observed by AFM imaging. Thus, AIM4 can be a lead molecule potentiating further therapeutic research for ALS. PMID:28000730

  5. In Situ Selected Area Doping of GaAs by Molecular Beam Epitaxy.

    DTIC Science & Technology

    1985-07-01

    several Sn-containing molecules (tetramethyltin, tetrabutyltin, dibutyltin dibromide and stannic chloride) as gas phase sources of Sn for use in molecular... Dibutyltin Dibromide A brief screening experiment with DBTB was performed. DBTB adsorbed, but similar to the above organometallic compounds, it...surfaces from a variety of tin containing compounds (tetramethyltin, tetrabutyltin, dibutyltin dibromide, stannic chloride, hexamethylditin

  6. Durable antibacterial and cross-linking cotton with colloidal silver nanoparticles and butane tetracarboxylic acid without yellowing.

    PubMed

    Montazer, Majid; Alimohammadi, Farbod; Shamei, Ali; Rahimi, Mohammad Karim

    2012-01-01

    Colloidal nano silver was applied on the surface of cotton fabric and stabilized using 1,2,3,4-butanetetracarboxylic acid (BTCA). The two properties of antimicrobial activity and resistance against creasing were imparted to the samples of fabric as a result of the treatment with silver nano colloid and BTCA. The antimicrobial property of samples was evaluated using two pathogenic bacteria including Escherichia coli and Staphylococcus aureus as outstanding barometers in this field. The durability of applied nanoparticles, color variation, wettability and wrinkle recovery angle of the treated samples were investigated employing related credible standards. The presence of nano silver particles on the surface of treated cotton fabric was proved using EDS spectrum as well as the SEM images. Furthermore, the creation of cross-links was confirmed by the means of both ATR-FTIR and Raman spectra. In conclusion, it was observed that BTCA plays a prominent role in stabilizing silver nanoparticle. Besides, Wettability and winkle recovery angle of finished samples decreased and increased, respectively. In addition, it is noteworthy that no obvious color variation was observed.

  7. Yes, But...(An Invitation to Dialogue)--Holistic vs. Systemic Approach to the Teaching of Reading.

    ERIC Educational Resources Information Center

    Murray, Dorothy S.

    Today, contrary to Euclid's view of things as they are, people are told that the whole is greater than the sum of its parts. Nowhere apparently has the concept of the whole been ignored more than in the teaching of reading. The "see and say" (holistic) approach, introduced in the early fifties, still dominates the classroom. Readers and…

  8. Flame Arrestor Design Requirements for Prolonged Exposure to Methane/Air, Butane/Air and Gasoline/Air Flames.

    DTIC Science & Technology

    1978-09-15

    EXPERIMENTAL FLAME ARRESTORS 9 Table 1 Summary of Instrumentation Variables Measured Measuring Instrument Accuracy Air tlow rate Meriam 50 MY 15-4 Flowmeter...with + 0.5% Meriam A844 Manometer Air temperature Omega CAIN-116G-24 Thermocouple + 11F Gas flow rate Meriam 50W201F flmnuter with + 0.5% Ellison IN

  9. Effect of spacer length on the interfacial behavior of N,N'-bis(dimethylalkyl)-α,ω-alkanediammonium dibromide gemini surfactants in the absence and presence of ZnO nanoparticles.

    PubMed

    Fereidooni Moghadam, Tahereh; Azizian, Saeid; Wettig, Shawn

    2017-01-15

    In this paper the interfacial behavior of aqueous solutions of cationic gemini surfactants of the, N,N'-bis(dimethylalkyl)-α,ω-alkanediammoniumdibromide type (known as the 12-s-12 series), in the absence and presence of ZnO nanoparticles was studied. Equilibrium and dynamic interfacial tension between n-decane and aqueous surfactant solutions were investigated. It was concluded that the synergistic effect between surfactants and nanoparticles increases the surfactant efficiency with respect to reducing the interfacial tension. Moreover, the magnitude of the effect of ZnO nanoparticles on the interfacial tension decreases with increasing length of the spacer group in the gemini surfactant structure. Dynamic studies illustrate that the migration mechanism of gemini surfactants (regardless of the presence of ZnO) from the bulk to the interface was controlled by both diffusion and adsorption. The effect of spacer length on the contact angle and emulsion stability both with and without nanoparticles was also studied.

  10. Assessment of ethylene dibromide, dibromochloropropane, other volatile organic compounds, radium isotopes, radon, and inorganic compounds in groundwater and spring water from the Crouch Branch and McQueen Branch aquifers near McBee, South Carolina, 2010-2012

    USGS Publications Warehouse

    Landmeyer, James E.; Campbell, Bruce G.

    2014-01-01

    The water-quality data collected between 2010 and 2012, in conjunction with groundwater flow pathways and historical aerial photographs of land uses near McBee, indicate an area where EDB-, DBCP-, 1,2-dichloropropane-, 1,3-dichloropropane-, and carbon disulfide-contaminated groundwater exists in the Crouch Branch aquifer in the Cedar Creek Basin and north of McBee and is most likely related to the past use of these compounds between the early 1900s and the 1980s as soil fumigants in predominately agricultural areas north of McBee. The highest EDB concentration detected (18.6 micrograms per liter) during the 3-year study was in a groundwater sample from an agricultural-supply well located north of McBee. Other VOCs, such as dichloromethane and 1,1,2-trichloroethane, also were detected in groundwater samples from this EDB-contaminated agricultural-supply well but are from unknown source(s). The fact that the agricultural area north of McBee is located in a recharge area for the Crouch Branch aquifer most likely facilitated the groundwater contamination in this area. DBCP-contaminated groundwater detected in three public-supply wells south of McBee in the deeper McQueen Branch aquifer appears to be related to past soil fumigation practices that used DBCP in agricultural areas located south of McBee. One of the three DBCP-contaminated public-supply wells also contained EDB, most likely present in groundwater due to the release of leaded gasolines that contained EDB as a fuel additive between the 1940s and 1970s. A gasoline-source of EDB, rather than a soil-fumigation source, is supported by the co-detection in groundwater from the well of 1,2-dichloroethane, a lead scavenger compound also added to leaded gasoline. Groundwater pumped from two public-supply wells located within and to the east of the McBee town limits and one domestic-supply well east of McBee was characterized by the detection of 1,1-dichloroethane, trichloroethylene, 1,1-dichloroethylene, and perchloroethylene. Groundwater flow pathways determined for these wells indicate that the potential source(s) of these compounds detected in one public-supply well and the domestic-supply well may be located within the McBee town limits, and that the potential source(s) of these compounds detected in the public-supply well to the east of McBee may be located in an area north of McBee formerly used for agriculture, but used for industry since at least the 1970s. Radium isotopes (defined in this study as the sum of radium-226 and radium-228 concentrations) and radon were detected in all wells sampled in the McBee area between 2010 and 2012. Wells characterized by radium isotope concentrations in groundwater that exceeded the MCL of 5.0 picocuries per liter were also characterized by specific conductance values greater than 30 microsiemens per centimeter and clustered north of McBee in a predominately agricultural area, and in agricultural and urban areas located within and east of McBee. The elevated specific conductance values measured in groundwater from these wells most likely are due to recharge by water mineralized by fertilizer application in agricultural areas, or due to the recharge by water mineralized by septic-tank drain-field effluent near urban areas. Radon was detected in groundwater from all wells sampled, and radon concentrations in groundwater from three monitoring wells exceeded the proposed MCL of 300 picocuries per liter. Concentrations of uranium in groundwater in the McBee area increased with increased groundwater-sample depth, most likely due to the proximity of the sample-collection location to basement rock that contains uranium-bearing minerals.

  11. Crystal structure of (±)-[trans-cyclo­hexane-1,2-diylbis(aza­nedi­yl)]di­phospho­nium dibromide dichloro­methane disolvate

    PubMed Central

    Rodríguez Álvarez, Aurora; Tlahuext, Hugo; Grévy, Jean-Michel

    2016-01-01

    The cation of the title solvated salt, C42H42N2P2 2+·2Br−·2CH2Cl2, lies on a crystallographic twofold rotation axis. The 1,2-di­amino­cyclo­hexane fragment has a chair conformation with two N atoms in a transoid conformation [N—C—C—N = 163.4 (2)°]. In the crystal, the cations are linked to the anions by N—H⋯Br and C—H⋯Br hydrogen bonds, forming a chain structure along the c axis. The di­chloro­methane mol­ecule takes part in the hydrogen-bond network through C—H⋯π and C—H⋯Br inter­actions. PMID:27375889

  12. Crystal structure of N-[3-(di-methyl-aza-nium-yl)prop-yl]-N',N',N'',N''-tetra-methyl-N-(N,N,N',N'-tetra-methyl-form-am-id-in-ium-yl)-guanidinium dibromide hydroxide monohydrate.

    PubMed

    Tiritiris, Ioannis; Kantlehner, Willi

    2015-12-01

    The asymmetric unit of the title hydrated salt, C15H37N6 (3+)·2Br(-)·OH(-)·H2O, contains one cation, three partial-occupancy bromide ions, one hydroxide ion and one water mol-ecule. Refinement of the site-occupancy factors of the three disordered bromide ions converges with occupancies 0.701 (2), 0.831 (2) and 0.456 (2) summing to approximately two bromide ions per formula unit. The structure was refined as a two-component inversion twin with volume fractions 0.109 (8):0.891 (8) for the two domains. The central C3N unit of the bis-amidinium ion is linked to the aliphatic propyl chain by a C-N single bond. The other two bonds in this unit have double-bond character as have the four C-N bonds to the outer NMe2 groups. In contrast, the three C-N bonds to the central N atom of the (di-methyl-aza-nium-yl)propyl group have single-bond character. Delocalization of the two positive charges occurs in the N/C/N and C/N/C planes, while the third positive charge is localized on the di-methyl-ammonium group. The crystal structure is stabilized by O-H⋯O, N-H⋯Br, O-H⋯Br and C-H⋯Br hydrogen bonds, forming a three-dimensional network.

  13. 75 FR 59617 - Notification of Arrival in U.S. Ports; Certain Dangerous Cargoes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-28

    ... cyanohydrin; (ii) Allyl alcohol; (iii) Chlorosulfonic acid; (iv) Crotonaldehyde; (v) Ethylene chlorohydrin; (vi) Ethylene dibromide; (vii) Methacrylonitrile; (viii) Oleum (fuming sulfuric acid); and...

  14. 27 CFR 21.56 - Formula No. 29.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... intermediates. 551.Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572.Ethylene gas. 573.Xanthates. 575.Drugs and medicinal chemicals. 579.Other chemicals....

  15. Nanoporous array anodic titanium-supported co-polymeric ionic liquids as high performance solid-phase microextraction sorbents for hydrogen bonding compounds.

    PubMed

    Jia, Jing; Liang, Xiaojing; Wang, Licheng; Guo, Yong; Liu, Xia; Jiang, Shengxiang

    2013-12-13

    A nanoporous array anodic titanium-supported co-polymeric ionic liquids (NAAT/PILs) solid-phase microextraction (SPME) fiber was prepared in situ on the titanium wire. NAAT was selected as the substrate, in view of its high surface-to-volume ratio, easy preparation, mechanical stability, and rich titanol groups on its surface which can anchor silica coupling agent containing vinyl and then introduce ionic liquid copolymers as sorbents. In this work, 1-vinyl-3-nonanol imidazolium bromide ([C9OHVIm]Br) and 1,4-di(3-vinylimidazolium) butane dibromide ([(VIM)2C4]2[Br]) were synthesized and used as monomer and crosslinker, respectively. Extraction properties of the NAAT/PILs fiber for polar alcohols and volatile fatty acids (VFAs) in aqueous matrix were examined using gaseous sampling-SPME (GS-SPME) and headspace SPME (HS-SPME) mode, respectively. Combining the superior properties of NAAT substrate and the strong hydrogen bond interaction of PILs to polar compounds, the NAAT/PILs SPME fiber showed much higher adsorption affinity to aliphatic alcohols than bare NAAT and pure PILs fibers. The detection limits (LOD) of established GS-SPME-GC-FID method are in the range of 0.35-17.30ngL(-1) with a linear range from 0.01 to 500ngmL(-1). Also, it showed high extraction performance toward volatile fatty acids (VFAs) compounds from aqueous matrix. Under the optimized SPME conditions, wide linear ranges were obtained with correlation coefficients (R(2)) greater than 0.99 and limits of detection were in the range of 0.85-8.74ngL(-1). Moreover, real-world samples were analyzed and good results were obtained.

  16. 1-(4-Carb­oxy­butan-2-yl­idene)-4-phenyl­thio­semicarbazide

    PubMed Central

    Mendoza-Meroño, Rafael; Menéndez-Taboada, Laura; García-Granda, Santiago

    2012-01-01

    The mol­ecule of the title compound, C12H15N3O2S, which belongs to the family of thio­semicarbazones, containing an acid group, adopts a semi-closed conformation with an intramolecular N—H⋯N hydrogen bond. In the crystal, molecules are linked by strong N—H⋯O and O—H⋯S hydrogen bonds between the acid group and thiosemicarbazone unit, with one additional intermolecular hydrogen C—H⋯O interaction. These three interactions form R 2 2(8) and a R 2 1(7) rings and the molecules related by the c-glide plane are linked into a zigzag chain along [001]. PMID:22719696

  17. 1-(3,5-Di­fluoro­phen­yl)-4,4,4-tri­fluoro­butane-1,3-dione

    PubMed Central

    Manoj Kumar, K.E.; Palakshamurthy, B. S.; Suchetan, P. A.; Madan Kumar, S.; Lokanath, N.K.; Sreenivasa, S.

    2013-01-01

    In the title compound, C10H5F5O2, the C=O bonds are syn to one another. In the crystal, mol­ecules are linked into C(9) chains parallel to [101] through weak C—H⋯O inter­actions, with the O atom adjacent to the –CF3 group acting as the acceptor. PMID:24454131

  18. Volumetric Properties of the Mixture Butan-1-ol C4H10O + C5H9NO2 N-Formylmorpholine (LB2004, VMSD1212)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Hnědkovský, L.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A `Binary Liquid Systems of Nonelectrolytes' of Volume 23 `Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV `Physical Chemistry'. It corresponds to the data set LB2004 of the ELBT database.

  19. Volumetric Properties of the Mixture Butan-1-ol C4H10O + C5H9NO2 N-Formylmorpholine (LB2015, VMSD1111)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Hnědkovský, L.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A `Binary Liquid Systems of Nonelectrolytes' of Volume 23 `Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV `Physical Chemistry'. It corresponds to the data set LB2015 of the ELBT database.

  20. Alkyl levulinates as `green chemistry' precursors: butane-1,4-diyl bis(4-oxopentanoate) and hexane-1,6-diyl bis(4-oxopentanoate).

    PubMed

    Gainsford, Graeme J; Hinkley, Simon

    2013-06-01

    Levulinic acid derivatives are potential `green chemistry' renewably sourced molecules with utility in industrial coatings applications. Suitable single crystals of the centrosymmetric title compounds, C14H22O6 and C16H26O6, respectively, were obtained with difficulty. The data for the latter hexane-1,6-diyl compound were extracted from the major fragment of a three-component twinned crystal. Both compounds crystallize in similar-sized unit cells with identical symmetry, utilizing the same weak nonconventional attractive C-H···O(ketone) hydrogen bonds via C(4) and C(5) motifs, which expand to R(2)(2)(30) ring and C(2)(2)(14) chain motifs. Their different packing orientations in similar-sized unit cells suggest that crystal growth involving packing mixes could lead to intergrowths or twins.

  1. Ethyl 1-(butan-2-yl)-2-(2-meth­oxy­phen­yl)-1H-benzimidazole-5-carboxyl­ate

    PubMed Central

    Arumugam, Natarajan; Ngah, Nurziana; Osman, Hasnah; Abdul Rahim, Aisyah Saad

    2011-01-01

    In the title compound, C21H24N2O3, the mean planes of the benzene ring and the benzimidazole ring system form a dihedral angle of 69.94 (7)°. The ethyl group atoms of the ethano­ate fragment are disordered over two sets of sites, with refined occupancies of 0.742 (6) and 0.258 (6). In the crystal, there are weak C—H⋯N hydrogen bonds which connect mol­ecules into chains along the b axis. A weak inter­molecular C—H⋯π inter­action is also observed. PMID:22199745

  2. 1-(4-Chloro­phenyl)-2-[tris­(4-methyl­phenyl)-λ5-phosphanyl­idene]butane-1,3-dione

    PubMed Central

    Sabounchei, Seyyed Javad; Shahriary, Parisa; Hosseini Fashami, Faegheh; Morales-Morales, David; Hernandez-Ortega, Simon

    2013-01-01

    In the title ylide, C31H28ClO2P [common name α-acetyl-α-p-chloro­benzoyl­methyl­enetri(p-tol­yl)phospho­rane], the dihedral angle between the 4-chloro­phenyl ring and that of the ylide moiety is 66.15 (10)°. The geometry around the P atom is slightly distorted tetra­hedral [angle range = 105.22 (8)–115.52 (9)°] and the carbonyl O atoms are syn-oriented with respect to the P atom. The ylide group is close to planar [maximum deviation from the least-squares plane = 0.006 (2) Å] and the P—C, C—C and C=O bond lengths are consistent with electron delocalization involving the O atoms. PMID:23424468

  3. {1,1'-[Butane-1,4-diylbis(nitrilo-methyl-idyne)]di-2-naphtho-lato}copper(II) ethanol monosolvate.

    PubMed

    Kargar, Hadi; Kia, Reza

    2010-12-24

    The asymmetric unit of the title compound, [Cu(C(26)H(22)N(2)O(2))]·C(2)H(5)OH, comprises a Schiff base complex and an ethanol mol-ecule of crystallization. The Cu(II) atom shows a distorted square-planar geometry. The dihedral angle between the two aromatic rings is 48.16 (13)°. The crystal structure is stabilized by inter-molecular O-H⋯O and C-H⋯O hydrogen bonds and inter-molecular π-π inter-actions with centroid-centroid distances in the range 3.485 (2)-3.845 (3) Å.

  4. Spectroscopic and pH-metric studies of the complexation of 3-[2-(4-methylquinolin-2-yl)hydrazono]butan-2-one oxime compound

    NASA Astrophysics Data System (ADS)

    Seleem, H. S.; El-Inany, G. A.; Mousa, M.; Hanafy, F. I.

    2010-05-01

    The electronic absorption spectra of the oximic quinolinyl hydrazone (MHQ; H 2L) and its Co(II) and Cu(II)-complexes have been studied in Britton-Rhobinson buffer solutions of varying pH's in 75% dioxane-water. The dissociation constant of the hydrazone (p KH) as well as the stability constants (log K) of its chelates were determined spectrophotometrically and pH-metrically. The obtained data are in good agreement. Beer's law is valid in the ranges (0.64-6.99) and (2.36-6.48) μg/mL for Cu(II) and Co(II)-ions, respectively. On the other hand, the p KH and log K were determined pH-metrically in 75% solvent-water; (solvent = dioxane, ethanol, methanol and isopropanol). The variation of p KH or log K as a function of solvent parameters viz. 1/ D, ET, AN and π* was used to evaluate the dissociation and stability constants in the aqueous medium. Furthermore, the reaction of the oximic hydrazone (H 2L) with copper(II)-nitrate and chloride in addition to copper(I)-iodide afforded square planar mononuclear and binuclear complexes in which the oximic hydrazone showed three different modes of bonding. The obtained complexes reflect the strong bridging ability of the oximato group as well as its ambidentate and flexidentate characters.

  5. Formal Alder-ene reaction of a bicyclo[1.1.0]butane in the synthesis of the tricyclic quaternary ammonium core of daphniglaucins

    PubMed Central

    Ueda, Masafumi; Walczak, Maciej A. A.; Wipf, Peter

    2008-01-01

    A tricyclic substructure of the tetracyclic nitrogen core of the daphniglaucins was formed by an oxidative activation of the allyl side chain of a bicyclo[1.1.0]butylmethylamine, a spontaneous intramolecular formal Alder-ene reaction, and a selective cyclization of a triol intermediate. PMID:19129907

  6. CHLOROFORM COMETABOLISM BY BUTANE-GROWN CF8, PSEUDOMONAS BUTANOVORA, MYCOBACTERIUM VACCAE JOB 5, AND METHANE-GROWN METHYLOSINUS TRICHOSPORIUM OB3B. (R825689C019)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  7. 76 FR 17646 - Registration Review; Pesticide Dockets Opened for Review and Comment and Other Docket Actions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-30

    ... is ensuring that each pesticide's registration is based on current scientific and other knowledge... work plan for the registration review of the pesticide diquat dibromide; this work plan has been... final work plan for the registration review of diquat dibromide. The work plan was revised...

  8. 75 FR 60114 - Notice of Receipt of Requests for Amendments to Delete Uses in Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ... Ingredient Delete from Label 228-675 Nufarm Diquat SPC 2 L Diquat dibromide Soybeans and Sorghum Herbicide... (seed crop Concentrate only) and Soybean (seed crop only) 83529-13 Diquash Ag Diquat dibromide Sorghum (seed crop only) and Soybean (seed crop only) Users of these products who desire continued use on...

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

    SciTech Connect

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

    2000-04-03

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

  10. Bis(2,2'-bipyridine)[1,9-bis(diphenylphos-phanyl)-1,2,3,4,6,7,8,9-octahydropyrim-ido[1,2-a]pyrimidin-5-ium]ruthenium(II) hexa-fluorido-phosphate dibromide di-chloro-methane disolvate monohydrate.

    PubMed

    Shang, Congcong; Vendier, Laure; Sutra, Pierre; Igau, Alain

    2013-11-06

    In the cation of the title complex, [Ru(C31H32N3P2)(C10H8N2)2](PF6)(Br)2·2CH2Cl2·H2O, the ruthenium ion is coordinated in a distorted octa-hedral geometry by two 2,2'-bi-pyridine (bpy) ligands and a chelating cationic N-di-phenyl-phosphino-1,3,4,6,7,8-hexa-hydro-2-pyrimido[1,2-a]pyrimidine [(PPh2)2-hpp] ligand. The tricationic charge of the complex is balanced by two bromide and one hexa-fluorido-phosphate counter-anions. The compound crystallized with two mol-ecules of di-chloro-methane (one of which is equally disordered about a Cl atom) and a water mol-ecule. In the crystal, one of the Br anions bridges two water mol-ecules via O-H⋯Br hydrogen bonds, forming a centrosymmetric diamond-shaped R (4) 2(8) motif. The cation and anions and the solvent mol-ecules are linked via C-H⋯F, C-H⋯Br, C-H⋯Cl and C-H⋯O hydrogen bonds, forming a three-dimensional network.

  11. Crystal structure of N-[3-(di­methyl­aza­nium­yl)prop­yl]-N′,N′,N′′,N′′-tetra­methyl-N-(N,N,N′,N′-tetra­methyl­form­am­id­in­ium­yl)­guanidinium dibromide hydroxide monohydrate

    PubMed Central

    Tiritiris, Ioannis; Kantlehner, Willi

    2015-01-01

    The asymmetric unit of the title hydrated salt, C15H37N6 3+·2Br−·OH−·H2O, contains one cation, three partial-occupancy bromide ions, one hydroxide ion and one water mol­ecule. Refinement of the site-occupancy factors of the three disordered bromide ions converges with occupancies 0.701 (2), 0.831 (2) and 0.456 (2) summing to approximately two bromide ions per formula unit. The structure was refined as a two-component inversion twin with volume fractions 0.109 (8):0.891 (8) for the two domains. The central C3N unit of the bis­amidinium ion is linked to the aliphatic propyl chain by a C—N single bond. The other two bonds in this unit have double-bond character as have the four C—N bonds to the outer NMe2 groups. In contrast, the three C—N bonds to the central N atom of the (di­methyl­aza­nium­yl)propyl group have single-bond character. Delocalization of the two positive charges occurs in the N/C/N and C/N/C planes, while the third positive charge is localized on the di­methyl­ammonium group. The crystal structure is stabilized by O—H⋯O, N—H⋯Br, O—H⋯Br and C—H⋯Br hydrogen bonds, forming a three-dimensional network. PMID:26870507

  12. 40 CFR Table 36 to Subpart G of... - Compound Lists Used for Compliance Demonstrations for Enhanced Biological Treatment Processes...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... Ethylene Glycol MonobutylEther Acetate Chloroprene. Ethylene Glycol MonomethylEther Acetate Cumene (isopropylbenzene). Ethylene Glycol Dimethyl Ether Dibromoethane 1,2. Hexachlorobenzene Dichlorobenzene 1,4.... Ethylbenzene. Ethylene Oxide. Ethylene Dibromide. Hexachlorobutadiene. Hexachloroethane. Hexane-n....

  13. 40 CFR Table 36 to Subpart G of... - Compound Lists Used for Compliance Demonstrations for Enhanced Biological Treatment Processes...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Ethylene Glycol MonobutylEther Acetate Chloroprene. Ethylene Glycol MonomethylEther Acetate Cumene (isopropylbenzene). Ethylene Glycol Dimethyl Ether Dibromoethane 1,2. Hexachlorobenzene Dichlorobenzene 1,4.... Ethylbenzene. Ethylene Oxide. Ethylene Dibromide. Hexachlorobutadiene. Hexachloroethane. Hexane-n....

  14. 40 CFR Table 36 to Subpart G of... - Compound Lists Used for Compliance Demonstrations for Enhanced Biological Treatment Processes...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... Ethylene Glycol MonobutylEther Acetate Chloroprene. Ethylene Glycol MonomethylEther Acetate Cumene (isopropylbenzene). Ethylene Glycol Dimethyl Ether Dibromoethane 1,2. Hexachlorobenzene Dichlorobenzene 1,4.... Ethylbenzene. Ethylene Oxide. Ethylene Dibromide. Hexachlorobutadiene. Hexachloroethane. Hexane-n....

  15. 40 CFR 142.62 - Variances and exemptions from the maximum contaminant levels for organic and inorganic chemicals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Dibromochloropropane X X (27) 2,4-D X (28) Ethylene dibromide X X (29) Heptachlor X (30) Heptachlor epoxide X (31... for the inorganic chemicals listed in § 141.62: BAT for Inorganic Compounds Listed in §...

  16. A study of the removal of heavy metals from aqueous solutions by Moringa oleifera seeds and amine-based ligand 1,4-bis[N,N-bis(2-picoyl)amino]butane.

    PubMed

    Obuseng, Veronica; Nareetsile, Florence; Kwaambwa, Habauka M

    2012-06-12

    Uptake for lead, copper, cadmium, nickel and manganese from aqueous solution using the Moringa oleifera seeds biomass (MOSB) and amine-based ligand (ABL) was investigated. Experiments on two synthetic multi-solute systems revealed that MOSB performed well in the biosorption and followed the decreasing orders Pb(II)>Cu(II)>Cd(II)>Ni(II)>Mn(II) and Zn(II)>Cu(II)>Ni(II). The general trend of the heavy metal ions uptake by the amine-based ligand followed decreased in the order Mn>Cd>Cu>Ni>Pb, which is the reverse trend for what was observed for MOSB. Comparing the single- and multi-metal solutions, there was no clear effect in the biosorption capacity of MOSB suggesting the presence of sufficient active binding sites for all metal ions studied. The MOSB performance is also not affected by pH in the range 3.5-8.

  17. catena-Poly[copper(II)-{μ(3)-4,4'-dichloro-2,2'-[butane-1,4-diylbis(nitrilo-methanyl-yl-idene)]diphenolato-κN,O:N',O':O'}].

    PubMed

    Kargar, Hadi; Kia, Reza

    2011-04-01

    The asymmetric unit of the title coordination polymer, [Cu(C(18)H(16)Cl(2)N(2)O(2))](n), consists of a Schiff base complex in which the Cu(II) atom adopts a square-pyramidal coordination geometry, being coordinated by two N and two O atoms of symmetry-related ligands and by a third O atom from a complex related by an inversion center. In the structure, a crystallographic twofold rotation axis bis-ects the central C-C bonds of the n-butyl spacers of the designated Schiff base ligands, making symmetry-related dimeric units, which are twisted around Cu(II) atoms in a bis-bidentate coordination mode. In the crystal, these dimeric units are connected through the third bridging Cu-O bonds [2.3951 (13) Å], forming one-dimensional coordination polymers, which propagate along [001]. Furthermore, inter-molecular π-π inter-actions [centroid-centroid distance = 3.811 (1) Å] stabilize the crystal packing.

  18. catena-Poly[copper(II)-{μ(3)-4,4'-dibromo-2,2'-[butane-1,4-diylbis(nitrilo-methanyl-yl-idene)]diphenolato-κN,O:N',O':O'}].

    PubMed

    Kargar, Hadi; Kia, Reza

    2011-04-01

    The asymmetric unit of the title coordination polymer, [Cu(C(18)H(16)Br(2)N(2)O(2))](n), consists of a Schiff base complex in which a crystallographic twofold rotation axis bis-ects the central C-C bonds of the n-butyl spacers of the designated Schiff base ligands, making symmetry-related dimer units, which are twisted around Cu(II) atoms in a bis-bidentate coordination mode. In the crystal, these dimeric units are connected through Cu-O bonds, forming one-dimensional coordination polymers, which propagate along [001]. The Cu(II) atom adopts a square-based pyramidal coordination geometry, being coordinated by two N and two O atoms of symmetry-related ligands and by a third O atom of a neighboring complex. Furthermore, inter-molecular π-π inter-actions [centroid-centroid distance = 3.786 (2) Å] and C-H⋯O inter-actions stabilize the crystal packing.

  19. Synthesis of 4-Amino-1-Hydroxy-Butane-1,1-Diphosphonate (AHBDP) - Stannous Complexes for the Preparation of Ahbdp-Sn(II)-Tc and its Biodistribution in Rats

    PubMed Central

    Mankhetkorn, Samlee; Blanchot, Caroline; Duran-Cordobes, Muriel; El Manouni, Driss; Leroux, Yves; Moretti, Jean-Luc

    1995-01-01

    The new potential tracer of bone imaging, AHBDP-Sn(II)-TcO.3H2O was synthesized by reducing the TcO4− to TcO2+ in the presence of AHBDP and Sn(ll)’s reducing agent. We found that tin rapidly forms a stable complex with AHBDP, giving AHBDP-Sn(II).3H2O. In the excess of AHBDP-Sn(ll).3H2O, the AHBDP-Sn(II).3H2O coordinates with TcO2+ to give AHBDP-Sn(II)-TcO.3H2O which could polymerise or oligomerise to give hydrophobic species. The overall process appears as a first-order reaction (K= 0.67 ± 0.005s−1). In rats, the fixation of AHBDP-Sn(II)-99mTcO. 3H2O on bone is homogeneous and the scintigraphic images have the same quality as those of 1-hydroxymethane-1,1-diphosphonate-Technetium (HMDP-99mTc). The activity in non-target organs was neglible. PMID:18472767

  20. Modeling and optimizing surfactant structure to improve oil recovery by chemical flooding at the University of Texas: First annual report for the period October 1985-September 1986. [Sodium dodecylbenzene sulfonate, sodium chloride, water, n-decane and n-butane

    SciTech Connect

    Schechter, R.S.

    1987-07-01

    The objectives of this research program are (1) to characterize mineral oxide surfaces and to relate these parameters to surfactant adsorption, (2) to study chromatographic effects resulting from use of surfactant blends, (3) to understand the properties of microemulsions as related to surfactant structure, and (4) to develop a thermodynamic theory of microemulsions which includes surfactant structure, cosolvents, and surfactant blends as well as the properties of the system oil and water. Progress reports are presented for the following tasks: (1) thermodynamic stability of microemulsions; (2) surfactant adsorption from aqueous solutions; (3) dielectric relaxation in microemulsions; and (4) diffusion in microemulsions. 28 refs., 19 figs., 1 tab.

  1. Structural variety of mono- and binuclear transition metal complexes of 3-[(2-hydroxy-benzylidene)-hydrazono]-1-(2-hydroxyphenyl)-butan-1-one: Synthesis, spectral, thermal, molecular modeling, antimicrobial and antitumor studies

    NASA Astrophysics Data System (ADS)

    Shebl, Magdy; Adly, Omima M. I.; El-Shafiy, Hoda F.; Khalil, Saied M. E.; Taha, A.; Mahdi, Mohammed A. N.

    2017-04-01

    A new polydentate Schiff base ligand and its metal complexes were synthesized and characterized by elemental analyses, IR, 1H NMR, electronic, ESR and mass spectra, conductivity and magnetic susceptibility measurements as well as thermal analyses. The free ligand was synthesized by condensation of o-acetoacetylphenol with salicylaldehyde hydrazone. The analytical and spectroscopic tools showed that the obtained complexes are mono- and binuclear complexes, which can be generally formulated as: [(L)M2X2(H2O)m]·nZ; M = Cr, Fe, Ni or Cu, X = OAc or NO3, m = 5 or nil and n = 3, 1.5 or 0.5 and Z = EtOH or H2O, [(H2L)2M(X)m].nH2O; M = Mn, Zn, or Cd, X = EtOH, H2O or nil, m = 2 or nil and n = 3.5 or 0, [(HL)2Co2]·0.5H2O and [(H2L)2UO2(H2O)]. The metal complexes displayed octahedral, tetrahedral and square-planar geometrical arrangements, while uranium complex displayed seven-coordinate. Kinetic parameters (Ea, A, ΔH, ΔS and ΔG) of the thermal decomposition stages have been evaluated using Coats-Redfern equations. The molecular structural parameters of the ligand and its metal complexes have been calculated and correlated with the experimental data such as IR. The antimicrobial activity of the ligand and its complexes was screened against some kinds of bacteria and fungi. The antitumor activity of the ligand and its Ni(II) and Cu(II) complexes was investigated against HepG2 cell line.

  2. The Heterogeneous Photocatalytic Decomposition of Benzoic Acid and Adipic Acid on Platinized TiO2 Powder. The Photo-Kolbe Decarboxylative Route to the Breakdown of the Benzene Ring and to the Production to Butane.

    DTIC Science & Technology

    1980-10-29

    photocatalyst design dis- cussed previously, lb’Ic where the rate of reaction at the catalyst powder is determined by the system operating at a potential... photocatalyst half reaction, as opposed to the results on aliphatic carboxylates. The reduction of oxygen on Pt (curve 7) occurs ai. potentials much more positive...semiconductor powders have been shown to behave as photocatalysts and promote the oxidation of sub- strates. 1-6 Irradiation of a semiconductor with

  3. The preparation of 3-substituted-1,5-dibromopentanes as precursors to heteracyclohexanes

    PubMed Central

    Ringstrand, Bryan; Oltmanns, Martin; Batt, Jeffrey A; Jankowiak, Aleksandra; Denicola, Richard P

    2011-01-01

    Summary The methodology to prepare 3-substituted 1,5-dibromopentanes I and their immediate precursors, which include 3-substituted 1,5-pentanediols VII or 4-substituted tetrahydropyrans VIII, is surveyed. Such dibromides I are important intermediates in the preparation of liquid crystalline derivatives containing 6-membered heterocyclic rings. Four dibromides 1a–1d containing simple alkyl and more complex fragments at the 3-position were prepared. 3-Propyl- and 3-pentyl-pentane-1,5-diol (2a,b) were prepared starting from either glutaconate or malonate diesters, while tetrahydropyrans 3c and 3d were obtained from tetrahydro-4H-pyran-4-one. The advantages and disadvantages of each route are discussed. Dibromides 1c and 1d were used to prepare sulfonium zwitterions 11c and 11d. PMID:21512596

  4. On the Formation of Maleic Anhydride on a Vanadyl Pyrophosphate Surface: A Theoretical Study of the Mechanism

    DTIC Science & Technology

    1990-05-25

    synthesis of maleic anhydride from n - butane over a vanadium phosphorous oxide surface in the presence of molecular oxygen [equation ( 1 )]. 7 / • 3.5 0 2 (g...active vanadium phosphorous oxide phase in the oxidation of n - butane has been disputed in the literature. 7 0, 0 Generally, it is agreed that the presence...mechanism for the selective oxidation of n - butane to maleic anhydride. Satsuma et al. have described the surface structure in terms of the number of

  5. Refiners match Rvp reduction measures to operating problems

    SciTech Connect

    Musumeci, J.

    1997-02-03

    Reduction in gasoline vapor pressure specifications have created operational challenges for many refiners. Removal of butanes from gasoline blendstocks has become more critical to meeting product vapor pressure requirements. Some refiners have made major unit modifications, such as adding alkylation capacity for butane conversion. Others have debottlenecked existing fractionation equipment, thus increasing butane removal. Three case studies will illustrate vapor pressure reduction solutions. The solutions include: changing unit operating targets, maintaining existing equipment, and debottlenecking minor equipment.

  6. Turbine Engine Exhaust Hydrocarbon Analysis. Task 1 and 2

    DTIC Science & Technology

    1983-06-01

    outlet) Ethane , Ethylene Cryogenic/g.c. 2995 2860 Acety1en Propene 369 359 Propane 516 503 i-Butane 402 390 n-Butane 1900 1850 t-2-Butene 637 607... Ethylene 91 101 93 (d) Acetylene 93 100 94 d) Provene 104 108 98 102 Propane 104 110 109 102 I-Butane 102 100 109 100 n-Butane 100 100 100 100 t-2...Analytical of Found Compound Method Determinations ppbC Z RSD Ethane Cryogenic/g.c. 4 700 2.1 Ethylene 4 1220 3.0 Propene 4 508 1.6 Acetylene 4 980 2.7 i

  7. Potential hazards of fumigant residues.

    PubMed Central

    Fishbein, L

    1976-01-01

    A spectrum of fumigants (primarily ethylene dibromide, 1,2-dibromo-3-chloropropane, ethylene oxide, symdibromotetetrachloroethane, 1,3-dichloropropene, dichlorovos, carbon tetrachloride, methyl bromide) as well as their degradation products in foodstuffs and soil have been examined mainly in regard to the potential mutagenicity of their residues. PMID:789068

  8. Adsorption on bacterial spores depending on the aggregation properties of antimicrobial tensides.

    PubMed

    Cupková, V; Devínsky, F; Mlynarcík, D; Lacko, I; Bittererová, J

    1991-01-01

    A change in interaction with spores of Bacillus cereus occurred in the range of critical concentrations of micelle formation. With 1-methyldodecyldimethylamine-N-oxide and N,N'-bis(dodecyldimethyl)-1,2-ethanediammonium dibromide, the induced release of dipicolinic acid was blocked and the adsorption dynamics changed, respectively.

  9. Cancer prevention: Strategies in the workplace

    SciTech Connect

    Becker, C.E.; Coye, M.J.

    1986-01-01

    This article discusses cancer prevention strategies for the workplace. Contents include: The exposure-potency index; ranking carcinogenic hazards of volatile industrial chemicals; ethylene dibromide toxicity and fatal consequences; danger of handling oncological agents, asbestos contamination of drinking water; sunlight and occupation skin cancer; smoking and occupational lung cancer; and controversies in the assessment of carcinogenic risk of formaldehyde.

  10. Operation of platinum-palladium catalysts with leaded gasoline.

    PubMed Central

    Teague, D M; Clougherty, L B; Speca, A N

    1975-01-01

    The effect of various fuel additives on the ability of platinum-palladium catalytic converters to remove the carbon monoxide and hydrocarbon components of automotive exhaust has been examined. Engine dynamometer studies suggest that these catalysts may be successfully used in conjunction with fuels of relatively high tetraethyllead concentrations, provided the ethylene dibromide portion of the scavenger is excluded. PMID:50929

  11. Focused Feasibility Study Final Quality Assurance Program Plan

    DTIC Science & Technology

    1993-10-01

    other hydrocarbons attached, including specificaly: Ethylene Heptenes Cyclopentene Cyclodecene Propylene Octenes Cyclohexene Methylpentn Butylenes...8217 0.007’ Diquat 0.028 0.022 Endothall 0.18 0.16 Endrn 0.0022 0.00021 0.0022 Epichlorohydrin 02 Ethylene dibromide 02 0.00005’ Glyphosate 0.7d 0.7

  12. 75 FR 70248 - Endocrine Disruptor Screening Program; Second List of Chemicals for Tier 1 Screening

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... Ethylbenzene 100-41-4 X Ethylene dibromide 106-93-4 X Ethylene glycol 107-21-1 X Ethylene thiourea 96-45-7 X... be affected. The North American Industrial Classification System (NAICS) codes have been provided to... releases to the environment, pesticide application rates, and production volumes (73 FR 9628, February...

  13. New Development of Polymer-Based Cotton for Breathable Material

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, we converted the poly (ethylene oxide) dibromide to poly (ethylene oxide) diazides and reacted to study cycloaddition polymerization with bisphenol-A dipropargyl ether to produce elastomers compatible with cotton (Polymer Preprints, 2005, 46(1), 737-738). The reactants were characterized w...

  14. Preparation and Characterization of Macro- & Monomers for Azide & Alkyne Cycloaddition Polyerization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 1970 Robert Harper and colleagues, showed that poly(ethylene oxide)s and Poly(propylene oxide)s (PEOs and PPOs, respectively) are effective softeners for cotton fabrics (Textile Chemist and Colorist, 1970, 2(1), 37-41. Using this information, we developed PEO and PPO dibromides and diepoxides to ...

  15. SUCCESSFUL APPLICATION OF AIR SPARGING TO REMEDIATE ETHYLENE DEBROMIDE (EDB) IN GROUND WATER INKANSAS

    EPA Science Inventory

    Although Ethylene Dibromide (EDB) was banned in conventional motor fuel in the USA by 1990, EDB continues to contaminate ground water at many old gasoline service station sites. Although EDB contamination is widespread, there is little performance data on technology to remediat...

  16. Removal of EDB and 1,2-DCA by Abiotic Reaction with Iron(II) Sulfide

    EPA Science Inventory

    Ethylene Dibromide (EDB) and 1,2-Dichloroethane (1,2-DCA) were used as lead scavengers in leaded motor gasoline in the USA until the late 1980s. Leaded gasoline in contact with ground water should produce concentrations of EDB near 1900 µg/L, and concentrations of 1,2-DCA near 3...

  17. 27 CFR 21.56 - Formula No. 29.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... intermediates. 551.Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide... less than 20 percent acetaldehyde, or 1 gallon of ethyl acetate having an ester content of 100 percent... pounds if solid, or 1 gallon if liquid, of any chemical. When material other than acetaldehyde or...

  18. 27 CFR 21.59 - Formula No. 32.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... gallons of ethyl ether. (b) Authorized uses. (1) As a solvent: 031.Photographic film and emulsions. 034.... 523.Other ethyl esters. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572.Ethylene gas....Collodion, U.S.P. 311.Ethyl cellulose compounds (dehydration). 332.Processing miscellaneous food...

  19. 27 CFR 21.33 - Formula No. 2-B.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....Processing miscellaneous products. (2) As a raw material: 521.Ethyl acetate. 522.Ethyl chloride. 523.Other ethyl esters. 524.Sodium ethylate, anhydrous. 530.Ethylamines. 540.Dyes and intermediates. 551.Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572.Ethylene...

  20. Application of Pattern Recognition to Metal Ion Chemical Ionization Mass Spectra.

    DTIC Science & Technology

    1985-10-01

    experiments. ORGANICS FOR RECOGNITION OF SIX CLASSES ALJAJE AL-KE KETONE butane 1 - butene butanone pentane 1 -pentene 2-pentanone hexane 1 -hezene 2... butene cyclopentanone 1 -methyl cyclopentane cyclopentene methyl cyclopropyl k etone cyclobexane cyclohexene 3-methyl cyclopentanone * 1 -methyl...cyclobeiane vinyl cyclohexane cyclohexanone * ALDEH YDE ETHER ALCOHOL propanal ethyl ether ethanol butanal methyl butyl ether 1 -propanol pentanal ethyl

  1. Planar gas chromatography column on aluminum plate with multi-walled carbon nanotubes as stationary phase

    NASA Astrophysics Data System (ADS)

    Platonov, I. A.; Platonov, V. I.; Pavelyev, V. S.

    2016-04-01

    The high selectivity of the adsorption layer for low-boiling alkanes is shown, the separation factor (α) couple iso-butane / butane is 1.9 at a column temperature of 50 °C.The paper presents sorption and selective properties of planar gas chromatography column on aluminum plate with multi-walled carbon nanotubes as the stationary phase.

  2. 40 CFR 86.132-96 - Vehicle preconditioning.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 1977 and Later Model Year New Light-Duty Vehicles and New Light-Duty Trucks and New Otto-Cycle Complete... of the following: (i) An initial one hour minimum soak and, one, two, or three driving cycles of the... mixture composed of 50 percent butane and 50 percent nitrogen by volume at a rate of 15±2 grams butane...

  3. 2,4-Bis(diphenyl­phosphan­yl)-1,1,2,3,3,4-hexa­phenyl-1,3-diphospha-2,4-dibora­cyclo­butane tetra­hydro­furan sesqui­solvate

    PubMed Central

    Peulecke, Normen; Müller, Bernd H.; Spannenberg, Anke; Rosenthal, Uwe

    2012-01-01

    In the title compound, C60H50B2P4·1.5C4H8O, the diphospha­diborane mol­ecule lies on an inversion centre, whereas the disordered tetra­hydro­furan solvent mol­ecule is in a general position with a partial occupancy of 0.75. The diphosphadiborane mol­ecule consists of an ideal planar four-membered B2P2 ring with an additional phenyl and a –PPh2 group attached to each B atom. PMID:22589980

  4. Superacid catalysis of light hydrocarbon conversion. Final report, August 26, 1993--August 26, 1996

    SciTech Connect

    Gates, B.C.

    1996-12-31

    Motivated by the goal of finding improved catalysts for low- temperature conversion of light alkanes into fuel components or precursors of fuel components, the researchers have investigated sulfated zirconia and promoted sulfated zirconia for conversion of butane, propane, and ethane. Catalyst performance data for sulfated zirconia promoted with iron and manganese show that it is the most active noncorrosive, nonhalide catalyst known for n-butane isomerization, and it is an excellent candidate catalyst for new low- temperature n-butane isomerization processes to make isobutane, which can be converted by established technology into methyl t-butyl ether (MTBE). Various transition metals have been found to work as promoters of sulfated zirconia for n-butane isomerization. The combination of iron and manganese is the best known combination of promoters yet discovered. The iron- and manganese-promoted sulfated zirconia is also a catalyst for conversion of propane and of ethane. Ethane is converted into ethylene and butanes in the presence of the iron- and manganese-promoted sulfated zirconia; propane is also converted into butane, among other products. However, the activities of the catalyst for these reactions are orders of magnitude less than the activity for n-butane conversion, and there is no evidence that the catalyst would be of practical value for conversion of alkanes lighter than butane. The product distribution data for ethane and propane conversion provide new insights into the nature of the catalyst and its acidity. These data suggest the involvement of Olah superacid chemistry, whereby the catalyst protonates the alkane itself, giving carbonium ions (as transition states). The mechanism of protonation of the alkane may also pertain to the conversion of butane, but there is good evidence that the butane conversion also proceeds via alkene intermediates by conventional mechanisms of carbenium ion formation and rearrangement.

  5. Nitrogen limitation and nitrogen fixation during alkane biodegradation in a sandy soil.

    PubMed Central

    Toccalino, P L; Johnson, R L; Boone, D R

    1993-01-01

    We investigated nutrient limitations during hydrocarbon degradation in a sandy soil and found that fixed nitrogen was initially a limiting nutrient but that N limitation could sometimes be overcome by N2 fixation. Hydrocarbon biodegradation was examined in an unsaturated sandy soil incubated aerobically at 20 degrees C with propane or butane and various added nutrients. Propane and butane degradation proceeded similarly during the first 3 months of incubation. That is, bacteria in soil amended with N oxidized these hydrocarbons more rapidly than in controls without nutrient additions or in soil with added phosphate or trace minerals. Both propane- and butane-amended soil apparently became N limited after the initial available inorganic N was utilized, as indicated by a decrease in the rates of hydrocarbon degradation. After 3 months, propane and butane degradation proceeded differently. Bacteria in propane-degrading soil apparently remained N limited because propane degradation rates stayed low unless more N was added. In contrast, bacteria in butane-degrading soil appeared to overcome their N limitation because butane degradation rates later increased regardless of whether more N was added. Analyses of total N and acetylene reduction assays supported this apparent surplus of N in butane-amended soil. Total N was significantly (P < 0.01) higher in soil incubated with butane and no N amendments than in soil incubated with propane, even when the latter was amended with N. Acetylene reduction occurred only in butane-amended soil. These results indicate that N2 fixation occurred in butane-amended soil but not in propane-amended soil. PMID:8215369

  6. Energy Conversion and Combustion Sciences

    DTIC Science & Technology

    2013-03-08

    al) 2-methyl alkanes (LLNL) Biodiesel (LLNL) before 2000 2000-2004 2005-2009 since 2010 iso-octane (LLNL) iso-octane (ENSIC-CNRS) n-butane (LLNL...methyl alkanes (LLNL) Biodiesel (LLNL) before 2000 2000-2004 2005-2009 since 2010 iso-octane (LLNL) iso-octane (ENSIC-CNRS) n-butane (LLNL) CH4...alkanes (LLNL) Biodiesel (LLNL) before 2000 2000-2004 2005-2009 since 2010 iso-octane (LLNL) iso-octane (ENSIC-CNRS) n-butane (LLNL) CH4 (Konnov

  7. Current Intelligence Bulletins: summaries, September 1987

    SciTech Connect

    Not Available

    1987-09-01

    Brief summaries of 49 NIOSH Current Intelligence Bulletins were provided in a cumulative listing. Permissible Exposure Limits were included where applicable, and notes were provided with some summaries indicating further action or data since original publication. Topics covered include chloroprene, trichloroethylene, ethylene-dibromide, chrome pigment, asbestos, hexamethylphosphoric-triamide, polychlorinated-biphenyls, 4,4'-diaminodiphenylmethane, chloroform, radon daughters, dimethylcarbamoyl-chloride, diethylcarbamoyl-chloride, explosive azide hazard, arsenic, nitrosamines, metabolic precursors of beta-naphthylamine, 2-nitropropane, acrylonitrile, 2,4-diaminoanisole, tetrachloroethylene, trimellitic-anhydride, ethylene-thiourea, ethylene-dibromide, disulfiram, dyes, ethylene-dichloride, chloroethanes, vinyl halides, glycidyl ethers, epichlorohydrin, smoking, arsine, radiofrequency sealers, formaldehyde, ethylene-oxide, silica flour, vibration syndrome, glycol ethers, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,3-butadiene, cadmium, monohalomethanes, dinitrotoluenes, methylene-chloride, 4,4'-methylenedianiline, organic solvents, and injuries and amputations from working with power presses.

  8. Health-hazard evaluation report HETA 84-311-1575, grain elevators, Superior, Wisconsin, and Duluth, Minnesota

    SciTech Connect

    Ahrenholz, S.H.

    1985-04-01

    Personal air samples were analyzed for carbon disulfide, ethylene dibromide, carbon tetrachloride, and grain dust at grain elevators. The survey was requested by a representative of Local 118 of the American Federation of Grain Millers to evaluate exposures to grain fumigants and dust among workers at the two sites. All concentrations of carbon disulfide, carbon tetrachloride, and ethylene dibromide were below the detection limit. Grain-dust concentrations ranged from 0.34 to 38 milligrams per cubic meter (mg/m/sup 3/). The American Conference of Governmental Industrial Hygienists threshold limit value for airborne grain dust is 4 mg/m/sup 3/. Short-term sampling for the fumigants was performed; however, the results were inconclusive. The author concludes that a health hazard due to overexposure to grain dust exists at the grain elevators. Recommendations were made.

  9. Root-knot Nematode Management and Yield of Soybean as Affected by Winter Cover Crops, Tillage Systems, and Nematicides.

    PubMed

    Minton, N A; Parker, M B

    1987-01-01

    Management of Meloidogyne incognita on soybean as affected by winter small grain crops or fallow, two tillage systems, and nematicides was studied. Numbers of M. incognita did not differ in plots planted to wheat and rye. Yields of soybean planted after these crops also did not differ. Numbers of M. incognita were greater in fallow than in rye plots, but soybean yield was not affected by the two treatments. Soybean yields were greater in subsoil-plant than in moldboard plowed plots. Ethylene dibromide reduced nematode population densities more consistently than aldicarb and phenamiphos. Also, ethylene dibromide increased yields the most and phenamiphos the least. There was a positive correlation (P = 0.001) of seed size (weight of 100 seeds) with yield (r = 0.79), indicating that factors affecting yield also affected seed size.

  10. Degradation of halogenated aliphatic compounds by the ammonia-oxidizing bacterium nitrosomonas europaea

    SciTech Connect

    Vannelli, T.; Logan, M.; Arciero, D.M.; Hooper, A.B. )

    1990-04-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane. Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded.

  11. Degradation of halogenated aliphatic compounds by the ammonia-oxidizing bacterium Nitrosomonas europaea

    SciTech Connect

    Vannelli, T.; Logan, M.; Arciero, D.M.; Hooper, A.B.

    1990-01-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane. Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded.

  12. Facile synthesis of beta-tribromomethyl and dibromomethylenated nitroalkanes via conjugate addition of bromoform to nitroalkenes.

    PubMed

    Sahu, Bichismita; Gururaja, Guddeangadi N; Mobin, Shaikh M; Namboothiri, Irishi N N

    2009-03-20

    Addition of bromoform to conjugated nitroalkenes in the presence of Mg provided beta-tribromomethyl nitroalkanes in good to excellent yields and diastereoselectivity. These novel Michael adducts, formed under radical conditions, underwent elimination of HBr in the same pot under reflux to afford beta-dibromomethylenated nitroalkanes in good yield. Alternatively, a one-pot high yielding synthesis of the dibromides was possible under anionic conditions via LDA mediated addition of bromoform to nitroalkenes.

  13. The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow

    PubMed Central

    Roper, Kimberley A; Berry, Malcolm B

    2013-01-01

    Summary The application of a monolithic form of triphenylphosphine to the Ramirez gem-dibromoolefination reaction using flow chemistry techniques is reported. A variety of gem-dibromides were synthesised in high purity and excellent yield following only removal of solvent and no further off-line purification. It is also possible to perform the Appel reaction using the same monolith and the relationship between the mechanisms of the two reactions is discussed. PMID:24062843

  14. United States Air Force Summer Research Program 1991. High School Apprenticeship Program (HSAP) Reports. Volume 10. Armstrong Laboratory

    DTIC Science & Technology

    1992-01-09

    75003 Ethyl chloride (Chloroethane) 106934 Ethylene dibromide (Dibromoethane) 107062 Ethylene dichloride (l,2-Dichloroethane) 107211 Ethylene glycol ...Chemical name 0 Cyanide Compounds 1 0 Glycol ethers 2 0 Lead compounds 0 Manganese Compounds 0 Mercury Compounds 0 Fine mineral fibers 3 0 Nickel...for glycol others the following applies:Unless otherwise specified, these listings are defined as including any unique chemical substance that

  15. SERDP and ESTCP Workshop on Long Term Management of Contaminated Groundwater Sites

    DTIC Science & Technology

    2013-11-01

    compound used primarily as a biocide in antifouling paints ); ethylene dibromide (EDB, which is used as a scavenger for lead in anti-knock gasoline...hydrocarbons (oxy-PAHs); and 1-bromopropane (which is used as a solvent for cleaning metal surfaces and adhesives , and has also been deployed as a...ER- 200829) ● Field Demonstration of Propane Biosparging for In Situ Remediation of N-Nitrosodimethylamine (NDMA) in Groundwater (ER-200828

  16. Favorite Demonstrations: A "Rainstorm" in a Bag--A Demonstration of States of Matter and Changes.

    ERIC Educational Resources Information Center

    Hilton, Don B.; Kelley, Judith A.

    1988-01-01

    Explains procedures, observations, and directions for demonstrating properties of butane using reclosable plastic storage bags. States that the demonstration provides for discussion of topics such as the liquefaction of gases, heat of vaporization and refrigeration techniques, and thermodynamics. (RT)

  17. Lighter fluid poisoning

    MedlinePlus

    ... in lighter fluids are called hydrocarbons. They include: Benzene Butane Hexamine Lacolene Naptha Propane Where Found Various ... PA: Elsevier Saunders; 2014:chap 158. Mirkin DB. Benzene and related aromatic hydrocarbons. In: Shannon MW, Borron ...

  18. Rate Constants for the Reactions of Hydroxyl Radical with Several Alkanes, Cycloalkanes, and Dimethyl Ether

    NASA Technical Reports Server (NTRS)

    DeMore, W.; Bayes, K.

    1998-01-01

    Relative rate experiements were used to measure rate constants and temperature denpendencies of the reactions of OH with propane, n-butane, n-pentane, n-hexane, cyclopropane, cyclobutane, cyclopentane, and dimethyl ether.

  19. 40 CFR 80.126 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...% independent lab testing, the laboratory analysis shall consist of the results reported to the refinery or importer by the independent lab. Where assumed properties used (e.g., for butane) the assumed...

  20. 40 CFR 80.126 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...% independent lab testing, the laboratory analysis shall consist of the results reported to the refinery or importer by the independent lab. Where assumed properties used (e.g., for butane) the assumed...

  1. 40 CFR 80.126 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...% independent lab testing, the laboratory analysis shall consist of the results reported to the refinery or importer by the independent lab. Where assumed properties used (e.g., for butane) the assumed...

  2. 40 CFR 80.126 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...% independent lab testing, the laboratory analysis shall consist of the results reported to the refinery or importer by the independent lab. Where assumed properties used (e.g., for butane) the assumed...

  3. 30 CFR 256.40 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... products means natural gas liquid products including the following: ethane, propane, butane, pentane... Processors Association (NGPA) or the American Society for Testing and Materials (ASTM): (A) Ethane—C2 H6...

  4. Short-Term Energy Outlook Model Documentation: Hydrocarbon Gas Liquids Supply and Demand

    EIA Publications

    2015-01-01

    The hydrocarbon gas liquids (ethane, propane, butanes, and natural gasoline) module of the Short-Term Energy Outlook (STEO) model is designed to provide forecasts of U.S. production, consumption, refinery inputs, net imports, and inventories.

  5. Secondhand Smoke: What It Means to You

    MedlinePlus

    ... car exhaust Toluene Found in paint thinners Hydrogen Cyanide Used in chemical weapons Butane Used in lighter ... severe asthma. Babies are hurt by secondhand smoke. Tobacco smoke harms babies before and after they are ...

  6. Current Intelligence Bulletins: summaries

    SciTech Connect

    Not Available

    1986-07-24

    Summaries are provided for the 47 Current Intelligence Bulletins issued to date by NIOSH; any revisions in NIOSH policy made after a bulletin was issued are included. Subjects of the bulletins include the following: chloroprene; trichloroethylene; ethylene-dibromide; chrome pigment; asbestos exposure; hexamethylphosphoric-triamide; polychlorinated biphenyls; 4,4'-diaminodipheylmethane; chloroform; radon daughters; dimethylcarbamoyl-chloride; diethylcarbamoyl-chloride; explosive azide hazard; inorganic arsenic; nitrosamines; metabolic precursors of beta-naphtylamine; 2-nitropropane; acryonitrile; 2,4-diaminoanisole; tetrachloroethylene; trimellitic-anhydride; ethylene-thiourea; ethylene-dibromide and disulfiram, toxic interaction; direct blue 6, direct black 38, direct brown 95, benzidine derived dyes; ethylene-dichloride; NIAX catalyst ESN; chloroethanes, review of toxicity; vinyl halides, carcinogenicity; glycidyl ethers; epichlorohydrin; smoking and the occupational environment; arsine poisoning in the workplace; radiofrequency sealers and heaters; formaldehyde; ethylene-oxide; silica flour; ethylene-dibromide; vibration syndrome; glycol ethers; 2,3,7,8-tetrachlorodibenzo-p-dioxin; 1,3-butadiene; cadmium; monohalomethanes; dinitrotoluenes; polychlorinated biphenyls in electrical equipment fires or failures; methylene-chloride; and 4,4' methylenedianiline.

  7. [Ventricular fibrillation following deodorant spray inhalation].

    PubMed

    Girard, F; Le Tacon, S; Maria, M; Pierrard, O; Monin, P

    2008-01-01

    We report one case of out-of-hospital cardiac arrest with ventricular fibrillation following butane poisoning after inhalation of antiperspiration aerosol. An early management using semi-automatic defibrillator explained the success of the resuscitation. The mechanism of butane toxicity could be an increased sensitivity of cardiac receptors to circulating catecholamines, responsible for cardiac arrest during exercise and for resuscitation difficulties. The indication of epinephrine is discussed.

  8. Advanced Thermally Stable Jet Fuel Development Program Annual Report. Volume 2. Compositional Factors Affecting Thermal Degradation of Jet Fuels

    DTIC Science & Technology

    1992-05-01

    the purpose of identification of peaks in the gas chromatogram, the retention times of methane, ethane, propane, butane, pentane, ethylene , propylene...olefinic hydrocarbons). While ethane and ethylene do not separate on the SP- 1700 column, it appears that the main products from thermal...decomposition of the three model compounds are methane, ethane+ ethylene , propane, propylene, butane and butene. The distribution patterns of the components in the

  9. Molecular and Cellular Fundamentals of Aerobic Cometabolism

    DTIC Science & Technology

    1998-10-01

    1 99 1 ) Butane Pseudomonas butane monooxygenase (Hamamura, et al . , butanovorars (BMO) 1 997) 2,4-Dichloro Alcaligenes eutrophus...Leadbetter and Foster, 1 960). These studies initially revealed that the methane-utilizing bacterium Pseudomonas (Methylomonas) methanica could not grow...enzyme is required for each insertion. Pseudomonas mendocina KR 1 toluene-4-monooxygenase (T4MO) produces p-cresol ; Pseudomonas picketii toluene

  10. From an equilibrium based MOF adsorbent to a kinetic selective carbon molecular sieve for paraffin/iso-paraffin separation.

    PubMed

    Li, Baiyan; Belmabkhout, Youssef; Zhang, Yiming; Bhatt, Prashant M; He, Hongming; Zhang, Daliang; Han, Yu; Eddaoudi, Mohamed; Perman, Jason A; Ma, Shengqian

    2016-11-24

    We unveil a unique kinetic driven separation material for selectively removing linear paraffins from iso-paraffins via a molecular sieving mechanism. Subsequent carbonization and thermal treatment of CD-MOF-2, the cyclodextrin metal-organic framework, afforded a carbon molecular sieve with a uniform and reduced pore size of ca. 5.0 Å, and it exhibited highly selective kinetic separation of n-butane and n-pentane from iso-butane and iso-pentane, respectively.

  11. [Using 2-DCOS to identify the molecular spectrum peaks for the isomer in the multi-component mixture gases Fourier transform infrared analysis].

    PubMed

    Zhao, An-Xin; Tang, Xiao-Jun; Zhang, Zhong-Hua; Liu, Jun-Hua

    2014-10-01

    The generalized two-dimensional correlation spectroscopy and Fourier transform infrared were used to identify hydrocarbon isomers in the mixed gases for absorption spectra resolution enhancement. The Fourier transform infrared spectrum of n-butane and iso-butane and the two-dimensional correlation infrared spectrum of concentration perturbation were used for analysis as an example. The all band and the main absorption peak wavelengths of Fourier transform infrared spectrum for single component gas showed that the spectra are similar, and if they were mixed together, absorption peaks overlap and peak is difficult to identify. The synchronous and asynchronous spectrum of two-dimensional correlation spectrum can clearly identify the iso-butane and normal butane and their respective characteristic absorption peak intensity. Iso-butane has strong absorption characteristics spectrum lines at 2,893, 2,954 and 2,893 cm(-1), and n-butane at 2,895 and 2,965 cm(-1). The analysis result in this paper preliminary verified that the two-dimensional infrared correlation spectroscopy can be used for resolution enhancement in Fourier transform infrared spectrum quantitative analysis.

  12. Autoignition and Combustion of Natural Gas in a 4 Stroke HCCI Engine

    NASA Astrophysics Data System (ADS)

    Jun, Daesu; Ishii, Kazuaki; Iida, Norimasa

    Homogeneous charge compression ignition (HCCI) is regarded as the next generation combustion regime in terms of high thermal efficiency and low emissions. It is difficult to control autoignition timing and combustion duration because they are controlled primarily by the chemical kinetics of fuel-air mixture. In this study, it was investigated the characteristics of autoignition and combustion of natural gas in a 4 stroke HCCI engine. And also, to clarify the influence of n-butane on autoignition and combustion of natural gas, it was changed the blend ratio of n-butane from 0mol% to 10mol% in methane/n-butane/air mixtures. Autoignition strongly depends on in-cylinder gas temperature. Autoignition of natural gas occurs when in-cylinder gas temperature reaches in a range of 1000±100K under this experimental condition. To realize high thermal efficiency and low CO emissions, it is necessary to prepare operation conditions that maximum cycle temperature is over 1500K. Autoignition temperature is 25K lower by increasing n-butane blend ratio of 10%. As the blend ratio of n-butane increases, the maximum cycle temperature increases, and THC, CO emissions reduce.

  13. Central Appalachian basin natural gas database: distribution, composition, and origin of natural gases

    USGS Publications Warehouse

    Román Colón, Yomayra A.; Ruppert, Leslie F.

    2015-01-01

    The U.S. Geological Survey (USGS) has compiled a database consisting of three worksheets of central Appalachian basin natural gas analyses and isotopic compositions from published and unpublished sources of 1,282 gas samples from Kentucky, Maryland, New York, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. The database includes field and reservoir names, well and State identification number, selected geologic reservoir properties, and the composition of natural gases (methane; ethane; propane; butane, iso-butane [i-butane]; normal butane [n-butane]; iso-pentane [i-pentane]; normal pentane [n-pentane]; cyclohexane, and hexanes). In the first worksheet, location and American Petroleum Institute (API) numbers from public or published sources are provided for 1,231 of the 1,282 gas samples. A second worksheet of 186 gas samples was compiled from published sources and augmented with public location information and contains carbon, hydrogen, and nitrogen isotopic measurements of natural gas. The third worksheet is a key for all abbreviations in the database. The database can be used to better constrain the stratigraphic distribution, composition, and origin of natural gas in the central Appalachian basin.

  14. In Vitro Evaluation of the Biocompatibility of Newly Synthesized Bis-Quaternary Ammonium Compounds with Spacer Structures Derived from Pentaerythritol or Hydroquinone.

    PubMed

    Yamamoto, Masashi; Takami, Takashi; Matsumura, Reiko; Dorofeev, Alexander; Hirata, Yoshihiko; Nagamune, Hideaki

    2016-01-01

     With the object of developing new biocides milder for human use than the current antiseptics, we synthesized a series of bis-quaternary ammonium compounds (bis-QACs). The antimicrobial activity of the newly synthesized bis-QACs and common biocides used as antiseptics was compared by examining minimum inhibitory concentrations and minimum bactericidal concentrations (MBCs). Moreover, the cytotoxicity of these compounds against human cells was determined to calculate the biocompatibility index (BI) of these compounds. BI was the ratio of the concentration of a biocide giving a 50% lethal effect on normal human epidermal keratinocytes to its MBC against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The commonly used antiseptics tested were benzalkonium chloride (BAC), octenidine dihydrochloride (OCT), chlorhexidine digluconate (CHG) and polyhexamethylene biguanide (PHMB). In comparison with these antiseptics, it was shown that some of new bis-QACs exhibited a wider and more potent antimicrobial spectrum than OCT. The cytotoxicity of these bis-QACs was equal or lower compared to that of the quaternary ammonium compounds (BAC and OCT), although these bis-QACs showed higher toxicity than the biguanide-based compounds (CHG and PHMB). Finally, the comparison of BIs revealed that new bis-QACs such as N-dodecyl {4,4'-(2,4,8,10-tetraoxaspiro[5.5]undecan-3,9-diyl) }dipyridinium dibromide (4TOSU-12), 3,3'-[1,4-Phenylenebis (oxy)]bis (1-dodecylpyridinium) dibromide (3PHBO-12) and 3-(3-Hydroxy-2-(hydroxymethyl)-2-{[(1-dodecylpyridinium-3-yl) oxy]methyl}propoxy)-1-dodecylpyridinium dibromide (3HHDMP-12) had equal or greater biocompatibility than the commonly used biocides tested. Thus, these results strongly suggested that 4TOSU-12, 3PHBO-12 and 3HHDMP-12 could be useful as antiseptics for topical application to the skin.

  15. Regio- and stereoselective isomerization of hexabromocyclododecanes (HBCDs): kinetics and mechanism of gamma- to alpha-HBCD isomerization.

    PubMed

    Heeb, Norbert V; Schweizer, W Bernd; Mattrel, Peter; Haag, Regula; Gerecke, Andreas C; Schmid, Peter; Zennegg, Markus; Vonmont, Heinz

    2008-11-01

    Hexabromocyclododecanes (HBCDs) are high production volume chemicals (>20000 ty(-1)) used as flame retardants for plastics and textiles. Lately, we reported on the stereoselective isomerization of beta-HBCDs. Herein we present insights into the mechanism and kinetics of (+)gamma- to (+)alpha- and of (-)gamma- to (-)alpha-HBCD isomerization. Only two of the six bromine atoms migrated, indicating that rearrangements of gamma- to alpha-HBCDs are regio- and stereoselective as well. The apparent first-order isomerization rate constants increased from 0.0013 to 0.0031 to 0.0070 min(-1) at 120, 130, and 140 degrees C, respectively, corresponding to half-lives of 540, 230, and 99 min. Thus, a thermal treatment of materials containing gamma-HBCDs at temperatures >100 degrees C may induce the formation of alpha-HBCDs and, hence, may alter the diastereomeric ratio of a HBCD mixture. The inversion of vicinal dibromides in like-configurations (RR/SS) prevailed, whereas unlike-configurations (RS/SR) were not affected. An intramolecular, stereoselective migration of neighboring bromine atoms via a four-center transition state would explain the observed stereoisomer pattern and first-order kinetics. Despite the fact that vicinal dibromides in HBCDs prefer synclinal (gauche) conformations, antiperiplanar (staggered) conformations are assumed to facilitate concerted 1.2-shifts of both bromine atoms. A conformation analysis revealed that under kinetic control, only those bromine atoms in the more flexible part of the molecules are migrating, whereas those in the conserved triple-turn motive were not affected. Thus, this structural motive, common to all alpha-, beta-, and gamma-HBCDs, is more rigid and less reactive than the flexible part, containing the reacting dibromides in like-configurations.

  16. Relative rate studies of the reactions of chlorine atoms with simple alkanes and the chlorinated methanes

    SciTech Connect

    Wingen, L.; Lee, J.J.; Neavyn, R.

    1995-12-01

    The reactions of chlorine atoms with organics are of interest because atomic chlorine is a potential tropospheric oxidant. Relative rate constants for the reaction of pairs of simple alkanes (ethane/propane, ethane/n-butane, and isobutane/n-butane) and the chlorinated methanes (chloromethane, dichloromethane, and chloroform relative to methane) were measured, using the photolysis of Cl{sub 2} as the source of chlorine atoms and following the loss of the organics by GC-FID. The ratios of the relative rate constants were in excellent agreement with the literature except for ethane/n-butane, where our results are approximately 20% lower than recently published values, and for chloroform/methane, where our value is approximately 50% higher than the values recommended by JPL and JPCRD. Our results will be compard to previously published relative rate studies as well as to the results of absolute rate constant studies, and the differences will be discussed.

  17. Occupational exposure to 1,3-dichloropropene (Telone II) in Hawaiian pineapple culture

    SciTech Connect

    Albrecht, W.N.

    1987-09-01

    1,3-dichloropropene (DCP), the primary constituent of Telone II, is a subsoil fumigant that has supplanted 1,2-dibromo-3-chloropropane (DBCP) and ethylene dibromide (EDB) as primary fumigant in Hawaiian pineapple culture. To determine the potential for adverse health effects, an environmental survey was done to assess worker exposures. Exposures were predominantly below 1 ppm, which is the no-effect level determined with experimental animals, and the Threshold Limit Value (TLV) recommended by the American Conference of Governmental Industrial Hygienists (ACGIH).

  18. Irradiation and fumigation effects on flavor, aroma and composition of grapefruit products

    SciTech Connect

    Moshonas, M.G.; Shaw, P.E.

    1982-05-01

    Effects were evaluated on grapefruit treated to meet quarantine restrictions against Caribbean fruit fly infestation. Differences were found in flavor of fresh sections, fresh juice, and aroma of peel oil when obtained from fruit irradiated with x-rays, as compared with products from nonirradiated fruit. Flavor differences were found in all pasteurized juices from fruit irradiated at 50-60 krad. Vitamin C levels were significantly lower in juice from most irradiated fruit. Flavor differences were found in fresh and pasteurized juice from fruit treated with methyl bromide, and in pasteurized juice from fruit treated with ethylene dibromide. Aroma differences were found in peel oil from fruit treated with phosphine.

  19. Dissociative excitation of the manganese atom quartet levels by collisions e-MnBr2

    NASA Astrophysics Data System (ADS)

    Smirnov, Yu M.

    2017-04-01

    Dissociative excitation of quartet levels of the manganese atom was studied in collisions of electrons with manganese dibromide molecules. Eighty-two cross-sections for transitions originating at odd levels and eleven cross-sections for transitions originating at even levels have been measured at an incident electron energy of 100 eV. An optical excitation function has been recorded in the electron energy range of 0–100 eV for transitions originating from 3d 64p z 4 F° levels. For the majority of transitions, a comparison of the resulting cross-section values to cross-sections produced by direct excitation is provided.

  20. Hazardous Waste Minimization Initiation Decision Report. Volume 2. Appendixes.

    DTIC Science & Technology

    1988-06-01

    The oxidation of aLrazine, butyl phthalate, chloroaniline, diphenyl hydrazine, ethylene dibromide, malathion , pentachlorophenol, and xylene was rapid...solution Equilibrium composition Reaction Kinetics Reaction rate model Rate constants Corrosion Resistance Plant Data Toxicity Explosion and fire...formation 0.0 0.2 0.0 Heat of solution 0.0 0.0 0.0 Eqjilibrium composition 0.2 0.5 0.0 Reaction Kinetics Reaction rate model 0.5 0.0 1.0 Rate constants

  1. New Synthetic Approach for the Incorporation of 3,2-Hydroxypyridinone (HOPO) Ligands: Synthesis of Structurally Diverse Poly HOPO Chelators

    PubMed Central

    Arumugam, Jayanthi; Brown, Hayley A.; Jacobs, Hollie K.; Gopalan, Aravamudan S.

    2011-01-01

    The HOPO sulfonamide reagent, 3, was prepared from commercial 2,3-dihydroxypyridine in four steps in good yields. Sulfonamide 3 readily underwent selective alkylation with dibromides in the presence of base or could be coupled to alcohols using Mitsunobu conditions. The utility of this nucleophilic HOPO reagent was demonstrated by the synthesis some tris and tetraHOPO chelators. This approach for tethering HOPO ligands is unique and flexible as shown by the preparation of HOPO/iminocarboxylic acid chelator 17. PMID:21709749

  2. Kinetics of Mediated Electron Transfer Between Viologen Groups in a Self-Assembled Monolayer and Metal Complexes in Solution

    DTIC Science & Technology

    1993-05-12

    was prepared in a similar manner to 1V1OSH. Bis [N-(n-decyl)-N’-(10-mercaptodecyl)-4,4’-bypridinium] disulfide dibromide (0OV10S-) 2 was prepared as...previously reported (5). Bis [N-(cholesteryl)-N’-(5-mercaptopentyl)-4,4’bipyridium] disulfide tosylate iodide (ChoV5S-) 2 Cholesteryl p-toluene...and excess Proton Sponge which was extracted by washing with 1% HCL 3 times. Bis [N-(n-lH,1H,2H,2H-perfluorododecyl)-N’-(5-mercaptopentyl)-4, 4

  3. 3,3′-Dimethyl-1,1′-[(1,3-dihy­droxy­propane-2,2-di­yl)dimethyl­idene]diimidazolium bis­(hexa­fluoro­phosphate)

    PubMed Central

    Yuan, Ai-Lin; Wang, Chang-Sheng; Zhuang, Ling-Hua; Wang, Guo-Wei

    2010-01-01

    The title compound, C13H22N4O2 2+·2PF6 −, was prepared by the anion exchange of the dibromide ionic liquid with potassium hexa­fluoro­phosphate. The two imidazole rings are each planar (r.m.s. deviations = 0.0016 and 0.0060 Å) and make a dihedral angle of 45.3 (18)°. Intra­molecular O—H⋯F hydrogen bonds occur. Inter­molecular C—H⋯F, O—H⋯O and C—H⋯O hydrogen bonds stabilize the crystal structure. PMID:21589562

  4. Crystalline mesoporous zirconia catalysts having stable tetragonal pore wall structure

    DOEpatents

    Sachtler, Wolfgang M. H.; Huang, Yin-Yan

    1998-01-01

    Methods for the preparation of new sulfated mesoporous zirconia materials/catalysts with crystalline pore walls of predominantly tetragonal crystal structure, characterized by nitrogen physisorption measurement, X-ray diffraction, transmission electron microscopy and catalytic tests using n-butane isomerization to iso-butane and alkylation of 1-naphthol with 4-tert-butylstyrene as probe reactions. Sulfate deposition is preferred for the transformation of a mesoporous precursor with amorphous pore walls into a material with crystalline pore walls maintaining the mesoporous characteristics.

  5. Crystalline mesoporous zirconia catalysts having stable tetragonal pore wall structure

    DOEpatents

    Sachtler, W.M.H.; Huang, Y.Y.

    1998-07-28

    Methods are disclosed for the preparation of new sulfated mesoporous zirconia materials/catalysts with crystalline pore walls of predominantly tetragonal crystal structure, characterized by nitrogen physical sorption measurement, X-ray diffraction, transmission electron microscopy and catalytic tests using n-butane isomerization to iso-butane and alkylation of 1-naphthol with 4-tert-butylstyrene as probe reactions. Sulfate deposition is preferred for the transformation of a mesoporous precursor with amorphous pore walls into a material with crystalline pore walls maintaining the mesoporous characteristics. 17 figs.

  6. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    DOEpatents

    Koch, Daniel J.; Arnold, Frances H.

    2012-11-13

    AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

  7. Retrofitting olefin cracking plants

    SciTech Connect

    Sumner, C.; Fernandez-Baujin, J.M.

    1983-12-01

    This article discusses the retrofitting of liquid crackers which produce olefins so that gaseous feedstocks can be used. Naphtha and gas oil are the predominant design feedstocks for producing olefins. The price of gaseous feedstocks such as ethane, propane and butane have become economically more attractive than liquid feedstocks. Existing liquid crackers will be able to produce ethylene at 85% or higher capacity when cracking propane and butane feedstock with only minor changes. Topics considered include revamping for vacuum gas oil (VGO) feedstocks and revamping for liquefied petroleum gas (LPG) feedstocks.

  8. Bioaugmentation of an Aerobic Culture Capable of Chlorinated Solvent Cometabolism to a Subsurface Test Zone

    NASA Astrophysics Data System (ADS)

    Dolan, M. E.; Semprini, L.; McCarty, P. L.; Hopkins, G.

    2002-12-01

    A butane-utilizing culture able to cometabolize chlorinated aliphatic hydrocarbons (CAHs) was bioaugmented into an aquifer test zone at Moffett Federal Airfield, CA. Microcosm bioaugmentation tests conducted with groundwater and aquifer solids collected from the test site indicated a strong potential for viability of the bioaugmented culture in the site subsurface. Microcosms bioaugmented with the butane-utilizing culture were able to degrade aqueous concentrations of 1,1-dichloroethylene (1,1-DCE) up to 1 mg/L and could successfully transform mixtures of 1,1-DCE, 1,1,1-trichloroethane (TCA) and 1,1-dichloroethane (DCA) when fed butane. T-RFLP analyses showed the presence of bioaugmented organisms within the microcosms throughout the 10-month test period. An isolate from the butane-utilizing culture was grown in batch bottles containing mineral media and a butane-in-air headspace. Approximately 4 g dry weight of culture was harvested and bioaugmented to the field site. The site consisted of two parallel well legs, each with an injection well, two fully penetrating monitoring wells containing solid support media, three groundwater monitoring wells and an extraction well. One well leg was bioaugmented with the isolate and the other was used as an indigenous control leg. A mixture of 1,1-DCE, TCA and DCA (~50 ug/L, 135 ug/L and 150 ug/L respectively) was continuously pumped through both well legs with alternate pulses of dissolved oxygen and butane. Fifty percent removal of 1,1-DCE occurred within one day in the bioaugmented leg; however, it took about 6 days to achieve complete butane utilization and 1,1-DCE removal to below 2 ug/L. During this period DCA and TCA were reduced by 70- 90 percent and 30-50 percent respectively. When the butane/oxygen pulses were changed from a 1-hr cycle to a 24-hr cycle 1,1-DCE removal fell to 50 percent and DCA and TCA concentrations increased to influent levels. Upon returning to short pulse cycles, 1,1-DCE removal efficiency

  9. Comprehensive study of tartrazine/cationic surfactant interaction.

    PubMed

    Shahir, Afshin Asadzadeh; Javadian, Soheila; Razavizadeh, Bi Bi Marzieh; Gharibi, Hussein

    2011-12-15

    Interaction of a food dye, tartrazine, with some cationic conventional and gemini surfactants, tetradecyltrimethylammonium bromide (TTAB), N,N'-ditetradecyl-N,N,N',N'-tetramethyl-N,N'-butanediyl-diammonium dibromide (14,4,14), and N,N'-didodecyl-N,N,N',N'-tetramethyl-N,N'-butanediyl-diammonium dibromide (12,4,12), were first investigated comprehensively employing conductometry, tensiometry, and UV-visible spectroscopy. Tartrazine was found to behave in the same manner as aromatic counterions. The formation of ion pairs reflected as a considerable increase of the surfactant efficiency in tensiometry plots and their stoichiometry were determined by Job's method of continuous variations. For the tartrazine/TTAB system, nonionic DS(3), ionic DS(2-), and/or DS(2)(-) ion pairs, their small premicelles, and tartrazine-rich micelles were constituted as well as dye-containing TTAB-rich micelles. Insoluble J-aggregates of DS(-) ion pairs and cylindrical surfactant-rich micelles were also formed in tartrazine/gemini surfactant systems and recognized by transmission electron microscopy. The zeta potential and the size of the aggregates were determined using dynamic light scattering and confirmed the suggested models for the processes happening in each system. Cyclic voltammetry was applied successfully to track all of these species using tartrazine's own reduction peak current for the first time.

  10. 43 CFR 2361.0-5 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... resources which include crude oil, gases of all kinds (natural gas, hydrogen, carbon dioxide, helium, and any others), natural gasoline, and related hydrocarbons (tar sands, asphalt, propane butane, etc... described in Public Land Order 2344 (the Naval Arctic Research Laboratory—surface estate only) dated...

  11. 43 CFR 2361.0-5 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... resources which include crude oil, gases of all kinds (natural gas, hydrogen, carbon dioxide, helium, and any others), natural gasoline, and related hydrocarbons (tar sands, asphalt, propane butane, etc... described in Public Land Order 2344 (the Naval Arctic Research Laboratory—surface estate only) dated...

  12. 78 FR 52679 - Safety Standard for Cigarette Lighters; Adjusted Customs Value for Cigarette Lighters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-26

    ... 1210 Safety Standard for Cigarette Lighters; Adjusted Customs Value for Cigarette Lighters AGENCY: Consumer Product Safety Commission. ACTION: Final rule. SUMMARY: The Commission has a safety standard... standard defines ``disposable lighters,'' in part, as refillable lighters that use butane or similar...

  13. 49 CFR Appendix B to Part 195 - Risk-Based Alternative to Pressure Testing Older Hazardous Liquid and Carbon Dioxide Pipelines

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) (Propane, butane, Natural Gas Liquid (NGL), ammonia) Highly toxic (Benzene, high Hydrogen Sulfide content crude oils). M Flammable—flashpoint Three spills in last 10 years. L ≤Three spills in last 10 years. H=HighL=Low. 1 Pipeline segments with greater than three product spills in the last 10 years should...

  14. 49 CFR Appendix B to Part 195 - Risk-Based Alternative to Pressure Testing Older Hazardous Liquid and Carbon Dioxide Pipelines

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) (Propane, butane, Natural Gas Liquid (NGL), ammonia) Highly toxic (Benzene, high Hydrogen Sulfide content crude oils). M Flammable—flashpoint Three spills in last 10 years. L ≤Three spills in last 10 years. H=HighL=Low. 1 Pipeline segments with greater than three product spills in the last 10 years should...

  15. 49 CFR Appendix B to Part 195 - Risk-Based Alternative to Pressure Testing Older Hazardous Liquid and Carbon Dioxide Pipelines

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) (Propane, butane, Natural Gas Liquid (NGL), ammonia) Highly toxic (Benzene, high Hydrogen Sulfide content crude oils). M Flammable—flashpoint Three spills in last 10 years. L ≤Three spills in last 10 years. H=HighL=Low. 1 Pipeline segments with greater than three product spills in the last 10 years should...

  16. Nanoparticles of antimony doped tin dioxide as a liquid petroleum gas sensor: effect of size on sensitivity

    NASA Astrophysics Data System (ADS)

    Banerjee, Suparna; Bumajdad, Ali; Devi, P. Sujatha

    2011-07-01

    The gas sensitivity exhibited by nanoparticles of 1 wt% Pd catalysed antimony doped tin dioxide (ATO) prepared by a citrate-nitrate process is reported here. The reduction of particle size to < 3 nm, a dimension smaller than double the thickness of the charge depletion layer, has resulted in an exceptionally high butane sensitivity and selectivity. The sensitivity and selectivity of ATO particles of different sizes unequivocally proved that reducing the size of particles to below twice the Debye length dimension produces materials with exceptionally high sensitivity and selectivity for sensor applications. The sensitivity of the samples towards 1000 ppm butane varied in the order 98% > 55% > 47%, for CNP > SP > CP samples having crystallite sizes of the order of 2.4 nm to 18 nm to 25 nm, respectively. The ATO nanoparticles exhibited not only a remarkable increase in gas sensitivity of around 98% towards 1000 ppm butane at 350 °C, but also a preferential selectivity to butane compared to other gases such as CO, CO2, SO2, CH4 and H2. In addition to the exceptionally high sensitivity and selectivity, the developed sensors also exhibited an improved response time and long term stability, which are of paramount importance for practical device development.

  17. 40 CFR 1060.810 - What materials does this part reference?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Method for Determination of Butane Working Capacity of Activated Carbon (“ASTM D5228”) 1060.801 (b) SAE... the Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096 or http://www.sae.org. Table 2 follows: Table 2 to § 1060.810—SAE Materials Document number and name Part...

  18. 40 CFR 1060.810 - What materials does this part reference?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Method for Determination of Butane Working Capacity of Activated Carbon (“ASTM D5228”) 1060.801 (b) SAE... the Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096 or http://www.sae.org. Table 2 follows: Table 2 to § 1060.810—SAE Materials Document number and name Part...

  19. Licensing: BP, Lurgi unveil new butanediol process

    SciTech Connect

    Rotman, D.

    1995-07-26

    BP Chemicals and Lurgi (Frankfurt) say they have jointly developed a direct butane-to-1,4-butanediol process and are ready to license the technology. The companies-which began cooperating on the technology in early 1994-say the process, which is being marketed under the name Geminox, promises to be about 40% cheaper to operate than existing butandiol technologies.

  20. Generation of mutagenic transformation products during the irradiation of simulated urban atmospheres

    SciTech Connect

    Kleindienst, T.E.; Smith, D.F.; Hudgens, E.E.; Claxton, L.D.; Bufalini, J.J.

    1992-01-01

    Mixtures of air pollutants simulating urban atmospheres were irradiated in a smog chamber, and the resultant products were monitored for the production of mutagenic and other hazardous compounds. The production of biologically active compounds was detected through use of the Ames mutagenicity assay with Salmonella typhimurium, strain TA100. Irradiations of the pollutant mixture were conducted at HC/NOx ratios of 20 and 11. Overall, the mutagenicity of the products and the formation of oxygenated primary and secondary reactions products were greater for the simulations with the higher initial HC/NOx value. The origin of the mutagenicity from the reactant mixture was examined by conducting experiments with individual paraffinic, olefinic, and aromatic hydrocarbons. The chemicals examined during this aspect of the study were the paraffin n-butane, the olefin propylene, and the aromatic toluene. For the conditions studied, the activity of the toluene products was generally greater than that of propylene or n-butane, and the propylene products showed greater activity than did the n-butane products. The production of n-butane products was generally limited by its low rate of reaction with hydroxyl radicals. Photooxidation products from secondary reactions were most important in the toluene and propylene systems.

  1. Seasonal behavior of non-methane hydrocarbons in the firn air at Summit, Greenland

    NASA Astrophysics Data System (ADS)

    Helmig, D.; Stephens, C. R.; Caramore, J.; Hueber, J.

    2014-03-01

    Non-methane hydrocarbons (NMHC) were measured in the ambient air and in the snowpack interstitial firn air at ˜1 m depth continuously for nearly two years at Summit, Greenland, from fall 2008 through summer 2010. Additionally, five firn air depth profiles were conducted to a depth of 3 m spanning winter, spring, and summer seasons. Here we report measurements of ethane, ethene, ethyne, propane, propene, i-butane, n-butane, i-pentane, n-pentane, and benzene and discuss the seasonal behavior of these species in the ambient and firn air. The alkanes, ethyne, and benzene in the firn air closely reflect the ambient air concentrations during all the seasons of the year. In spring and summer seasons, ethene and propene were enhanced in the near-surface firn over that in the ambient air, indicating a photochemical production mechanism for these species within the snowpack interstitial air. Evaluation of the NMHC ratios of i-butane/n-butane, i-pentane/n-pentane, and benzene/ethyne in both ambient and firn air does not provide evidence for chlorine or bromine radical chemistry significantly affecting these gases, except in a few summer samples, where individual data points may suggest bromine oxidation influence.

  2. 75 FR 17706 - Flint Hills Resources, LP, Complainant v. Mid-America Pipeline Company, LLC, Respondent; Notice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-07

    ... sections 2, 3, 13, and 15 of the Interstate Commerce Act, 49 U.S.C. App. 2, 3, 13, and 15 (1988), Flint... and refinery grade butane on the Respondent's Northern interstate pipeline system as unjustly... in lieu of paper using the ``eFiling'' link at http://www.ferc.gov . Persons unable to...

  3. Pharmacokinetics, Pharmacodynamics, and Stereoselective Metabolism of the 1,2,4-Triazole Fungicide, Triadimefon, in Vertebrate Species

    EPA Science Inventory

    Questions Agricultural and pharmaceutical 1,2,4-triazole fungicides are potent cytochrome P450 modulators that can disrupt mammalian steroid biosynthesis. Triadimefon [(RS)-1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one] is unique with respect to tumorige...

  4. ALTERNATIVE ROUTES FOR CATALYST PREPARATION: USE OF ULTRASOUND AND MICROWAVE IRRADIATION FOR THE PREPARATION OF VANADIUM PHOSPHORUS OXIDE CATALYST AND ITS ACTIVITY FOR HYDROCARBON OXIDATION

    EPA Science Inventory

    Vanadium phosphorus oxide (VPO) is a well-known catalyst used for the vapor phase n-butane oxidation to maleic anhydride. It is prepared by a variety of methods, all of which, however, eventually result in the same active phase. The two main methods for the preparation of its pr...

  5. Worldwide gas processing: Capacities as of January 1, 1997, and average production

    SciTech Connect

    1997-06-02

    Tables are presented on the capacity for and average production of ethane, propane, isobutane, butane, liquid petroleum gases, natural gas liquids, and natural gasoline. Data are presented by country and by company within each country, state, or province. Another table presents data on sulfur production by company within each country, state, or province. Design capacity, production, desulfurization process, and sulfur source are listed.

  6. 26 CFR 1.927(a)-1T - Temporary regulations; definition of export property.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., including— (A) Natural gas, (B) Condensates, (C) Liquefied petroleum gases such as ethane, propane, and butane, and (D) Liquid products such as natural gasoline. (iii) Primary products and changing technology... products. For purposes of this paragraph, petrochemicals, medicinal products, insecticides and alcohols...

  7. 26 CFR 1.927(a)-1T - Temporary regulations; definition of export property.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., including— (A) Natural gas, (B) Condensates, (C) Liquefied petroleum gases such as ethane, propane, and butane, and (D) Liquid products such as natural gasoline. (iii) Primary products and changing technology... products. For purposes of this paragraph, petrochemicals, medicinal products, insecticides and alcohols...

  8. 26 CFR 1.927(a)-1T - Temporary regulations; definition of export property.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., including— (A) Natural gas, (B) Condensates, (C) Liquefied petroleum gases such as ethane, propane, and butane, and (D) Liquid products such as natural gasoline. (iii) Primary products and changing technology... products. For purposes of this paragraph, petrochemicals, medicinal products, insecticides and alcohols...

  9. 26 CFR 1.927(a)-1T - Temporary regulations; definition of export property.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., including— (A) Natural gas, (B) Condensates, (C) Liquefied petroleum gases such as ethane, propane, and butane, and (D) Liquid products such as natural gasoline. (iii) Primary products and changing technology... products. For purposes of this paragraph, petrochemicals, medicinal products, insecticides and alcohols...

  10. 26 CFR 1.927(a)-1T - Temporary regulations; definition of export property.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., including— (A) Natural gas, (B) Condensates, (C) Liquefied petroleum gases such as ethane, propane, and butane, and (D) Liquid products such as natural gasoline. (iii) Primary products and changing technology... products. For purposes of this paragraph, petrochemicals, medicinal products, insecticides and alcohols...

  11. 40 CFR 80.131 - Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline... Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline, and butane blenders. (a) Attest procedures for GTAB. The following...

  12. 40 CFR 80.131 - Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline... Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline, and butane blenders. (a) Attest procedures for GTAB. The following...

  13. 40 CFR 80.131 - Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline... Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline, and butane blenders. (a) Attest procedures for GTAB. The following...

  14. 40 CFR 80.131 - Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline... Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline, and butane blenders. (a) Attest procedures for GTAB. The following...

  15. The Stirling Project

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Stirling Engine's advanced technology engine offers multiple advantages, principal among them reduced fuel consumption and lower exhaust emissions than comparable internal combustion auto engines, plus multifuel capability. Stirling can use gasoline, kerosene, diesel fuel, jet fuel, alcohol, methanol, butane and that's not the whole list. Applications include irrigation pumping, heat pumps, and electricity generation for submarine, Earth and space systems.

  16. 40 CFR 80.131 - Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline... Agreed upon procedures for GTAB, certain conventional gasoline imported by truck, previously certified gasoline used to produce gasoline, and butane blenders. (a) Attest procedures for GTAB. The following...

  17. In situ vibrational spectroscopic investigation of C4 hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    SciTech Connect

    Xue, Zhi -Yang

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  18. Studies of vanadium-phosphorus-oxygen selective oxidation catalysts by sup 31 P and sup 51 V NMR spin-echo and volume susceptibility measurements

    SciTech Connect

    Li, Juan.

    1991-10-01

    The purpose of this work is to characterize the vanadium-phosphorous oxide (V-P-O) catalysts for the selective oxidation of n-butane and 1-butene to maleic anhydride. The utility of solid state nuclear magnetic resonance as an analytical tool in this investigation lies in its sensitivity to the electronic environment surrounding the phosphorous and vanadium nuclei, and proximity of paramagnetic species. Spin-echo mapping NMR of {sup 31}p and {sup 51}v and volume magnetic susceptibility measurements were used as local microscopic probes of the presence of V{sup 5+}, V{sup 4+}, V{sup 3+} species in the model compounds: {beta}-VOPO{sub 4}, {beta}-VOPO{sub 4} treated with n-butane/1-butene, (VO){sub 2}P{sub 2}O{sub 7} treated with n-butane/1-butene; and industrial catalysts with P/V (phosphorus to vanadium) ratio of 0.9, 1.0 and 1.1, before and after treatment with n-butane and 1-butene. The NMR spectra provide a picture of how the oxidation states of vanadium are distributed in these catalysts. 73 refs., 32 figs., 8 tabs.

  19. 27 CFR 19.746 - Authorized materials.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... mixture of butane, pentane, and hexane hydrocarbons extracted from natural gas; and (ii) Distillation...): 66-70; (ii) Distillation, in degrees Fahrenheit: 10 percent: 120-150 °F; 50 percent: 144-180 °F; 90....; (v) Distillation in degrees Fahrenheit: I.B.P.: 85 °F Max.; 10 percent: 130 °F Max.; 50 percent:...

  20. 27 CFR 19.746 - Authorized materials.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... mixture of butane, pentane, and hexane hydrocarbons extracted from natural gas; and (ii) Distillation...): 66-70; (ii) Distillation, in degrees Fahrenheit: 10 percent: 120-150 °F; 50 percent: 144-180 °F; 90....; (v) Distillation in degrees Fahrenheit: I.B.P.: 85 °F Max.; 10 percent: 130 °F Max.; 50 percent:...

  1. 27 CFR 19.746 - Authorized materials.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... mixture of butane, pentane, and hexane hydrocarbons extracted from natural gas; and (ii) Distillation...): 66-70; (ii) Distillation, in degrees Fahrenheit: 10 percent: 120-150 °F; 50 percent: 144-180 °F; 90....; (v) Distillation in degrees Fahrenheit: I.B.P.: 85 °F Max.; 10 percent: 130 °F Max.; 50 percent:...

  2. 27 CFR 19.746 - Authorized materials.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... mixture of butane, pentane, and hexane hydrocarbons extracted from natural gas; and (ii) Distillation...): 66-70; (ii) Distillation, in degrees Fahrenheit: 10 percent: 120-150 °F; 50 percent: 144-180 °F; 90....; (v) Distillation in degrees Fahrenheit: I.B.P.: 85 °F Max.; 10 percent: 130 °F Max.; 50 percent:...

  3. NEW CHEMICAL ALTERNATIVES FOR THE PROTECTION OF STRATOSPHERIC OZONE

    EPA Science Inventory

    The report gives results of a study that focused on the investigation of fluorinated derivatives of propane and butane to determine if synthesis routes of such compounds were feasible and economical and to measure the physical properties needed to evaluate the compounds as altern...

  4. 40 CFR 98.408 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Ethane 3.082 MMBtu/bbl 59.58 Isobutane 3.974 MMBtu/bbl 65.08 Pentanes plus 4.620 MMBtu/bbl 66.90 Table NN... butane Barrel 0.280887 Ethane Barrel 0.183626 Isobutane Barrel 0.258628 Pentanes plus Barrel 0.309078...

  5. Computer Series, 60: Bits and Pieces, 23.

    ERIC Educational Resources Information Center

    Moore, John W., Ed.

    1985-01-01

    Describes: (1) an interactive computer simulation for a science fair display of chromatography inks; (2) analytical chemistry programs; (3) microcomputer-assisted drills in organic synthesis; (4) programs for conformation analysis of ethane and butane; (5) MOLPIX--a program for generating and displaying molecular structures; and (6) chemical…

  6. Stoichiometric Experiments with Alkane Combustion: A Classroom Demonstration

    ERIC Educational Resources Information Center

    Zhilin, Denis M.

    2012-01-01

    A simple, effective demonstration of the concept of limiting and excess reagent is presented. Mixtures of either air/methane (from a gas line) or air/butane (from a disposable cigarette lighter) contained in a plastic 2 L soda bottles are ignited. The mixtures combust readily when air/fuel ratios are stoichiometric, but not at a 2-fold excess of…

  7. Computational Study of Low-Temperature Catalytic C-C Bond Activation of Alkanes for Portable Power

    DTIC Science & Technology

    2013-06-05

    inhibiting the reaction. We found that Fluorinated phosphines are sufficiently π-accepting to satisfy this role. In our next step, we wanted to determine...of butane by Sen’s catalyst, Chepaikin et al. [5] proposed that CH cleavage occurs first. But the resulting catalyst fragment “X” is so electrophilic

  8. MEMS-based fuel cells with integrated catalytic fuel processor and method thereof

    DOEpatents

    Jankowski, Alan F.; Morse, Jeffrey D.; Upadhye, Ravindra S.; Havstad, Mark A.

    2011-08-09

    Described herein is a means to incorporate catalytic materials into the fuel flow field structures of MEMS-based fuel cells, which enable catalytic reforming of a hydrocarbon based fuel, such as methane, methanol, or butane. Methods of fabrication are also disclosed.

  9. Influence of NaA Zeolite Crystal Expansion/Contraction on Zeolite Membrane Separations

    SciTech Connect

    Sorenson, Stephanie G; Payzant, E Andrew; Gibbons, Will T; Soydas, Belma; Kita, Hidetoshi; Noble, Richard D; Falconer, John L.

    2011-01-01

    In-situ powder XRD measurements showed that the NaA zeolite unit cell contracts and expands upon adsorption, and these changes in zeolite crystal size correlate with permeation changes through NaA zeolite membranes. These membranes had high pervaporation selectivities, even though gas permeation was mainly through defects, as indicated by Knudsen selectivities for gases. At 300 K and a thermodynamic activity of 0.03, water contracted the NaA crystals by 0.22 vol%, and this contraction increased the helium flux through two NaA membranes by approximately 80%. Crystal contraction also increased the fluxes of i-butane during vapor permeation and i-propanol (IPA) during pervaporation (~ 0.03 wt% water). At activities above 0.07, water expanded NaA crystals and correspondingly decreased the membrane fluxes of helium, i-butane, and IPA. Similarly, methanol contracted NaA crystals by 0.05 vol% at an activity of 0.02, and this contraction slightly increased the helium and i-butane fluxes through a NaA membrane. Above an activity of 0.06, methanol expanded the crystals, and the fluxes of helium and i-butane through a NaA membrane decreased. The adsorbate-induced changes explain some pervaporation behavior reported by others, and they indicate that crystal expansion and contraction may increase or decrease zeolite NaA membrane selectivity by changing the defect sizes.

  10. Combustion and Energy Transfer Experiments: A Laboratory Model for Linking Core Concepts across the Science Curriculum

    ERIC Educational Resources Information Center

    Barreto, Jose C.; Dubetz, Terry A.; Schmidt, Diane L.; Isern, Sharon; Beatty, Thomas; Brown, David W.; Gillman, Edward; Alberte, Randall S.; Egiebor, Nosa O.

    2007-01-01

    Core concepts can be integrated throughout lower-division science and engineering courses by using a series of related, cross-referenced laboratory experiments. Starting with butane combustion in chemistry, the authors expanded the underlying core concepts of energy transfer into laboratories designed for biology, physics, and engineering. This…

  11. 46 CFR 169.601 - General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical... (Electrical Engineering) of this chapter. (c) The use of liquefied inflammable gases, such as propane, methane, butane, etc., as fuel, except for cooking purposes, is prohibited. Internal Combustion...

  12. Increased productivity of Clostridium acetobutylicum fermentation of acetone, butanol, and ethanol by pervaporation through supported ionic liquid membrane.

    PubMed

    Izák, Pavel; Schwarz, Katrin; Ruth, Wolfgang; Bahl, Hubert; Kragl, Udo

    2008-03-01

    Pervaporation proved to be one of the best methods to remove solvents out of a solvent producing Clostridium acetobutylicum culture. By using an ionic liquid (IL)-polydimethylsiloxane (PDMS) ultrafiltration membrane (pore size 60 nm), we could guarantee high stability and selectivity during all measurements carried out at 37 degrees C. Overall solvent productivity of fermentation connected with continuous product removal by pervaporation was 2.34 g l(-1) h(-1). The supported ionic liquid membrane (SILM) was impregnated with 15 wt% of a novel ionic liquid (tetrapropylammonium tetracyano-borate) and 85 wt% of polydimethylsiloxane. Pervaporation, accomplished with the optimized SILM, led to stable and efficient removal of the solvents butan-1-ol and acetone out of a C. acetobutylicum culture. By pervaporation through SILM, we removed more butan-1-ol than C. acetobutylicum was able to produce. Therefore, we added an extra dose of butan-1-ol to run fermentation on limiting values where the bacteria would still be able to survive its lethal concentration (15.82 g/l). After pervaporation was switched off, the bacteria died from high concentration of butan-1-ol, which they produced.

  13. 40 CFR Table Nn-2 to Subpart Nn of... - Default Values for Calculation Methodology 2 of This Subpart

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Natural Gas and Natural Gas Liquids Pt. 98, Subpt. NN, Table NN-2 Table NN-2 to Subpart NN of Part 98.../Unit) 1 Natural Gas Mscf 0.0544 Propane Barrel 0.241 Normal butane Barrel 0.281 Ethane Barrel...

  14. Low Level Exposure to Sulfur Mustard: Development of a SOP for Analysis of Albumin Adducts and of a System for Non-Invasive Diagnosis on Skin

    DTIC Science & Technology

    2005-12-01

    Phenylethanethiol, Fluka - 3-(2-Aminoethylamino)propylamine, Fluka - N-Biotinylated cysteamin , Fluka - 1,4 Bis-(3-aminopropylamino)butane, - 2(3...SAGAAS was used to evaluate the use of nucleophiles other than ethanethiol. See Figure 26 for a list of nucleophiles that were used. The cysteamine

  15. Low Level Exposure to Sulfur Mustard: Development of a SOP for Analysis of Albumin Adducts and of a System for Non-Invasive Diagnosis on Skin

    DTIC Science & Technology

    2007-08-01

    Fluka - 3-(2-Aminoethylamino)propylamine, Fluka - N-Biotinylated cysteamin , Fluka - 1,4 Bis-(3-aminopropylamino)butane, - 2(3-Aminopropyl...use of nucleophiles other than ethanethiol. See Figure 34 for a list of nucleophiles that were used. The cysteamine derivatives were prepared in our

  16. Effects of glycerol monosterate on TPUs crystallization and its foaming behavior

    NASA Astrophysics Data System (ADS)

    Hossieny, N.; Nofar, M.; Shaayegan, V.; Park, C. B.

    2014-05-01

    Thermoplastic polyurethane (TPU) containing 0-2 wt% glycerol monosterate (GMS) were compounded by a twin screw compounder and then foamed using a batch process and n-butane. Differential scanning calorimetry (DSC) and high-pressure DSC were performed to evaluate the effects of GMS and pressurized butane on the crystallization kinetics of TPU. The results showed that the synergistic effect of GMS and high pressure butane significantly promoted hard segment (HS) crystallization in the TPU-GMS samples. The TPU-GMS samples showed significant increase in crystallinity over a wide range of saturation temperatures in the presence of butane compared to neat melt-compounded TPU (PR-TPU). Comparing the foam characteristics of PR-TPU and TPU-GMS samples, it was observed that both samples exhibited microcellular morphology with high cell density over a wide range of processing temperatures of 150°C - 170°C. However at a high foaming temperature (170°C), PR-TPU foams showed high cell coalescence compared to TPU-GMS. Furthermore, TPU-GMS samples showed a much higher expansion ratio compared to PR-TPU over a wide range of processing temperatures. The lubricating effect of GMS assisted the HS to stack together and form crystalline domains. These HS crystalline domains are present at high temperature acting both as a heterogeneous nucleating sites as well as reinforcement leading to the observed microcellular morphology with a high expansion ratio in TPU-GMS samples.

  17. 40 CFR 1060.810 - What materials does this part reference?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Particle Size Distribution of Granular Activated Carbon (“ASTM D2862”) 1060.240 ASTM D3802-79 (Reapproved 2005), Standard Test Method for Ball-Pan Hardness of Activated Carbon (“ASTM D3802”) 1060.240 ASTM... Method for Determination of Butane Working Capacity of Activated Carbon (“ASTM D5228”) 1060.801 (b)...

  18. 40 CFR 1060.810 - What materials does this part reference?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Particle Size Distribution of Granular Activated Carbon (“ASTM D2862”) 1060.240 ASTM D3802-79 (Reapproved 2005), Standard Test Method for Ball-Pan Hardness of Activated Carbon (“ASTM D3802”) 1060.240 ASTM... Method for Determination of Butane Working Capacity of Activated Carbon (“ASTM D5228”) 1060.801 (b)...

  19. 40 CFR 86.1232-96 - Vehicle preconditioning.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and one, two or three driving cycles of the dynamometer driving schedule, as described in paragraph (c... follows each driving cycle. (f)(1) Gasoline- and methanol-fueled vehicles. After completion of the... percent nitrogen by volume at a rate of 15±2 grams butane per hour. If the canister loading at that...

  20. 40 CFR 710.46 - Chemical substances for which information is not required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Gases (petroleum), blend oil, hydrogen-nitrogen-rich 68477-69-0 Gases (petroleum), butane splitter... (petroleum), hydrogen-rich 68477-98-5 Gases (petroleum), hydrotreater blend oil recycle, hydrogen-nitrogen... copies of these responses in a public docket that will be established for each reporting cycle. (B)...

  1. Ventilation of liquefied petroleum gas components from the Valley of Mexico

    NASA Astrophysics Data System (ADS)

    Elliott, Scott; Blake, Donald R.; Rowland, F. Sherwood; Lu, Rong; Brown, Michael J.; Williams, Michael D.; Russell, Armistead G.; Bossert, James E.; Streit, Gerald E.; Santoyo, Marisa Ruiz; Guzman, Francisco; Porch, William M.; McNair, Laurie A.; Keyantash, John; Kao, Chih-Yue Jim; Turco, Richard P.; Eichinger, William E.

    1997-09-01

    The saturated hydrocarbons propane and the butane isomers are both indirect greenhouse gases and key species in liquefied petroleum gas (LPG). Leakage of LPG and its component alkanes/alkenes is now thought to explain a significant fraction of the volatile organic burden and oxidative potential in the basin which confines Mexico City. Propane and the butanes, however, are stable enough to escape from the basin. The gas Chromatographie measurements which have drawn attention to their sources within the urban area are used here to estimate rates of ventilation into the free troposphere. The calculations are centered on several well studied February/March pollution episodes. Carbon monoxide observations and emissions data are first exploited to provide a rough time constant for the removal of typical inert pollutant species from the valley. The timescale obtained is validated through an examination of meteorological simulations of three-dimensional flow. Heuristic arguments and transport modeling establish that propane and the butanes are distributed through the basin in a manner analogous to CO despite differing emissions functions. Ventilation rates and mass loadings yield outbound fluxes in a box model type computation. Estimated in this fashion, escape from the Valley of Mexico constitutes of the order of half of 1% of the northern hemispheric inputs for both propane and n-butane. Uncertainties in the calculations are detailed and include factors such as flow into the basin via surface winds and the size of the polluted regime. General quantification of the global propane and butane emissions from large cities will entail studies of this type in a variety of locales.

  2. Volatile carbonylic compounds in downtown Santiago, Chile.

    PubMed

    Rubio, María A; Zamorano, Natalia; Lissi, Eduardo; Rojas, Alicia; Gutiérrez, Luis; von Baer, Dietrich

    2006-02-01

    Formaldehyde, acetaldehyde, acetone, propanal, butanal, 2-butenal, 3-methylbutanal, hexanal, benzaldehyde, 2-methylbenzaldehyde, and 2,5-dimethylbenzaldehyde were measured during six spring days at downtown Santiago de Chile. Measurements were performed 24h/day and averaged over three hour periods. The averages of the maxima (ppbv) were, formaldehyde: 3.9+/-1.4; butanal: 3.3+/-3.4; acetaldehyde: 3.0+/-0.9; acetone: 2.4+/-1.0; 2-butenal: 0.56+/-0.52; propanal: 0.46+/-0.21; benzaldehyde: 0.34+/-0.3; 3-butanal: 0.11+/-0.05; hexanal: 0.11+/-0.08; 2-methylbenzaldehyde: 0.08+/-0.05; 2,5-dimethylbenzaldehyde: 0.05+/-0.03. Aliphatic aldehydes (C1-C3) are strongly correlated among them and weakly with primary (toluene) and secondary (ozone plus nitrogen dioxide or PAN) pollutants. In particular, the correlation between acetaldehyde and propanal values remains even if diurnal and nocturnal data are considered separately, indicating similar sources. All these aldehydes present maxima values in the morning (9-12h) and minima at night (0-3h). The best correlation is observed when butanal and 2-butenal data are considered (r=0.99, butanal/2-butenal=6.2). These compounds present maxima values during the 3-6h period, with minima values in the 0-3h period. These data imply a strong pre-dawn emission. Other aldehydes show different daily profiles, suggesting unrelated origins. Formaldehyde is the aldehyde whose concentration values best correlate with the levels of oxidants. The contribution of primary emissions and photochemical processes to formaldehyde concentrations were estimated by using a multiple regression. This treatment indicates that (32+/-16)% of measured values arise from direct emissions, while (79+/-23)% is attributable to secondary formation.

  3. Analysis of 10 Years online C2-C11 NMHC Measurements close to the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Rappenglück, Bernhard

    2015-04-01

    Speciated C2-C11 non-methane hydrocarbons (NMHC) have been measured online on an hourly basis at Lake Jackson/TX close to the Gulf of Mexico. Altogether 48 NMHCs, including the GAW NMHC compounds, along with NO, NO2, NOx, O3 have been collected continuously from January 2004-December 2013 under the auspices of the Texas Commission on Environmental Quality. Data was screened for background conditions representing marine wind sectors. The data set represents a combination of marine air masses mixed with local biogenic emissions. The data analysis addresses photochemical processing of air masses as reflected in the relationship of ln(n-butane/ethane) vs. ln(propane/ethane) and ln(i-butane/ethane) vs. ln(n-butane/ethane). In addition, key NMHC relationships for radical chemistry, e.g. i-butane vs n-butane for OH and Cl chemistry and i-pentane vs. n-pentane for NO3 chemistry, are discussed. Results are compared to other sites, where available (e.g. GAW site Mace Head). Seasonal analysis revealed a clear trend with maximum NMHC mixing ratios in winter time and lowest mixing ratios in summer reflecting the impact of photochemical processes in summer. Propene equivalents were highest during summertime, with significant contributions from alkenes, including isoprene. The relation of propane/ethane vs ethane indicates seasonal variation with lowest values (i.e. most aged air masses) in winter. Contrary to usual GAW NMHC sampling procedures, which at least requires routine daytime samples (e.g. for canister samplings), continuous NMHC data collection allows to analyze nighttime data, which is least impacted by photochemical processes and potentially well-suited for trend analysis. Corresponding trend analysis for the Lake Jackson data suggests an overall slight decrease of selected NMHCs over the 2004-2013 period.

  4. Interannual Variability and Trends of C2-C11 Non-Methane Hydrocarbons in a Subtropical Area close to the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Rappenglück, Bernhard

    2016-04-01

    Speciated C2-C11 non-methane hydrocarbons (NMHC) have been measured online on an hourly basis at Lake Jackson/TX close to the Gulf of Mexico. Altogether 48 NMHCs, including the GAW NMHC compounds, along with NO, NO2, NOx, O3 have been collected continuously from January 2004-December 2013 under the auspices of the Texas Commission on Environmental Quality. Data was screened for background conditions representing marine wind sectors. The data set represents a combination of marine air masses mixed with local biogenic emissions. The data analysis addresses photochemical processing of air masses as reflected in the relationship of ln(n-butane/ethane) vs. ln(propane/ethane) and ln(i-butane/ethane) vs. ln(n-butane/ethane). In addition, key NMHC relationships for radical chemistry, e.g. i-butane vs n-butane for OH and Cl chemistry and i-pentane vs. n-pentane for NO3 chemistry, are discussed. Seasonal analysis revealed a clear trend with maximum NMHC mixing ratios in winter time and lowest mixing ratios in summer reflecting the impact of photochemical processes in summer. Propene equivalents were highest during summertime, with significant contributions from alkenes, including isoprene. The relation of propane/ethane vs ethane indicates seasonal variation with lowest values (i.e. most aged air masses) in winter. Contrary to usual GAW NMHC sampling procedures, which at least requires routine daytime samples (e.g. for canister samplings), continuous NMHC data collection allows to analyze nighttime data, which is least impacted by photochemical processes and potentially well-suited for trend analysis. Corresponding trend analysis for the Lake Jackson data suggests an overall slight decrease of selected NMHCs over the 2004-2013 period.

  5. Effect of plasma spraying regimes on structure and properties of Ni3Al coatings

    NASA Astrophysics Data System (ADS)

    Kornienko, E. E.; Mul', D. O.; Rubtsova, O. A.; Vaschenko, S. P.; Kuzmin, V. I.; Gulyaev, I. P.; Sergachev, D. V.

    2016-11-01

    The structure and tribological properties of coatings made of PN85YU15 powder were studied. The coatings were deposited on the mild steel blanks by the technology of air-plasma spraying using a unit of annular input and gas-dynamic powder focusing. Efficiency of heating and acceleration of powder particles was studied preliminarily. Measurement results on temperature and velocity distributions of particles at a certain spraying distance by the method of spectral pyrometry and time-of-flight method are presented. The effect of plasmatorch arc current and amount of propane-butane in the plasma flow on the structure and properties of coatings is analyzed in this paper. It is determined that the phase composition of coatings and initial powder is the same: the main phase is Ni3Al compound; moreover, the structure contains Ni5Al3 phase. It is shown that an increase in the amount of propane-butane increases coatings porosity. The densest coatings (5.77%) were obtained at the plasmatorch arc current of 200 A with the reduced amount of propane-butane. The coatings obtained at the minimal arc current of 100 A with an increased amount of propane-butane are characterized by maximal porosity (20.38%). The results of tribological testing of the coatings under the conditions of sliding friction with a lubricant by the disc-plane scheme are presented. From the standpoint of obtaining the densest coatings with high performance, the optimal regimes of plasma spraying of PN85YU15 powder are the current from 140 A to 200 and using the air and propane-butane mixture only as the shielding gas (anode curtain).

  6. Fish embryo toxicity test: identification of compounds with weak toxicity and analysis of behavioral effects to improve prediction of acute toxicity for neurotoxic compounds.

    PubMed

    Klüver, Nils; König, Maria; Ortmann, Julia; Massei, Riccardo; Paschke, Albrecht; Kühne, Ralph; Scholz, Stefan

    2015-06-02

    The fish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, but concerns have been raised for its predictivity given that a few compounds have been shown to exhibit a weak acute toxicity in the fish embryo. In order to better define the applicability domain and improve the predictive capacity of the fish embryo test, we performed a systematic analysis of existing fish embryo and acute fish toxicity data. A correlation analysis of a total of 153 compounds identified 28 compounds with a weaker or no toxicity in the fish embryo test. Eleven of these compounds exhibited a neurotoxic mode of action. We selected a subset of eight compounds with weaker or no embryo toxicity (cyanazine, picloram, aldicarb, azinphos-methyl, dieldrin, diquat dibromide, endosulfan, and esfenvalerate) to study toxicokinetics and a neurotoxic mode of action as potential reasons for the deviating fish embryo toxicity. Published fish embryo LC50 values were confirmed by experimental analysis of zebrafish embryo LC50 according to OECD guideline 236. Except for diquat dibromide, internal concentration analysis did not indicate a potential relation of the low sensitivity of fish embryos to a limited uptake of the compounds. Analysis of locomotor activity of diquat dibromide and the neurotoxic compounds in 98 hpf embryos (exposed for 96 h) indicated a specific effect on behavior (embryonic movement) for the neurotoxic compounds. The EC50s of behavior for neurotoxic compounds were close to the acute fish toxicity LC50. Our data provided the first evidence that the applicability domain of the fish embryo test (LC50s determination) may exclude neurotoxic compounds. However, neurotoxic compounds could be identified by changes in embryonic locomotion. Although a quantitative prediction of acute fish toxicity LC50 using behavioral assays in fish embryos may not yet be possible, the identification of neurotoxicity could trigger the conduction of a conventional fish

  7. Reactivation of human brain homogenate cholinesterases inhibited by Tabun using newly developed oximes K117 and K127.

    PubMed

    Kuca, Kamil; Cabal, Jiri; Jung, Yung Sik; Musilek, Kamil; Soukup, Ondrej; Jun, Daniel; Pohanka, Miroslav; Musilova, Lucie; Karasová, Jana; Novotný, Ladislav; Hrabinova, Martina

    2009-09-01

    Newly developed acetylcholinesterase reactivators K117 [1,5-bis(4-hydroxyiminomethylpyridinium)-3-oxapentane dichloride] and K127 [(1-(4-hydroxyiminomethylpyridinium)-5-(4-carbamoylpyridinium)-3-oxapentane dibromide)] were tested for their potency to reactivate tabun-inhibited human brain cholinesterases. Pralidoxime and trimedoxime were chosen as standard reference reactivators. Human tissue was used, as that was closer on the real treatment of human beings. As a result, oxime K127 was found as the best tested reactivator according to the constant k(r), characterizing the overall reactivation process. On the contrary, the maximal reactivation ability expressed as percentage of reactivation was the best for trimedoxime. This differences were caused as a result of using the enzyme from different species. Due to this, experiments on human tissue should be conducted after in vitro and in vivo tests on animals to eliminate such important failures of promising oximes.

  8. Monooxime reactivators of acetylcholinesterase with (E)-but-2-ene linker: preparation and reactivation of tabun- and paraoxon-inhibited acetylcholinesterase.

    PubMed

    Musilek, Kamil; Holas, Ondrej; Jun, Daniel; Dohnal, Vlastimil; Gunn-Moore, Frank; Opletalova, Veronika; Dolezal, Martin; Kuca, Kamil

    2007-11-01

    Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Fifteen new monooxime reactivators of acetylcholinesterase with a (E)-but-2-ene linker were developed in an effort to extend the properties of K-oxime (E)-1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide (K203). The known reactivators (pralidoxime, HI-6, obidoxime, K075, K203) and the new compounds were tested in vitro on a model of tabun- and paraoxon-inhibited AChE. Monooxime reactivators were not able to exceed the best known compounds for tabun poisoning, but some of them did show reactivation comparable with known compounds for paraoxon poisoning. However, extensive differences were found by a SAR study for various substitutions on the non-oxime part of the reactivator molecule.

  9. Ionol (BHT). Distribution in the organism, metabolism, and biological effect. II. Biological effects of ionol (survey)

    SciTech Connect

    Degterev, I.A.; Zaikov, G.E.

    1986-08-01

    In these experiments, a 25 mg/kg dose of ionol, administered to mice immediately after transplantation of melanoma B-16 or injection of tumor cells, inhibited the growth of pigmented B-16 cells and somewhat decreased the number of metastases. Ionol inhibited the mutagenic effect of benz(a)pyrene in vitro and in a culture of Salmonella typhimurium. In a mix with butylhydroxyanisole and propyl gallate, it decreased the number of mutations induced by gamma irradiation in the same culture. It protected mice from dominant lethal mutations and hereditary translocations induced by ethyl methanesulfonate (EMS). When ionol was present in the feed in a dose of 0.75% it reduced the lethal effect in mice of dimethylnitrosamine, EMS, ethylene dibromide and cyclophosphamide.

  10. Gated Channels and Selectivity Tuning of CO2 over N2 Sorption by Post-Synthetic Modification of a UiO-66-Type Metal-Organic Framework.

    PubMed

    Kronast, Alexander; Eckstein, Sebastian; Altenbuchner, Peter T; Hindelang, Konrad; Vagin, Sergei I; Rieger, Bernhard

    2016-08-26

    The highly porous and stable metal-organic framework (MOF) UiO-66 was altered using post-synthetic modifications (PSMs). Prefunctionalization allowed the introduction of carbon double bonds into the framework through a four-step synthesis from 2-bromo-1,4-benzenedicarboxylic acid; the organic linker 2-allyl-1,4-benzenedicarboxylic acid was obtained. The corresponding functionalized MOF (UiO-66-allyl) served as a platform for further PSMs. From UiO-66-allyl, epoxy, dibromide, thioether, diamine, and amino alcohol functionalities were synthesized. The abilities of these compounds to adsorb CO2 and N2 were compared, which revealed the structure-selectivity correlations. All synthesized MOFs showed profound thermal stability together with an increased ability for selective CO2 uptake and molecular gate functionalities at low temperatures.

  11. Photochemical etching during ultraviolet photolytic deposition of metal films on semiconductor surfaces

    NASA Astrophysics Data System (ADS)

    Kowalczyk, Steven P.; Miller, D. L.

    1986-01-01

    UV photochemical deposition of Sn films on GaAs (001) surfaces from a variety of tin-containing compounds (tetramethyltin, tetrabutyltin, dibutyltin dibromide, stannic chloride, hexamethylditin, dibutyltin sulfide, and iodotrimethyltin) was studied. X-ray photoelectron spectroscopy showed that during the initial stages of deposition from the halogenated compounds, the GaAs surface was photochemically etched, most likely by a halogen radical species. The photochemical etching resulted in an arsenic deficient surface which was particularly dramatic for the case of SnCl4. These results have important implications for the choice of sources for photochemical deposition when the metal-semiconductor interface is important and for photochemical etching if stoichiometric surfaces are required.

  12. Synthesis of novel E-2-chlorovinyltellurium compounds based on the stereospecific anti-addition of tellurium tetrachloride to acetylene.

    PubMed

    Musalova, Maria V; Potapov, Vladimir A; Amosova, Svetlana V

    2012-05-15

    The reaction of tellurium tetrachloride with acetylene proceeds in a stereospecific anti-addition manner to afford the novel products E-2-chlorovinyltellurium trichloride and E,E-bis(2-chlorovinyl)tellurium dichloride. Reaction conditions for the selective preparation of each of these products were found. The latter was obtained in 90% yield in CHCl(3) under a pressure of acetylene of 10-15 atm, whereas the former product was formed in up to 72% yield in CCl(4) under a pressure of acetylene of 1-3 atm. Synthesis of the previously unknown E,E-bis(2-chlorovinyl) telluride, E,E-bis(2-chlorovinyl) ditelluride, E-2-chlorovinyl 1,2,2-trichloroethyl telluride and E,E-bis(2-chlorovinyl)-tellurium dibromide is described.

  13. NIOSH (National Institute for Occupational Safety and Health) manual of analytical methods (Third Edition). Second supplement

    SciTech Connect

    Not Available

    1987-08-15

    This supplement contains air and biological analytical methods which have been evaluated by NIOSH for use in determining concentrations of the following substances: acetaldehyde, alkaline dusts, aminoethanol compounds, arsenic, asbestos fibers, soluble barium, benzene, beryllium, biphenyl, bromotrifluoromethane, 1,3-butadiene, cadmium, chlorinated diphenyl ether, chloroacetic acid, diborane, dichlorodifluoromethane, 1,2-dichlorotetrafluoroethane, ethylene dibromide, ethylene oxide, fibers, furfural, halogenated hydrocarbons, iodine, methyl chloride, methyl ethyl ketone peroxide, methylene chloride, mineral oil mist, naphthylamines, nickel carbonyl, nitroethane, nitromethane, 2-nitropropane, organotin compounds, phosphorus, polychlorobenzenes, polychlorobiphenyls, pyridine, stibine, sulfur dioxide, tetrachlorodifluoroethanes, 1,1,2,2-tetrachloroethaylene, tetraethyl lead, toluene, toluene-2,4-diisocyanate, trichloroethylene, trichlorofluoromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, vanadium oxide, and vinylidene chloride.

  14. Removing EDB with GAC filters

    SciTech Connect

    Narbaitz, R.M.; Baratta, A.; Parsons, F.Z. )

    1994-08-01

    Nearly 1,000 point-of-entry granular activated carbon (GAC) filters are efficiently removing ethylene dibromide (EDB) from contaminated groundwater throughout Florida. This article discusses the design, performance, and operational problems of the filters and assesses the possibility of extending the interval between GAC replacement from the current six months. Few breakthroughs have occurred in these filters, and most were caused by desorption during periods of sharp decreases in well-water EDB concentrations. Because GAC loading data from the literature described the program data very well, they were used in conjunction with the equilibrium column model to predict the performance of the program's filters for different GAC replacement periods. Based on the most conservative estimates, maintenance for 50% of the filters could be extended to every nine months.

  15. NIOSH current intelligence bulletins: summaries

    SciTech Connect

    Not Available

    1988-09-01

    Summaries were offered of the current intelligence bulletins issued from January 20, 1975 to August of 1988. They include information on the following topics: chloroprene, trichloroethylene, ethylene dibromide, chrome pigment, asbestos, hexamethylphosphoric triamide, polychlorinated biphenyls, 4,4'-diaminodiphenylmethane, chloroform, radon daughters, dimethylcarbamoyl chloride, diethylcarbamoyl-chloride, explosive azide hazard, inorganic arsenic, nitrosamines in cutting fluids, metabolic precursors of beta-naphthylamine, 2-nitropropane, acrylonitrile, 2,4-diaminoanisole, tetrachloroethylene, trimellitic anhydride, ethylene thiourea, disulfiram, direct-blue-6, direct-black-38, direct-brown-95, benzidine derived dyes, ethylene dichloride, NIAX catalyst ESN, chloroethanes, vinyl halides, glycidyl ethers, epichlorohydrin, smoking, arsine poisoning, radiofrequency sealers and heaters, formaldehyde, ethylene oxide, silica flour, vibration syndrome, glycol ethers, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,3-butadiene, cadmium, monohalomethanes, dinitrotoluenes, methylene chloride, 4,4'-methylenedianiline, organic solvent neurotoxicity, mechanical power press injuries, and the carcinogenic effects of diesel exhaust.

  16. Exploratory studies aimed at a synthesis of vinigrol. 4. Probe of possible means for direct connection of the side arms and of ring-contraction alternatives.

    PubMed

    Paquette, Leo A; Liu, Zuosheng; Efremov, Ivan

    2005-01-21

    Attempts have been made to gain access to the vinigrol structural framework by way of three routes. These include reductive transannular cyclization, adaptation of the Ramberg-Backlund rearrangement, and deployment of the lactam-sulfoxide ring contraction protocol. While the first of these options involves direct transannular C-C bond formation, the other two embody the concept of larger ring construction as a prelude to ring contraction. The initial installation of a sulfur atom involves prior thiacyclononane formation, a process believed to be potentially easier to accomplish. However, arrival at 13, 14, or 17 was not achieved. Installation of the heterocyclic ring contained in 31 proved to be equally problematic. Increased disassembly of the molecular structure as featured in dibromide 20 did allow for direct conversion to sulfone 22. This advanced building block proved not be conducive to in situ alpha-chlorination and extrusion of the sulfur atom.

  17. Simple synthesis of P(Cbz-alt-TBT) and PCDTBT by combining direct arylation with suzuki polycondensation of heteroaryl chlorides.

    PubMed

    Lombeck, Florian; Matsidik, Rukiya; Komber, Hartmut; Sommer, Michael

    2015-01-01

    Direct arylation (DA) of 2-chlorothiophene and 2-chloro-3-hexylthiophene with 4,7-dibromo-2,1,3-benzothiadiazole is used to synthesize 4,7-bis(5-chloro-2-thienyl)-2,1,3-benzothiadiazole (TBTCl2) and 4,7-bis(5-chloro-4-hexyl-2-thienyl)-2,1,3-benzothiadiazole (DH-TBTCl2) in one step. Suitable conditions of the Suzuki polycondensations (SPC) of TBTCl2 and DH-TBTCl2 with the carbazole comonomer CbzPBE2 are established, furnishing PCDTBT and P(Cbz-alt-TBT) with high molecular weight and yield. Compared with control samples made from the corresponding dibromides, high-temperature NMR and UV-vis spectroscopy indicate similar properties for PCDTBT but an increased content of Cbz-Cbz homocouplings for P(Cbz-alt-TBT).

  18. Electron attachment to 14 halogenated alkenes and alkanes, 300-600 K.

    PubMed

    Shuman, Nicholas S; Friedman, Jeffrey F; Miller, Thomas M; Viggiano, A A

    2012-10-28

    Thermal electron attachment to 14 alkenes and alkanes with bromine, fluorine, and iodine substituents has been studied over the temperature range 300-600 K using a flowing-afterglow Langmuir-probe apparatus. Rate coefficients and anion products are reported, most for the first time. Among these were 3 isomers of C(3)F(5)Br and the 2 isomers of C(3)F(7)I. Four dibromide compounds were studied, all of which yield Br(2)(-) product in addition to Br(-) product. The results are analyzed using a statistical kinetic modeling approach, which is able to reproduce both attachment rate coefficients and product branching ratios within experimental uncertainty. The kinetic modeling indicates that factor of 2 differences in attachment rate coefficients to the isomeric species can be explained by subtle variations in the potential surfaces.

  19. Electron attachment to halogenated alkenes and alkanes, 300-600 K

    NASA Astrophysics Data System (ADS)

    Miller, Thomas M.; Friedman, Jeffrey F.; Shuman, Nicholas S.; Viggiano, Albert A.

    2012-10-01

    Rate coefficients (ka) and ion product distributions have been measured for 14 alkenes and alkanes with bromine, fluorine, and iodine substituents over the temperature range T = 300-600 K using a flowing-afterglow Langmuir-probe apparatus (FALP), most for the first time. Among these are 3 isomers of C3F5Br and 2 isomers of C3F7I. Four dibromide compounds yield Br2^- in addition to Br^-. The results follow the expected trends: ka values near the capture limit decrease slightly with T according to Vogt-Wannier theory, while ka increase with T for molecules which have small ka at 300 K. The results are analyzed using a statistical kinetic modeling approach, which is able to reproduce ka values and product branching within experimental uncertainty. The modeling indicates that factor of 2 differences in ka for the isomeric species can be explained by subtle variations in the potential surfaces.

  20. Electron attachment to 14 halogenated alkenes and alkanes, 300-600 K

    NASA Astrophysics Data System (ADS)

    Shuman, Nicholas S.; Friedman, Jeffrey F.; Miller, Thomas M.; Viggiano, A. A.

    2012-10-01

    Thermal electron attachment to 14 alkenes and alkanes with bromine, fluorine, and iodine substituents has been studied over the temperature range 300-600 K using a flowing-afterglow Langmuir-probe apparatus. Rate coefficients and anion products are reported, most for the first time. Among these were 3 isomers of C3F5Br and the 2 isomers of C3F7I. Four dibromide compounds were studied, all of which yield Br2- product in addition to Br- product. The results are analyzed using a statistical kinetic modeling approach, which is able to reproduce both attachment rate coefficients and product branching ratios within experimental uncertainty. The kinetic modeling indicates that factor of 2 differences in attachment rate coefficients to the isomeric species can be explained by subtle variations in the potential surfaces.

  1. Novel spectrophotometric method for detection and estimation of butanol in acetone-butanol-ethanol fermenter.

    PubMed

    Maiti, Sampa; Sarma, Saurabh Jyoti; Brar, Satinder Kaur; Bihan, Yann Le; Drogui, Patrick; Buelna, Gerardo; Verma, Mausam; Soccol, Carlos Ricardo

    2015-08-15

    A new, simple, rapid and selective spectrophotometric method has been developed for detection and estimation of butanol in fermentation broth. The red colored compound, produced during reduction of diquat-dibromide-monohydrate with 2-mercaptoethanol in aqueous solution at high pH (>13), becomes purple on phase transfer to butanol and gives distinct absorption at λ520nm. Estimation of butanol in the fermentation broth has been performed by salting out extraction (SOE) using saturated K3PO4 solution at high pH (>13) followed by absorbance measurement using diquat reagent. Compatibility and optimization of diquat reagent concentration for detection and estimation of butanol concentration in the fermentation broth range was verified by central composite design. A standard curve was constructed to estimate butanol in acetone-ethanol-butanol (ABE) mixture under optimized conditions. The spectrophotometric results for butanol estimation, was found to have 87.5% concordance with the data from gas chromatographic analysis.

  2. Enhancement of Shelf Life of Button Mushroom, Agaricus bisporus (Higher Basidiomycetes) by Fumigant Application of Lippia alba Essential Oil.

    PubMed

    Vishwakarma, Pratima; Pandey, Abhay K; Mishra, Priyanka; Singh, Pooja; Tripathi, N N

    2015-01-01

    Eleven essential oils isolated from higher plant species were assessed against the four isolates of Verticillium fungicola found on fruiting bodies of Agaricus bisporus. Eucalyptus citriodora and Lippia alba oils were more efficacious and completely inhibited the mycelial growth of fungal isolates. L. alba oil was fungistatic and fungicidal at 10- and 20-µL concentrations against all of the isolates, respectively, and was more potent than E. citriodora oil as well as some prevalent synthetic fungicides such as benomyl, ethylene dibromide, and phosphine. Eighty microliters of L. alba oil protected 500 g of fruiting bodies of A. bisporus for up to 7 d from infection of the fungus under in vivo conditions. The findings strengthen the possibility of L. alba oil as a plant-based protectant to enhance the shelf life of A. bisporus fruiting bodies.

  3. Public health assessment for petitioned public health assessment, Union Carbide (Byers Warehouse), St. Joseph, Buchanan County, Missouri, Region 7. Final report

    SciTech Connect

    Not Available

    1993-05-04

    In response to a petition from a St. Joseph, Missouri resident, the Agency for Toxic Substances and Disease Registry (ATSDR) conducted a public health assessment of the Union Carbide (Byers Warehouse) site in St. Joseph, Missouri. The basement of Byers Warehouse was used by Vulcan Chemicals to store ethylene dibromide (EDB), chloroform, and carbon tetrachloride (CCI4). The first and second floors were used by Union Carbide to store 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4,5-trichlorophenoxyproprionic acid (2,4,5-TP). The Byers Warehouse (Union Carbide) Petition site is not a current public health hazard. That conclusion is based on the complete removal of the toxic substances stored in the warehouse, and the lack of any current or future completed exposure pathways. Past storage of herbicides and other chemical products represented a public health hazard.

  4. Influence of inorganic and organic nutrients on aerobic biodegradation and on the adaptation response of subsurface microbial communities

    SciTech Connect

    Swindoll, C.M.; Aelion, C.M.; Pfaender, F.K.

    1988-01-01

    The influence of inorganic and organic amendments on the mineralization of ethylene dibromide, rho-nitrophenol, phenol, and toluene was examined in subsurface soil samples from a pristine aquifer near Lula, Oklahoma. The responses indicate that the metabolic abilities and nutrient requirements of ground water microorganisms vary substantially within an aquifer. In some samples, additions of inorganic nutrients resulted in a more rapid adaptation to the test substrate and a higher rate of metabolism, indicating that metabolism may have been limited by these nutrients. In other samples from the same aquifer layer, inorganic amendments had little or no influence on mineralization. In general, the addition of multiple inorganic nutrients resulted in a greater enhancement of degradation than did the addition of single substances. Additions of alternate carbon sources, such as glucose or amino acids, inhibited the mineralization of the xenobiotic substrates. This inhibition appears to be the result of the preferential utilization of the more easily degradable carbon amendments.

  5. Troubled waters: a Florida nightmare

    SciTech Connect

    Cooper, W.

    1984-12-01

    Results of studies of pollution of groundwater in Florida are reported. Vast amounts of the underground water were found to be polluted with ethylene dibromide (EDB) used by Florida farmers since the 1950s as an insecticide. Pollution levels of water in the middle of the citrus belt were found to be as high as 775 ppB when 0.02 ppB has been set by the Florida Agriculture Department as the level for concern. EDB can be removed using activated charcoal filters, or new wells can tap aquifers separated from contaminated ones by beds of impermeable clay. Evidences of contamination of water in specific sites by cresote, sulfuric acid, and heavy metals such as lead and arsenic are mentioned.

  6. 1,1′-[(1,3-Dihydroxypropane-2,2-diyl)dimethylene]dipyridinium bis­(hexa­fluoro­phosphate)

    PubMed Central

    Yuan, Ai-lin; Zheng, Chun-ling; Zhuang, Ling-hua; Wang, Chang-sheng; Wang, Guo-wei

    2011-01-01

    The title compound, C15H20N2O2 2+·2PF6 −, was prepared by anion exchange of two bromide ions in the ionic liquid 2,2′-bis-(pyridinium-1-ylmeth­yl)-propane-1,3-diol dibromide with potassium hexa­fluoro­phosphate. The two pyridine rings are planar (r.m.s. deviations = 0.008 and 0.00440 Å) and make a dihedral angle of 44.0 (2)°. Intermolecular O—H⋯F and C—H⋯F interactions occur. The four F atoms in each anion were refined as disordered over two sets of sites with an occupancy ration of 0.700 (19):0.300 (19). PMID:21754422

  7. 1,1'-[(1,3-Dihydroxypropane-2,2-diyl)dimethylene]dipyridinium bis-(hexa-fluoro-phosphate).

    PubMed

    Yuan, Ai-Lin; Zheng, Chun-Ling; Zhuang, Ling-Hua; Wang, Chang-Sheng; Wang, Guo-Wei

    2011-05-01

    The title compound, C(15)H(20)N(2)O(2) (2+)·2PF(6) (-), was prepared by anion exchange of two bromide ions in the ionic liquid 2,2'-bis-(pyridinium-1-ylmeth-yl)-propane-1,3-diol dibromide with potassium hexa-fluoro-phosphate. The two pyridine rings are planar (r.m.s. deviations = 0.008 and 0.00440 Å) and make a dihedral angle of 44.0 (2)°. Intermolecular O-H⋯F and C-H⋯F interactions occur. The four F atoms in each anion were refined as disordered over two sets of sites with an occupancy ration of 0.700 (19):0.300 (19).

  8. A theoretical study of the oxidation of Hg0 to HgBr2 in the troposphere.

    PubMed

    Goodsite, M E; Plane, J M C; Skov, H

    2004-03-15

    The oxidation of elemental mercury (Hg0) to the divalent gaseous mercury dibromide (HgBr2) has been proposed to account for the removal of Hg0 during depletion events in the springtime Arctic. The mechanism of this process is explored in this paper by theoretical calculations of the relevant rate coefficients. Rice-Ramsberger-Kassel-Marcus (RRKM) theory, together with ab initio quantum calculations where required, are used to estimate the following: recombination rate coefficients of Hg with Br, I, and O; the thermal dissociation rate coefficient of HgBr; and the recombination rate coefficients of HgBr with Br, I, OH, and O2. A mechanism based on the initial recombination of Hg with Br, followed by the addition of a second radical (Br, I, or OH) in competition with thermal dissociation of HgBr, is able to account for the observed rate of Hg0 removal, both in Arctic depletion events and at lower latitudes.

  9. Best Demonstrated Available Technology (BDAT) background document for newly listed wastes: K107, k108, k109, k110, k111, k112, u328, u353, k117, k118, k136, k123, k124, k125, k126, k131, k132, u359. Final technical report

    SciTech Connect

    1992-06-30

    The U.S. Environmental Protection Agency (the Agency or EPA) is establishing best demonstrated available technology (BDAT) treatment standards for the following listed hazardous wastes identified in Title 40, Code of Federal Regulations, Sections 261.32 and 261.33(f) (40 CFR 261.32 and 261.33(f)): 1,1-Dimethylhydrazine (UDMH) Production Wastes: K107, K108, K109, and K110; Dinitrotoluene (DNT) and Toluenediamine (TDA) Production Wastes: K111, K112, U328, and U353; Ethylene Dibromide (EDB) Production Wastes: K117, K118, and K136; Ethylenebisdithiocarbamic acid (EBDC) Production Wastes: K123, K124, K125, and K126; Methyl Bromide Production Wastes: K131 and K132; and 2-Ethoxyethanol Waste: U359.

  10. Characterization of a white-colour DBD-driven cadmium bromide exciplex lamp

    NASA Astrophysics Data System (ADS)

    Guivan, Mykola M.; Guyvan, Anna M.

    2010-10-01

    The emission spectra from an atmospheric-pressure gas-discharge plasma in mixtures of cadmium dibromide vapour with gases (Ne, Ar, Kr, Xe and N2), as well as the temporal characteristics of voltage and current, have been investigated. A dielectric barrier discharge at a repetition frequency of sinusoidal voltage pulses up to 140 kHz was used to create the gas-discharge plasma. The discharge radiation has been analysed in the spectral range 200-900 nm with a resolution of 0.05 nm. In the spectra, the study has revealed radiation from CdBr(B-X, C-X) exciplex molecules, atomic lines of cadmium and rare gases, and in mixtures with xenon, radiation of XeBr(B-X, B-A) exciplex molecules. The most intense CdBr(B-X) radiation was observed in CdBr2/Xe mixtures. A discharge radiation of a silvery-white colour was observed when the temperature of the mixture was above 250 °C. The XeBr(B-X) radiation predominated in the spectra at temperatures of the mixture up to 200 °C. A further increase in the temperature resulted in the prevalence of the CdBr(B-X) radiation. Regularities in the spectral characteristics of the radiation from the gas-discharge plasma are discussed. The high-frequency atmospheric-pressure barrier discharge in mixtures of cadmium dibromide with gases can be used in multiwave exciplex lamps, operating in the UV and visible regions.

  11. Ultrasound-assisted phase-transfer catalysis: benzoylation of sodium 4-acetylphenoxide by dual-site phase-transfer catalyst in a tri-liquid system.

    PubMed

    Yang, Hung-Ming; Chiu, Chun-Cheng

    2011-01-01

    A novel dual-site phase-transfer catalyst (PTC) was prepared and used to conduct the benzoylation of sodium 4-acetylphenoxide by ultrasound-assisted third-liquid phase-transfer catalysis. The catalyst 1,4-bis(tributylammoniomethyl)benzene dibromide (BTBAMBB) was synthesized from the reaction of p-xylylene dibromide and tributylamine in toluene at 70°C. The dual-site PTC was employed to form the third-liquid phase by extra addition of 0.04-0.05 mol of NaCl into 10 cm(3) of water. In the condition of 0.0425 mol of NaCl at 30°C, the catalytic intermediate in the third-liquid phase reached a maximum value. Almost 80% of the catalyst was transferred from the aqueous phase into the third-liquid phase. The distributions of the catalytic intermediate and dual-site PTC between phases and the kinetics of benzoylation of sodium 4-acetylphenoxide catalyzed by BTBAMBB with ultrasound irradiation were performed. The pseudo-first-order kinetic equation was applied to describe the overall reaction. Under ultrasound irradiation (28 kHz/300 W) in a batch reactor, the yield of product 4-acetylphenyl benzoate in the organic phase was 98.1% in 2 min at 30°C and 250 rpm with the apparent rate constant k(app) to be 0.0075 s(-1), which was 6 times faster than that without using ultrasound (yield=14.4%, k(app)=0.0013 s(-1)). The present study provides a green method to synthesize esters by ultrasound-assisted third-liquid phase-transfer catalysis.

  12. Assessment of potential aquatic herbicide impacts to California aquatic ecosystems.

    PubMed

    Siemering, Geoffrey S; Hayworth, Jennifer D; Greenfield, Ben K

    2008-10-01

    A series of legal decisions culminated in 2002 with the California State Water Resources Control Board funding the San Francisco Estuary Institute to develop and implement a 3-year monitoring program to determine the potential environmental impacts of aquatic herbicide applications. The monitoring program was intended to investigate the behavior of all aquatic pesticides in use in California, to determine potential impacts in a wide range of water-body types receiving applications, and to help regulators determine where to direct future resources. A tiered monitoring approach was developed to achieve a balance between program goals and what was practically achievable within the project time and budget constraints. Water, sediment, and biota were collected under "worst-case" scenarios in close association with herbicide applications. Applications of acrolein, copper sulfate, chelated copper, diquat dibromide, glyphosate, fluridone, triclopyr, and 2,4-D were monitored. A range of chemical analyses, toxicity tests, and bioassessments were conducted. At each site, risk quotients were calculated to determine potential impacts. For sediment-partitioning herbicides, sediment quality triad analysis was performed. Worst-case scenario monitoring and special studies showed limited short-term and no long-term toxicity directly attributable to aquatic herbicide applications. Risk quotient calculations called for additional risk characterizations; these included limited assessments for glyphosate and fluridone and more extensive risk assessments for diquat dibromide, chelated copper products, and copper sulfate. Use of surfactants in conjunction with aquatic herbicides was positively associated with greater ecosystem impacts. Results therefore warrant full risk characterization for all adjuvant compounds.

  13. Regio- and stereoselective isomerization of hexabromocyclododecanes (HBCDs): kinetics and mechanism of beta-HBCD racemization.

    PubMed

    Heeb, Norbert V; Schweizer, W Bernd; Mattrel, Peter; Haag, Regula; Kohler, Martin; Schmid, Peter; Zennegg, Markus; Wolfensberger, Max

    2008-04-01

    Hexabromocyclododecanes (HBCDs) are high production volume chemicals currently produced in quantities exceeding 20000ty(-1). They are used as flame retardants for plastics and textiles. HBCDs are thermally labile compounds, rapidly decomposing at temperatures above 250 degrees C to form bromine radicals, which scavenge other radicals formed during pyrolysis. But certain HBCD stereoisomers must reach the environment without decomposition, because their levels in soils, sediments, and biota are increasing worldwide. The fate of individual HBCD stereoisomers during production, product use, disposal, and transformation in the environment remains unclear. Herein we report on the thermally induced, highly selective isomerization of (+) and (-)beta-HBCD. Regio- and stereoselective migration of only two of the six bromine atoms resulted in the racemization of both beta-HBCDs. First order rate constants (k(rac)) increased from 0.005, 0.011, 0.021, to 0.055min(-1) at 130, 140, 150, and 160 degrees C, corresponding to half life times tau(1/2) of 143, 63, 29, and 14min, respectively. From the deduced kinetic model, we conclude that any thermal treatment of enantiomerically enriched beta-HBCDs in the range of 100-160 degrees C will result in a loss of most optical activity within few hours. The simultaneous inversion of two asymmetric centers occurred with perfect stereocontrol. Selectively, vicinal dibromides with the RR- and the SS-configurations migrated at these temperatures. An intramolecular reaction mechanism with a four-center transition state is postulated, based on the obtained stereoisomer pattern and the observed reaction kinetics. Crystal structure analysis revealed that all vicinal dibromides in beta-HBCDs prefer synclinal (gauche) conformations. However, an antiperiplanar (staggered) conformation is assumed to facilitate the concerted 1.2-shifts of both bromine atoms, resulting in an inversion of both neighboring carbon atoms. First experiments with other HBCD

  14. Communist China’s Progress in Inorganic, Organic, and Physical Chemistry in Recent Decade

    DTIC Science & Technology

    1960-03-16

    Ethylenc- butane and butane - butene gaz mixtures are ob- tained by cracking ethane on nickel catalyst, dehydrogerdzation on chromium oxidd-aliinum oxide ...kuA4.ý m tM P, t voci "oer. 1j t I n t tro*4 ic I~- a) -Padv. The -major re- 4--C!!- Fe T d-4 -20 1 2 2. The ili ~ -io f Products fror ’,);3 𔃻reatynent...normal pressureUZnCj-0r;? 3-.4iO2 (2) Ni-C - Ali high pressure_ (3) N -itmcosearthi, high pressure (2) F7 § S-) ~2~ -4c Cl C1 ( 1 ) Go-catalyst, high

  15. Electrophysiological and behavioral responses of Thanatophilus sinuatus Fabricius (Coleoptera: Silphidae) to selected cadaveric volatile organic compounds.

    PubMed

    Dekeirsschieter, Jessica; Frederickx, Christine; Lognay, Georges; Brostaux, Yves; Verheggen, Francois J; Haubruge, Eric

    2013-07-01

    Soon after death, carcasses release volatile chemicals that attract carrion insects including Silphidae. Nevertheless, it is not known which chemical cues are involved in the attractiveness of the carcass. So far, little information is available on the chemical ecology of carrion beetles, particularly concerning the subfamily of Silphinae. The biological role of selected cadaveric volatile organic compounds including dimethyldisulfide (DMDS), butan-1-ol, n-butanoic acid, indole, phenol, p-cresol, putrescine, and cadaverine on the silphine species, Thanatophilus sinuatus Fabricius, was investigated using both electrophysiological and behavioral techniques. Among the tested cadaveric compounds, butan-1-ol and DMDS elicited the strongest electroantennography (EAG) from both T. sinuatus male and female antennae. In a two-arm olfactometer, males and females were significantly attracted to DMDS for both tested doses, whereas only males were attracted to p-cresol at 100 ng. Putrescine was repellent to males at the dose of 1 μg.

  16. Determination of alternative fuels combustion products: Phase 2 final report

    SciTech Connect

    Whitney, K.A.

    1997-06-01

    This report describes the laboratory efforts to accomplish four independent tasks: (1) speciation of hydrocarbon exhaust emissions from a light-duty vehicle operated over the chassis dynamometer portion of the light-duty FTP after modifications for operation on butane and butane blends; (2) evaluation of NREL`s Variable Conductance Vacuum Insulated Catalytic Converter Test Article 4 for the reduction of cold-start FTP exhaust emissions after extended soak periods for a Ford FFV Taurus operating on E85; (3) support of UDRI in an attempt to define correlations between engine-out combustion products identified by SwRI during chassis dynamometer testing, and those found during flow tube reactor experiments conducted by UDRI; and (4) characterization of small-diameter particulate matter from a Ford Taurus FFV operating in a simulated fuel-rich failure mode on CNG, LPG, M85, E85, and reformulated gasoline. 22 refs., 18 figs., 17 tabs.

  17. Response surface optimization and identification of isothiocyanates produced from broccoli sprouts.

    PubMed

    Guo, Qianghui; Guo, Liping; Wang, Zhiying; Zhuang, Yan; Gu, Zhenxin

    2013-12-01

    Isothiocyanates (ITCs) are proved as one of natural anticarcinogenic compounds, which are produced from the decomposition of glucosinolates by myrosinase. The present study optimized the enzymolysis conditions (pH, addition of EDTA and ascorbic acid) for ITCs production from glucosinolates in broccoli sprouts using response surface methodology. ITCs production was clearly enhanced by a suitable pH, addition content of EDTA and ascorbic acid. The optimal enzymolysis conditions were determined to be adding EDTA 0.02 mmol and 0.16 mg ascorbic acid to 4 ml of the homogenized phosphate-citrate buffer solution (pH 4.00). ITCs profiles were identified and seven kinds of individual ITCs were detected, among which sulforaphane accounted the most. Four kinds of individual ITCs including isobutyl isothiocyanate, 4-isothiocyanato-1-butene, 1-isothiocyanato-3-methyl-butane and 1-isothiocyanato-butane are firstly reported in broccoli sprouts.

  18. Monte Carlo simulation of a complex fluid confined to a pore with nanoscopically rough walls

    NASA Astrophysics Data System (ADS)

    Porcheron, Fabien; Schoen, Martin; Fuchs, Alain H.

    2002-04-01

    Understanding the properties of fluid films of nanometer scale thickness confined between two solid substrates is of fundamental interest as well as of practical importance for engineering applications such as lubrication, adhesion, and friction. We address here the question of the effect of the wall corrugation on the confined fluid structure. We report configurational bias grand canonical Monte Carlo simulations for model butane confined between planar and nonplanar walls. Furrowed walls have been used to model surface roughness effects on the nanometer length scale, while the confining walls remain smooth on the atomic scale. It is shown that the fluid confined between planar walls exhibits a damped oscillatory solvation pressure profile. A transition from an oscillatory to a nonoscillatory behavior is observed when the characteristic length of the furrow reaches the typical dimensions of a butane molecule. It is inferred from these simulations that disrupted oscillatory forces observed in the experiments may reflect the coupling between molecular and nanoscopic roughness length scales.

  19. LED-based NDIR natural gas analyzer

    NASA Astrophysics Data System (ADS)

    Fanchenko, Sergey; Baranov, Alexander; Savkin, Alexey; Sleptsov, Vladimir

    2016-03-01

    A new generation of the light-emitting diodes (LEDs) and photodiodes (PDs) was used recently to develop an open path non-dispersive infrared (NDIR) methane analyzer. The first open path detector prototype was constructed using LEDs for measurement and reference channels, accordingly, and first measurements for methane gas have been performed using optical paths of the order of several meters [3]. The natural gas consists of several first alkanes, mainly methane, and it is important to have a possibility of measuring all of them. In the present work we report the results of NDIR measurements for propane-butane mixture and new measurements of methane using LEDs for measurement and reference channels at 2300 and 1700 nm wavelengths, accordingly. The necessity of the double beam scheme is demonstrated and obtained results for methane and propane-butane mixture are compared.

  20. Thermodynamic and acoustical properties of mixtures p-anisaldehyde—alkanols (C1-C4)—2-methyl-1-propanol at 303.15 K

    NASA Astrophysics Data System (ADS)

    Saini, Balwinder; Kumar, Ashwani; Rani, Ruby; Bamezai, Rajinder K.

    2016-07-01

    The density, viscosity and speed of sound of pure p-anisaldehyde and some alkanols, for example, methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, and the binary mixtures of p-anisaldehyde with these alkanols were measured over the entire composition range at 303.15 K. From the experimental data, various thermodynamic parameters such as excess molar volume ( V E), excess Gibbs free energy of activation (Δ G*E), and deviation parameters like viscosity (Δη), speed of sound (Δ u), isentropic compressibility (Δκs), are calculated. The excess as well as deviation parameters are fitted to Redlich—Kister equation. Additionally, the viscosity data for the systems has been used to correlate the application of empirical relation given by Grunberg and Nissan, Katti and Chaudhari, and Hind et al. The results are discussed in terms of specific interactions present in the mixtures.

  1. Fuel property effects on engine combustion processes. Final report

    SciTech Connect

    Cernansky, N.P.; Miller, D.L.

    1995-04-27

    A major obstacle to improving spark ignition engine efficiency is the limitations on compression ratio imposed by tendency of hydrocarbon fuels to knock (autoignite). A research program investigated the knock problem in spark ignition engines. Objective was to understand low and intermediate temperature chemistry of combustion processes relevant to autoignition and knock and to determine fuel property effects. Experiments were conducted in an optically and physically accessible research engine, static reactor, and an atmospheric pressure flow reactor (APFR). Chemical kinetic models were developed for prediction of species evolution and autoignition behavior. The work provided insight into low and intermediate temperature chemistry prior to autoignition of n-butane, iso-butane, n-pentane, 1-pentene, n-heptane, iso-octane and some binary blends. Study of effects of ethers (MTBE, ETBE, TAME and DIPE ) and alcohols (methanol and ethanol) on the oxidation and autoignition of primary reference fuel (PRF) blends.

  2. Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City.

    PubMed

    Rodolfo Sosa, E; Humberto Bravo, A; Violeta Mugica, A; Pablo Sanchez, A; Emma Bueno, L; Krupa, Sagar

    2009-03-01

    Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at the University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed.

  3. Experimental selectivity curves of gaseous binary mixtures of hydrocarbons and carbon dioxide on activated carbon and silica gel

    SciTech Connect

    Olivier, M.G.; Jadot, R.

    1998-07-01

    The selectivity curves of gaseous binary mixtures of ethane + ethylene, methane + carbon dioxide at 303 K and 700 kPa and butane + 2 methylpropane at 318 K and 200 kPa have been determined on activated carbon and silica gel using an original apparatus. In this paper, a brief description of this apparatus is given. The difference in behavior of these two adsorbents is discussed.

  4. Evaluation of IMO (International Marine Organization) Preliminary Draft Recommendation on Fire Test Procedures for Upholstered Furniture (FP 32/WP.9 Annex 6)

    DTIC Science & Technology

    1988-12-01

    cigarettes from each of five packs per brand were tested. An average smoldering rate was then calculated for each brand. The data is presented in Table I...difficult to use. o The butane "match" test may limit the use of some types of upholstery materials. These materials may include lightweight...by smokers’ materials. However, there are two important limitations , as follows: (a) The tests are concerned only with ignitability, and any controls

  5. Olfactory Impact of Higher Alcohols on Red Wine Fruity Ester Aroma Expression in Model Solution.

    PubMed

    Cameleyre, Margaux; Lytra, Georgia; Tempere, Sophie; Barbe, Jean-Christophe

    2015-11-11

    This study focused on the impact of five higher alcohols on the perception of fruity aroma in red wines. Various aromatic reconstitutions were prepared, consisting of 13 ethyl esters and acetates and 5 higher alcohols, all at the average concentrations found in red wine. These aromatic reconstitutions were prepared in several matrices. Sensory analysis revealed the interesting behavior of certain compounds among the five higher alcohols following their individual addition or omission. The "olfactory threshold" of the fruity pool was evaluated in several matrices: dilute alcohol solution, dilute alcohol solution containing 3-methylbutan-1-ol or butan-1-ol individually, and dilute alcohol solution containing the mixture of five higher alcohols, blended together at various concentrations. The presence of 3-methylbutan-1-ol or butan-1-ol alone led to a significant decrease in the "olfactory threshold" of the fruity reconstitution, whereas the mixture of alcohols raised the olfactory threshold. Sensory profiles highlighted changes in the perception of fruity nuances in the presence of the mixture of higher alcohols, with specific perceptive interactions, including a relevant masking effect on fresh- and jammy-fruit notes of the fruity mixture in both dilute alcohol solution and dearomatized red wine matrices. When either 3-methylbutan-1-ol or butan-1-ol was added to the fruity reconstitution in dilute alcohol solution, an enhancement of butyric notes was reported with 3-methylbutan-1-ol and fresh- and jammy-fruit with butan-1-ol. This study, the first to focus on the impact of higher alcohols on fruity aromatic expression, revealed that these compounds participate, both quantitatively and qualitatively, in masking fruity aroma perception in a model fruity wine mixture.

  6. Bundles of aligned carbon nanotubes obtained by the pyrolysis of ferrocene hydrocarbon mixtures: role of the metal nanoparticles produced in situ

    NASA Astrophysics Data System (ADS)

    Satishkumar, B. C.; Govindaraj, A.; Rao, C. N. R.

    1999-07-01

    Aligned nanotube bundles have been produced by the pyrolysis of ferrocene along with methane, acetylene or butane. Ferrocene-acetylene mixtures are found to be ideal for the production of compact aligned nanotube bundles. The nanotube bundles are associated with iron nanoparticles of diameters in the range 2-13 nm. These nanoparticles are ferromagnetic, showing low saturation magnetization compared to bulk iron. The ferromagnetism of the transition metal nanoparticles is likely to be responsible for the alignment of the nanotubes.

  7. Self-organized Spiral and Circular Waves in Premixed Gas Flames

    NASA Technical Reports Server (NTRS)

    Pealman, Howard G.; Ronney, Paul D.

    1994-01-01

    A diffusive-thermal high Lewis number (Le) gas-phase oscillator has been observed in premixed flames using a lean mixture of butane and oxygen diluted with helium (Le approx. 3.0). This reactive-diffusive system exhibits both propagating radial pulsations and rotating spiral waves perhaps,analogous to those observed in other excitable media such as the Belousov-Zhabotinsky reaction.

  8. Self-organized spiral and circular waves in premixed gas flames

    NASA Technical Reports Server (NTRS)

    Pearlman, Howard G.; Ronney, Paul D.

    1994-01-01

    A diffusive-thermal high Lewis number (Le) gas-phase oscillator has been observed in premixed flames using a lean mixture of butane and oxygen diluted with helium (Le approximately equals 3.0). This reactive-diffusive system exhibits both propagating radial pulsations and rotating spiral waves perhaps analogous to those observed in other excitable media such as the Belousov-Zhabotinsky reaction.

  9. Pure isobutylene from C/sub 4/ mix

    SciTech Connect

    Miranda, M.

    1987-08-01

    This article points out that the ADIB process can isolate and purify isobutylene from a butane-butylene stream such as might be obtained from catalytic and thermal crackers. The process uses the selectivity of the alkylation reaction between isobutylene and phenol. The alkylate product, a liquid that is easily separated from the gaseous feed, is then dealkylated to yield pure isobutylene and the recycle phenol.

  10. Vapor-liquid equilibria for the ternary system N2 + CO2 + n-C4H10 at 250 and 270 K1

    NASA Astrophysics Data System (ADS)

    Brown, T. S.; Sloan, E. D.; Kidnay, A. J.

    1994-11-01

    The system studied was nitrogen + carbon dioxide + n-butane at 250 and 270 K and at pressures from 1.5 to 14 MPa. The Peng-Robinson equation was used to model the results, since it is the most widely accepted equation of state in the gas processing industry. In general, the predictions are most accurate at low and moderate pressures and poorest at high pressures, especially near the critical region.

  11. Quinoxaline derivatives as corrosion inhibitors for mild steel in hydrochloric acid medium: Electrochemical and quantum chemical studies

    NASA Astrophysics Data System (ADS)

    Olasunkanmi, Lukman O.; Kabanda, Mwadham M.; Ebenso, Eno E.

    2016-02-01

    The corrosion inhibition potential of four quinoxaline derivatives namely, 1-[3-(4-methylphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Me-4-PQPB), 1-(3-(4-methoxyphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl)butan-1-one (Mt-4-PQPB), 1-[3-(3-methoxyphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Mt-3-PQPB) and 1-[3-(2H-1,3-benzodioxol-5-yl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Oxo-1,3-PQPB) was studied for mild steel corrosion in 1 M HCl solution using electrochemical, spectroscopic techniques and quantum chemical calculations. The results of both potentiodynamic polarization and electrochemical impedance spectroscopic studies revealed that the compounds are mixed-type inhibitors and the order of corrosion inhibition efficiency at 100 ppm is Me-4-PQPB>Mt-3-PQPB>Oxo-1,3-PQPB>Mt-4-PQPB. Fourier transform infrared (FTIR) and ultraviolet-visible (UV-vis) spectroscopic analyses confirmed the presence of chemical interactions between the inhibitors and mild steel surface. The adsorption of the inhibitor molecules on mild steel surface was found to be both physisorption and chemisorption but predominantly chemisorption. The experimental data obey Langmuir adsorption isotherm. Scanning electron microscopy studies revealed the formation of protective films of the inhibitors on mild steel surface. Quantum chemical parameters obtained from density functional theory (DFT) calculations support experimental results.

  12. Extended use of photovoltaic solar panels

    NASA Astrophysics Data System (ADS)

    Guazzoni, Guido E.; Rose, M. Frank

    1996-02-01

    The use of photovoltaic solar panels (and related generation of electric power) can be extended to a 24 hours per day under any environmental condition by equipping them with an artificial source of light, with emitting wavelengths matched to the photovoltaic solar panels, to be turned on in the absence of sunlight. This source of light can be obtained by heating a mantle to an incandescent temperature via the efficient, low polluting combustion of Natural Gas, Butane, Propane, or other gaseous Hydrocarbon fuel.

  13. Heat pipe temperature control utilizing a soluble gas absorption reservior

    NASA Technical Reports Server (NTRS)

    Saaski, E. W.

    1976-01-01

    A new gas-controlled heat pipe design is described which uses a liquid matrix reservior, or sponge, to replace the standard gas reservior. Reservior volume may be reduced by a factor of five to ten for certain gas-liquid combinations, while retaining the same level of temperature control. Experiments with ammonia, butane, and carbon dioxide control gases with methanol working fluid are discussed.

  14. Worldwide gas processing

    SciTech Connect

    Radler, M.

    1998-06-08

    Tables are presented on capacity and production in natural gas processing plants by country (by province or by state when appropriate), and by company within each country. Production figures are presented separately for ethane, propane, isobutane, butane, LP-gas mixtures, raw NGL mixtures, debutanized natural gasoline, an other. Another table gives world sulfur production by company within each country. The sulfur production table gives the source of the sulfur, type of process used, and figures for design capacity and production.

  15. Metabolism of Diethyl Ether and Cometabolism of Methyl tert-Butyl Ether by a Filamentous Fungus, a Graphium sp

    PubMed Central

    Hardison, L. K.; Curry, S. S.; Ciuffetti, L. M.; Hyman, M. R.

    1997-01-01

    In this study, evidence for two novel metabolic processes catalyzed by a filamentous fungus, Graphium sp. strain ATCC 58400, is presented. First, our results indicate that this Graphium sp. can utilize the widely used solvent diethyl ether (DEE) as the sole source of carbon and energy for growth. The kinetics of biomass accumulation and DEE consumption closely followed each other, and the molar growth yield on DEE was indistinguishable from that with n-butane. n-Butane-grown mycelia also immediately oxidized DEE without the extracellular accumulation of organic oxidation products. This suggests a common pathway for the oxidation of both compounds. Acetylene, ethylene, and other unsaturated gaseous hydrocarbons completely inhibited the growth of this Graphium sp. on DEE and DEE oxidation by n-butane-grown mycelia. Second, our results indicate that gaseous n-alkane-grown Graphium mycelia can cometabolically degrade the gasoline oxygenate methyl tert-butyl ether (MTBE). The degradation of MTBE was also completely inhibited by acetylene, ethylene, and other unsaturated hydrocarbons and was strongly influenced by n-butane. Two products of MTBE degradation, tert-butyl formate (TBF) and tert-butyl alcohol (TBA), were detected. The kinetics of product formation suggest that TBF production temporally precedes TBA accumulation and that TBF is hydrolyzed both biotically and abiotically to yield TBA. Extracellular accumulation of TBA accounted for only a maximum of 25% of the total MTBE consumed. Our results suggest that both DEE oxidation and MTBE oxidation are initiated by cytochrome P-450-catalyzed reactions which lead to scission of the ether bonds in these compounds. Our findings also suggest a potential role for gaseous n-alkane-oxidizing fungi in the remediation of MTBE contamination. PMID:16535667

  16. Branch-Selective Alkene Hydroarylation by Cooperative Destabilization: Iridium-Catalyzed ortho-Alkylation of Acetanilides

    PubMed Central

    Crisenza, Giacomo E M; Sokolova, Olga O; Bower, John F

    2015-01-01

    An iridium(I) catalyst system, modified with the wide-bite-angle and electron-deficient bisphosphine dFppb (1,4-bis(di(pentafluorophenyl)phosphino)butane) promotes highly branch-selective hydroarylation reactions between diverse acetanilides and aryl- or alkyl-substituted alkenes. This provides direct and ortho-selective access to synthetically challenging anilines, and addresses long-standing issues associated with related Friedel–Crafts alkylations. PMID:26490739

  17. Thermodynamic and kinetic aspects of surface acidity. Progress report, July 1, 1994--June 30, 1995

    SciTech Connect

    Dumesic, J.A.

    1995-06-01

    Catalytic cracking of isobutane and 2-methyl-hexane over various USY-zeolite catalysts was studied. A kinetic model was developed for isobutane cracking over calcined and steamed Y-zeolite catalysts. Catalyst steaming leads to decreased Bronsted acidity. The studies of catalyst acid and basic properties were broadened to include alumina-supported metal oxides and a sulfated zirconia catalyst (isomerization of normal butane).

  18. Development of a Surface Plasmon Resonance n-dodecane Vapor Sensor

    PubMed Central

    Aguirre, Narcizo Muñoz; Pérez, Lilia Martínez; Colín, Jose Alfredo; Buenrostro-Gonzalez, Eduardo

    2007-01-01

    Using a high density polyethylene thin film over gold layer, a Surface Plasmon Resonance sensor for detecting n-dodecane vapor is developed. Preliminary results will be presented, showing that samples in the range of a few hundred ppm(V) of n-dodecane vapor in butane gas can be sensed. Also, studying the response as a function of time, it is demonstrated that the sensing process is quickly reversible.

  19. Combustion Characteristics of Sprays

    DTIC Science & Technology

    1989-08-01

    regarded by implication or otherwise, or in any way licensing the holder or any other person or corporation, or conveying any rights or permission to...00 _’N 1. TI TLE inctuat Security CZaaafication5 Combustion Characteristics of Sprays 12. PERSONAL AUTHOR(S) Sohrab, Siavash H. 13& TYPE OF REPORT...to ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

  20. Electrophilic nitration of alkanes with nitronium hexafluorophosphate

    PubMed Central

    Olah, George A.; Ramaiah, Pichika; Prakash, G. K. Surya

    1997-01-01

    Nitration of alkanes such as methane, ethane, propane, n-butane, isobutane, neopentane, and cyclohexane was carried out with nitronium hexafluorophosphate in methylene chloride or nitroethane solution. Nitration of methane, albeit in poor yield, required protolytic activation of the nitronium ion. The results indicate direct electrophilic insertion of NO2+ into C 000000000000 000000000000 000000000000 000000000000 111111111111 000000000000 000000000000 000000000000 000000000000 H and CC σ-bonds. PMID:11038587

  1. Fort Bliss Standards for the Treatment of Historic Buildings

    DTIC Science & Technology

    2008-05-01

    workmanship. Sometimes peeling paint is caused by moisture build-up in the wall. Cracking is often caused by poor adhesion , which comes from incompatible... adhesion , which comes from incompatible types of paint layered over each other, or from the build-up of many layers of old paint . Care- ful scraping to...destructive paint removal methods such as propane or butane torches, sandblasting, or water blasting. These methods can irreversibly damage historic woodwork

  2. Airway Management and Smoke Inhalation Injury in the Burn Patient

    DTIC Science & Technology

    2009-10-01

    injury, using cotton ties or similar methods. Note that care must be taken to protect the corner of the mouth, if possible. (B) Adhesive tape will not...especially during transport. Thus, cotton ties (1/2-in umbilical ties), rather than adhesive tape, are used to secure the endotracheal tube...containing compounds such as cellulosics (eg, wood, paper, coal, charcoal), natural gases (eg, methane, butane, propane ), and petroleum products. Carbon

  3. Jet Engine Exhaust Analysis by Subtractive Chromatography

    DTIC Science & Technology

    1978-12-01

    and J. J. Brooks. Development of a portable miniature collection system for the exposure as- sessment within the microenvironment for carcinogens ...65 A-2. Recovery of acrylonitrile from standard sample generation system ...... ............. 66 B-I. Jet engine exhaust sampling and analysis...7 n-Butane 0.16 2.6 minutes 8 Propylene oxide 3.14 52 minutes 9 Acrylonitrile 9.35 2.6 hours 10 Phenanthrene 1.9 x 106 61 years 11 4-Bromodiphenyl

  4. Experimental preparation and UV/IR spectroscopic characterization of 1,3-dibutanal-1,2,4,5-tetroxane.

    PubMed

    Ayala, D A; Romero, J M; Jorge, N L; Gómez-Vara, M E; Jubert, A H; Castro, E A

    2006-06-01

    We report the experimental preparation of the 1,3-butanal-1,2,4,5-tetroxane by oxidation of glutataldehyde with oxygen peroxide in presence of concentrated sulfuric acid, following the Bayer and Viller method modified by Jorge et al. The UV and IR spectra are studied from the experimental and theoretical standpoint. A rather complete vibrational assignment was performed and the nature of the electronic transitions was discussed in detail.

  5. Macrokinetic characteristics of isobutylene polymerization

    SciTech Connect

    Minsker, K.S.; Berlin, A.A.; Enikolopyan, N.S.; Prochukhan, Y.A.; Svinkov, A.G.

    1986-08-01

    This paper describes a method of obtaining oligo and polyisobutylene with a molecular mass of 112-50,000: the cationic polymerization of isobutylene carried out in the presence of AlCl/sub 3/, in an environment of hydrocarbons (butanes, etc.) or chlorinated hydrocarbons (ethyl chloride, methyl chloride, etc.) at a temperature of 173-353 K/sub 3/ and in mixer-reactors of complicated design with a volume of 1.5-30 m.

  6. Investigation of Source of Irritant Gas Produced by PATRIOT Missile System Air Conditioners

    DTIC Science & Technology

    1986-03-31

    Octafluoro- 1 C3F8 188 Heptane, Hexadecafluoro- 2 CF 1 6 388 Propene, Hexafluoro- 1 C3F6 150 Pentane, Dodecafluoro- 2 C5F12 288 Butane, Decafluoro- 1...FORMULA M.WT. Cyclobutane, Octafluoro- 3 C4 F8 200 Ethene, Tetrafluoro- 2 C2F4 - 100 Ethane, Hexafluoro- 2 C2F6 138 Propane, Ocflouoro- 1 C3F8 188

  7. 40 CFR 60.707 - Chemicals affected by subpart RRR.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Amylene 513-35-9 Amylenes, mixed Aniline 62-53-3 Benzene 71-43-2 Benzenesulfonic acid 98-11-3...-Butanediol 110-63-4 Butanes, mixed 1-Butene 106-98-9 2-Butene 25167-67-3 Butenes, mixed n-Butyl acetate 123... 123-42-2 1,4-Dichlorobutene 110-57-6 3,4-Dichloro-1-butene 64037-54-3 Dichlorodifluoromethane...

  8. 40 CFR 60.707 - Chemicals affected by subpart RRR.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Amylene 513-35-9 Amylenes, mixed Aniline 62-53-3 Benzene 71-43-2 Benzenesulfonic acid 98-11-3...-Butanediol 110-63-4 Butanes, mixed 1-Butene 106-98-9 2-Butene 25167-67-3 Butenes, mixed n-Butyl acetate 123... 123-42-2 1,4-Dichlorobutene 110-57-6 3,4-Dichloro-1-butene 64037-54-3 Dichlorodifluoromethane...

  9. 40 CFR 60.707 - Chemicals affected by subpart RRR.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Amylene 513-35-9 Amylenes, mixed Aniline 62-53-3 Benzene 71-43-2 Benzenesulfonic acid 98-11-3...-Butanediol 110-63-4 Butanes, mixed 1-Butene 106-98-9 2-Butene 25167-67-3 Butenes, mixed n-Butyl acetate 123... 123-42-2 1,4-Dichlorobutene 110-57-6 3,4-Dichloro-1-butene 64037-54-3 Dichlorodifluoromethane...

  10. 40 CFR 60.707 - Chemicals affected by subpart RRR.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Amylene 513-35-9 Amylenes, mixed Aniline 62-53-3 Benzene 71-43-2 Benzenesulfonic acid 98-11-3...-Butanediol 110-63-4 Butanes, mixed 1-Butene 106-98-9 2-Butene 25167-67-3 Butenes, mixed n-Butyl acetate 123... 123-42-2 1,4-Dichlorobutene 110-57-6 3,4-Dichloro-1-butene 64037-54-3 Dichlorodifluoromethane...

  11. 40 CFR 60.707 - Chemicals affected by subpart RRR.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Amylene 513-35-9 Amylenes, mixed Aniline 62-53-3 Benzene 71-43-2 Benzenesulfonic acid 98-11-3...-Butanediol 110-63-4 Butanes, mixed 1-Butene 106-98-9 2-Butene 25167-67-3 Butenes, mixed n-Butyl acetate 123... 123-42-2 1,4-Dichlorobutene 110-57-6 3,4-Dichloro-1-butene 64037-54-3 Dichlorodifluoromethane...

  12. Experimental Verification and Revision of the Venting Rate Model of the Hazard Assessment Computer System and the Vulnerability Model.

    DTIC Science & Technology

    1980-11-01

    are: anhydrous ammnonia, butane, chlorine, LNG, methyl alcohol, and propane. Based on this review of the representative chemicals, the following...van Wvlen and R. E. Sonnzag, Fundamentals cf Clas- sical Thermodynamics, Table A.2, Thermodynamic Proterties of Amonia , john Wiley and Sonis, 1973. 13...given in the CPF were reviewed and converted to cgs. 1. ANHYDROUS A-4ONIA [16,17,18], molecular weight = 17.698 Range of validity: -400 C to 380 C (71.8

  13. Design of Energetic Ionic Liquids

    DTIC Science & Technology

    2007-06-01

    much stronger while the structural organization of the water network and aggregation tendency than butane. The above resultsf161, the micelle exhibits...nonpolar groups and the break up of the charged polar network with increasing water content, while the turnover of the water network results from the...water, while the Chem Phys. 88 5818 1998. structural organization of the water network and the 1a micelle exhibits a "turnover." In contrast

  14. Synthesis of task specific and reusable protic ionic liquids for one-pot multicomponent syntheses

    NASA Astrophysics Data System (ADS)

    Sardar, Sabahat; Wilfred, Cecilia Devi; Marc, Leveque Jean

    2016-11-01

    Protic ionic liquids (ILs) synthesized from 1-methylimidazole with 1,3-propane sultone and 1,4-butane sultone catalyzed Mannich reaction at 25 °C to afford Mannich bases in high yield (76%) and less time duration (20 min). Ionic liquids have been used as dual reagent i.e., as catalyst as well as solvent. Simple extraction by water separated ionic liquid from reaction mixture with 4 times recycling without any significant loss in activity.

  15. Annual West Coast Theoretical Chemistry/Statistical Mechanics Conference (14th), held at Los Angeles, California on 17-19 June 1993

    DTIC Science & Technology

    1993-06-19

    O ) D +H 2 (vj) -> DH+H reaction, yielding initial-state- selected reaction probabilities over a range of energies and initial rovibrational states... 01 MD Simulation of Shape-Selective Separation in Zeolite Molecular Sieves: Butane and Isobutane in Silicalite John B . Nicholas, Robert J. Harrison...California, Los Angeles, Ca 90024, a n d il l a 1 a o Laboratoiw de Physique Theorique des Liquides, Universite I terre et Marie Curie, 4 Place Jussieu, 75252

  16. LPG Dependence after a Suicide Attempt

    PubMed Central

    Aldemir, Ebru; Akyel, Betül; Altıntoprak, A. Ender; Aydın, Rezzan; Coşkunol, Hakan

    2015-01-01

    Inhalant abuse is a problem that is getting more common all around the world. The increase in prevalence of inhalant abuse escalates morbidity and mortality rates. About 22% of people using inhalant have died at their first attempt. Particularly propane, butane, or propane-butane mixture has highest mortality rates. Sudden sniffing death syndrome, cardiomyopathy, central nervous system toxicity, hematological abnormalities, kidney toxicity, and hepatocellular toxicities are the major complications of inhalant abuse. Herein we present a patient with inhalant use disorder. At the age of 19, after a stressful life event he had unsuccessfully tried to suicide by inhaling LPG (liquefied petroleum gas, a mixture of butane and propane gases). After he realized that he had hallucinations and felt better during the inhalation, he started to abuse it. He was addicted to LPG for 10 years at the time of admission. Besides being dangerous for the society security, this intense level of LPG inhalation (12 liters a day) not giving any physical harm makes this case interesting. PMID:25664196

  17. Identification of a Male-Produced Pheromone Component of the Citrus Longhorned Beetle, Anoplophora chinensis

    PubMed Central

    Hansen, Laura; Xu, Tian; Wickham, Jacob; Chen, Yi; Hao, Dejun; Hanks, Lawrence M.; Millar, Jocelyn G.; Teale, Stephen A.

    2015-01-01

    The Asian wood-boring beetle Anoplophora chinensis (Forster) (Coleoptera: Cerambycidae) is an important pest of hardwood trees in its native range, and has serious potential to invade other areas of the world through worldwide commerce in woody plants and wood products. This species already has been intercepted in North America, and is the subject of ongoing eradication efforts in several countries in Europe. Attractants such as pheromones would be immediately useful as baits in traps for its detection. Because long-range pheromones are frequently conserved among closely related species of cerambycids, we evaluated two components of the volatile pheromone produced by males of the congener A. glabripennis (Motschulsky), 4-(n-heptyloxy)butan-1-ol and 4-(n-heptyloxy)butanal, as potential pheromones of A. chinensis. Both compounds subsequently were detected in headspace volatiles from male A. chinensis, but not in volatiles from females. Only 4-(n-heptyloxy)butanol elicited responses from beetle antennae in coupled gas chromatography-electroantennogram analyses, and this compound attracted adult A. chinensis of both sexes in field bioassays. These data suggest that 4-(n-heptyloxy)butan-1-ol is an important component of the male-produced attractant pheromone of A. chinensis, which should find immediate use in quarantine monitoring for this pest. PMID:26241651

  18. Solubility and diffusivity study for light gases in heavy oil and its fractions

    NASA Astrophysics Data System (ADS)

    Ganapathi, Rajkumar

    Solvent-based recovery (VAPEX) is one of the most promising alternatives to thermal techniques to enhance heavy oil/bitumen recovery. Knowledge of the phase behavior and diffusion coefficients of gases in heavy oil is very important when designing recovery operations and facilities. In this work, a gravimetric microbalance was used to measure the solubility of carbon dioxide, ethane, propane and butane in a Lloydminster heavy oil and its fractions. Measurements were carried out on carbon dioxide and ethane at (290, 298 and 313) K over a pressure range from (200 to 2000) kPa. Similar measurements were performed on propane and butane below their vapor pressures. The Peng-Robinson equation of state was used to correlate the experimental results. The Solubility Parameter Theory was used to predict the solubility of CO2 and propane in heavy oil/bitumen over a wide range of pressures and temperatures. The associated Henry's Law constants for carbon dioxide, ethane and propane in heavy oil, its saturate fractions and aromatic fractions, were also determined from the absorption data. The gases had higher solubilities and the strongest interactions at lower temperatures in the heavy oil and its fractions. The diffusion coefficients of carbon dioxide, ethane and propane in heavy oil, its saturate and aromatic fractions were calculated using a simple diffusion model. The diffusion coefficient of carbon dioxide, ethane, propane and butane in heavy oil were calculated at different pressures. Estimated values were in agreement with published results and were found satisfactory.

  19. A field-space conformal-solution method: Binary vapor-liquid phase behavior

    NASA Astrophysics Data System (ADS)

    Storvick, T. S.; Fox, J. R.

    1990-01-01

    The field-space conformal solution method provides an entirely new thermodynamic framework for the description of fluid mixtures in terms of the properties of a pure reference fluid. The utility and performance of the method are examined in the special case of vapor-liquid equilibrium correlation for simple mixtures. This is one of several cases in which field-space methods have numerical or theoretical advantages over methods presently used in mixture property correlation; only properties along the vapor pressure curve of the purefluid reference system are required for a complete description of the mixture phase behavior. Vapor-liquid equilibrium data for three binary hydrocarbon mixtures, n-butane + n-pentane, n-butane + n-hexane, and n-butane + n-octane, are correlated with a simple implementation of the method having two independent mixture parameters. Two pure-fluid equations of state, a Peng-Robinson equation and a 32-constant modified Benedict-Webb-Rubin equation, are tested as reference systems. The effects of differences in the quality of the reference system and of a range of mixture component size ratios are examined.

  20. Enhanced ethylene and ethane production with free-radical cracking catalysts.

    PubMed

    Kolts, J H; Delzer, G A

    1986-05-09

    A series of free-radical catalysts have been discovered that increase the yield of highly valuable olefins from the cracking of low molecular weight paraffins. For example, catalytic cracking of n-butane, isobutane, and propane over manganese or iron supported on magnesium oxide (MgO) gave product distributions different from those given by thermal (free-radical) cracking or cracking over traditional acid catalysts. With n-butane and propane feeds, the products from catalytic cracking included large amounts of ethylene and ethane; with isobutane feed, propylene was the major product. Physical characterization of the MgO-supported catalyst showed the manganese to be in a 2+ oxidation state in the reduced catalyst and a 4+ oxidation state in the fully oxidized catalyst. Manganese was also shown to be uniformly distributed in the support material with very little enrichment at the surface. Matrix isolation of the gasphase radicals from n-butane feed showed that ethyl and methyl radicals were produced over the active catalysts. In the thermal process, only methyl radicals were produced. The mechanism of the catalytic reaction appears to be selective formation of primary carbanions at the catalyst surface followed by electron transfer and release of primary hydrocarbon radicals to the gas phase.

  1. Identification of a Male-Produced Pheromone Component of the Citrus Longhorned Beetle, Anoplophora chinensis.

    PubMed

    Hansen, Laura; Xu, Tian; Wickham, Jacob; Chen, Yi; Hao, Dejun; Hanks, Lawrence M; Millar, Jocelyn G; Teale, Stephen A

    2015-01-01

    The Asian wood-boring beetle Anoplophora chinensis (Forster) (Coleoptera: Cerambycidae) is an important pest of hardwood trees in its native range, and has serious potential to invade other areas of the world through worldwide commerce in woody plants and wood products. This species already has been intercepted in North America, and is the subject of ongoing eradication efforts in several countries in Europe. Attractants such as pheromones would be immediately useful as baits in traps for its detection. Because long-range pheromones are frequently conserved among closely related species of cerambycids, we evaluated two components of the volatile pheromone produced by males of the congener A. glabripennis (Motschulsky), 4-(n-heptyloxy)butan-1-ol and 4-(n-heptyloxy)butanal, as potential pheromones of A. chinensis. Both compounds subsequently were detected in headspace volatiles from male A. chinensis, but not in volatiles from females. Only 4-(n-heptyloxy)butanol elicited responses from beetle antennae in coupled gas chromatography-electroantennogram analyses, and this compound attracted adult A. chinensis of both sexes in field bioassays. These data suggest that 4-(n-heptyloxy)butan-1-ol is an important component of the male-produced attractant pheromone of A. chinensis, which should find immediate use in quarantine monitoring for this pest.

  2. Evaluating the process of polishing borosilicate glass capillaries used for fabrication of in-vitro fertilization (iVF) micro-pipettes.

    PubMed

    Yaul, Mayur; Bhatti, Raj; Lawrence, Stephen

    2008-02-01

    In this paper we investigate a number of gas flames for fire polishing borosilicate glass capillaries used in the manufacturing of IVF micro-pipettes. Hydrofluoric acid (HF) was also used as an alternative to finish the pipette end. Glass micro tools in the IVF industry are drawn from hollow glass capillaries of diameter 1 mm. These capillaries are cut manually to a length of 100 mm from hollow glass rods resulting in sharp and chipped edges. These capillaries are held in a customised holder having padding of soft silicone or rubber. Sharp and uneven edges of these capillaries pick up particles of rubber or soft silicone shavings, rendering them ineffective for IVF treatments. The working range of borosilicate glass is 800-1,200 degrees C. The experiments involved analysis of fire polishing process for borosilicate glass capillaries using candle, butane, propane, 2350 butane propane, oxyacetylene gas flames, finding the optimum distance of the capillary relative to the flame, optimum time for which the capillary should be held in the flame and optimum region of the flame which gives the required temperature range. The results show that 2350 butane propane gas mix is optimum for fire polishing of borosilicate glass capillaries. The paper is concluded by comparing the results of fire polishing with the results of acid polishing, in which HF of 1.6% concentration is used to etch the ends of the borosilicate glass pipettes.

  3. Freshly Emitted, Unexpectedly High SO2, SO4=, NOx, CH4, and i-C4H10 Offshore of Los Angeles Attributed to Several Source Sectors

    NASA Astrophysics Data System (ADS)

    Chatfield, R. B.; Blake, D. R.; Crounse, J.; Diskin, G. S.; Esswein, R.; Nenes, A.; Singh, H. B.; Weinheimer, A. J.; Wisthaler, A.

    2013-12-01

    The NASA DC-8 made repeated flights over Los Angeles and the Southern California Bight, revealing very intermittent spikes of sulfur dioxide, sulfate, reactive nitrogen oxides, toluene, i-butane methane and black carbon. There was some coherence between spikes of these compounds, but often they were distinct. These samples were taken in the California portion of the ARCTAS sampling intensive (Cal-ARCTAS); the large compliment of simultaneous measurements on the DC-8 allow us to highlight or downplay source sectors. We will help confirm attributions using with local trajectory calculations. The NASA flights in 2008 went much further west than NOAA's CalNEX flights in 2010, and measurements reflecting these sources seem to be only occasionally apparent in published analyses of CalNEX. These analyses suggested that Los Angeles source inventories and observations were in good agreement. From the location of sampling and correlations, we surmise important sources included natural hydrocarbon seeps, petroleum production as well as shipping and perhaps aircraft emissions. These sources, often upwind of the South Coast cities, may be variable and may add to known emission databases. (Left) Influence of petroleum-associated emissions in the Southern California Bight. iso-Butane i excess over the traffic-associated butanes, indicating natural petroleum origin. (Right) SO2 (Georgia Tech) in a similar plot. Largest concentrations in South Coast area are offshore.

  4. Photoacoustic sensor for VOCs: first step towards a lung cancer breath test

    NASA Astrophysics Data System (ADS)

    Wolff, Marcus; Groninga, Hinrich G.; Dressler, Matthias; Harde, Hermann

    2005-08-01

    Development of new optical sensor technologies has a major impact on the progression of diagnostic methods. Specifically, the optical analysis of breath is an extraordinarily promising technique. Spectroscopic sensors for the non-invasive 13C-breath tests (the Urea Breath Test for detection of Helicobacter pylori is most prominent) are meanwhile well established. However, recent research and development go beyond gastroenterological applications. Sensitive and selective detection of certain volatile organic compounds (VOCs) in a patient's breath, could enable the diagnosis of diseases that are very difficult to diagnose with contemporary techniques. For instance, an appropriate VOC biomarker for early-stage bronchial carcinoma (lung cancer) is n-butane (C4H10). We present a new optical detection scheme for VOCs that employs an especially compact and simple set-up based on photoacoustic spectroscopy (PAS). This method makes use of the transformation of absorbed modulated radiation into a sound wave. Employing a wavelength-modulated distributed feedback (DFB) diode laser and taking advantage of acoustical resonances of the sample cell, we performed very sensitive and selective measurements on butane. A detection limit for butane in air in the ppb range was achieved. In subsequent research the sensitivity will be successively improved to match the requirements of the medical application. Upon optimization, our photoacoustic sensor has the potential to enable future breath tests for early-stage lung cancer diagnostics.

  5. Sorption and diffusion of light hydrocarbons on Na-Y zeolites

    SciTech Connect

    Palmas, S.; Polcaro, A.M.; Carta, R.; Tola, G. )

    1991-01-01

    This paper reports on the adsorption isotherms that were determined on zeolite Na-Y at 298, 313, and 333 K for propane and propylene and at 298 K for butane, trans-butene, 1-butene, and cis-butene. The pressure of the experiments ranged from 5 {times} 10{sup {minus}2} to 30 kPa. The weight of adsorbed hydrocarbons was determined by a gravimetric method with a vacuum microbalance. The Henry constants were evaluated from the equilibrium measurements in the low-concentration range, and their sequence propane {lt} butane {lt} trans-butene {lt} propylene {lt} 1-butene {lt} cis-butene, was discussed in terms of the different adsorbate-adsorbent interactions. Equilibrium data, over the whole pressure range, were correlated by using the simplified model by Ruthven, based on statistical thermodynamics, and the appropriate parameters are reported. For C4 hydrocarbons, the intracrystalline diffusion process was also investigated and the Darken equation was used to correlate the uptake curves at the higher pressures. The diffusion coefficients were found in the order butane {gt} trans-butene {gt} 1-butene {gt} cis-butene and were compared to the available values in literature.

  6. Estimation of lower flammability limits of C-H compounds in air at atmospheric pressure, evaluation of temperature dependence and diluent effect.

    PubMed

    Mendiburu, Andrés Z; de Carvalho, João A; Coronado, Christian R

    2015-03-21

    Estimation of the lower flammability limits of C-H compounds at 25 °C and 1 atm; at moderate temperatures and in presence of diluent was the objective of this study. A set of 120 C-H compounds was divided into a correlation set and a prediction set of 60 compounds each. The absolute average relative error for the total set was 7.89%; for the correlation set, it was 6.09%; and for the prediction set it was 9.68%. However, it was shown that by considering different sources of experimental data the values were reduced to 6.5% for the prediction set and to 6.29% for the total set. The method showed consistency with Le Chatelier's law for binary mixtures of C-H compounds. When tested for a temperature range from 5 °C to 100 °C, the absolute average relative errors were 2.41% for methane; 4.78% for propane; 0.29% for iso-butane and 3.86% for propylene. When nitrogen was added, the absolute average relative errors were 2.48% for methane; 5.13% for propane; 0.11% for iso-butane and 0.15% for propylene. When carbon dioxide was added, the absolute relative errors were 1.80% for methane; 5.38% for propane; 0.86% for iso-butane and 1.06% for propylene.

  7. Geochemical assessment of light gaseous hydrocarbons in near-surface soils of Kutch-Saurashtra: Implication for hydrocarbon prospects

    NASA Astrophysics Data System (ADS)

    Rao, P. Lakshmi Srinivasa; Madhavi, T.; Srinu, D.; Kalpana, M. S.; Patil, D. J.; Dayal, A. M.

    2013-02-01

    Light hydrocarbons in soil have been used as direct indicators in geochemical hydrocarbon exploration, which remains an unconventional path in the petroleum industry. The occurrence of adsorbed soil gases, methane and heavier homologues were recorded in the near-surface soil samples collected from Kutch-Saurashtra, India. Soil gas alkanes were interpreted to be derived from deep-seated hydrocarbon sources and have migrated to the surface through structural discontinuities. The source of hydrocarbons is assessed to be thermogenic and could have been primarily derived from humic organic matter with partial contribution from sapropelic matter. Gas chromatographic analyses of hydrocarbons desorbed from soil samples through acid extraction technique showed the presence of methane through n-butane and the observed concentrations (in ppb) vary from: methane (C1) from 4-291, ethane (C2) from 0-84, propane (C3) from 0-37, i-butane (iC4) from 0-5 and n-butane (nC4) from 0-4. Carbon isotopes measured for methane and ethane by GC-C-IRMS, range between -42.9‰ to -13.3‰ (Pee Dee Belemnite - PDB) and -21.2‰ to -12.4‰ (PDB), respectively. The increased occurrence of hydrocarbons in the areas near Anjar of Kutch and the area south to Rajkot of Saurashtra signifies the area potential for oil and gas.

  8. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report No. 13, April 1996--June 1996

    SciTech Connect

    McCormick, R.L.; Alptekin, G.O.

    1996-07-30

    This document is the thirteenth quarterly technical progress report under Contract No. DE-AC22-92PC92110 {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane{close_quotes} and covers the period April-June 1996. The basic premise of this project is that vanadyl pyrophosphate (VPO), a catalyst used commercially in the selective oxidation of butane to maleic anhydride, can be developed as a catalyst for selective methane oxidation. Data supporting this idea include published reports indicating moderate to high selectivity in oxidation of ethane, propane, and pentane, as well as butane. Methane oxidation is a much more difficult reaction to catalyze than that of other alkanes and it is expected that considerable modification of vanadyl pyrophosphate will be required for this application. It is well known that VPO can be modified extensively with a large number of different promoters and in particular that promoters can enhance selectivity and lower the temperature required for butane conversion.

  9. Assessing Subsurface Bioaugmentation of a Mixed Culture Capable of Chlorinated Solvent Cometabolism via Molecular Methods

    NASA Astrophysics Data System (ADS)

    Dolan, M. E.; Lim, H. K.; Semprini, L.; Giovanonni, S.; Vergin, K.; McCarty, P. L.; Hopkins, G. D.

    2001-12-01

    The goal of this project is the successful bioaugmentation of a mixed culture capable of aerobic cometabolism of chlorinated solvent mixtures into an aquifer test zone at Moffett Federal Airfield, CA (Moffett). The test zone consists of two parallel well legs both fed butane and oxygen. One leg will be bioaugmented and the other will serve as an indigenous control. Injection and extraction wells and six (3 per leg) intermediately placed groundwater monitoring points will be frequently monitored for chlorinated solvents, butane, dissolved oxygen, and pH. Groundwater will also be periodically analyzed for microbial content using terminal restriction fragment length polymorphism (T-RFLP) and fluorescence in-situ hybridization (FISH) analyses. In each well leg, two fully-penetrating wells containing solid media will be periodically analyzed for microbial colonization (T-RFLP). The mixed bioaugmentation culture originated from environmental samples taken from Hanford, WA. The culture was enriched on butane and tested for viability in Moffett groundwater and aquifer solids. A clone library was created from the 16S rDNA in the mixed culture and 86 clones were sorted based on RFLP patterns. Complete sequencing of the 16S rDNA gene from the three most prevalent clones revealed 45 clones similar to Acidovorax or Hydrogenophaga, gram negative proteobacterium, and 12 clones similar to Rhodococcus, a gram positive filamentous organism. Fluorescently-labeled rRNA probes were designed for FISH analyses and appropriate restriction enzymes were chosen for T-RFLP analyses based upon the sequence information. Microcosm tests were conducted prior to the initiation of the field study to evaluate butane, 1,1-dichloroethylene (1,1-DCE), and 1,1,1-trichloroethane (TCA) degradation kinetics and microbial community composition. Bioaugmented microcosms began butane utilization sooner than non-bioaugmented ones in the presence and absence of 1,1-DCE, and were able to degrade more 1,1-DCE (up

  10. Physics of the multi-functionality of lanthanum ferrite ceramics

    SciTech Connect

    Bhargav, K. K.; Ram, S.; Majumder, S. B.

    2014-05-28

    In the present work, we have illustrated the physics of the multifunctional characteristics of nano-crystalline LaFeO{sub 3} powder prepared using auto-combustion synthesis. The synthesized powders were phase pure and crystallized into centro-symmetric Pnma space group. The temperature dependence of dielectric constant of pure LaFeO{sub 3} exhibits dielectric maxima similar to that observed in ferroelectric ceramics with non-centrosymmetric point group. The dielectric relaxation of LaFeO{sub 3} correlates well with small polaron conduction. The occurrence of polarization hysteresis in LaFeO{sub 3} (with centro-symmetric Pnma space group) is thought to be spin current induced type. The canting of the Fe{sup 3+} spins induce weak ferromagnetism in nano-crystalline LaFeO{sub 3}. Room temperature saturation magnetization of pure LaFeO{sub 3} is reported to be 3.0 emu/g. Due to the presence of both ferromagnetic as well as polarization ordering, LaFeO{sub 3} behaves like a single phase multiferroic ceramics. The magneto-electric coupling in this system has been demonstrated through the magneto-dielectric measurements which yield about 0.8% dielectric tuning (at 10 kHz) with the application of 2 T magnetic field. As a typical application of the synthesized nano-crystalline LaFeO{sub 3} powder, we have studied its butane sensing characteristics. The efficient butane sensing characteristics have been correlated to their catalytic activity towards oxidation of butane. Through X-ray photoelectron spectroscopy analyses, we detect the surface adsorbed oxygen species on LaFeO{sub 3} surface. Surface adsorbed oxygen species play major role in their low temperature butane sensing. Finally, we have hypothesized that the desorbed H{sub 2}O and O{sub 2} (originate from surface adsorbed hydroxyl and oxygen) initiate the catalytic oxidative dehydrogenation of n-butane resulting in weakening of the electrostatics of the gas molecules.

  11. The use of acetylene and 1,3-butadiene as tracers for vehicular combustion in urban air and the estimation of the contributions of vehicular emissions to benzene, and alkane concentrations in the Edmonton industrial area

    SciTech Connect

    Bailey, R.; Wong, R.; Dann, T.; Wang, D.

    1998-12-31

    Acetylene, propylene and 1,3-butadiene concentrations at two downtown urban sites in Alberta, Canada were used to characterize an area dominated by vehicular emissions. The relationship of acetylene with 1,3-butadiene at the Edmonton industrial site was similar to that observed for the two downtown sites. This suggesting that these volatile organic compounds, VOCs, can be used as tracers for vehicular emissions for the Edmonton industrial area. The tracer VOCs were found to correlate with benzene, n-butane, iso-butane, n-pentane, iso-pentane, n-heptane and n-octane concentrations for the two Alberta downtown sites. The best fit lines from the downtown sites were used to predict daily concentrations of benzene and alkanes at the Edmonton industrial site. During the winter, when benzene levels are predicted to reach a maximum of 4.5 to 6.5 m g/m{sup 3}, it is estimated that industrial sources contribute < 1 m g/m{sup 3} to ambient levels at the Edmonton industrial site. During the summer, when predicted benzene levels are at a minimum of 1 to 2 m g/m{sup 3}, industrial area sources dominate the ambient benzene levels at the Edmonton industrial site, and can contribute up to 6 m g/m{sup 3}. For alkanes, such as butane and pentane, industrial area sources or evaporative storage tank emissions dominate throughout the year. This dominance of industrial sources is also observed for n-heptane and n-octane during summer months. During the winter when predicted n-heptane and n-octane concentrations reach a maximum, 11 to 100% of ambient daily levels can be attributed to vehicular emissions.

  12. Non-methane hydrocarbons over the Eastern Mediterranean during summer, measured from northwest Cyprus

    NASA Astrophysics Data System (ADS)

    Sauvage, Carina; Derstroff, Bettina; Bourtsoukidis, Efstratios; Keßel, Stephan; Thorenz, Ute; Baker, Angela; Williams, Jonathan; Lelieveld, Jos

    2015-04-01

    In summer 2014 the CYprus Photochemistry EXperiment (CYPHEX) field campaign took place at an elevated (600m) measurement site in the north western part of Cyprus close (10 km) to the coast (35,96N, 32,4E) in order to investigate the photochemistry and air mass transport of the eastern Mediterranean. Non-methane hydrocarbons were measured with a commercial GC-FID (AMA instruments GmbH, Ulm, Germany) with a final dataset consisting of two weeks of continuous, hourly measurements for 10 NMHC. NMHCs are a class of volatile organic compounds (VOC) which are emitted by both anthropogenic and natural sources. Their predominant sink in the atmosphere is photochemically driven oxidation by OH radicals. Their atmospheric lifetimes, which range from a few days for more reactive compounds such as pentanes and butanes and up to a month for less reactive ones like ethane, make it possible to deduce photochemical histories and transport regimes from NMHC observations. Furthermore, in the presence of NOx they are important precursors for tropospheric ozone. Backward trajectories show that the airmasses reaching the measurement site had been influenced periodically by emissions from western continental Europe (France, Spain) that crossed the Mediterranean Sea and from eastern continental Europe (Greece and Turkey) more recently influenced by industrial emissions. Varying patterns in NMHC data delineates these two regimes very well, with aged western European air masses being characterized by low level ethane and with toluene and benzene being higher and more variable in plumes from eastern Europe. Additionally, atypical n-butane and i-butane ratios suggest a deviation from the expected predominant oxidation by OH, possibly indicating reaction with chlorine radicals (Cl). The dataset has been evaluated with respect to NMHC sources and oxidative history using different methods of approach.

  13. Observed and simulated global distribution and budget of atmospheric C2-C5 alkanes

    NASA Astrophysics Data System (ADS)

    Pozzer, A.; Pollmann, J.; Taraborrelli, D.; Jöckel, P.; Helmig, D.; Tans, P.; Hueber, J.; Lelieveld, J.

    2010-05-01

    The primary sources and atmospheric chemistry of C2-C5 alkanes were incorporated into the atmospheric chemistry general circulation model EMAC. Model output is compared with new observations from the NOAA/ESRL GMD Cooperative Air Sampling Network. Based on the global coverage of the data, two different anthropogenic emission datasets for C4-C5 alkanes, widely used in the modelling community, are evaluated. We show that the model reproduces the main atmospheric features of the C2-C5 alkanes (e.g., seasonality). While the simulated values for ethane and propane are within a 20% range of the measurements, larger deviations are found for the other tracers. According to the analysis, an oceanic source of butanes and pentanes larger than the current estimates would be necessary to match the observations at some coastal stations. Finally the effect of C2-C5 alkanes on the concentration of acetone and acetaldehyde are assessed. Their chemical sources are largely controlled by the reaction with OH, while the reactions with NO3 and Cl contribute only to a little extent. The total amount of acetone produced by propane, i-butane and i-pentane oxidation is 11.2 Tg/yr, 4.3 Tg/yr, and 5.8 Tg/yr, respectively. Moreover, 18.1, 3.1, 3.4, 1.4 and 4.8 Tg/yr of acetaldehyde are formed by the oxidation of ethane, propane, n-butane, n-pentane and i-pentane, respectively.

  14. Strong Hydrogen Bonded Molecular Interactions between Atmospheric Diamines and Sulfuric Acid.

    PubMed

    Elm, Jonas; Jen, Coty N; Kurtén, Theo; Vehkamäki, Hanna

    2016-05-26

    We investigate the molecular interaction between methyl-substituted N,N,N',N'-ethylenediamines, propane-1,3-diamine, butane-1,4-diamine, and sulfuric acid using computational methods. Molecular structure of the diamines and their dimer clusters with sulfuric acid is studied using three density functional theory methods (PW91, M06-2X, and ωB97X-D) with the 6-31++G(d,p) basis set. A high level explicitly correlated CCSD(T)-F12a/VDZ-F12 method is used to obtain accurate binding energies. The reaction Gibbs free energies are evaluated and compared with values for reactions involving ammonia and atmospherically relevant monoamines (methylamine, dimethylamine, and trimethylamine). We find that the complex formation between sulfuric acid and the studied diamines provides similar or more favorable reaction free energies than dimethylamine. Diamines that contain one or more secondary amino groups are found to stabilize sulfuric acid complexes more efficiently. Elongating the carbon backbone from ethylenediamine to propane-1,3-diamine or butane-1,4-diamine further stabilizes the complex formation with sulfuric acid by up to 4.3 kcal/mol. Dimethyl-substituted butane-1,4-diamine yields a staggering formation free energy of -19.1 kcal/mol for the clustering with sulfuric acid, indicating that such diamines could potentially be a key species in the initial step in the formation of new particles. For studying larger clusters consisting of a diamine molecule with up to four sulfuric acid molecules, we benchmark and utilize a domain local pair natural orbital coupled cluster (DLPNO-CCSD(T)) method. We find that a single diamine is capable of efficiently stabilizing sulfuric acid clusters with up to four acid molecules, whereas monoamines such as dimethylamine are capable of stabilizing at most 2-3 sulfuric acid molecules.

  15. Unravelling the impact of hydrocarbon structure on the fumarate addition mechanism--a gas-phase ab initio study.

    PubMed

    Bharadwaj, Vivek S; Vyas, Shubham; Villano, Stephanie M; Maupin, C Mark; Dean, Anthony M

    2015-02-14

    The fumarate addition reaction mechanism is central to the anaerobic biodegradation pathway of various hydrocarbons, both aromatic (e.g., toluene, ethyl benzene) and aliphatic (e.g., n-hexane, dodecane). Succinate synthase enzymes, which belong to the glycyl radical enzyme family, are the main facilitators of these biochemical reactions. The overall catalytic mechanism that converts hydrocarbons to a succinate molecule involves three steps: (1) initial H-abstraction from the hydrocarbon by the radical enzyme, (2) addition of the resulting hydrocarbon radical to fumarate, and (3) hydrogen abstraction by the addition product to regenerate the radical enzyme. Since the biodegradation of hydrocarbon fuels via the fumarate addition mechanism is linked to bio-corrosion, an improved understanding of this reaction is imperative to our efforts of predicting the susceptibility of proposed alternative fuels to biodegradation. An improved understanding of the fuel biodegradation process also has the potential to benefit bioremediation. In this study, we consider model aromatic (toluene) and aliphatic (butane) compounds to evaluate the impact of hydrocarbon structure on the energetics and kinetics of the fumarate addition mechanism by means of high level ab initio gas-phase calculations. We predict that the rate of toluene degradation is ∼100 times faster than butane at 298 K, and that the first abstraction step is kinetically significant for both hydrocarbons, which is consistent with deuterium isotope effect studies on toluene degradation. The detailed computations also show that the predicted stereo-chemical preference of the succinate products for both toluene and butane are due to the differences in the radical addition rate constants for the various isomers. The computational and kinetic modeling work presented here demonstrates the importance of considering pre-reaction and product complexes in order to accurately treat gas phase systems that involve intra and inter

  16. The anaerobic degradation of gaseous, nonmethane alkanes — From in situ processes to microorganisms

    PubMed Central

    Musat, Florin

    2015-01-01

    The short chain, gaseous alkanes ethane, propane, n- and iso-butane are released in significant amounts into the atmosphere, where they contribute to tropospheric chemistry and ozone formation. Biodegradation of gaseous alkanes by aerobic microorganisms, mostly bacteria and fungi isolated from terrestrial environments, has been known for several decades. The first indications for short chain alkane anaerobic degradation were provided by geochemical studies of deep-sea environments around hydrocarbon seeps, and included the uncoupling of the sulfate-reduction and anaerobic oxidation of methane rates, the consumption of gaseous alkanes in anoxic sediments, or the enrichment in 13C of gases in interstitial water vs. the source gas. Microorganisms able to degrade gaseous alkanes were recently obtained from deep-sea and terrestrial sediments around hydrocarbon seeps. Up to date, only sulfate-reducing pure or enriched cultures with ethane, propane and n-butane have been reported. The only pure culture presently available, strain BuS5, is affiliated to the Desulfosarcina–Desulfococcus cluster of the Deltaproteobacteria. Other phylotypes involved in gaseous alkane degradation have been identified based on stable-isotope labeling and whole-cell hybridization. Under anoxic conditions, propane and n-butane are activated similar to the higher alkanes, by homolytic cleavage of the C—H bond of a subterminal carbon atom, and addition of the ensuing radical to fumarate, yielding methylalkylsuccinates. An additional mechanism of activation at the terminal carbon atoms was demonstrated for propane, which could in principle be employed also for the activation of ethane. PMID:25904994

  17. A study of molecular structure, UV, IR, and 1H NMR spectra of a new dichroic dye on the basis of quinoline derivative

    NASA Astrophysics Data System (ADS)

    Shahab, Siyamak; Almodarresiyeh, Hora Alhosseini; Kumar, Rakesh; Darroudi, Mahdieh

    2015-05-01

    In this study, the structure and some molecular properties of a new substance sodium 4-[(4E)-4-[(2E)-2-(2-chloro-3-{(E)-2-[1-(4-sulfonatobutyl)quinolinium-4-yl]ethenyl}-2,3-dihydro-1H-inden-1-ylidene)ethylidene]quinolin-1(4H)-yl]butane-1-sulfonate (Q) with maximum absorption in near-IR region (λmax = 832 nm) was modeled using the Density Functional Theory method (DFT) and then synthesized. The electronic absorption spectrum of Q in dimethylformamide (DMF) solution was calculated. The UV, IR, and PMR spectra of Q were also presented.

  18. Suicide Inhibitors of Reverse Transcriptase in the Therapy of AIDS and Other Retroviruses

    DTIC Science & Technology

    1989-07-01

    Acquired Immun Deficiency Syndrome (AIDS) (7-8). The most recent evaluation of the AIDS epidemic in the U.S. (4) indicates that the currer total of...are shown below. One of the first, [N-(L-3-tran carboxyxiran-2-carbonyl)-L-leucyl]-amido (4-guanido) butane was isolated from Asperg /II japonicus and...risk of acquired immune deficiency syndrome (AIDS). Science. 2.4: 497- 500 (1983). 9. Kopkrowski H., De Freitas E.C., Harper M.E., Woliheim S.M

  19. Raman spectroscopic study of reaction dynamics

    NASA Astrophysics Data System (ADS)

    MacPhail, R. A.

    1990-12-01

    The Raman spectra of reacting molecules in liquids can yield information about various aspects of the reaction dynamics. The author discusses the analysis of Raman spectra for three prototypical unimolecular reactions, the rotational isomerization of n-butane and 1,2-difluoroethane, and the barrierless exchange of axial and equatorial hydrogens in cyclopentane via pseudorotation. In the first two cases the spectra are sensitive to torsional oscillations of the gauche conformer, and yield estimates of the torsional solvent friction. In the case of cyclopentane, the spectra can be used to discriminate between different stochastic models of the pseudorotation dynamics, and to determine the relevant friction coefficients.

  20. Copper(I) Bromide: An Alternative Emitter for Blue-Colored Flame Pyrotechnics.

    PubMed

    Juknelevicius, Dominykas; Karvinen, Eero; Klapötke, Thomas M; Kubilius, Rytis; Ramanavicius, Arunas; Rusan, Magdalena

    2015-10-19

    Copper(I) bromide was evaluated as an alternative emitter for blue flame pyrotechnic compositions. CuBr and CuCl emission spectra were recorded from a butane torch flame and compared. Cu(BrO3 )2 was synthesized and used in pyrotechnic compositions as an oxidizer and the source for the generation of CuBr species. Pyrotechnic compositions, which contained copper and potassium bromates as oxidizers, were optimized for the generation of blue flames. The experimental data, including emission spectra of the flames, chromaticity coordinates, burning rates, luminous intensities, and sensitivity tests, were analyzed and compared.

  1. Process for restoring membrane permeation properties

    DOEpatents

    Pinnau, Ingo; Toy, Lora G.; Casillas, Carlos G.

    1997-05-20

    A process for restoring the selectivity of high-flee-volume, glassy polymer membranes for condensable components over less-condensable components or non-condensable components of a gas mixture. The process involves exposing the membrane to suitable sorbent vapor, such as propane or butane, thereby reopening the microvoids that make up the free volume. The selectivity of an aged membrane may be restored to 70-100% of its original value. The selectivity of a membrane which is known to age over time can also be maintained by keeping the membrane in a vapor environment when it is not in use.

  2. Technical and economic barriers to innovative gas storage. Final report, November 1991-July 1992

    SciTech Connect

    Copeland, R.J.; Feinberg, D.A.; Hastings, G.A.

    1993-03-01

    To evaluate the technical and economic barriers to innovative natural gas storage technologies, advantages and disadvantages of several end use applications were analyzed, including on-grid deliverability of natural gas, transporting natural gas to off-grid end users, and storage of natural gas at an off-grid end user's site. Three basic innovative approaches were investigated: (1) separation of the higher molecular weight components of the pipeline gas and storage of the separated ethane, propane, butane, etc., as a liquid; (2) separation of the components with storage in the separating media; and (3) storage of the pipeline gas without changing its composition.

  3. Measurements of fugitive hydrocarbon emissions with a tunable infrared DIAL

    NASA Technical Reports Server (NTRS)

    Milton, M. J. T.; Woods, P. T.; Jolliffe, B. W.; Swann, N. R. W.; Robinson, R. A.

    1992-01-01

    A tunable infrared differential absorption lidar (DIAL) system has been designed and developed at the National Physics Lab (NPL) which is capable of making measurements throughout the spectral region 3.0 to 4.2 micro-m. It is ideally suited to measuring a range of organic and inorganic species including methane, propane, and butane. The system also has an ultraviolet channel that is capable of making simultaneous measurements of aromatic hydrocarbons such as Toluene and benzene. This paper describes the source and detection system, together with some measurements of fugitive hydrocarbon emissions performed at various petrochemical plants.

  4. Carbonaceous adsorbent regeneration and halocarbon displacement by hydrocarbon gases

    DOEpatents

    Senum, G.I.; Dietz, R.N.

    1994-04-05

    This invention describes a process for regeneration of halocarbon bearing carbonaceous adsorbents through which a carbonaceous adsorbent is contacted with hydrocarbon gases, preferably propane, butane and pentane at near room temperatures and at atmospheric pressure. As the hydrocarbon gases come in contact with the adsorbent, the hydrocarbons displace the halocarbons by physical adsorption. As a result of using this process, the halocarbon concentration and the hydrocarbon eluant is increased thereby allowing for an easier recovery of pure halocarbons. By using the process of this invention, carbonaceous adsorbents can be regenerated by an inexpensive process which also allows for subsequent re-use of the recovered halocarbons. 8 figures.

  5. Revised Charge Equilibration Parameters for More Accurate Hydration Free Energies of Alkanes.

    PubMed

    Davis, Joseph E; Patel, Sandeep

    2010-01-01

    We present a refined alkane charge equilibration (CHEQ) force field, improving our previously reported CHEQ alkane force field[1] to better reproduce experimental hydration free energies. Experimental hydration free energies of ethane, propane, butane, pentane, hexane, and heptane are reproduced to within 3.6% on average. We demonstrate that explicit polarization results in a shift in molecular dipole moment for water molecules associated with the alkane molecule. We also show that our new parameters do not have a significant effect on the alkane-water interactions as measured by the radial distribution function (RDF).

  6. Atmospheric Chemistry of Toxic Industrial Chemicals (Briefing Slides)

    DTIC Science & Technology

    2007-01-11

    22 days≥ 188 days≥ 400 days14 daysAcetylene ~4 days35 min36 min4.3 hourstrans- 2 - Butene 5 days205 days≥ 1300 yr5 daysn-Butane Cl [1 x 104 cm- 3 ...REPORT DATE (DD-MM-YYYY) 2 . REPORT TYPE 3 . DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...identical except that the lower right is accounting for the reactivity of 2 - methyl propene in the atmosphere. I’ve placed two arrows on the map to help

  7. Carbonaceous adsorbent regeneration and halocarbon displacement by hydrocarbon gases

    DOEpatents

    Senum, Gunnar I.; Dietz, Russell N.

    1994-01-01

    This invention describes a process for regeneration of halocarbon bearing carbonaceous adsorbents through which a carbonaceous adsorbent is contacted with hydrocarbon gases, preferably propane, butane and pentane at near room temperatures and at atmospheric pressure. As the hydrocarbon gases come in contact with the adsorbent, the hydrocarbons displace the halocarbons by physical adsorption. As a result of using this process, the halocarbon concentration and the hydrocarbon eluant is increased thereby allowing for an easier recovery of pure halocarbons. By using the process of this invention, carbonaceous adsorbents can be regenerated by an inexpensive process which also allows for subsequent re-use of the recovered halocarbons.

  8. Features of Transitional Regimes for Hydrocarbon Combustion in Closed Volumes and in Opened Clouds

    NASA Astrophysics Data System (ADS)

    Lin, E. E.; Tanakov, Z. V.

    2006-08-01

    We present brief review and analysis of experimental results concerned to simulation of processes both in power-plants and in open-air surface space, when burning hydrocarbons gaseous mixtures. Combustion regimes in closed volumes are considered for acetylene mixtures C2H2 + mO2 + nN2, C2H2 + mN2O + nN2 in tubes with relative length L/d = 4 - 60. Combustion of opened fuel-air clouds under regime of their collisions is considered for propane-butane, when dispersing in atmosphere from several closely located reservoirs with liquefied gas.

  9. Volatile Profiles of Emissions from Different Activities Analyzed Using Canister Samplers and Gas Chromatography-Mass Spectrometry (GC/MS) Analysis: A Case Study

    PubMed Central

    Orecchio, Santino; Fiore, Michele; Barreca, Salvatore; Vara, Gabriele

    2017-01-01

    The objective of present study was to identify volatile organic compounds (VOCs) emitted from several sources (fuels, traffic, landfills, coffee roasting, a street-food laboratory, building work, indoor use of incense and candles, a dental laboratory, etc.) located in Palermo (Italy) by using canister autosamplers and gas chromatography-mass spectrometry (GC-MS) technique. In this study, 181 VOCs were monitored. In the atmosphere of Palermo city, propane, butane, isopentane, methyl pentane, hexane, benzene, toluene, meta- and para-xylene, 1,2,4 trimethyl benzene, 1,3,5 trimethyl benzene, ethylbenzene, 4 ethyl toluene and heptane were identified and quantified in all sampling sites. PMID:28212294

  10. Analysis and tests of NASA coverted groove heat pipe

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A low-cost thermal control heat pipe having nearly covered grooves extruded in aluminum was developed at NASA. Analytical predictions of transport capability are in excellent agreement with experimental results using ammonia. Axial heat transport predictions as a function of fluid charge are presented also for methane, ethane, propane, and butane. Experimental tests show performance considerably better than that of open groove extruded pipes and comparing favorably with that of more complicated arterial/wick configurations. For ammonia at 20 C, the covert groove pipe obtained a static wicking height of 2.5 cm and an axial heat transport capability of 143 W-m.

  11. A novel triterpenoid carbon skeleton in immature sulphur-rich sediments

    NASA Astrophysics Data System (ADS)

    Schouten, Stefan; Sinninghe Damsté, Jaap S.; de Leeuw, Jan W.

    1995-03-01

    A novel S compound, 1,4-bis(2',5',5',8a'-tetramethylhexahydrothiochroman)-butane has been detected in several immature S-rich sediments, of which the desulphurized counterpart was unambiguously identified by synthesis of an authentic standard and coinjection experiments. This C skeleton of the S compound, 1,10-bis(2',2',6'-trimethylcyclohexyl)-3,8-dimethyldodecane(I), has not been reported yet in any sediment or organism. We suggest that it may be biosynthesized through an enzymatic cyclization reaction of squalene (II), which shows similarities with the biosynthesis of β,β-carotene (III) from lycopene (IV).

  12. Kinetic Studies of Nonequilibrium Plasma-Assisted Combustion

    DTIC Science & Technology

    2010-02-25

    Relative atomic oxygen concentration data is put on an absolute scale using the xenon-based optical calibration scheme of Niemi, et al [1,2...and O + O3 —> 20T . In air, the relatively low rate of recombination results in a considerable build-up of O atoms, to mole fractions of up to -1...studies by Bromley, et al .,[3], that trace (a few ppm) quantities of NO accelerate low tcmperature(~650-700 K) oxidation of butane. To study the

  13. Volatile Profiles of Emissions from Different Activities Analyzed Using Canister Samplers and Gas Chromatography-Mass Spectrometry (GC/MS) Analysis: A Case Study.

    PubMed

    Orecchio, Santino; Fiore, Michele; Barreca, Salvatore; Vara, Gabriele

    2017-02-15

    The objective of present study was to identify volatile organic compounds (VOCs) emitted from several sources (fuels, traffic, landfills, coffee roasting, a street-food laboratory, building work, indoor use of incense and candles, a dental laboratory, etc.) located in Palermo (Italy) by using canister autosamplers and gas chromatography-mass spectrometry (GC-MS) technique. In this study, 181 VOCs were monitored. In the atmosphere of Palermo city, propane, butane, isopentane, methyl pentane, hexane, benzene, toluene, meta- and para-xylene, 1,2,4 trimethyl benzene, 1,3,5 trimethyl benzene, ethylbenzene, 4 ethyl toluene and heptane were identified and quantified in all sampling sites.

  14. Hydrogen-assisted catalytic ignition characteristics of different fuels

    SciTech Connect

    Zhong, Bei-Jing; Yang, Fan; Yang, Qing-Tao

    2010-10-15

    Hydrogen-assisted catalytic ignition characteristics of methane (CH{sub 4}), n-butane (n-C{sub 4}H{sub 10}) and dimethyl ether (DME) were studied experimentally in a Pt-coated monolith catalytic reactor. It is concluded that DME has the lowest catalytic ignition temperature and the least required H{sub 2} flow, while CH{sub 4} has the highest catalytic ignition temperature and the highest required H{sub 2} flow among the three fuels. (author)

  15. Future perspectives of using hollow fibers as structured packings in light hydrocarbon distillation

    SciTech Connect

    Yang, Dali; Orler, Bruce; Tornga, Stephanie; Welch, Cindy

    2011-01-26

    Olefin and paraffin are the largest chemical commodities. Furthermore, they are major building blocks for the petrochemical industry. Each year, petroleum refining, consumes 4,500 TBtu/yr in separation energy, making it one of the most energy-intensive industries in the United States). Just considering liquefied petroleum gas (ethane/propane/butane) and olefins (ethylene and propylene) alone, the distillation energy consumption is about 400 TBtu/yr in the US. Since petroleum distillation is a mature technology, incremental improvements in column/tray design will only provide a few percent improvements in the performance. However, each percent saving in net energy use amounts to savings of 10 TBtu/yr and reduces CO{sub 2} emissions by 0.2 MTon/yr. In practice, distillation columns require 100 to 200 trays to achieve the desired separation. The height of a transfer unit (HTU) of conventional packings is typical in the range of 36-60 inch. Since 2006, we had explored using several non-selective membranes as the structured packings to replace the conventional packing materials used in propane and propylene distillation. We obtained the lowest HTU of < 8 inch for the hollow fiber column, which was >5 times shorter than that of the conventional packing materials. In 2008, we also investigated this type of packing materials in iso-/n-butane distillation. Because of a slightly larger relative volatility of iso-/n-butane than that of propane/propylene, a wider and a more stable operational range was obtained for the iso-/n-butane pair. However, all of the experiments were conducted on a small scale with flowrate of < 25 gram/min. Recently, we demonstrated this technology on a larger scale (<250 gram/min). Within the loading range of F-factor < 2.2 Pa{sup 0.5}, a pressure drop on the vapor side is below 50 mbar/m, which suggests that the pressure drop of hollow fibers packings is not an engineering barrier for the applications in distillations. The thermal stability study

  16. Atroposelective [2+2+2] cycloadditions catalyzed by a rhodium(I)-chiral phosphate system.

    PubMed

    Augé, Mylène; Barbazanges, Marion; Tran, Anh Tuan; Simonneau, Antoine; Elley, Paulin; Amouri, Hani; Aubert, Corinne; Fensterbank, Louis; Gandon, Vincent; Malacria, Max; Moussa, Jamal; Ollivier, Cyril

    2013-09-14

    Enantioselective cationic Rh(I)-catalyzed [2+2+2] cycloaddition reactions between diynes and isocyanates relying on the chiral anion strategy have been devised. In the presence of [Rh(cod)Cl]2, 1,4-bis(diphenylphosphino)butane, and the silver phosphate salt Ag(S)-TRIP as the unique source of chirality, axially chiral pyridones were isolated with ees up to 82%. This approach is novel in the field of chiral anion-mediated asymmetric catalysis since atroposelective transformations have so far remained unprecedented. It also proves to be complementary to the classical strategy based on chiral L-type ligands.

  17. Hybrid MP2/MP4 potential surfaces in VSCF calculations of IR spectra: applications for organic molecules.

    PubMed

    Knaanie, Roie; Šebek, Jiří; Kalinowski, Jaroslaw; Benny Gerber, R

    2014-02-05

    This study introduces an improved hybrid MP2/MP4 ab initio potential for vibrational spectroscopy calculations which is very accurate, yet without high computational demands. The method uses harmonic vibrational calculations with the MP4(SDQ) potential to construct an improved MP2 potential by coordinate scaling. This improved MP2 potential is used for the anharmonic VSCF calculation. The method was tested spectroscopically for four molecules: butane, acetone, ethylene and glycine. Very good agreement with experiment was found. For most of the systems, the more accurate harmonic treatment considerably improved the MP2 anharmonic results.

  18. First observations of light non-methane hydrocarbons (C2-C5) over a high altitude site in the central Himalayas

    NASA Astrophysics Data System (ADS)

    Sarangi, Tapaswini; Naja, Manish; Lal, S.; Venkataramani, S.; Bhardwaj, Piyush; Ojha, N.; Kumar, R.; Chandola, H. C.

    2016-01-01

    This study presents observations of methane (CH4) and light non-methane hydrocarbons (NMHCs) for the first time from a high altitude site Nainital (29.4°N, 79.5°E, 1958 m amsl) in the central Himalayas. The whole air samples collected with a frequency of 3 samples per week during April 2009-December 2011 are analyzed using a Gas Chromatograph equipped with Flame Ionization Detector (GC-FID). Additionally, samples were collected from two semi-urban sites (Haldwani and Pantnagar) in the adjoining Indo Gangetic plain region. CH4 and NMHCs show a distinct seasonal cycle over this region with more frequent observations of higher levels during winter (DJF) and late autumn (SON) and lower levels during the summer-monsoon (JJA). Different NMHCs exhibit better correlations during autumn/winter as compared to the summer-monsoon season. The annual mean mixing ratios of methane, ethane, ethene, propane, propene, i-butane, n-butane, acetylene, and i-pentane at Nainital are measured to be 1.9 ± 0.1 ppmv, 1.8 ± 1.0, 0.7 ± 0.9, 0.6 ± 0.8, 0.6 ± 0.7, 0.6 ± 0.7, 0.5 ± 0.6, 1.0 ± 0.8, and 0.5 ± 0.6, respectively (all in ppbv). The seasonal cycle of CH4 at Nainital is found to be similar to other global high altitude sites (Jungfraujoch and Mauna Loa) but somewhat different than a high altitude site Mt. Abu in India. NMHCs, other than ethane and propane, are found to be higher over this central Himalayan region than other sites. Additionally, composition of NMHCs is shown to be different over the study region when compared with other sites in the IGP region. A correlation study between ln((n-butane)/(ethane)) and ln((i-butane)/(ethane)) showed that oxidation by the OH radical is the main removal mechanism of these species over the central Himalaya and dilution maintains the ratios of these species. The lowest slope of propane and acetylene with CO during summer and spring are indicating absence of fresh air mass over this region. This study fills a major gap in

  19. Urban leakage of liquefied petroleum gas and its impact on Mexico City air quality

    SciTech Connect

    Blake, D.R.; Rowland, F.S.

    1995-08-18

    Alkane hydrocarbons (propane, isobutane, and n-butane) from liquefied petroleum gas (LPG) are present in major quantities throughout Mexico City air because of leakage of the unburned gas from numerous urban sources. These hydrocarbons, together with olefinic minor LPG components, furnish substantial amounts of hydroxyl radical reactivity, a major precursor to formation of the ozone component of urban smog. The combined processes of unburned leakage and incomplete combustion of LPG play significant role in causing the excessive ozone characteristic of Mexico City. Reductions in ozone levels should be possible through changes in LPG composition and lowered rates of leakage. 23 refs., 3 tabs.

  20. Laser-Initiated Free Radical Chain Reactions: Synthesis Of Hydroperoxides

    NASA Astrophysics Data System (ADS)

    Bray, R. G.; Chou, M. S.

    1984-05-01

    We have investigated the advantages of using laser-initiation for the synthesis of cumenehydroperoxide and t-butylhydroperoxide. Laser-initiation significantly improves the oxidation rates of cumene in the liquid phase and iso-butane in the vapor phase (using HBr promoters) with moderate photoefficiencies (418 and 490 respectively). The primary effect of laser-initiation is to reduce the induction period of the reaction. For the oxidation of cumene the beneficial effect of laser initiation is strongly dependent on laser wavelength, alternately enhancing (at 351 nm) or inhibiting (at 249 nm) the oxidation rate. For isobutane oxidation, laser-initiation also minimizes the HBr depletion rate relative to oxidation rate.

  1. Review of Vaccinia Virus and Baculovirus Viability Versus Virucides

    DTIC Science & Technology

    2008-03-01

    including 55% ethanol (w/w) with 10% (w/w) propan -1-ol, 5.9% (w/w) propan -1.2-diol, 5.7% (w/w) butan-1.3-diol and 0.75% phosphoric acid. In suspension...to UV radiation. TiO2 prevents UV degradation by reflecting light energy rather than absorbing and is commonly used in paints , foods and sunscreens...et al., 2003). * Virucidal effects of an alcohol-based formulation including 55% ethanol (w/w) with 10% (w/w) propan -1-ol, 5.9% (w/w) propan -1.2-diol

  2. Role of phospholipase D and diacylglycerol in activating constitutive TRPC-like cation channels in rabbit ear artery myocytes.

    PubMed

    Albert, A P; Piper, A S; Large, W A

    2005-08-01

    Previously we have described a constitutively active Ca2+-permeable non-selective cation channel in freshly dispersed rabbit ear artery myocytes that has similar properties to canonical transient receptor potential (TRPC) channel proteins. In the present study we have investigated the transduction pathways responsible for stimulating constitutive channel activity in these myocytes. Application of the pharmacological inhibitors of phosphatidylcholine-phospholipase D (PC-PLD), butan-1-ol and C2 ceramide, produced marked inhibition of constitutive channel activity in cell-attached patches and also butan-1-ol produced pronounced suppression of resting membrane conductance measured with whole-cell recording whereas the inactive isomer butan-2-ol had no effect on constitutive whole-cell or channel activity. In addition butan-1-ol had no effect on channel activity evoked by the diacylglycerol (DAG) analogue 1-oleoyl-2-acetyl-sn-glycerol (OAG). Inhibitors of PC-phospholipase C (PC-PLC) and phospholipase A2 (PLA2) had no effect on constitutive channel activity. Application of a purified PC-PLD enzyme and its metabolite phosphatidic acid to inside-out patches markedly increased channel activity. The phosphatidic acid phosphohydrolase (PAP) inhibitor dl-propranolol also inhibited constitutive and phosphatidic acid-induced increases in channel activity but had no effect on OAG-evoked responses. The DAG lipase and DAG kinase inhibitors, RHC80267 and R59949 respectively, which inhibit DAG metabolism, produced transient increases in channel activity which were mimicked by relatively high concentrations (40 microm) of OAG. The protein kinase C (PKC) inhibitor chelerythrine did not prevent channel activation by OAG but blocked the secondary inhibitory response of OAG. It is proposed that endogenous DAG is involved in the activation of channel activity and that its effects on channel activity are concentration-dependent with higher concentrations of DAG also inhibiting channel

  3. Laminar Soot Processes

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Interior of the Equipment Module for the Laminar Soot Processes (LSP-2) experiment that fly in the STS-107 Research 1 mission in 2002 (LSP-1 flew on Microgravity Sciences Lab-1 mission in 1997). The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner (yellow ellipse), similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a radiometer or heat sensor (blue circle), and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

  4. Laminar Soot Processes

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Image of soot (smoke) plume made for the Laminar Soot Processes (LSP) experiment during the Microgravity Sciences Lab-1 mission in 1997. LSP-2 will fly in the STS-107 Research 1 mission in 2002. The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner, similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a temperature sensor, and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

  5. Laminar Soot Processes

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Laminar Soot Processes (LSP) experiment under way during the Microgravity Sciences Lab-1 mission in 1997. LSP-2 will fly in the STS-107 Research 1 mission in 2001. The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner, similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a temperature sensor, and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

  6. From Saturated BN Compounds to Isoelectronic BN/CC Counterparts: An Insight from Computational Perspective.

    PubMed

    Sagan, Filip; Piękoś, Łukasz; Andrzejak, Marcin; Mitoraj, Mariusz Paweł

    2015-10-19

    In the present study, the inorganic analogues of alkanes as well as their isoelectronic BN/CC counterparts that bridge the gap between organic and inorganic chemistry are comparatively studied on the grounds of static DFT and Car-Parrinello molecular dynamics simulations. The BN/CC butanes CH3 CH2 BH2 NH3 , BH3 CH2 NH2 CH3 , and NH3 CH2 BH2 CH3 were considered and compared with their isoelectronic counterparts NH3 BH2 NH2 BH3 and CH3 CH2 CH2 CH3 . In addition, systematical replacement of the NH2 BH2 fragment by the isoelectronic CH2 CH2 moiety is studied in the molecules H3 N(NH2 BH2 )3-m (CH2 CH2 )m BH3 (for m=0, 1, 2, or 3) and H3 N(NH2 BH2 )2-m (CH2 CH2 )m BH3 (for m=0, 1, or 2). The DFT and Car-Parrinello simulations show that the isosteres of the BN/CC butanes CH3 CH2 BH2 NH3 , BH3 CH2 NH2 CH3 , and NH3 CH2 BH2 CH3 and of larger oligomers of the type (BN)k (CC)l where k≥l are stable compounds. The BN/CC butane H3 NCH2 CH2 BH3 spontaneously produces molecular hydrogen at room temperature. The reaction, prompted by very strong dihydrogen bonding NH⋅⋅⋅HB, undergoes through the neutral, hypervalent, pentacoordinated boron dihydrogen complex RBH2 (H2 ) [R=(CH2 CH2 )n NH2 ]. The calculations suggest that such intermediate and the other BN/CC butanes CH3 CH2 BH2 NH3 , BH3 CH2 NH2 CH3 , and NH3 CH2 BH2 CH3 as well as larger BN/CC oligomers are viable experimentally. A simple recipe for the synthesis of CH3 CH2 BH2 NH3 is proposed. The strength of the dihydrogen bonding appeared to be crucial for the overall stability of the saturated BN/CC derivatives.

  7. Process for restoring membrane permeation properties

    DOEpatents

    Pinnau, I.; Toy, L.G.; Casillas, C.G.

    1997-05-20

    A process is described for restoring the selectivity of high-free-volume, glassy polymer membranes for condensable components over less-condensable components or non-condensable components of a gas mixture. The process involves exposing the membrane to suitable sorbent vapor, such as propane or butane, thereby reopening the microvoids that make up the free volume. The selectivity of an aged membrane may be restored to 70--100% of its original value. The selectivity of a membrane which is known to age over time can also be maintained by keeping the membrane in a vapor environment when it is not in use. 8 figs.

  8. Monte Carlo simulation of several biologically relevant molecules and zwitterions in water

    NASA Astrophysics Data System (ADS)

    Patuwo, Michael Y.; Bettens, Ryan P. A.

    2012-02-01

    In this work, we study the hydration free energies of butane, zwitterionic alanine, valine, serine, threonine, and asparagine, and two neuraminidase inhibitors by means of Monte Carlo (MC) simulation. The solute molecule, represented in the form of distributed multipoles and modified 6-12 potential, was varied from a non-interacting 'ghost' molecule to its full potential functions in TIP4P water. Intermediate systems with soft-core solute-solvent interaction potentials are simulated separately and then subjected to Bennett's Acceptance ratio (BAR) for the free energy calculation. Hydration shells surrounding the solute particles were used to assess the quality of potential functions.

  9. Regioselective alkane hydroxylation with a mutant CYP153A6 enzyme

    SciTech Connect

    Koch, Daniel J.; Arnold, Frances H.

    2013-01-29

    Cytochrome P450 CYP153A6 from Myobacterium sp. strain HXN1500 was engineered using in-vivo directed evolution to hydroxylate small-chain alkanes regioselectively. Mutant CYP153A6-BMO1 selectively hydroxylates butane and pentane at the terminal carbon to form 1-butanol and 1-pentanol, respectively, at rates greater than wild-type CYP153A6 enzymes. This biocatalyst is highly active for small-chain alkane substrates and the regioselectivity is retained in whole-cell biotransformations.

  10. Investigation of a Bicyclo[1.1.1]pentane as a Phenyl Replacement within an LpPLA2 Inhibitor.

    PubMed

    Measom, Nicholas D; Down, Kenneth D; Hirst, David J; Jamieson, Craig; Manas, Eric S; Patel, Vipulkumar K; Somers, Don O

    2017-01-12

    We describe the incorporation of a bicyclo[1.1.1]pentane moiety within two known LpPLA2 inhibitors to act as bioisosteric phenyl replacements. An efficient synthesis to the target compounds was enabled with a dichlorocarbene insertion into a bicyclo[1.1.0]butane system being the key transformation. Potency, physicochemical, and X-ray crystallographic data were obtained to compare the known inhibitors to their bioisosteric counterparts, which showed the isostere was well tolerated and positively impacted on the physicochemical profile.

  11. Thermal non-oxidative aromatization of light alkanes catalyzed by gallium nitride.

    PubMed

    Li, Lu; Mu, Xiaoyue; Liu, Wenbo; Kong, Xianghua; Fan, Shizhao; Mi, Zetian; Li, Chao-Jun

    2014-12-15

    The thermal catalytic activity of GaN in non-oxidative alkane dehydroaromatization has been discovered for the first time. The origin of the catalytic activity was studied experimentally and theoretically. Commercially available GaN powders with a wurtzite crystal structure showed superior stability and reactivity for converting light alkanes, including methane, propane, n-butane, n-hexane and cyclohexane into benzene at an elevated temperature with high selectivity. The catalyst is highly robust and can be used repeatedly without noticeable deactivation.

  12. Atmospheric Chemistry of Hydrocarbon Fuels. Volume 2. Outdoor Chamber Data Tabulations. Part 1

    DTIC Science & Technology

    1981-11-01

    measurements of temperature, WV intensity, and (in some cases) dew point. 1 "* Initial concentrations of NO, N02 , toval hydrocarbon, and (for n- butane...RATE ID LABEL DESCRIPTION (ML/ MTN ) 1790 D-1790 DASIBI 1790 OZONE MONITOR 4600 B-NOX-1 BENDIX 8101BX NOX ANALYZER) SN300038-2 1600 BK6800-2 BECKMAN...3 1505 3245 4, 3 1515 3255 14, NO DATA WAKEN S S AFF- 55 JP-1O, DYNAMIC 1980,DEC 10-12 DAY 1 (DEC 10) 705: BAG FILLED WITH PURE AIR. 705: DEW PT

  13. Towards reproducible, scalable lateral molecular electronic devices

    SciTech Connect

    Durkan, Colm Zhang, Qian

    2014-08-25

    An approach to reproducibly fabricate molecular electronic devices is presented. Lateral nanometer-scale gaps with high yield are formed in Au/Pd nanowires by a combination of electromigration and Joule-heating-induced thermomechanical stress. The resulting nanogap devices are used to measure the electrical properties of small numbers of two different molecular species with different end-groups, namely 1,4-butane dithiol and 1,5-diamino-2-methylpentane. Fluctuations in the current reveal that in the case of the dithiol molecule devices, individual molecules conduct intermittently, with the fluctuations becoming more pronounced at larger biases.

  14. Synthesis and characterization of group V metal carbide and nitride catalysts

    NASA Astrophysics Data System (ADS)

    Kwon, Heock-Hoi

    1998-11-01

    Group V transition metal carbides and nitrides were prepared via the temperature programmed reaction (TPR) of corresponding oxides with NHsb3 or a CHsb4/Hsb2 mixture. Except for the tantalum compounds, phase-pure carbides and nitrides were prepared. The vanadium carbides and nitrides were the most active and selective catalysts. Therefore the principal focus of the research was the preparation, characterization, and evaluation of high surface area vanadium nitride catalysts. A series of vanadium nitrides with surface areas up to 60 msp2/g was prepared. Thermal gravimetric analysis coupled with x-ray diffraction and scanning electron microscopy indicated that the solid-state reaction proceeded by the sequential reduction of Vsb2Osb5 to VOsb{0.9} and concluded with the topotactic substitution of nitrogen for oxygen in VOsb{0.9}. The transformation of Vsb2Osb5 to VN was pseudomorphic. An experimental design was executed to determine effects of the heating rates and space velocities on the VN microstructures. The heating rates had minor effects on the surface areas and pore size distributions; however, increasing the space velocity significantly increased the surface area. The materials were mostly mesoporous. Oxygen chemisorption on the vanadium nitrides scaled linearly with the surface area. The corresponding O/Vsbsurface ratio was ≈0.6. The vanadium nitrides were active for butane activation and pyridine hydrodenitrogenation. During butane activation, their selectivities towards dehydrogenation products were as high as 98%. The major product in pyridine hydrodenitrogenation was pentane. The reaction rates increased almost linearly with the surface area suggesting that these reactions were structure insensitive. The vanadium nitrides were not active for crotonaldehyde hydrogenation; however, they catalyzed an interesting ring formation reaction that produced methylbenzaldehyde and xylene from crotonaldehyde. A new method was demonstrated for the production of very

  15. LABORATORY STUDIES ON THE IRRADIATION OF SOLID ETHANE ANALOG ICES AND IMPLICATIONS TO TITAN'S CHEMISTRY

    SciTech Connect

    Kim, Y. S.; Bennett, C. J.; Chen, L-H; Kaiser, R. I.; O'Brien, K.

    2010-03-10

    Pure ethane ices (C{sub 2}H{sub 6}) were irradiated at 10, 30, and 50 K under contamination-free, ultrahigh vacuum conditions with energetic electrons generated in the track of galactic cosmic-ray (GCR) particles to simulate the interaction of GCRs with ethane ices in the outer solar system. The chemical processing of the samples was monitored by a Fourier transform infrared spectrometer and a quadrupole mass spectrometer during the irradiation phase and subsequent warm-up phases on line and in situ in order to extract qualitative (products) and quantitative (rate constants and yields) information on the newly synthesized molecules. Six hydrocarbons, methane (CH{sub 4}), acetylene (C{sub 2}H{sub 2}), ethylene (C{sub 2}H{sub 4}), and the ethyl radical (C{sub 2}H{sub 5}), together with n-butane (C{sub 4}H{sub 10}) and butene (C{sub 4}H{sub 8}), were found to form at the radiation dose reaching 1.4 eV per molecule. The column densities of these species were quantified in the irradiated ices at each temperature, permitting us to elucidate the temperature and phase-dependent production rates of individual molecules. A kinetic reaction scheme was developed to fit column densities of those species produced during irradiation of amorphous/crystalline ethane held at 10, 30, or 50 K. In general, the yield of the newly formed molecules dropped consistently for all species as the temperature was raised from 10 K to 50 K. Second, the yield in the amorphous samples was found to be systematically higher than in the crystalline samples at constant temperature. A closer look at the branching ratios indicates that ethane decomposes predominantly to ethylene and molecular hydrogen, which may compete with the formation of n-butane inside the ethane matrix. Among the higher molecular products, n-butane dominates. Of particular relevance to the atmosphere of Saturn's moon Titan is the radiation-induced methane production from ethane-an alternative source of replenishing methane into the

  16. Evaluation of oxime k203 as antidote in tabun poisoning.

    PubMed

    Kovarik, Zrinka; Vrdoljak, Ana Lucić; Berend, Suzana; Katalinić, Maja; Kuc, Kamil; Musilek, Kamil; Radić, Bozica

    2009-03-01

    We studied bispyridinium oxime K203 [(E)-1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide] with tabun-inhibited human acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in vitro, and its antidotal effect on tabun-poisoned mice and rats in vivo. We compared it with oximes K048 and TMB-4, which have proven the most efficient oxime antidotes in tabun poisoning by now. Tabun-inhibited AChE was completely reactivated by K203, with the overall reactivation rate constant of 1806 L mol(-1) min(-1). This means that K203 is a very potent reactivator of tabun-inhibited AChE. In addition, K203 reversibly inhibited AChE (Ki = 0.090 mmol L(-1)) and BChE (K(i) = 0.91 mmol L(-1)), and exhibited its protective effect against phosphorylation of AChE by tabun in vitro. In vivo, a quarter of the LD50 K203 dose insured survival of all mice after the application of as many as 8 LD50 doses of tabun, which is the highest dosage obtained compared to K048 and TMB-4. Moreover, K203 showed high therapeutic potency in tabun-poisoned rats, preserving cholinesterase activity in rat plasma up to 60 min after poisoning. This therapeutic improvement obtained by K203 in tabun-poisoning places this oxime in the spotlight for further development.

  17. The antidotal efficacy of the bispyridinium oximes K027 and TMB-4 against tabun poisoning in mice.

    PubMed

    Berend, Suzana; Radić, Bozica; Kuca, Kamil; Lucić Vrdoljak, Ana

    2010-09-06

    A toxic effect of highly toxic nervous agents is irreversible inhibition of vitally important enzyme acethylcholinesterase (AChE). Inhibition of AChE results in accumulation of acetylcholine (ACh) at the synaptic cleft of the cholinergic neurons, leading to overstimulation of cholinergic receptors. The highly toxic nature of tabun has been known for many years, but there are still serious limitations to the antidotal therapy. In this paper a bispyridinium compound K027 [1-(4-hydroxyiminomethylpyridinium)-3-(-4-carbamoylpyridinium) propane dibromide] was tested as potential antidote in tabun poisoned mice. Oxime TMB-4 was included for comparison. The therapeutic efficacy of applied antidotal regimens was tested as pretreatment given 15 min before tabun poisoning and/or as therapy given 1 min after tabun poisoning. Using oxime K027 (25% of its LD(50)) plus atropine as both, pretreatment and therapy, we showed that this combination can protect mice 8 times better than the therapy alone. Under these experimental conditions we confirmed good antidotal efficacy of K027. Moreover, its low acute toxicity is as much as beneficial effect in contrast to high toxicity of currently used TMB-4.

  18. Glucose and lactate are equally effective in energizing activity-dependent synaptic vesicle turnover in purified cortical neurons.

    PubMed

    Morgenthaler, F D; Kraftsik, R; Catsicas, S; Magistretti, P J; Chatton, J-Y

    2006-08-11

    This study examines the role of glucose and lactate as energy substrates to sustain synaptic vesicle cycling. Synaptic vesicle turnover was assessed in a quantitative manner by fluorescence microscopy in primary cultures of mouse cortical neurons. An electrode-equipped perfusion chamber was used to stimulate cells both by electrical field and potassium depolarization during image acquisition. An image analysis procedure was elaborated to select in an unbiased manner synaptic boutons loaded with the fluorescent dye N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl)pyridinium dibromide (FM1-43). Whereas a minority of the sites fully released their dye content following electrical stimulation, others needed subsequent K(+) depolarization to achieve full release. This functional heterogeneity was not significantly altered by the nature of metabolic substrates. Repetitive stimulation sequences of FM1-43 uptake and release were then performed in the absence of any metabolic substrate and showed that the number of active sites dramatically decreased after the first cycle of loading/unloading. The presence of 1 mM glucose or lactate was sufficient to sustain synaptic vesicle cycling under these conditions. Moreover, both substrates were equivalent for recovery of function after a phase of decreased metabolic substrate availability. Thus, lactate appears to be equivalent to glucose for sustaining synaptic vesicle turnover in cultured cortical neurons during activity.

  19. Adaptive downregulation of pheomelanin-related Slc7a11 gene expression by environmentally induced oxidative stress.

    PubMed

    Galván, Ismael; Inácio, Ângela; Romero-Haro, Ana Angela; Alonso-Alvarez, Carlos

    2017-02-01

    Pheomelanin is a sulphur-containing yellow-to-reddish pigment whose synthesis consumes the main intracellular antioxidant (glutathione; GSH) and its precursor cysteine. Cysteine used for pheomelanogenesis cannot be used for antioxidant protection. We tested whether the expression of Slc7a11, the gene regulating the transport of cysteine to melanocytes for pheomelanogenesis, is environmentally influenced when cysteine/GSH are most required for antioxidant protection. We found that zebra finches Taeniopygia guttata developing pheomelanin-pigmented feathers during a 12-day exposure to the pro-oxidant diquat dibromide downregulated the expression of Slc7a11 in feather melanocytes, but not the expression of other genes that affect pheomelanogenesis by mechanisms different from cysteine transport such as MC1R and Slc45a2. Accordingly, diquat-treated birds did not suffer increased oxidative stress. This indicates that some animals have evolved an adaptive epigenetic lability that avoids damage derived from pheomelanogenesis. This mechanism should be explored in human Slc7a11 to help combat some cancer types related to cysteine consumption.

  20. DFT investigation of the mecahanism and stereochemistry of electrophilic transannular addition reaction of bromine to tricyclo[4.2.2.02,5]deca-3,7-diene.

    PubMed

    Abbasoglu, Rza; Misir, Miraç Nedim

    2012-03-01

    Full geometric optimization of tricyclo[4.2.2.02,5]deca-3,7-diene (TDD) has been done by DFT/B3LYP methods and the structure of the molecule was investigated. Cyclobuten double bond (I) of molecule is syn pyramidalized, and bicyclookten double bond (II) is also exo pyramidalized. The double bond (I) is more pyramidalized than the double bond (II) and it has higher reactivity. The TDD-Br2 system has been investigated by B3LYP/6-311++G(d,p) method and their stable configurations have been determined. The cationic intermediates and products obtained as a result of the addition reaction has been studied using B3LYP/6-311G(d,p) and B3LYP/6-311++G(d,p) methods. Bridged bromonium cation is more stable than U-type cation. Considering that the bridged cation does not isomerize to the less stable U-type cation, it is not possible for the U-type product to be obtained in the reaction. The bridged bromonium cation transformed into the more stable N-type cation and the N-type product was obtained via this cation. The thermodynamic stability of the anti, exo and anti, endo isomers of N-type dibromide molecule were almost identical. N-type product is 11.759 kcal mol more stable than U-type product.