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

  1. AUTOMOTIVE EMISSIONS OF ETHYLENE DIBROMIDE

    EPA Science Inventory

    Ethylene dibromide, a suspected carcinogen, and ethylene dichloride are commonly used in leaded gasoline as scavengers. Ethylene dibromide emission rates were determined from seven automobiles which had a wide range of control devices, ranging from totally uncontrolled to evapora...

  2. Bithalamic lesions of butane encephalopathy.

    PubMed

    Kile, Shawn J; Camilleri, Christopher C; Latchaw, Richard E; Tharp, Barry R

    2006-12-01

    Butane inhalation can cause serious medical complications and is particularly toxic to the nervous system. This is a report of an acutely encephalopathic youth with prominent abulia. MRI revealed severe bithalamic injury attributed to butane toxicity. Clinical issues, including particular radiologic findings, related to butane inhalation are reviewed. PMID:17138017

  3. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR ETHYLENE DIBROMIDE

    EPA Science Inventory

    Ethylene dibromide (EDB; C2H4BR2; CASRN 106-93-4), also known as 1,2-dibromoethane, is a colorless, heavy liquid that has a mildly sweet, chloroform-like odor. It is currently used as a solvent for resins, gums, and waxes, as a chemical intermediate in the synthesis of dyes and ...

  4. 40 CFR 80.82 - Butane blending.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.82 Butane blending. A refiner for any refinery that produces gasoline by blending butane with conventional gasoline or reformulated gasoline or RBOB may meet... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Butane blending. 80.82 Section...

  5. 40 CFR 80.82 - Butane blending.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.82 Butane blending. A refiner for any refinery that produces gasoline by blending butane with conventional gasoline or reformulated gasoline or RBOB may meet... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Butane blending. 80.82 Section...

  6. 40 CFR 80.82 - Butane blending.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.82 Butane blending. A refiner for any refinery that produces gasoline by blending butane with conventional gasoline or reformulated gasoline or RBOB may meet... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Butane blending. 80.82 Section...

  7. 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...

  8. 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...

  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, 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 FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1165 n-Butane and iso-butane....

  11. Genetic effects of ethylene dibromide in Drosophila melanogaster

    SciTech Connect

    Kale, P.; Baum, J.W.

    1981-01-01

    Drosophila, an organism known to be one of the best among the available systems for mutation detection, can be used for detecting very low concentrations of airborne mutagens. Using ethylene dibromide (EDB), it was demonstrated that Drosophila could detect concentrations as low as 0.2 ppM in air when exposed for a relatively short period of 11 hrs. The exposure period can be prolonged to as many as 700 hrs using Drosophila. Response was proportional to integrated exposure in ppM-hr at low exposure values. It is, therefore, possible to detect airborne mutagens in the parts per billion range using proper germ cell stages in this system. Drosophila may, therefore, be used as a biological monitor to detect mutagenicity of air in polluted areas. Thus, the system may complement Tradescantia, another sensitive system being used for this purpose. Ethylene dibromide was selected as a test chemical in these studies since its mutagenic properties had previously been demonstrated in Drosophila and in Tradescantia. In Tradescantia, extensive data on the dose vs. mutation relation were available and these data were considered useful in evaluating the comparative sensitivity of the two systems for detecting airborne mutagens.

  12. Postmortem diffusion of n-butane and i-butane used for anticontagious plugging spray.

    PubMed

    Okuda, Katsuhiro; Maseda, Chikatoshi; Asari, Masaru; Isozaki, Shotaro; Kiya, Hiroshi; Yajima, Daisuke; Shiono, Hiroshi; Shimizu, Keiko

    2016-03-01

    Blood and tissue samples from a forensic autopsy of a man in his late 60s, who developed dementia and died of multiple head traumas due to a fall from a moving vehicle, contained certain amounts of n-butane and i-butane. The concentration of n-butane was in the range of 0.48-70.5 μL/g, which would be considered as toxic or lethal levels. We had to distinguish whether the cause of his unexplained behavior was due to his pre-existing condition (dementia), or from a confused state induced by butane abuse. No traces of butane use were found at the scene. Police investigation revealed that a propellant used in an anticontagious plugging spray had been administered to him during a postmortem treatment in the emergency hospital. In order to prove the postmortem butane diffusion had resulted from the spray administration and to estimate the diffused concentration, experimental simulation was conducted by using rats. As a result of postmortem treatment with the spray, n-butane at concentrations of 0.54-15.5 μL/mL or g were found in the rat blood and tissues. In this case, we provided further evidence that the postmortem butane diffusion, caused by using the anticontagious plugging spray containing butane gas as a propellant administered to a cadaver during a postmortem procedure prior to forensic autopsy, should be distinguished from cases of actual butane poisoning. PMID:26318540

  13. 40 CFR 80.82 - Butane blending.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.82 Butane blending. A refiner for any refinery that... the provisions of § 80.101(g)(3). For purposes of this paragraph (h)(1), the property values in §...

  14. 40 CFR 80.82 - Butane blending.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.82 Butane blending. A refiner for any refinery that...). For purposes of this paragraph (i)(1), the property values in § 80.82(c) or (d), as appropriate,...

  15. 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 FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  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. A cytogenetic study of papaya workers exposed to ethylene dibromide.

    PubMed

    Steenland, K; Carrano, A; Ratcliffe, J; Clapp, D; Ashworth, L; Meinhardt, T

    1986-06-01

    Ethylene dibromide (EDB) has been shown to be carcinogenic in animal studies and mutagenic in vitro. One cytogenetic study of workers exposed to low levels of EDB for short durations was negative. To test whether exposure to low levels of EDB over long periods caused cytogenetic changes, we have assessed the frequencies of sister-chromatid exchanges (SCE) and chromosomal aberrations (CA) in the peripheral blood lymphocytes of 60 men occupationally exposed to EDB. These men worked in papaya-packing plants where EDB was used to fumigate the fruit after harvest to kill fruit-fly larvae. 42 other men who worked at a nearby sugar mill served as controls. The average duration of exposure of the papaya workers was 5 years. 82 full shift personal breathing-zone air samples indicated that the papaya workers were exposed to a geometric mean of 88 ppb of EDB, as an 8-h time weighted average (TWA). Peaks up to 262 ppb were measured. The proposed OSHA 8-h TWA for EDB is 100 ppb, while NIOSH recommends 45 ppb. No differences in SCE levels were found between exposed and nonexposed workers. No differences were found in the total CA frequency between exposed and nonexposed workers. SCE levels were significantly increased in men who smoked cigarettes (p = 0.0001) and in men who smoked marijuana (p = 0.01). CA levels showed a significant increasing trend with age (p = 0.03). PMID:3520305

  19. Excess molar enthalpies of ternary systems butan-1-ol or butan-2-ol + aniline + propanone and of binary systems butan-1-ol or butan-2-ol + propanone at the temperature 298.15 K

    SciTech Connect

    Nagata, Isamu; Tamura, Kazuhiro; Kataoka, Hideo; Ksiazczak, A.

    1996-05-01

    The excess molar enthalpies at the temperature 298.15 K for ternary systems butan-1-ol + aniline + propanone and butan-2-ol + aniline + propanone and their constituent binary systems butan-1-ol + propanone and butan-2-ol + propanone, measured with an isothermal dilution calorimeter, are reported. The experimental results have been analyzed and compared with a polynomial equation and the UNIQUAC-associated solution model with binary and ternary additional parameters.

  20. 21 CFR 582.1165 - Butane.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives §...

  1. 21 CFR 582.1165 - Butane.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Butane. 582.1165 Section 582.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives §...

  2. DNA adducts of ethylene dibromide: Aspects of formation and mutagenicity

    SciTech Connect

    Cmarik, J.L.

    1991-01-01

    1,2-Dibromoethane (ethylene dibromide, EDB), a potential human carcinogen, undergoes bioactivation by the pathway of glutathione (GSH) conjugation, which generates a reactive intermediate capable of alkylating DNA. The major DNA adduct formed is S-[2-(N[sup 7]-guanyl)ethyl]GSH. This dissertation examined the bioactivation of EDB and the formation of DNA adducts. The selectivity of purified rat and human GSH S-transferases for EDB was examined in vitro. An assay was developed to measure the formation of S,S[prime]-ethylene-bis(GSH). The [alpha] class of the GSH S-transferases was responsible for the majority of EDB-GSH conjugation with both the rat and human enzymes. Human tissue samples for a victim of EDB poisoning were analyzed for S-[2-(N[sup 7]-guanyl)ethyl]GSH utilizing electrochemical detection. No adducts were detected in samples of brain, heart, or kidney. The pattern of alkylation of guanines in fragments of plasmid pBR322 DNA by S-(2-chloroethyl)GSH and related compounds was determined. Alkylation varied approximately ten-fold in intensity and was strongest in runs of guanines. Few differences were observed in the alkylation patterns generated by the different compounds tested. The spectrum of mutations caused by S-(2-chloroethyl)GSH was determined using an M13 bacteriophage forward mutation assay. The majority of mutations (70%) were G:C to A:T transitions. Participation of the N[sup 7]-guanyl adduct in the mutagenic process is strongly implicated. The sequence selectivity of alkylation in the region of M13 sequenced in the mutation assay was determined. Comparison of the sequence selectivity with the mutation spectrum revealed no obligate relationship between the extent of adduct formation and the number of mutations which resulted at different sites. Sequence context appears to exert a strong influence on the processing of lesions. These studies strongly implicate S-[2-(N[sup 7]-guanyl)-ethyl]GSH as a mutagenic lesion formed by EDB.

  3. 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

  4. 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... delete certain uses which are identified in Table 1 of Unit III. Chloropicrin is a nonselective soil... (seed Concentrate. crop only). 5785-17 Chlor-O-Pic Chloropicrin Mushroom casing soil, potting soil,...

  5. 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...

  6. 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.

  7. 40 CFR 80.835 - What requirements apply to butane blenders?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics Gasoline Toxics Performance Requirements § 80.835 What requirements apply to butane blenders? Butane blenders who blend butane...

  8. Alkyl bromides as mechanistic probes of reductive dehalogenation: reactions of vicinal dibromide stereoisomers with zerovalent metals.

    PubMed

    Totten, L A; Jans, U; Roberts, A L

    2001-06-01

    Whether reductive dehalogenation proceeds via a one- or a two-electron mechanism has been suggested to affect product distributions, hence potentially influencing the success of engineered treatment systems. In this work, we explore vicinal dibromide stereoisomers as "probes" of the concertedness of electron transfer in reduction by aqueous suspensions of iron and zinc metal. Dibromides consisted of 2,3-dibromopentane (diBP) stereoisomers and (+/-)-1,2-dibromo-1,2-diphenylethane. All dibromides reacted with metals to give the same E:Z ratio of olefins observed during dehalogenation by iodide (a two-electron reductant). Reduction by Cr(II) (a one-electron reductant) yielded distinctly different proportions of E and Z olefins. Although this might be construed as evidence that metals function as two-electron reductants, high stereo-specificity was also obtained for reduction of diBPs by Fe(II) adsorbed to goethite, a presumed one-electron reductant; this can be explained by two single-electron transfers in rapid succession, facilitated by the locally elevated concentration of reducing equivalents at the oxide-water interface. The results suggest that reduction of alkyl halides by metals is not likely to produce free radicals that persist long enough to undergo radical-radical coupling or hydrogen-atom abstraction from minor dissolved constituents. Apparent free-radical coupling products are more likely to result from (possibly surface-bound) organometallic intermediates. PMID:11414030

  9. 40 CFR 80.835 - What requirements apply to butane blenders?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false What requirements apply to butane blenders? 80.835 Section 80.835 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Requirements § 80.835 What requirements apply to butane blenders? Butane blenders who blend butane...

  10. 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.

  11. The molecular structure of barium dibromide: an electron diffraction and quantum chemical study

    NASA Astrophysics Data System (ADS)

    Hargittai, Magdolna; Kolonits, Mária; Schultz, György

    2001-06-01

    The molecular structure of barium dibromide was determined by gas-phase electron diffraction, ab initio quantum chemical calculations, and joint electron diffraction/vibratonal spectroscopic analyses. All techniques yield consistently an unambiguously bent geometry. The following geometrical parameters were obtained: rg(Ba-Br) 2.911±0.006 Å, re(Ba-Br) 2.899±0.007 Å, ∠ aBr-Ba-Br 137.0±2.5° and ∠ eBr-Ba-Br 137.1±4.9°.

  12. 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. PMID:26800050

  13. 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.

  14. Toxic exposure to ethylene dibromide and mercuric chloride: effects on laboratory-reared octopuses.

    PubMed

    Adams, P M; Hanlon, R T; Forsythe, J W

    1988-01-01

    The effects of acute and chronic exposure to either ethylene dibromide (EDB) or mercuric chloride (MC) were studied in laboratory-reared Octopus joubini, O. maya and O. bimaculoides. The advantages of using octopuses were that the responses were immediate, highly visible and sensitive. All species demonstrated signs of toxicity to acute and chronic exposure to EDB and to MC. A dosage-sensitive relationship for the loss and subsequent recovery of locomotor response and of chromatophore expansion was found for each species after acute exposure. For each species the LC50 for chronic exposure occurred within 12 hr at 100 mg/l for EDB and within 3 hr at 1,000 mg/l for MC. This study demonstrated the potential usefulness of laboratory-reared octopuses in evaluating the toxicity of marine environmental pollutants. PMID:3072470

  15. 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.

  16. 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.

  17. Ethylene dibromide: Biochemical effects and environmental concerns. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning the toxicity and environmental issues pertaining to the fumigant ethylene dibromide. Topics include effects on liver activity, respiratory systems and DNA synthesis in laboratory animals, comparisons and synergistic effects with other pesticides, and occupational health considerations. The distribution of the compound in the environment and its effectiveness as a fumigant are also considered. (Contains a minimum of 100 citations and includes a subject term index and title list.)

  18. Diffusion of 2-iodo-butane (1); helium (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) 2-iodo-butane; (2) helium

  19. Diffusion of 1-iodo-butane (1); helium (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) 1-iodo-butane; (2) helium

  20. 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.

  1. Two cases of acute propane/butane poisoning in prison.

    PubMed

    Rossi, Riccardo; Suadoni, Fabio; Pieroni, Ludovica; De-Giorgio, Fabio; Lancia, Massimo

    2012-05-01

    Hydrocarbon inhalation is seldom chosen as a means to commit suicide. This practice is exclusively a prerogative of the prison population; it is, however, only exceptionally found in this environment. The two cases of lethal inhalation of propane/butane gas observed by us over a very short time occurred in this context. Toxicologic analyses were performed by means of gas chromatography (head space) and revealed a propane/butane mixture in all specimens (heart blood, bile, and urine) except vitreous humor. Although fatal arrhythmia posthydrocarbon gas abuse is well known, the concentrations of the two hydrocarbons were sufficient to induce death by asphyxiation and were distributed (fairly) homogeneously in all biological fluids and organs examined, a parameter permitting one to assume that death occurred within a relatively short period of time. The absence of finding in vitreous humor and the trace amount in urine suggests that both men died very quickly. PMID:22150071

  2. Use fluid bed reactor for maleic anhydride from butane

    SciTech Connect

    Arnold, S.C.; Neri, A.; Suciu, G.D.; Verde, L.

    1985-09-01

    A new process is described that incorporates three major improvements over the conventional air oxidation of benzene in a fixed-bed reactor system. The new ALMA Process was developed jointly by Alusuisse Italia and Lummus Crest. It includes the following process improvements: n-Butane feedstock, fluidized-bed reactor system, and a continuous maleic anhydride recovery system using an organic solvent. A summary of the process is given, as well as the steps in its development and its economic advantages.

  3. 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).

  4. Derivatization of ethylene dibromide with silica-supported silver picrate for improved high-performance liquid chromatographic detection

    SciTech Connect

    Colgan, S.T.; Krull, I.S.; Dorschel, C.; Bidlingmeyer, B.

    1986-10-01

    Silica-supported silver picrate was used as an off-line, precolumn derivatization reagent for ethylene dibromide (EDB). Two products were obtained, the ratio of which, as a function of reaction conditions, is characteristic of EDB. The derivatives were monitored with UV, reductive electrochemical, and photolysis/oxidative electrochemical detection. Sub-parts-per-billion detection limits were obtained. The method was used to quantitate EDB in leaded gasoline, and the results were confirmed with gas chromatography with electron capture detection (GC/ECD). The method was further validated with a single blind analysis of spiked EDB in gasoline. This is the first report of an HPLC method for EDB.

  5. Oxidation of butane to butanol coupled to electrochemical redox reaction of NAD+/NADH.

    PubMed

    Kang, Hye Sun; Na, Byung Kwan; Park, Doo Hyun

    2007-08-01

    A crude cell extract from a butane-utilizing bacterium, Alcaligenes sp., catalyzed the oxidation of butane to butanol coupled to NADH. A graphite electrode modified with Neutral Red (NR-electrode) catalyzed the reduction of NAD(+) to NADH. About 4.9 mM butanol was produced from 50% n-butane/O(2) mixture through the combined reactions of the crude enzyme and the NR-electrode in 250 ml reactor for 3 h. PMID:17549436

  6. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    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 (λmax = 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 × 10-15 m3/s.

  8. 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. PMID:26289652

  9. 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.

  10. ASSESSMENT OF THE MUTAGENIC POTENTIAL OF CARBON DISULFIDE, CARBON TETRACHLORIDE, DICHLOROMETHANE, ETHYLENE DICHLORIDE, AND METHYL BROMIDE: A COMPARATIVE ANALYSIS IN RELATION TO ETHYLENE DIBROMIDE

    EPA Science Inventory

    The document provides an evaluation of the mutagenic potential of five alternative fumigants to ethylene dibromide(EDB). These include carbon disulfide(CS2), carbon tetrachloride(CCl4), dichloromethane(DCM), ethylene dichloride(EDC), and methyl bromide (MB). Of the five proposed ...

  11. Explosive burns during abusive inhalation of butane gas.

    PubMed

    Oh, S J; Lee, S E; Burm, J S; Chung, C H; Lee, J W; Chang, Y C; Kim, D C

    1999-06-01

    Explosion burns during abusive inhalation of butane gas rarely occurred in the past, but recently it has become a social problem among groups of teenagers. This cause constitutes 1.6% of admissions due to flame burn at the burn unit of Hallym Medical Center. A retrospective review during a five-year period identified 48 patients. The male to female ratio was 3:1. The mean age of patients was 16 years and 8 months. The places where the accidents occurred were commonly bedrooms or motel rooms. There were nine group settings of 27 patients at the time of the accident. Inhalation injury (n = 12) was noted on admission. The average burn size was 28.5 percent of the total body surface area. All patients sustained burn injury on the face, arms and hands and 24 patients among them had extended burn areas on the trunk and/or lower extremity. 22 patients (mean hospital stay; 51.6 d) required skin grafting and 12 patients (mean hospital stay; 22.3 d) were treated with conservative management. The mortality rate was 10.4 percent. Explosion burns during abusive inhalation of butane gas can result in mortality as well as major burn injuries. PMID:10431983

  12. Radiation chemical behavior of aqueous butanal oxime solutions irradiated with helium ion beams

    NASA Astrophysics Data System (ADS)

    Costagliola, A.; Venault, L.; Deroche, A.; Garaix, G.; Vermeulen, J.; Omnee, R.; Duval, F.; Blain, G.; Vandenborre, J.; Fattahi-Vanani, M.; Vigier, N.

    2016-02-01

    Samples of butanal oxime in aqueous solution have been irradiated with the helion (4He2+) beam of the ARRONAX (Nantes) and the CEMHTI (Orléans) cyclotrons. The consumption yield of butanal oxime has been measured by gas-chromatography coupled with mass spectrometry. Yields of gaseous products (mainly H2) have also been measured by micro-gas-chromatography. Butanal oxime can react with H• radicals by abstraction mechanism to enhance H2 production. Yields of liquid phase products (hydrogen peroxide and nitrite ion) have been measured by colorimetric methods. Butanal oxime acts as a scavenger of OH• radical to inhibit the production of H2O2. The observation of the radiolytic products allows then to discuss a degradation mechanism of butanal oxime in aqueous solutions.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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 × 10-14 m3/s for a reduced electric field of E/ N = 15 Td, at which the maximum emission intensity in the blue-green spectral region (λmax = 502 nm) was observed in this experiment.

  15. Fragmentation patterns of novel dispirocyclopiperazinium dibromides with strong analgesic activity under electrospray ionization tandem mass spectrometry conditions

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Sha, Yaowu; Li, Runtao

    2004-07-01

    The fragmentation patterns of a series of dispirocyclopiperazinium dibromides with strong analgesic activity were analyzed by positive ion electrospray ionization mass spectrometry in conjunction with tandem mass spectrometry (ESI-MSn). The [C2+Br-]+ ions showed the characteristic isotopic peaks with high intensity. In each of their MS2 spectra, only the [C2+Br----HBr]+ ion peak was observable. Further analysis indicated that a selective rearrangement occurred in the unsaturated spirocyclopiperazine ring to achieve dihydropyrrole moiety. Meanwhile, the [C]2+ ions were unique and always the base peaks. The ions [C2+Br-]+ and [C]2+ were formed from the equilibrium of precursor molecules 1 in solution, and the latter ions could not be observed in the MS2 spectra of ions [C2+Br-]+. The related fragmentation mechanisms were proposed.

  16. 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.

  17. 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...

  18. Synthesis of renewable diesel with the 2-methylfuran, butanal and acetone derived from lignocellulose.

    PubMed

    Li, Guangyi; Li, Ning; Yang, Jinfan; Wang, Aiqin; Wang, Xiaodong; Cong, Yu; Zhang, Tao

    2013-04-01

    In this work, the hydroxyalkylation/alkylation of 2-methylfuran (2-MF) with acetone and butanal was investigated over a series of solid acid catalysts. Among the investigated candidates, Nafion-212 resin demonstrated the highest activity and stability for both reactions. Butanal is more reactive than acetone in hydroxyalkylation/alkylation, which can be rationalized by the steric and electronic effects of alkyl group. Finally, the hydroxyalkylation/alkylation products as prepared were directly hydrodeoxygenated over Pd/C, Pt/C and Ni-WxC/C catalysts. Evidently higher carbon yields to diesel were obtained when hydroxyalkylation/alkylation product of 2-MF with butanal was used as the feedstock. This can be considered as another advantage of 2-MF-butanal route. It is interesting that Ni-WxC/C catalyst exhibited excellent catalytic performance and good stability in the hydrodeoxygenation of hydroxyalkylation/alkylation products, which made it a promising substitute for the noble metal catalysts. PMID:23500561

  19. CELLULAR LIPIDS OF A NOCARDIA GROWN ON PROPANE AND N-BUTANE.

    PubMed

    DAVIS, J B

    1964-07-01

    Lipid fractions of propane- and n-butane-grown nocardial cells each contain a chloroform-soluble, ether-insoluble polymer not observed previously in liquid n-alkane-grown cells. The polymer in propane-grown cells is poly-beta-hydroxybutyrate. The polymer in n-butane-grown cells apparently contains unsaturation in the molecule, and is identified tentatively as a co-polymer of beta-hydroxybutyric and beta-hydroxybutenoic (specifically 3-hydroxy 2-butenoic) acids. The other major component of the lipid fraction consists of triglycerides containing principally palmitic and stearic acids. There seems to be little qualitative distinction in the glycerides of propane- or n-butane-grown cells. Oxidative assimilation of n-butane is described. PMID:14199017

  20. 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.

  1. Quasielastic neutron scattering measurements of n-butane in its crystalline, plastic, and liquid phases

    NASA Astrophysics Data System (ADS)

    Bradley, K. F.; Chen, S.-H.; Brun, T. O.

    1991-10-01

    We report here measurements of quasielastic neutron scattering from n-butane at temperatures of 90, 115, 125 and 190 K and in a momentum transfer range of 0.8-2.4 Å-1. These measurements confirm that between 115 and 125 K butane forms a plastic crystal in which the centers of mass of the butane molecules form a crystalline structure, but the individual molecules are free to rotate. At these two intermediate temperatures, there exists both an elastic peak, characteristic of a solid structure, and quasielastic components arising from the rotational motions of the butane molecules. At 90 K, the butane scatters neutrons only elastically, while at 190 K, the butane scatters neutrons only quasielastically. In both the plastic and the liquid phases, the presence of at least two quasielastic processes must be assumed in order to explain the measurements. In the plastic crystal, we associate a broad Lorentzian component with intramolecular reorientations about the central carbon-carbon bond and a second, relatively narrow, Lorentzian component with whole molecule rotations. The latter process gives rise to a rotational quasielastic peak having a width of 400 μeV, which is constant to within the instrumental resolution of 70 μeV at both temperatures and at all measured momentum transfers. In a continuous diffusion model, this width corresponds to a rotational diffusion constant of 0.277 rad2/ps, a value which is about 3.5 times larger than one extracted from a molecular dynamics simulation of n-butane in the plastic phase recently published by Refson and Pawley [Mol. Phys. 61, 669 (1987); 61, 693 (1987)]. On the other hand, the first process, which corresponds to the carbon-carbon reorientation peak, is about 16 meV wide, indicating that this reorientation occurs on a time scale of about 0.1 ps. The absence of this broad peak in the solid butane at 90 K indicates that this fast carbon-carbon reorientation is coupled to an aspect of the structure or dynamics of the plastic

  2. Mechanism for oxidation of n-butane to maleic anhydride on a vanadium-phosphorus oxide catalyst

    SciTech Connect

    Nechiporuk, P.P.; Mishchenko, Yu.A.; Avetisov, A.K.; Dulin, D.A.; Kalinovskii, I.O.; Gel'bshtein, A.I.

    1987-06-01

    The values of the kinetic isotope effect have been determined in reactions where n-butane is converted to partial (maleic anhydride) and complete oxidation products on a vanadium-phosphorus oxide catalyst when hydrogen is replaced by deuterium in different positions of the n-butane molecule. The absence of intra- and intermolecular H-D exchange in butane under conditions of its catalytic oxidation has been established. On the basis of the observed effects it has been concluded that the interaction of n-butane with the surface of the catalyst is irreversible under the conditions of catalysis and that the rate-limiting stage due to cleavage of the C-H bond in a methylene group of butane is common to reactions of partial and complete oxidation of butane.

  3. Contamination of groundwater by the fumigants ethylene dibromide (EDB) and dibromochloropropane (DBCP) near McBee, South Carolina

    USGS Publications Warehouse

    Landmeyer, James E.; Campbell, Bruce G.

    2010-01-01

    McBee is a small town of about 700 people located in Chesterfield County, South Carolina, in the Sandhills region of the upper Coastal Plain. The halogenated organic compounds ethylene dibromide (EDB) and dibromochloropropane (DBCP) have been detected in several public and domestic supply and irrigation wells since 2002 at concentrations above their U.S. Environmental Protection Agency Maximum Contaminant Limits of 0.05 and 0.2 microgram per liter (µg/L), respectively. The source(s) and release histories of EDB and DBCP to local groundwater are unknown, but believed to be related to their historical use between the 1940s and their ban in the late 1970s as fumigants to control nematode damage in peach orchards. However, gasoline and jet-fuel supplies also contained EDB and are an alternative source of contamination to groundwater. The detection of EDB and DBCP in water wells has raised health concerns because groundwater is the sole source of water supply in the McBee area. In April 2010, forensic, geochemical-based investigation was initiated by the U.S. Geological Survey in cooperation with the Alligator Rural Water & Sewer Company to provide additional data regarding EDB and DBCP in local groundwater. The investigation includes an assessment of the use, release, and disposal history of EDB and DBCP in the area, the distribution of EDB and DBCP concentrations in the unsaturated zone, and transport and fate in groundwater.

  4. Unidirectional growth of non-linear optical triglycine calcium dibromide single crystal by a Sankaranaryanan-Ramasamy method

    NASA Astrophysics Data System (ADS)

    Babu Rao, G.; Rajesh, P.; Ramasamy, P.

    2016-04-01

    Single crystals oriented along prerequisite direction are very important in terms of reducing loss of material and cost during nonlinear optical device fabrication. A transparent uniaxial triglycine calcium dibromide single crystal having dimension of 10 mm diameter and 126 mm length was grown by a Sankaranarayanan-Ramasamy (SR) method with a growth rate of 2 mm per day. From the optical transmittance study it is observed that the crystal grown by the SR method has 10% higher transmittance compared to a conventional method grown crystals. High intense luminescence at 368 nm for the SR method grown crystal is observed from the photoluminescence study. The etch pit density of the conventional and SR method grown crystal is found as 4.5×103 cm-2 and 3.5×103 cm-2 respectively. The average laser damage threshold obtained on the conventional method grown crystal was 3.74 Gw/cm2 whereas a high damage threshold of 4.78 Gw/cm2 was obtained for the SR grown crystal. The crystal grown by the SR method shows high mechanical strength and good laser damage stability with low dislocation density which make it suitable for the SHG device fabrication.

  5. 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

  6. 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.

  7. Kinetics and fixed-bed reactor modeling of butane oxidation to maleic anhydride

    SciTech Connect

    Sharma, R.K.; Cresswell, D.L. ); Newson, E.J. )

    1991-01-01

    This paper reports on selective oxidation kinetics of n-butane to maleic anhydride in air studied over a commercial, fixed-bed vanadium-phosphor oxide catalyst. The temperature range was 573-653 K with butane concentrations up to 3 mol % in the feed, which is within flammability limits but below ignition temperatures. The rate data were modeled using power law kinetics with product inhibition and included total oxidation and decomposition reactions. Kinetic parameters were estimated using a multiresponse, nonlinear regression algorithm showing intercorrelation effects. The kinetics were combined with independent measurements of catalyst diffusivity and reactor heat transfer using a one- dimensional heterogeneous reactor model.

  8. Emission of mercury monobromide exciplex in gas-discharge plasma based on mixture of mercury dibromide vapor with sulfur hexafluoride and helium

    NASA Astrophysics Data System (ADS)

    Malinina, A. A.; Shuaibov, A. K.

    2011-02-01

    We present the results of investigations of an emission of a mercury monobromide exciplex in gas-discharge plasma of an atmospheric pressure barrier discharge based on a mixture of mercury dibromide vapor, sulfur hexafluoride, and helium. We optimized the emission power of mercury monobromide exciplexes with respect to the partial pressures of the working mixture. An average emission power of 0.42 W (λmax = 502 nm) is achieved in a cylindrical emission source with a small working volume (0.8 cm3) at a pumping pulse repetition rate of 6 kHz. We determined electron energy distribution functions, transport characteristics, specific discharge power losses for electron processes, electron concentration and temperature, as well as rate constants of elastic and inelastic scattering of electrons by components of the working mixture in relation to the ratio of the field strength to the total concentration of components of the working mixture. We discuss processes that increase the population of the mercury monobromide exciplex. Gas-discharge plasma created in a mixture of mercury dibromide vapor with sulfur hexafluoride and helium can be used as a working medium of an emission source in the blue-green spectral range for the use in scientific research in biotechnology, photonics, and medicine, as well as for creating indicator gas-discharge panels.

  9. 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...

  10. 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...

  11. Marine microbes rapidly adapt to consume ethane, propane, and butane within the dissolved hydrocarbon plume of a natural seep

    NASA Astrophysics Data System (ADS)

    Mendes, Stephanie D.; Redmond, Molly C.; Voigritter, Karl; Perez, Christian; Scarlett, Rachel; Valentine, David L.

    2015-03-01

    Simple hydrocarbon gases containing two to four carbons (ethane, propane, and butane) are among the most abundant compounds present in petroleum reservoirs, and are introduced into the ocean through natural seepage and industrial discharge. Yet little is known about the bacterial consumption of these compounds in ocean waters. To assess the timing by which microbes metabolize these gases, we conducted a three-phase study that tested and applied a radiotracer-based method to quantify the oxidation rates of ethane, propane, and butane in fresh seawater samples. Phase 1 involved the synthesis of tritiated ethane, propane, and butane using Grignard reagents and tritiated water. Phase 2 was a systematic assessment of experimental conditions, wherein the indigenous microbial community was found to rapidly oxidize ethane, propane, and butane. Phase 3 was the application of this tritium method near the Coal Oil Point seeps, offshore California. Spatial and temporal patterns of ethane, propane, and butane oxidation down current from the hydrocarbon seeps demonstrated that >99% of these gases are metabolized within 1.3 days following initial exposure. The oxidation of ethane outpaced oxidation of propane and butane with patterns indicating the microbial community responded to these gases by rapid adaptation or growth. Methane oxidation responded the slowest in plume waters. Estimates based on the observed metabolic rates and carbon mass balance suggest that ethane, propane, and butane-consuming microorganisms may transiently account for a majority of the total microbial community in these impacted waters.

  12. Chloroform Cometabolism by Butane-Grown CF8, Pseudomonas butanovora, and Mycobacterium vaccae JOB5 and Methane-Grown Methylosinus trichosporium OB3b

    PubMed Central

    Hamamura, N.; Page, C.; Long, T.; Semprini, L.; Arp, D. J.

    1997-01-01

    Chloroform (CF) degradation by a butane-grown enrichment culture, CF8, was compared to that by butane-grown Pseudomonas butanovora and Mycobacterium vaccae JOB5 and to that by a known CF degrader, Methylosinus trichosporium OB3b. All three butane-grown bacteria were able to degrade CF at rates comparable to that of M. trichosporium. CF degradation by all four bacteria required O(inf2). Butane inhibited CF degradation by the butane-grown bacteria, suggesting that butane monooxygenase is responsible for CF degradation. P. butanovora required exogenous reductant to degrade CF, while CF8 and M. vaccae utilized endogenous reductants. Prolonged incubation with CF resulted in decreased CF degradation. CF8 and P. butanovora were more sensitive to CF than either M. trichosporium or M. vaccae. CF degradation by all three butane-grown bacteria was inactivated by acetylene, which is a mechanism-based inhibitor for several monooxygenases. Butane protected all three butane-grown bacteria from inactivation by acetylene, which indicates that the same monooxygenase is responsible for both CF and butane oxidation. CF8 and P. butanovora were able to degrade other chlorinated hydrocarbons, including trichloroethylene, 1,2-cis-dichloroethylene, and vinyl chloride. In addition, CF8 degraded 1,1,2-trichloroethane. The results indicate the potential of butane-grown bacteria for chlorinated hydrocarbon transformation. PMID:16535693

  13. 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.

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

    PubMed Central

    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.

    2007-01-01

    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 (IC50 = 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 μM) inhibited the response to acetylcholine at α3β4, α4β4, α4β2, and α1β1εδ receptors expressed in Xenopus oocytes. TMPD had a 2-fold higher affinity for the blood-brain barrier choline transporter, suggesting that is brain bioavailable. TMPD did not inhibit the 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. PMID:17727820

  15. 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.

  16. 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. PMID:15028501

  17. 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. PMID:25676506

  18. Is it worth carrying out determination of N-butane in postmortem samples? A case report and a comprehensive review of the literature.

    PubMed

    El Balkhi, Souleiman; Coutaz-Fluck, Caroline; Moreau, Fanny; Paraf, François; Gaulier, Jean-Michel

    2016-09-01

    The aim of this article is to illustrate the importance of N-butane determination in postmortem samples through a case report and to propose actions and precautions to be taken into consideration when butane is suspected to be involved in cases of death. The case concerns a 15-year-old boy found dead after sniffing a cigarette lighter refill. Toxicological investigation revealed the presence of butane in the heart and femoral blood (1280 and 1170 μg/L, respectively), in the gastric contents (326 μg/L), and in the liver (1010 μg/kg) and lung tissues (210 μg/kg). Propane was present only in the blood samples at concentrations tenfolds lower.Butane can be involved in three kinds of fatalities: deliberate inhalations including volatile substance abuse (VSA), involuntary exposure, and homicides. A fatal outcome of butane inhalation can be caused by asphyxia and/or cardiac arrhythmia. In the context where butane exposure is evidenced by non-toxicological investigations, the usefulness of the determination of butane in postmortem samples is often questionable. However, it is admitted that butane-related deaths are generally underreported. Several difficulties including sample handling and storage, substantial variation in tissue concentrations, and lack of a lethal threshold make the interpretation of butane results challenging. In our opinion, systematic toxicological methods should be developed in order to analyze butane, at least when it concerns a typical VSA victim, even when butane is not actually suspected to be the cause of death. PMID:26364197

  19. Isolation and Characterization of Ethane, Propane, and Butane Consuming Bacteria from Marine Hydrocarbon Seeps

    NASA Astrophysics Data System (ADS)

    Redmond, M. C.; Valentine, D. L.

    2005-12-01

    Three strains of ethane, propane, or butane consuming bacteria were isolated from marine hydrocarbon seep sediments at Coal Oil Point, off shore Santa Barbara, CA. These three isolates (MR1, MR2 and MR3) were capable of growth at natural environmental temperatures and salinity. Isolate MR2 was capable of growth on ethane or propane as the sole carbon source, isolate MR4 on propane or butane, and isolate MR3 on ethane, propane, or butane. All three isolates were also able to grow on other carbon-containing molecules, including ethanol, 1-propanol, 2-propanol, acetate, butyrate, sucrose, and dextrose, and isolates MR3 and MR4 were able to grow on 1-butanol and 2-butanol. None showed significant growth with methane, methanol, or formate as the sole carbon source. 16S rDNA sequencing indicated that isolate MR2 was most closely related to the gamma-Proteobacterium Pseudomonas stutzeri, while isolates MR3 and MR4 were both Gram-positive and most similar to Rhodococcus wratislaviensis and Rhodococcus opacus, respectively. Compared to methanotrophs, relatively little is known about the organisms that consume the C2-C4 alkanes, but both our isolates and the previously described species appear to be capable of metabolizing a wide variety of carbon compounds, including several common pollutants. The growth of these hydrocarbon-oxidizing bacteria on other organic compounds raises the possibility that the abundance and distribution of organic matter might be expected to impact the oxidation of C2-C4 hydrocarbons. Additional studies will further characterize the range of metabolism, and will investigate the importance of these organisms in natural hydrocarbon seep environments.

  20. Selective oxidation of n-butane to maleic anhydride; 4. Recycle reactor studies

    SciTech Connect

    Bej, S.K.; Rao, M.S. )

    1992-09-01

    This paper reports on the selective oxidation of n-butane to aleic anhydride which has been modeled using recycle reactor data. Two different types of models have been tested based on the concept that V[sup 5+] is the selective site and V[sup 4+] is the nonselective site and vice versa. Recycle reactor data support the model which assumes V[sup 5+] as the selective site as the selective site and V[sup 4+] as the nonselective site. The model has been used to predict the performance of an integral reactor and tested with experimental integral reactor data.

  1. 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

  2. In situ FTIR study of n-butane selective oxidation to maleic anhydride on V-P-O catalysts

    SciTech Connect

    Wenig, R.W.; Schrader, G.L.

    1986-11-20

    The selective oxidation of n-butane to maleic anhydride on vanadium-phosphorus-oxygen (V-P-O) catalysts having P to V ratios of 0.9, 1.0, and 1.1 was studied by transmission infrared spectroscopy. Catalysts were exposed to mixtures of 1.5% n-butane in air at temperatures from 100 to 500/sup 0/C. Adsorbed n-butane, maleic anhydride, and carbon oxide species were observed on the catalyst surfaces. In addition, adsorbed maleic acid and highly reactive olefinic species could be detected. The nature of the adsorbed species present on the catalyst surface was dependent on the catalyst phosphorus loading, the reaction temperature, and the time of exposure under reaction conditions.

  3. 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.

  4. 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.

  5. 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.

  6. Bis-pyridinium dibromides modified organo-bentonite for the removal of aniline from wastewater: A positive role of π-π polar interaction

    NASA Astrophysics Data System (ADS)

    Gu, Zheng; Gao, Manglai; Luo, Zhongxin; Lu, Laifu; Ye, Yage; Liu, Yuening

    2014-01-01

    Aniline removal is of great importance for water treatment, and adsorption is an efficient treatment method. Hexamethylene bis-pyridinium dibromide modified bentonite (HEMBP-B) was firstly prepared and characterized by XRD, FT-IR, BET, SEM, TEM and TG-DTG analysis. Adsorptive experiments of aniline on the organo-bentonite were carried out using batch method as a function of the length of linking carbon chain (n), concentration of HEMBP (C), contact time (t), temperature (T) and pH. The optimal conditions for aniline removal on HEMBP-B were as follows: n of 5 or 6, C of 1.0 CEC, t of 120 min, T of 298 K, and natural pH of 6.6. The π-π polar interaction existed between the aromatic rings of aniline and HEMBP has successfully explained the main adsorption mechanism. The equilibrium data of aniline removal on HEMBP-B followed Freundlich and D-R isothermal models precisely, which indicated a less favorable and physical process of aniline adsorption. The kinetic data could be best described by the pseudo-second-order model. Besides, the thermodynamic study revealed that aniline adsorption on HEMBP-B was non-spontaneous, exothermic and physical.

  7. n-Butane: Ignition delay measurements at high pressure and detailed chemical kinetic simulations

    SciTech Connect

    Healy, D.; Curran, H.J.; Donato, N.S.; Aul, C.J.; Petersen, E.L.; Zinner, C.M.; Bourque, G.

    2010-08-15

    Ignition delay time measurements were recorded at equivalence ratios of 0.3, 0.5, 1, and 2 for n-butane at pressures of approximately 1, 10, 20, 30 and 45 atm at temperatures from 690 to 1430 K in both a rapid compression machine and in a shock tube. A detailed chemical kinetic model consisting of 1328 reactions involving 230 species was constructed and used to validate the delay times. Moreover, this mechanism has been used to simulate previously published ignition delay times at atmospheric and higher pressure. Arrhenius-type ignition delay correlations were developed for temperatures greater than 1025 K which relate ignition delay time to temperature and concentration of the mixture. Furthermore, a detailed sensitivity analysis and a reaction pathway analysis were performed to give further insight to the chemistry at various conditions. When compared to existing data from the literature, the model performs quite well, and in several instances the conditions of earlier experiments were duplicated in the laboratory with overall good agreement. To the authors' knowledge, the present paper presents the most comprehensive set of ignition delay time experiments and kinetic model validation for n-butane oxidation in air. (author)

  8. 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

  9. Platinum-Tin Nano-Catalysts Supported on Alumina for Direct Dehydrogenation of n-Butane.

    PubMed

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

    2015-10-01

    Al2O3 supports were prepared by a precipitation method using various basic solutions (NaOH, KOH, NH4OH, and Na2CO3) as precipitation agents, and Pt/Sn/Al2O3 nano-catalysts were then prepared by a sequential impregnation method. The prepared catalysts were applied to the direct dehydrogenation of n-butane to n-butenes and 1,3-butadiene. The effect of precipitation agents on the physicochemical properties and catalytic activities of Pt/Sn/Al2O3 nano-catalysts in the direct dehydrogenation of n-butane was investigated. Catalytic performance of Pt/Sn/Al2O3 nano-catalysts decreased in order of Pt/Sn/Al2O3 (NaOH) > Pt/Sn/Al2O3 (KOH) > Pt/Sn/Al2O3 (NH4OH) > Pt/Sn/Al2O3 (Na2CO3). Among the catalysts tested, Pt/Sn/Al2O3 (NaOH) nano-catalyst showed the best catalytic performance in terms of yield for total dehydrogenation products (TDP, n-butenes and 1,3-butadiene). Hydrogen chemisorption experiments revealed that platinum surface area of the catalyst was closely related to the catalytic performance. Yield for TDP increased with increasing platinum surface area of the catalyst. PMID:26726508

  10. Catalysis at experimentally designed surfaces: n-Butane hydrogenolysis at Sn/Group VIII surface alloys

    SciTech Connect

    Logan, A.D.; Paffett, M.T.

    1992-01-01

    Bimetallic {radical}3x{radical}3R30{degrees}-Sn/M(111) (M=Ni, Pt) surface alloys have been prepared in an ultrahigh vacuum system and used in model moderate pressure (1--200 Torr) catalytic reactions. Hydrogenolysis of n-butane (H{sub 2}/n-C4=20) has been used to characterize the effects of ordered bimetallic ensembles relative to those available at the respective (111) surfaces. The effect of alloying Sn into the Ni(111) surface produced an overall lowering of the catalytic reactivity nearly equal to the number of Ni surface sites lost upon producing the {radical}3x{radical}3R30{degrees} surface alloy. In addition, the overall rate of hydrogenolysis of n-butane at the {radical}3x{radical}R30{degrees}-Sn/Pt(111) surface alloy was also found to have decreased (although not in proportion to the loss of total Pt atoms). Catalytic deactivation due to carbon buildup was observed to decrease significantly at both of the ordered {radical}3x{radical}3R30{degrees}-Sn/M(111) surface alloys under reaction conditions.

  11. Surface effects during pyrolysis of normal and iso-butanes using a continuous flow thermal gravimetric reactor

    SciTech Connect

    Chen, C.T.

    1987-01-01

    The purpose of the study was to examine the coke structures, coking rates and surface effects during the pyrolysis of butane and isobutane. Several types of surfaces were investigated such as stainless steel 304, quartz, Incoloy 800 and Alonized 800, and polished and pretreated (by hydrogen sulfide) surfaces. A coking model with a coke decay coefficient was developed to represent coke formation on the surface of a S. S. 304 coupon. Surface conditions influenced the coke formation significantly. The polished surface was found to be an excellent means to reduce coke formation. A hydrogen sulfide pretreated surface inhibited coke formation too. Alonized 800 retarded coke formation, effectively, due to the addition of Al on the Incoloy 800 surface. The coking rate was rapid during an initial growth period, then reduced to a steady level. A coke decay coefficient was found to be the same for the coking model for butane and isobutane. Coke structures were similar under the same operating conditions for the pyrolysis of butane and isobutane. Filamentous carbon predominated on the surface of S. S. 304. Amorphous carbon was the major product on the surface of Incoloy 800. A three-halves order was estimated to be the global reaction of butane and isobutane pyrolyses.

  12. Studies of n-butane conversion over silica-supported platinum, platinum-silver and platinum-copper catalysts

    SciTech Connect

    Gu, Junhua

    1992-06-09

    The present work was undertaken to elucidate effect of adding silver and copper to silica-supported platinum catalyst on the activity and selectivity in the n-butane reactions. At the conditions of this study n-butane underwent both hydrogenolysis and structural isomerization. The catalytic activity and selectivities between hydrogenolysis and isomerization and within hydrogenolysis were measured at temperature varying from 330 C to 370 C. For platinum-silver catalysts, at lower temperatures studied the catalytic activity per surface platinum atom (turnover frequency) remained constant at lower silver content (between 0 at. % and 30 at. %) and decreased with further increased silver loading, suggesting that low- index planes could be dominant in the hydrogenolysis of n-butane. Moreover, increasing silver content resulted in an enhancement of the selectivity of isomerization products relative to hydrogenolysis products. At the higher temperature studied, no suppression in catalytic activity was observed. It is postulated that surface structure could change due to the mobility of surface silver atoms, leading to surface silver atoms forming islands or going to the bulk, and leaving large portions of basal planes exposed with active platinum atoms. It is also suggested that the presence of inert silver atoms results in weakening of the H-surface bond. This results in increased mobility of hydrogen atoms on the surface and hence, higher reactivity with other adsorbed species. For platinum copper catalysts, the mixed ensembles could play an active role in the hydrogenolysis of n-butane.

  13. 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

  14. Conformational statistics of n-butane in the condensed phase and the effects of temperature

    NASA Astrophysics Data System (ADS)

    Weber, Adrian C. J.; Burnell, E. Elliott

    2011-04-01

    Experimental dipolar couplings are obtained from the 1H NMR spectra of n-butane dissolved in a liquid crystal over an 80° temperature range with Covariance Matrix Adaptation Evolutionary Strategies (CMA-ES). These observables are rationalized using a size-and-shape potential [E.E. Burnell, C.A. de Lange, Chem. Rev. 98 (1998) 2359], CI (2k), and with a modified chord model [D.J. Photinos, E.T. Samulski, H. Toriumi, J. Phys. Chem. 94 (1990) 4694], CCd, for the orientational ordering potential. The trans- gauche energy difference, Etg, is temperature dependent when using the CCd model and temperature independent when using the CI (2k) model for the orientational ordering potential.

  15. 1-Aza-niumyl-cyclo-butane-1-carboxyl-ate monohydrate.

    PubMed

    Butcher, Ray J; Brewer, Greg; Burton, Aaron S; Dworkin, Jason P

    2014-02-01

    In the title compound, C5H9NO2·H2O, the amino acid is in the usual zwitterionic form involving the α-carboxyl-ate group. The cyclo-butane backbone of the amino acid is disordered over two conformations, with occupancies of 0.882 (7) and 0.118 (7). In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the zwitterions [with the water molecule involved as both acceptor (with the NH3 (+)) and donor (through a single carboxylate O from two different aminocyclobutane carb-oxylate moities)], resulting in a two-dimensional layered structure lying parallel to (100). PMID:24764920

  16. On the mechanism of n-butane oxidation to maleic anhydride on VPO catalysts. II. Study of the evolution of the VPO catalysts under n-butane, butadiene, and furan oxidation conditions

    SciTech Connect

    Zhang-Lin, Y.; Vedrine, J.C.; Volta, J.C. ); Forissier, M. )

    1994-02-01

    The evolution of the VOPO[sub 4] phases and of (VO)[sub 2]P[sub 2]O[sub 7] and the activated VPO catalyst has been studied by XRD, [sup 31]P MAS-NMR, laser Raman spectroscopy, and electron spin resonance after the oxidation of butane, butadiene, and furan. With the exception of [sigma]VOPO[sub 4], which partly changes to [alpha][sub 11] VOPO[sub 4], almost no evolution of the bulk structure has been observed. It is concluded that the mechanism of butane oxidation on the VPO catalyst implies principally the participation of a limited number of superficial layers of the structure. Catalytic properties depend on the redox properties of a limited number of V[sup 5+] ensembles on the (VO)[sub 2]P[sub 2]O[sub 7] matrix. A proposal for the mechanism of n-butane oxidation which implies an alkoxide route is presented. 22 refs., 10 figs., 1 tab.

  17. Experimental investigation on butane diffusion flames under the influence of magnetic field by using digital speckle pattern interferometry.

    PubMed

    Kumar, Manoj; Agarwal, Shilpi; Kumar, Varun; Khan, Gufran S; Shakher, Chandra

    2015-03-20

    In this paper, the effect of magnetic fields on the temperature and temperature profile of a diffusion flame obtained from a butane torch burner are investigated experimentally by using digital speckle pattern interferometry (DSPI). Experiments were conducted on a diffusion flame generated by a butane torch burner in the absence of a magnetic field and in the presence of uniform and nonuniform magnetic fields. A single DSPI fringe pattern was used to extract phase by using a Riesz transform and monogenic signal. Temperature inside the flame was determined experimentally both in the absence and in the presence of magnetic fields. Experimental results reveal that the maximum temperature of the flame is increased under the influence of an upward-decreasing magnetic gradient and decreased under an upward-increasing magnetic gradient while a negligible effect on temperature in a uniform magnetic field was observed. PMID:25968534

  18. Low-pressure lipase-catalyzed production of mono- and diglycerides with and without N-butane and AOT surfactant.

    PubMed

    Valério, Alexsandra; Fiametti, Karina G; Rovani, Suzimara; Treichel, Helen; de Oliveira, Débora; Oliveira, J Vladimir

    2010-03-01

    The aim of this work is to report the production of mono- and diglycerides from olive oil at ambient condition and in pressurized n-butane as solvent medium. For this purpose, a commercial immobilized lipase (Novozym 435) was employed as catalyst and sodium (bis-2-ethyl-hexyl) sulfosuccinate (Aerosol-OT or AOT) as surfactant. The experiments were conducted in batch mode varying the temperature, pressure, and AOT concentration. Results showed that lipase-catalyzed glycerolysis either with compressed n-butane or in solvent-free system with AOT as surfactant might be a potential alternative route to conventional methods, as high contents of reaction products, especially monoglycerides ( approximately 60 wt.%), were achieved at mild temperature and pressure with a relatively low solvent to substrates mass ratio (4:1) in short reaction times (2 h). PMID:19641856

  19. Immunohistochemical detection of early myocardial damage in two sudden deaths due to intentional butane inhalation. Two case reports with review of literature.

    PubMed

    Novosel, Irena; Kovačić, Zdravko; Gusić, Stjepan; Batelja, Lovorka; Nestić, Marina; Seiwerth, Sven; Skavić, Josip

    2011-04-01

    The abuse of household and other commercially available products containing volatile organic solvents is underrecognized. Not infrequently intentional butane inhalation results in high morbidity and mortality. A fatal outcome of butane abuse can be caused by asphyxia, cardiac arrhythmia or trauma. The reported number of cases in which death was the consequence of pure butane inhalation is limited, and in most cases a mixture of propellants was involved. This report covers two cases of sudden death due to the sniffing of a cigarette lighter refill containing butane. Autopsy was followed by toxicological, pathohistological and immunohistochemical analysis. Butane gas was confirmed in samples of blood, urine, brain and lungs by the gas chromatography method - "headspace" technique. Histology showed almost identical changes in the lungs and heart in both cases. The morphology of heart damage on standard H/E stains was of special interest because it displayed all the characteristics of chronic and acute myocardial hypoxia found in the absence of atherosclerotic heart disease. In order to confirm early cardiac death caused by asphyxia due to butane inhalation a panel of immunohistochemical agents was used: Myoglobin, Desmin, Fibronectin, Fibrinogen and CC9. PMID:21420651

  20. The use of human in vitro metabolic parameters to explore the risk assessment of hazardous compounds: the case of ethylene dibromide.

    PubMed

    Ploemen, J P; Wormhoudt, L W; Haenen, G R; Oudshoorn, M J; Commandeur, J N; Vermeulen, N P; de Waziers, I; Beaune, P H; Watabe, T; van Bladeren, P J

    1997-03-01

    Ethylene dibromide (1,2-dibromoethane, EDB) is metabolized by two routes: a conjugative route catalyzed by glutathione S-transferases (GST) and an oxidative route catalyzed by cytochrome P450 (P450). The GST route is associated with carcinogenicity. An approach is presented to use human purified GST and P450 enzymes to explore the importance of these metabolic pathways for man in vivo. This strategy basically consists of four steps: (i) identification of the most important isoenzymes in vitro, (ii) scaling to rate per milligram cytosolic and microsomal protein, (iii) scaling to rate per gram liver, and (iv) incorporation of data in a physiologically based pharmacokinetic (PBPK) model. In the first step, several GST isoenzymes were shown to be active toward EDB and displayed pseudo-first-order kinetics, while the EDB oxidation was catalyzed by CYP2E1, 2A6, and 2B6, which all displayed saturable kinetics. In the second step, the predictions were in agreement with the measured activity in a batch of 21 human liver samples. In the third step, rat liver P450 and GST metabolism of EDB was predicted to be in the same range as human metabolism (expressed per gram). Interindividual differences in GST activity were modeled to determine "extreme cases." For the most active person, an approximately 1.5-fold increase of the amount of conjugative metabolites was predicted. Lastly, it was shown that the GST route, even at low concentrations, will always contribute significantly to total metabolism. In the fourth step, a PBPK model describing liver metabolism after inhalatory exposure to EDB was used. The saturation of the P450 route was predicted to occur faster in the rat than in man. The rat was predicted to have a higher turnover of EDB from both routes. Nevertheless, when all data are combined, it is crucial to recognize that the GST remains significantly active even at low EDB concentrations. The limitations and advantages of the presented strategy are discussed. PMID

  1. 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.

  2. 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.

  3. 4-(Phenylsulfanyl)butan-2-One Suppresses Melanin Synthesis and Melanosome Maturation In Vitro and In Vivo.

    PubMed

    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:26404245

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

    PubMed

    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

  5. 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. PMID:22280759

  6. 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%.

  7. Synthesis and characterization of new VPO catalysts for partial n-butane oxidation to maleic anhydride

    SciTech Connect

    Batis, N.H.; Batis, H. ); Ghorbell, A.; Vedrine, J.C.; Volta, J.C. )

    1991-03-01

    In order to try to control the V{sup 4+}/V{sup 5+} ratio of VPO catalysts for butane oxidation to maleic anhydride, a new method of preparation of these catalysts has been developed: it consists of the reaction of VC1{sub 3} (V{sup 3+}) with V{sub 2}O{sub 5} (V{sup 5+}) for the preparation of the precursor. Two series of catalysts have been prepared in aqueous and organic media. The V{sup 3+}/V{sup 5+} ratio has been varied and its influence on the physicochemical features and on the catalytic properties of the catalysts has been studied. The best catalysts in both preparation media correspond to V{sup 3+}/V{sup 5+} = 1 in the starting material. Catalysts have been characterized using X-ray diffraction, infrared spectroscopy, UV diffuse reflectance, Raman spectroscopy, {sup 31}P MAS NMR, and XPS techniques. The combination of all these techniques let the authors to conclude that the best catalyst consisted of an oxidized surface ({gamma}-VOPO{sub 4}) (V{sup 5+}) in interaction with reduced matrix ((VO){sub 2}P{sub 2}O{sub 7}) (V{sup 4+}).

  8. [Sulforaphane (1-isothiocyanato-4-(methylsulfinyl)-butane) content in cruciferous vegetables].

    PubMed

    Campas-Baypoli, Olga N; Bueno-Solano, Carolina; Martínez-Ibarra, Diana M; Camacho-Gil, Francisco; Villa-Lerma, Alma G; Rodríguez-Núñez, Jesús R; Lóez-Cervantes, Jaime; Sánchez-Machado, Dalia I

    2009-03-01

    Sulforaphane (1-isothiocyanato-4-(methylsulfinyl)-butane) content in cruciferous vegetables. Sulforaphane is an isothiocyanate which has antimicrobial and anticarcinogenic properties, this compound is found in a wide variety of plants from genus Brassica oleracea, being the most important broccoli and cabbage. The objective of this research was to quantify sulforaphane in the edible parts of broccoli and cabbage leaves by high-performance liquid chromatography (HPLC). Sample preparation for the quantification of sulforaphane include the conversion of glucoraphanin to sulforaphane (45 +/- 2 degrees C for 2.5 h), extracted with dichloromethane, purification of the extract in columns of solid phase extraction and detection by HPLC- UV. Sulforaphane concentration in broccoli is in the range of 214 microg/g DW (stems) to 499 microg/g DW (inflorescences). The purple cabbage (101.99 microg/g DW) has values greater than the green cabbage (7.58 microg/g DW). The inflorescences of broccoli and red cabbage leaves are rich in sulforaphane. PMID:19480351

  9. The stereospecific hydroxylation of [2,2-2H2]butane and chiral dideuteriobutanes by the particulate methane monooxygenase from Methylococcus capsulatus (Bath).

    PubMed

    Yu, Steve S-F; Wu, Lo-Ying; Chen, Kelvin H-C; Luo, Wen-I; Huang, Ded-Shih; Chan, Sunney I

    2003-10-17

    Experiments on cryptically chiral ethanes have indicated that the particulate methane monooxygenase (pMMO) from Methylococcus capsulatus (Bath) catalyzes the hydroxylation of ethane with total retention of configuration at the carbon center attacked. This result would seem to rule out a radical mechanism for the hydroxylation chemistry, at least as mediated by this enzyme. The interpretation of subsequent experiments on n-propane, n-butane, and n-pentane has been complicated by hydroxylation at both the pro-R and pro-S secondary C-H bonds, where the hydroxylation takes place. It has been suggested that these results merely reflect presentation of both the pro-R and pro-S C-H bonds to the hot "oxygen atom" species generated at the active site, and that the oxo-transfer chemistry, in fact, proceeds concertedly with retention of configuration. In the present work, we have augmented these earlier studies with experiments on [2,2-2H2]butane and designed d,l form chiral dideuteriobutanes. Essentially equal amounts of (2R)-[3,3-2H2]butan-2-ol and (2R)-[2-2H1]butan-2-ol are produced upon hydroxylation of [2,2-2H2]butane. The chemistry is stereospecific with full retention of configuration at the secondary carbon oxidized. In the case of the various chiral deuterated butanes, the extent of configurational inversion has been shown to be negligible for all the chiral butanes examined. Thus, the hydroxylation of butane takes place with full retention of configuration in butane as well as in the case of ethane. These results are interpreted in terms of an oxo-transfer mechanism based on side-on singlet oxene insertion across the C-H bond similar to that previously noted for singlet carbene insertion (Kirmse, W., and Ozkir, I. S. (1992) J. Am. Chem. Soc. 114, 7590-7591). Finally, we discuss how even the oxene insertion mechanism, with "spin crossover" in the transition state, could lead to small amounts of radical rearrangement products, if and when such products are observed. A

  10. The six-membered ring chair conformation of butane-1,3-diol in the gas phase

    NASA Astrophysics Data System (ADS)

    Caminati, Walther; Corbelli, Giorgio

    1982-02-01

    Only one conformer of butane-1,3-diol is detectable by conventional microwave spectroscopy. Analysis of the CH 2OHCH 2CHOHMe and CH 2ODCH 2CHODMe isotopic species has allowed the determination of this conformation as a hydrogen-chelated six-membered ring in a distorted chair configuration. The hydrogen atom in position 1 is the proton donor; the methyl group is trans to the C 1-C 2 bond and the hydroxyl hydrogen in position 3 is trans to the C 2-C 3 bond.

  11. 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. PMID:26012694

  12. Neuroprotective effect of 4-(Phenylsulfanyl)butan-2-one on optic nerve crush model in rats.

    PubMed

    Chien, Jia-Ying; Sheu, Jyh-Horng; Wen, Zhi-Hong; Tsai, Rong-Kung; Huang, Shun-Ping

    2016-02-01

    This study is to investigate the effect of coral-related compound, 4-(phenylsulfanyl)butan-2-one (4-PSB-2) on optic nerves (ON) and retinal ganglion cells (RGC) in a rat model subjected to ON crush. The ONs of adult male Wistar rat (150-180 g) were crushed by a standardized method. The control eyes received a sham operation. 4-PSB-2 (5 mg/kg in 0.2 mL phosphate-buffered saline) or phosphate-buffered saline (PBS control) was immediately administered after ON crush once by subcutaneous injection. Rats were euthanized at 2 weeks after the crush injury. RGC density was counted by retrograde labeling with FluoroGold (FG) application to the superior colliculus, and visual function was assessed by flash visual evoked potentials (FVEP). TUNEL assay, immunoblotting analysis of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) in the retinas, and immunohistochemistry of ED1 in the ON were evaluated. Two weeks after the insult, the RGC densities in the central and mid-peripheral retinas in ON-crushed, 4-PSB-2-treated rats were significantly higher than that of the corresponding ON-crushed, PBS-treated rats FVEP measurements showed a significantly better preserved latency of the P1 wave in the ON-crushed, 4-PSB-2-treated rats than the ON-crushed, PBS treated rats. TUNEL assays showed fewer TUNEL positive cells in the ON-crushed, 4-PSB-2-treated rats. The number of ED1 positive cells was reduced at the lesion site of the optic nerve in the ON-crushed, 4-PSB-2-treated group. Furthermore, administration of 4-PSB-2 significantly attenuated ON crush insult-stimulated iNOS and COX2 expression in the retinas. These results demonstrated that 4-PSB-2 protects RGCs and helps preserve the visual function in the rat model of optic nerve crush. 4-PSB-2 may work by being anti-apoptotic and by attenuation of the inflammatory responses involving less ED1 positive cells infiltration in ON as well as suppression of iNOS/COX-2 signaling pathway in the retinas to rescue RGCs

  13. [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.). PMID:24167951

  14. 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.

  15. 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)

  16. Direct Dehydrogenation of n-Butane Over Pt/Sn/Zn-K/Al2O3 Catalyst: Effect of Hydrogen in the Feed.

    PubMed

    Lee, Jong Kwon; Seo, Hyun; Kim, Jeong Kwon; Seo, Hanuk; Cho, Hye-Ran; Lee, Jinsuk; Chang, Hosik; Song, In Kyu

    2016-05-01

    Al2O3 was prepared by a sol-gel method for use as a support. Pt/Sn/Zn-K/Al2O3 catalyst was then prepared by a sequential impregnation method, and it was applied to the direct dehydrogenation of n-butane to n-butenes and 1,3-butadiene. Physicochemical properties of Pt/Sn/Zn-K/Al2O3 catalyst were examined by X-ray diffraction (XRD), nitrogen adsorption-desorption isotherm, inductively coupled plasma atomic emission spectroscopy (ICP-AES), temperature-programmed reduction (TPR), CO chemisorption, and temperature-programmed oxidation (TPO) measurements. In order to improve the catalyst stability, the effect of hydrogen in the feed on the catalytic performance in the direct dehydrogenation of n-butane was studied. The catalyst stability and reusability in the direct dehydrogenation of n-butane was also investigated. Experimental results revealed that the addition of hydrogen in the feed decreased conversion of n-butane and yield for total dehydrogenation products but improved the stability of the catalyst. The catalytic activity and stability of regenerated Pt/Sn/Zn-K/Al2O3 catalyst in the presence of hydrogen slightly decreased compared to those of fresh Pt/Sn/Zn-K/Al2O3 catalyst due to the slight sintering of platinum particles. PMID:27483794

  17. Shape-dependent plasma-catalytic activity of ZnO nanomaterials coated on porous ceramic membrane for oxidation of butane.

    PubMed

    Sanjeeva Gandhi, M; Mok, Young Sun

    2014-12-01

    In order to explore the effects of the shape of ZnO nanomaterials on the plasma-catalytic decomposition of butane and the distribution of byproducts, three types of ZnO nanomaterials (nanoparticles (NPs), nanorods (NRs) and nanowires (NWs)) were prepared and coated on multi-channel porous alumina ceramic membrane. The structures and morphologies of the nanomaterials were confirmed by X-ray diffraction method and scanning electron microscopy. The observed catalytic activity of ZnO in the oxidative decomposition of butane was strongly shape-dependent. It was found that the ZnO NWs exhibited higher catalytic activity than the other nanomaterials and could completely oxidize butane into carbon oxides (COx). When using the bare or ZnO NPs-coated ceramic membrane, several unwanted partial oxidation and decomposition products like acetaldehyde, acetylene, methane and propane were identified during the decomposition of butane. When the ZnO NWs- or ZnO NRs-coated membrane was used, however, the formation of such unwanted byproducts except methane was completely avoided, and full conversion into COx was achieved. Better carbon balance and COx selectivity were obtained with the ZnO NWs and NRs than with the NPs. PMID:25195119

  18. 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

  19. 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. PMID:26506981

  20. IMPROVEMENT OF THE MODELLING OF THE LOW-TEMPERATURE OXIDATON OF N-BUTANE - STUDY OF THE PRIMARY REACTIONS

    PubMed Central

    CORD, Maximilien; SIRJEAN, Baptiste; FOURNET, René; TOMLIN, Alison; RUIZ-LOPEZ, Manuel; BATTIN-LECLERC, Frédérique

    2013-01-01

    This paper revisits the primary reactions involved in the oxidation of n-butane from low to intermediate temperatures (550-800 K) including the negative temperature coefficient (NTC) zone. A model which was automatically generated is used as a starting point and a large number of thermochemical and kinetic data are then re-estimated. The kinetic data of the isomerization of alkylperoxy radicals giving ·QOOH radicals and the subsequent decomposition to give cyclic ethers has been calculated at the CBS-QB3 level of theory. The newly obtained model allows a satisfactory prediction of experimental data recently obtained in a jet-stirred reactor and in rapid compression machines. A considerable improvement of the prediction of the selectivity of cyclic ethers is especially obtained compared to previous models. Linear and global sensitivity analyses have been performed in order to better understand which reactions are of influence in the NTC zone. PMID:22257166

  1. 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.

  2. 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

  3. 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

    2016-01-01

    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. PMID:26823356

  4. Toward understanding the nature of internal rotation barriers with a new energy partition scheme: ethane and n-butane.

    PubMed

    Liu, Shubin; Govind, Niranjan

    2008-07-24

    On the basis of an alternative energy partition scheme where density-based quantification of the steric effect was proposed [Liu, S. B. J. Chem. Phys. 2007, 126, 244103], the origin of the internal rotation barrier between the eclipsed and staggered conformers of ethane and n-butane is systematically investigated in this work. Within the new scheme, the total electronic energy is decomposed into three independent components, steric, electrostatic, and fermionic quantum. The steric energy defined in this way is repulsive, exclusive, and extensive and intrinsically linked to Bader's atoms in molecules approach. Two kinds of differences, adiabatic (with optimal structure) and vertical (with fixed geometry), are considered for the molecules in this work. We find that in the adiabatic case the eclipsed conformer possesses a larger steric repulsion than the staggered conformer for both molecules, but in the vertical cases the staggered conformer retains a larger steric repulsion. For ethane, a linear relationship between the total energy difference and the fermionic quantum energy difference is discovered. This linear relationship, however, does not hold for n-butane, whose behaviors in energy component differences are found to be more complicated. The impact of basis set and density functional choices on energy components from the new energy partition scheme has been investigated, as has its comparison with another definition of the steric effect in the literature in terms of the natural bond orbital analysis through the Pauli Exclusion Principle. In addition, profiles of conceptual density functional theory reactivity indices as a function of dihedral angle changes have been examined. Put together, these results suggest that the new energy partition scheme provides insights from a different perspective of internal rotation barriers. PMID:18563887

  5. Influence of reductive pretreatments on the activity and selectivity of vanadium-phosphorus oxide catalysts for n-butane partial oxidation

    SciTech Connect

    Hodnett, B.K.; Delmon, B.

    1984-11-01

    The catalytic activities for n-butane conversion to maleic anhydride of two series of vanadium-phosphorus oxide catalysts with phosphorus:vanadium ratios in the range 0.94 to 1.10 and calcined at 773 or 923 K were compared before and after reduction by hydrogen. In almost all cases studied, reduction gave rise to increased conversion, and for catalysts with low phosphorus:vanadium ratios increased selectivity was also noted. When n-butane was contacted with these catalysts in the absence of gas phase oxygen, maleic anhydride and total oxidation products continued to be formed until changes in average oxidation state of vanadium of up to -1.5 were recorded. From considerations of the dynamic state of the catalysts during catalysis, it was concluded that a morphology consisting of oxidized surface layers on a reduced core favors high activities and selectivities for this process.

  6. Effect of the pore structure and granule shape of V-P-O catalyst on the selectivity of oxidation of n-butane

    SciTech Connect

    Zazhigalov, V.A.; Belousov, V.M.; Pyatnitskaya, A.I.; Komashko, G.A.; Shkarin, A.V.; Khuzhakaeva, L.S.

    1988-07-10

    The process of oxidation of n-butane on vanadium-phosphorus oxide catalyst (V-P-O) with a granule size of less than 1 mm takes place in the kinetic region. At the same time, conducting the reaction in reactors with a stationary bed of catalyst requires using larger catalyst grains. It is shown that the process of oxidation of n-butane in a stationary bed on large catalyst granules is complicated by intradiffusion factors. It is necessary to increase the concentration of pores with r > 50 nm and to use ring-shaped pellets instead of solid granules to increase the rate of formation of the product of partial oxidation (maleic anhydride) and the selectivity with respect to this product.

  7. New layered vandyl(IV) phosphite as a precursor to vanadyl pyrophosphate catalysts for partial oxidation of n-Butane to maleic anhydride

    SciTech Connect

    Guliants, V.V.; Benziger, J.B.; Sundaresan, S.

    1995-10-01

    The synthesis and characterization of layered vanadyl(IV) phosphonates, VOC{sub n}H{sub 2n+1}PO{sub 3}{center_dot}xH{sub 2}O containing the V{sub 2}O{sub 8} dimers have been recently reported. The authors present here the results of partial oxidation of n-butane on VPO catalysts derived from the simplest of these phosphonates, vanadyl phosphite. The results indicate that vanadyl(IV) phosphite is the precursor to vanadyl pyrophosphate catalysts with high surface area (ca. 45 m{sup 2}/g) and selectivity to maleic anhydride in n-butane partial oxidation comparable to the conventional unpromoted catalyst. 10 refs., 3 figs., 1 tab.

  8. N,N′-[(2E,3E)-Butane-2,3-diylidene]bis[4-fluoro-2-(1-phenyl­eth­yl)aniline

    PubMed Central

    Wei, Juanjuan; She, Houde; Shi, Lijun; Lei, Ziqiang

    2014-01-01

    The title mol­ecule, C32H30F2N2, a product of the condensation reaction of butane-2,3-dione and 4-fluoro-2-(1-phenyl­eth­yl)aniline, is located about an inversion centre. In the asymmetric unit, the dihedral angle between the planes of the benzene and phenyl rings is 84.27 (5)°. Neither hydrogen bonding nor aromatic stacking is observed in the crystal structure. PMID:24764988

  9. On the mechanism of n-butane oxidation to maleic anhydride on VPO catalysts. I. A kinetics study on a VPO catalyst as compared to VPO reference phases

    SciTech Connect

    Zhang-Lin, Y.; Sneeden, R.P.; Vedrine, J.C.; Volta, J.C. ); Forissier, M. )

    1994-02-01

    In order to obtain more information on the mechanism of butane oxidation, the oxidation of n-butane, butadiene, furan, and maleic anhydride (MA) is studied on different VPO structures: [alpha][sub 11], [beta], [gamma], and [sigma] VOPO[sub 4], on the one hand, and (VO)[sub 2]P[sub 2]O[sub 7] and the activated VPO catalyst, on the other hand. A general scheme is proposed for the oxidation of butane on these different structures. A direct route to maleic anhydride which implies alkoxide intermediates without desorption in the gas phase of butene, butadiene, and furan is proposed as an alternative to the olefinic route. The activated VPO catalyst is more selective to MA than is (VO)[sub 2]P[sub 2]O[sub 7], while [alpha][sub 11] VOPO[sub 4] dehydrogenates to butadiene. [beta] VOPO[sub 4] gives mainly CO[sub x] while [gamma] and [sigma] VOPO[sub 4] are fairly selective to MA. 20 refs., 14 figs., 8 tabs.

  10. Conformational equilibria in butane-1,4-diol: a benchmark of a prototypical system with strong intramolecular H-bonds.

    PubMed

    Kozuch, Sebastian; Bachrach, Steven M; Martin, Jan M L

    2014-01-01

    Explicitly correlated CCSD(T) valence basis limit relative energies were obtained for the 65 conformers of butane-1,4-diol, a prototypical system with a strong internal hydrogen bond. The performance of a variety of ab initio and DFT methods (with and without empirical dispersion corrections) was assessed in detail. Consideration of all pairwise conformer energies provides a performance gauge for both H-bonds and van der Waals interactions, aside from internal strain of angles and bonds. In the post-HF realm, it was found that SCS(MI)CCSD-F12/cc-pVDZ-F12 can be a cost-effective alternative to CCSD(T)/CBS, almost without any loss in accuracy. In the DFT arena, the double-hybrid DSD-PBEP86-D3BJ surpasses the accuracy of all other methods (except for SCS(MI)CCSD, but at a small fraction of its cost). Several hybrid functionals provide an acceptable accuracy with the def2-QZVP basis set, especially BMK, M06, LC-ωPBE-D3, and TPSS0-D3. With the more modest 6-311+G(d,p) basis set, the H-bonds are far from basis set completeness and, due to error compensation, the inclusion of a dispersion correction is generally counterproductive. Some functionals that represent "Pauling points" at this level are LC-ωPBE, TPSS0, B1B95, BMK, TPSSh, PBE0, TPSS, and ωB97X. PMID:24328111

  11. Kinetic and inhibition studies for the aerobic cometabolism of 1,1,1-trichloroethane, 1,1-dichloroethylene, and 1,1-dichloroethane by a butane-grown mixed culture.

    PubMed

    Kim, Young; Arp, Daniel J; Semprini, Lewis

    2002-12-01

    Batch kinetic and inhibition studies were performed for the aerobic cometabolism of 1,1,1-trichloroethane (1,1,1-TCA), 1,1-dichloroethylene (1,1-DCE), and 1,1-dichloroethane (1,1-DCA) by a butane-grown mixed culture. These chlorinated aliphatic hydrocarbons (CAHs) are often found together as cocontaminants in groundwater. The maximum degradation rates (k(max)) and half-saturation coefficients (K(s)) were determined in single compound kinetic tests. The highest k(max) was obtained for butane (2.6 micromol/mg TSS/h) followed by 1,1-DCE (1.3 micromol/mg TSS/h), 1,1-DCA (0.49 micromol/mg TSS/h), and 1,1,1-TCA (0.19 micromol/mg TSS/h), while the order of K(s) from the highest to lowest was 1,1-DCA (19 microM), butane (19 microM), 1,1,1-TCA (12 microM) and 1,1-DCE (1.5 microM). The inhibition types were determined using direct linear plots, while inhibition coefficients (K(ic) and K(iu)) were estimated by nonlinear least squares regression (NLSR) fits to the kinetic model of the identified inhibition type. Two different inhibition types were observed among the compounds. Competitive inhibition among CAHs was indicated from direct linear plots, and the CAHs also competitively inhibited butane utilization. 1,1-DCE was a stronger inhibitor than the other CAHs. Mixed inhibition of 1,1,1-TCA, 1,1-DCA, and 1,1-DCE transformations by butane was observed. Thus, both competitive and mixed inhibitions are important in cometabolism of CAHs by this butane culture. For competitive inhibition between CAHs, the ratio of the K(s) values was a reasonable indicator of competitive inhibition observed. Butane was a strong inhibitor of CAH transformation, having a much lower inhibition coefficient than the K(s) value of butane, while the CAHs were weak inhibitors of butane utilization. Model simulations of reactor systems where both the growth substrate and the CAHs are present indicate that reactor performance is significantly affected by inhibition type and inhibition coefficients. Thus

  12. Reaction-path calculations and crystal structures of 1,1'-(ethylene-1,2-diyl)dipyridinium dichloride dihydrate and 1,1'-(ethylene-1,2-diyl)dipyridinium dibromide.

    PubMed

    Rukiah, Mwaffak; Al-Ktaifani, Mahmoud M; Sabra, Mohammad K

    2016-02-01

    The design of new organic-inorganic hybrid ionic materials is of interest for various applications, particularly in the areas of crystal engineering, supramolecular chemistry and materials science. The monohalogenated intermediates 1-(2-chloroethyl)pyridinium chloride, C5H5NCH2CH2Cl(+)·Cl(-), (I'), and 1-(2-bromoethyl)pyridinium bromide, C5H5NCH2CH2Br(+)·Br(-), (II'), and the ionic disubstituted products 1,1'-(ethylene-1,2-diyl)dipyridinium dichloride dihydrate, C12H14N2(2+)·2Cl(-)·2H2O, (I), and 1,1'-(ethylene-1,2-diyl)dipyridinium dibromide, C12H14N2(2+)·2Br(-), (II), have been isolated as powders from the reactions of pyridine with the appropriate 1,2-dihaloethanes. The monohalogenated intermediates (I') and (II') were characterized by multinuclear NMR spectroscopy, while (I) and (II) were structurally characterized using powder X-ray diffraction. Both (I) and (II) crystallize with half the empirical formula in the asymmetric unit in the triclinic space group P-1. The organic 1,1'-(ethylene-1,2-diyl)dipyridinium dications, which display approximate C2h symmetry in both structures, are situated on inversion centres. The components in (I) are linked via intermolecular O-H...Cl, C-H...Cl and C-H...O hydrogen bonds into a three-dimensional framework, while for (II), they are connected via weak intermolecular C-H...Br hydrogen bonds into one-dimensional chains in the [110] direction. The nucleophilic substitution reactions of 1,2-dichloroethane and 1,2-dibromoethane with pyridine have been investigated by ab initio quantum chemical calculations using the 6-31G** basis. In both cases, the reactions occur in two exothermic stages involving consecutive SN2 nucleophilic substitutions. The isolation of the monosubstituted intermediate in each case is strong evidence that the second step is not fast relative to the first. PMID:26846494

  13. Using degrees of rate control to improve selective n-butane oxidation over model MOF-encapsulated catalysts: sterically-constrained Ag3Pd(111).

    PubMed

    Dix, Sean T; Scott, Joseph K; Getman, Rachel B; Campbell, Charles T

    2016-07-01

    Metal nanoparticles encapsulated within metal organic frameworks (MOFs) offer steric restrictions near the catalytic metal that can improve selectivity, much like in enzymes. A microkinetic model is developed for the regio-selective oxidation of n-butane to 1-butanol with O2 over a model for MOF-encapsulated bimetallic nanoparticles. The model consists of a Ag3Pd(111) surface decorated with a 2-atom-thick ring of (immobile) helium atoms which creates an artificial pore of similar size to that in common MOFs, which sterically constrains the adsorbed reaction intermediates. The kinetic parameters are based on energies calculated using density functional theory (DFT). The microkinetic model was analysed at 423 K to determine the dominant pathways and which species (adsorbed intermediates and transition states in the reaction mechanism) have energies that most sensitively affect the reaction rates to the different products, using degree-of-rate-control (DRC) analysis. This analysis revealed that activation of the C-H bond is assisted by adsorbed oxygen atoms, O*. Unfortunately, O* also abstracts H from adsorbed 1-butanol and butoxy as well, leading to butanal as the only significant product. This suggested to (1) add water to produce more OH*, thus inhibiting these undesired steps which produce OH*, and (2) eliminate most of the O2 pressure to reduce the O* coverage, thus also inhibiting these steps. Combined with increasing butane pressure, this dramatically improved the 1-butanol selectivity (from 0 to 95%) and the rate (to 2 molecules per site per s). Moreover, 40% less O2 was consumed per oxygen atom in the products. Under these conditions, a terminal H in butane is directly eliminated to the Pd site, and the resulting adsorbed butyl combines with OH* to give the desired 1-butanol. These results demonstrate that DRC analysis provides a powerful approach for optimizing catalytic process conditions, and that highly selectivity oxidation can sometimes be achieved by

  14. 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.

  15. 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).

  16. Volumetric Properties of the Mixture Propenenitrile C3H3N + C4H10O Butan-2-ol (VMSD1212, LB4923_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-2-ol (VMSD1212, LB4923_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  17. Volumetric Properties of the Mixture Propenenitrile C3H3N + C4H10O Butan-2-ol (VMSD1111, LB4915_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-2-ol (VMSD1111, LB4915_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  18. Volumetric Properties of the Mixture Propenenitrile C3H3N + C4H10O Butan-1-ol (VMSD1212, LB4919_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 (VMSD1212, LB4919_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  19. Volumetric Properties of the Mixture Propenenitrile C3H3N + C4H10O Butan-1-ol (VMSD1111, LB4911_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 (VMSD1111, LB4911_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  20. A Gallium-Substituted Distibene and an Antimony-Analogue Bicyclo[1.1.0]butane: Synthesis and Solid-State Structures.

    PubMed

    Tuscher, Lars; Ganesamoorthy, Chelladurai; Bläser, Dieter; Wölper, Christoph; Schulz, Stephan

    2015-09-01

    RGa {R=HC[C(Me)N(2,6-iPr2C6H3)]2} reacts with Sb(NMe2)3 with insertion into the Sb-N bond and elimination of RGa(NMe2)2 (2), yielding the Ga-substituted distibene R(Me2N)GaSb=SbGa(NMe2 )R (1). Thermolysis of 1 proceeded with elimination of RGa and 2 and subsequent formation of the bicyclo[1.1.0]butane analogue [R(Me2N)Ga]2Sb4 (3). PMID:26248643

  1. r-1,t-3-Bis[4-(di­methyl­amino)­phen­yl]-c-2,t-4-bis­(pyridin-4-yl)cyclo­butane

    PubMed Central

    Zhang, Shuguang; Zhuang, Junpeng

    2014-01-01

    The title compound, C30H32N4, was synthesized by the photodimerization of trans-4-{2-[4-(di­methyl­amino)­phen­yl]ethen­yl}pyridine in benzene upon irradiation with UV light. This photodimer has a puckered cyclo­butane ring with the four aryl substituents in an r-1,t-2,c-3,t conformation. The puckering angle of the cyclo­butane ring is 32.22 (7)°, which is the largest among reported tetra­aryl-substituted cyclo­butanes. In the crystal, the mol­ecules form a hollow, one-dimensional structure extending parallel to the c axis via two different pairs of C—H⋯π inter­actions. PMID:24765012

  2. 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.

  3. Temperature measurement of axi- symmetric butane diffusion flame under the influence of upward decreasing gradient magnetic field using digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Kumar, Varun; Kumar, Manoj; Shakher, Chandra

    2015-08-01

    In this paper, digital holographic interferometry (DHI) is implemented to investigate the effect of upward decreasing gradient magnetic field on the temperature and temperature profile of diffusion flame created by butane torch burner. In the experiment double exposure digital holographic interferometry is used to calculate the temperature distribution inside the flame. First a digital hologram is recorded in the absence of flame and second hologram is recorded in the presence of flame. Phases in two different states of air (i.e. in absence of flame and presence of flame) are reconstructed individually by numerical method. The phase difference map is obtained by subtracting the reconstructed phase of air in presence and absence of flame. Refractive index inside the flame is obtained from the axi-symmetric phase difference data using the Abel inversion integral. Temperature distribution inside the flame is calculated from the refractive index data using Lorentz - Lorentz equation. Experiment is conducted on a diffusion flame created by butane torch burner in the absence of magnetic field and in presence of upward decreasing gradient magnetic field. Experimental investigations reveal that the maximum temperature inside the flame increases under the influence of upward decreasing magnetic field.

  4. Direct Dehydrogenation of n-Butane Over Pt/Sn/Zn/γ-Al2O3 Nano-Catalyst: Effect of Zn Content.

    PubMed

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

    2015-10-01

    A series of Pt/Sn/XZn/γ-Al2O3 nano-catalysts with different Zn content (X = 0, 0.25, 0.5, 0.75, and 1.0 wt%) were prepared by a sequential impregnation method. They were applied to the direct dehydrogenation of n-butane to n-butene and 1,3-butadiene. The effect of zinc content of Pt/Sn/XZn/γ-Al2O3 nano-catalysts on their physicochemical properties and catalytic activities in the direct dehydrogenation of n-butane was investigated. The catalytic performance of Pt/Sn/XZn/γ-Al2O3 nano-catalysts strongly depended on zinc content. Among the catalysts tested, Pt/Sn/0.5Zn/γ-Al2O3 nano-catalyst showed the best catalytic performance in terms of yield for total dehydrogenation products (TDP, n-butene and 1,3-butadiene). TPR (temperature-programmed reduction) and H2-chemisorption experiments were carried out to measure metal-support interaction and Pt surface area of the catalysts. Experimental results revealed that metal-support interaction and Pt surface area of the catalysts were closely related to the catalytic performance. Yield for TDP increased with increasing metal-support interaction and Pt surface area of the catalysts. PMID:26726510

  5. Photophysical Behavior and Computational Investigation of Novel 1,4-Bis(2-(2-Phenylpyrimido[1,2-a]Benzimidazol-4-Yl)Phenoxy)Butan (BPPB) Macromolecule.

    PubMed

    Saleh, Tamer S; Hussein, Mahmoud A; Osman, Osman I; Alamry, Khalid A; Mekky, Ahmed E M; Asiri, Abdullah M; El-Daly, Samy A

    2016-09-01

    A new macromolecule pyrimido[l,2-a]benzimidazole derivative named 1,4-bis(2-(2-phenylpyrimido[1,2-a]benzimidazol-4-yl)phenoxy)butan (BPPB) has been synthesized in accepted yield using microwave assistance. The new compound BPPB has been formed by the interaction of 3,3'-((butane-1,4-diylbis(oxy))bis(2,1-phenylene))bis(1-phenylprop-2-en-1-one) (3) with 2- aminobenzimidazole (4) in the presence of potassium hydroxide as a basic catalyst in dimethylformamide (DMF) under microwave radiation for 20 min. The chemical structure of this novel compound was elucidated by elemental and spectral techniques including: FT-IR, (1)H-NMR, (13)C-NMR and mass spectra. The electronic absorption and emission spectra of BPPB were measured in different solvents. BPPB displayed a solvatochromic effect of the emission spectrum that is reflected by red shifts of its fluorescence emission maxima on increasing the solvent polarity, indicating a change of electronic charge distribution upon excitation. BPPB crystalline solids gave excimer-like emission at 535 nm with a bandwidth of ca. 60 nm. Ground and excited states electronic geometry optimizations using density functional theory (DFT) and time-dependent density functional theory (TD-DFT), respectively, complemented these spectral findings. The intramolecular charge transfer was investigated by natural bond orbital (NBO) technique. PMID:27476069

  6. 75 FR 29435 - Diquat Dibromide; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ...) 305-5805. II. Summary of Petitioned-For Tolerance In the Federal Register of February 4, 2010 (75 FR... margin of safety is commonly referred to as the Food Quality Protection Act (FQPA) Safety Factor (SF). In..., established in the Federal Register of March 27, 1996 (61 FR 13474) (FRL-5348-1). The statement...

  7. On the role of the VO(H{sub 2}PO{sub 4}){sub 2} precursor for n-butane oxidation into maleic anhydride

    SciTech Connect

    Sananes, M.T. |; Hutchings, G.J.; Volta, J.C.

    1995-07-01

    The catalytic role of VO(H{sub 2}PO{sub 4}){sub 2}, the precursor of the VO(PO{sub 3}){sub 2} phase, has been studied for N-butane oxidation to maleic anhydride. By comparison with the activated VPO catalyst, derived from the VOHPO{sub 4} {center_dot} 0.5H{sub 2}O precursor phase, VO(H{sub 2}PO{sub 4}){sub 2} gives a highly selective final catalyst. The total oxidation products CO and CO{sub 2} are not observed under any of the conditions examined, a result confirmed by extensive catalyst testing and carbon mass balances. The final catalyst derived from VO(H{sub 2}PO{sub 4}){sub 2} has a low surface area, ca. 1 m{sup 2}/g, and consequently demonstrates low specific activity on the basis of n-butane conversion per unit mass. However, the intrinsic activity (activity per unit surface area) is found to be higher than that for catalysts derived from VOHPO{sub 4}{center_dot}0.5H{sub 2}O. Since some VO(H{sub 2}PO{sub 4}){sub 2} is present in VOHPO{sub 4}{center_dot}0.5H{sub 2}O, which is the precursor of the industrial catalyst, the results of this study complicate the simple model in which the (VO){sub 2}O{sub 7} phase derived from VOHPO{sub 4} {center_dot}0.5H{sub 2}O is responsible for the selective oxidation of n-butane. The observation that the precursor VO(H{sub 2}PO{sub 4}){sub 2} can generate catalysts of high specific activity and of total selectivity to partial oxidation products might provide a useful insight into the design of a new series of high activity and high selectivity partial oxidation catalysts. 36 refs., 12 figs., 2 tabs.

  8. Bis(nona­fluoro­butane­sulfonato-κO)dioxidotris(tetra­hydro­furan-κO)uranium(VI)

    PubMed Central

    Takao, Koichiro; Ikeda, Yasuhisa

    2008-01-01

    In the title compound, [U(C4F9O3S)O2(C4H8O)3], each UVI ion is located on a twofold rotation axis and is seven-coordinated by two terminal O atoms in the axial positions [U—O = 1.737 (5) Å] and five O atoms from two monodentate nona­fluoro­butane­sulfonate (NfO−) and three tetra­hydro­furan ligands in the equatorial plane [U—O = 2.388 (5)–2.411 (4) Å] in a penta­gonal–bipyramidal geometry. The crystal packing exhibits weak inter­molecular C—H⋯O hydrogen bonds involving the non-coordinated O atoms of the NfO− ligands. PMID:21200516

  9. Synthesis and characterization of a three dimensional zinc(II) metal-organic framework constructed from flexible 1,2,3,4-tetra-(4-pyridyl)-butane ligand

    NASA Astrophysics Data System (ADS)

    Lin, Jianguo; Wu, Peiheng; Kang, Lin; Lu, Changsheng; Meng, Qingjin

    2011-08-01

    Employing the flexible tetrapodal ligand 1,2,3,4-tetra-(4-pyridyl)-butane (TPB) along with fumaric acid (H 2FMA) as the bridges, a metal-organic framework of [Zn(TPB)(FMA)·(2H 2O)] ( 1) was obtained and characterized by elemental analysis, spectral method (IR), single crystal X-ray diffraction, thermal gravimetric analysis (TGA) and fluorescent property. This polymer exhibits a three dimensional (3D) dense network with an interesting (4,4)-connected PtS topology. It also displays good thermal stability and strong photoluminescence in the blue region band. Thus it may serve as a candidate of thermally stable blue-light-emitting photoluminescent material.

  10. Process for improving phosphorus-vanadium oxide and phosphorus vanadium-co-metal oxide catalysts in the oxidation of -butane to maleic anhydride

    SciTech Connect

    Edwards, R.C.

    1989-03-07

    This patent describes a process for the manufacture of maleic anhydride in which a feedstock comprising butane and a gas containing molecular oxygen are contacted with a phosphorus-vanadium-oxygen catalyst on a catalyst bed having a portion thereof containing an initial exotherm of reaction. The improvement comprises: treating the catalyst by adding to the gaseous feed stream water and a phosphorus compound in an amount sufficient to (a) initiate deactivation of the portion of the catalyst bed containing the initial exotherm, and (b) initiate formation of a new exotherm downstream in the catalyst bed from the initial exotherm, and thereafter reducing or discontinuing application of the phosphorus compound at a point in time when the initial exotherm portion of the catalyst is still undergoing deactivation, thereby allowing the partially deactivated exotherm portion to reactivate producing a more isothermal catalyst bed.

  11. Adaptive control of a packedbed reactor for the partial oxidation of n-butane to maleic anhydride; I. unsteady-state model and dynamics of the reactor

    SciTech Connect

    Not Available

    1984-01-01

    A nonadiabatic, fixed-bed catalytic reactor is analyzed on the basis of data for the highly exothermic partial oxidation of n-butane to maleic anhydride, in order to study multivariable adaptive control. The nonlinear partial differential equations describing the axial and radial gradients of concentration and temperature are converted into a set of nonlinear, ordinary differential and algebraic equations using orthogonal collocation, preserving the nonlinearity of the reaction term. These equations describe satisfactorily the steady state and dynamic behavior. This two-dimensional model enables the relationship between the time and temperature of reaction, and between the concentration of maleic anhydride and the hot-spot temperature to be expressed adequately by seconddegree, low-order transfer functions. This technique is applicable for any process of reaction in a packed bed.

  12. 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.

  13. 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.

  14. Periodic Density Functional Theory Study of the Oxidative Dehydrogenation of n-butane on the (001) Surface of V2O5

    NASA Astrophysics Data System (ADS)

    Hà, Nguyën Ngoc; Hue, Trán Thành; Tho, Nguyen Minh

    2009-03-01

    The oxidative dehydrogenation (ODH) of light alkanes is an attractive alternative for the production of more valuable alkenes. Considerable research efforts have been made towards the development of catalysts active at low temperature and selective in the formation of alkenes. Most catalysts described in the literature are based on Vanadium oxide as the main component and many studies concerning the reaction mechanism during the ODH of short alkanes have been performed but debates still today exist. The objective of this work is to study in detail theoretically the kinetics of n-butane ODH on the (001) surface of V2O5. The density functional theory using a plane-waves basis set and pseudopotential has been used for this purpose.

  15. Experimental and Modeling Study of the Oxidation of n-Butane in a Jet Stirred Reactor using cw-CRDS Measurements

    PubMed Central

    Bahrini, Chiheb; Morajkar, Pranay; Schoemeacker, Coralie; Frottier, Ophélie; Herbinet, Olivier; Glaude, Pierre-Alexandre; Battin-Leclerc, Frédérique; Fittschen, Christa

    2013-01-01

    The gas-phase oxidation of n-butane has been studied in an atmospheric jet-stirred reactor (JSR) at temperatures up to 950 K. For the first time, continuous wave cavity ring-down spectroscopy (cw-CRDS) in the near-infrared has been used, together with gas chromatography (GC), to analyze the products formed during the oxidation. In addition to the quantification of formaldehyde and water, which is always difficult by GC, cw-CRDS allowed as well the quantification of hydrogen peroxide (H2O2). A comparison of the obtained mole fraction temperature profiles with simulations using a detailed gas-phase mechanism shows a good agreement at temperatures below 750 K, but an overestimation of the overall reactivity above this temperature. Also, a strong overestimation was found for the H2O2 mole fraction at the higher temperatures. In order to improve the agreement between model and experimental results, two modifications have been implemented to the model: (a) the rate constant for the decomposition of H2O2 (+M) ↔ 2 OH (+M) has been updated to the value recently proposed by Troe (Combust. Flame, 2011, 158, 594-601) and (b) a temperature dependant heterogeneous destruction of H2O2 on the hot reactor walls with assumed rate parameters has been added. The improvement (a) slows down the overall reactivity at higher temperatures, but has a negligible impact on the maximal H2O2 mole fraction. Improvement (b) has also a small impact on the overall reactivity at higher temperatures, but a large effect on maximal H2O2 mole fraction. Both modifications lead to an improved agreement between model and experiment for the oxidation of n-butane in a JSR at temperatures above 750 K. PMID:24135810

  16. 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. PMID:25958621

  17. 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). PMID:24266201

  18. Density and viscosity of mixtures of nitrobenzene with methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, 2-methylpropan-1-ol, and 2-methylpropan-2-ol at 298.15 and 303.15 K

    SciTech Connect

    Nikam, P.S.; Jadhav, M.C.; Hasan, M.

    1995-07-01

    Densities and viscosities of mixtures of nitrobenzene with methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, 2-methylpropan-1-ol, and 2-methylpropan-2-ol were measured at 298.15 and 303.15 K. From these measurements, the excess volumes (V{sup E}) and deviation in viscosity ({delta}{eta}) were calculated. These results were fitted to the Redlich-Kister polynomial.

  19. Density and viscosity of mixtures of dimethyl sulfoxide + methanol, + ethanol, + propan-1-ol, + propan-2-ol, + butan-1-ol, + 2-methylpropan-1-ol, and + 2-methylpropan-2-ol at 298.15 K and 303.15 K

    SciTech Connect

    Nikam, P.S.; Jadhav, M.C.; Hasan, M.

    1996-09-01

    Densities and viscosities have been measured for the binary mixtures of dimethyl sulfoxide + methanol, + ethanol, + propan-1-ol, + propan-2-ol, + butan-1-ol, + 2-methylpropan-1-ol, and + 2-methylpropan-2-ol at 298.15 K and 303.15 K. From these results, the excess molar volume (V{sup E}) and deviation in viscosity ({Delta}{eta}) have been computed. These properties are used to calculate regression coefficients of the Redlich-Kister equation.

  20. 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.

  1. 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.

  2. Bimetallic Ni-Rh catalysts with low amounts of Rh for the steam and autothermal reforming of n-butane for fuel-cell applications.

    SciTech Connect

    Ferrandon, M.; Kropf, A. J.; Krause, T.; Chemical Sciences and Engineering Division

    2010-05-15

    Mono-metallic nickel and rhodium catalysts and bimetallic Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}, CeZrO{sub 2} and CeMgOx were prepared and evaluated for catalyzing the steam and autothermal reforming of n-butane. The binary Ni-Rh supported on La-Al{sub 2}O{sub 3} catalysts with low weight loading of rhodium exhibited higher H{sub 2} yields than Ni or Rh alone. The Ni-Rh/CeZrO{sub 2} catalyst exhibited higher performance and no coke formation, compared to the same metals on other supports. A NiAl{sub 2}O{sub 4} spinel phase was obtained on all Ni and Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}. The presence of rhodium stabilized the spinel phase as well as NiOx species upon reforming while Ni alone was mostly reduced into metallic species. Extended X-ray absorption fine-structure analysis showed evidence of Ni-Rh alloy during preparation and even further after an accelerated aging at 900C in a H{sub 2}/H{sub 2}O atmosphere.

  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. PMID:26621259

  4. 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.

  5. 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. PMID:25173323

  6. 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. PMID:25314616

  7. (Cyclo-butane-1,1-di-carboxyl-ato-κ(2) O,O')(1,10-phenanthroline-κ(2) N,N')platinum(II) dihydrate.

    PubMed

    Starha, Pavel; Trávníček, Zdeněk

    2013-06-01

    The title compound, [Pt(C6H6O4)(C12H8N2)]·2H2O, which crystallizes as two independent formula units, has the metal atom in a square-planar geometry defined by two O atoms of the chelating cyclo-butane-1,1-di-carboxyl-ate dianion and two N atoms of the chelating 1,10-phenanthroline mol-ecule (r.m.s. deviations of the PtO2N2 units = 0.026 and 0.026 Å). Adjacent complex and water mol-ecules are connected through inter-molecular O-H⋯O hydrogen bonds and C-H⋯O, C⋯O [shortest C⋯O distance = 3.140 (5) Å], π-π [shortest C⋯C distances = 3.234 (6) and 3.347 (6) Å] and Pt⋯π [shortest Pt⋯C distance = 3.358 (4) Å] inter-actions into a three-dimensional network. PMID:23794996

  8. 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.

  9. 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

  10. Syntheses, structures and photoluminescent properties of Zn(Ⅱ)/Co(Ⅱ) coordination polymers based on flexible tetracarboxylate ligand of 5,5‧-(butane-1,4-diyl)-bis(oxy)-di isophthalic acid

    NASA Astrophysics Data System (ADS)

    Gao, Yan-Peng; Guo, Le; Dong, Wei; Jia, Min; Zhang, Jing-Xue; Sun, Zhong; Chang, Fei

    2016-08-01

    Three new mixed-ligand metal-organic frameworks based on 5,5‧-(butane-1,4- diyl)-bis(oxy)-diisophthalic acid and transitional metal cations with the help of two ancillary bridging N-donor pyridyl and imidazole linkers, [Zn(L)0.5(4,4‧-bpy)]·2(H2O) (1), [M(L)0.5(bib)]·4(H2O) (M = Zn (2), Co (3)), (4,4‧-bpy=4,4‧-bipyridine, bib=1,4-bis (1H-imidazol-1-yl)-butane), have been synthesized under solvothermal conditions. Their structures and properties were determined by single-crystal and powder X-ray diffraction analyses, IR spectra, elemental analyses and thermogravimetric analyses (TGA). Compounds 1-3 display a 3D 3-fold interpenetrated frameworks linked by the L4- ligands, ancillary N-donor linkers and the free water molecules in the crystal lattice. Topological analysis reveals that 1-3 are a (4,4)-connected bbf topology net with the (64·82)(66) topology. The effects of the L4- anions, the N-donor ligands, and the metal ions on the structures of the coordination polymers have been discussed. Furthermore, luminescence properties and thermogravimetric properties of these compounds were investigated.

  11. 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.

  12. 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.

  13. 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. PMID:22966706

  14. The IMOMO method: Integration of different levels of molecular orbital approximations for geometry optimization of large systems: Test for n-butane conformation and SN2 reaction: RCl+Cl -

    NASA Astrophysics Data System (ADS)

    Humbel, Stéphane; Sieber, Stefan; Morokuma, Keiji

    1996-08-01

    A new theoretical method, called IMOMO (integrated MO (molecular orbital)+MO), for integration of two different levels of MO approximation is presented. Only the active or more difficult part of a molecule is treated at a higher level of approximation and the rest of the molecule at a lower level of approximation. The integrated total energy and energy derivatives are defined from three different calculations, and the structure of transition state as well as the equilibrium structure can be optimized using the integrated energy. Any combination of any molecular orbital approximations (ab initio, density functional to semi-empirical) can be used. Test calculations in the IMOMO method have been performed and compared with normal MO calculations for the conformation energy of ethane and n-butane and the SN2 reaction of ethyl, propyl, isobutyl, and neopentyl chloride with Cl-. The results indicate that these methods have a tremendous potential for theoretical study of larger molecules, in particular for transition states.

  15. 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.

  16. Determination of γ-hydroxybutyrate (GHB), β-hydroxybutyrate (BHB), pregabalin, 1,4-butane-diol (1,4BD) and γ-butyrolactone (GBL) in whole blood and urine samples by UPLC-MSMS.

    PubMed

    Dahl, Sandra Rinne; Olsen, Kirsten Midtbøen; Strand, Dag Helge

    2012-02-15

    The demand of high throughput methods for the determination of gamma-hydroxybutyrate (GHB) and its precursors gamma-butyrolactone (GBL) and 1,4-butane-diol (1,4BD) as well as for pregabalin is increasing. Here we present two analytical methods using ultra-high pressure liquid chromatography (UPLC) and tandem mass spectrometric (MS/MS) detection for the determination of GHB, beta-hydroxybutyrate (BHB), pregabalin, 1,4BD and GBL in whole blood and urine. Using the 96-well formate, the whole blood method is a simple high-throughput method suitable for screening of large sample amounts. With an easy sample preparation for urine including only dilution and filtration of the sample, the method is suitable for fast screening of urine samples. Both methods showed acceptable linearity, acceptable limits of detection, and limits of quantification. The within-day and between-day precisions of all analytes were lower than 10% RSD. The analytes were extracted from matrices with recoveries near 100%, and no major matrix effects were observed. Both methods have been used as routine screening analyses of whole blood and urine samples since January 2010. PMID:22226469

  17. 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.

  18. 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. PMID:26958391

  19. 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

  20. (Cyclo­butane-1,1-di­carboxyl­ato-κ2 O,O′)(1,10-phenanthroline-κ2 N,N′)platinum(II) dihydrate

    PubMed Central

    Štarha, Pavel; Trávníček, Zdeněk

    2013-01-01

    The title compound, [Pt(C6H6O4)(C12H8N2)]·2H2O, which crystallizes as two independent formula units, has the metal atom in a square-planar geometry defined by two O atoms of the chelating cyclo­butane-1,1-di­carboxyl­ate dianion and two N atoms of the chelating 1,10-phenanthroline mol­ecule (r.m.s. deviations of the PtO2N2 units = 0.026 and 0.026 Å). Adjacent complex and water mol­ecules are connected through inter­molecular O—H⋯O hydrogen bonds and C—H⋯O, C⋯O [shortest C⋯O distance = 3.140 (5) Å], π–π [shortest C⋯C distances = 3.234 (6) and 3.347 (6) Å] and Pt⋯π [shortest Pt⋯C distance = 3.358 (4) Å] inter­actions into a three-dimensional network. PMID:23794996

  1. 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. PMID:16023658

  2. 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.

  3. Vibrational assignment, HOMO-LUMO and NBO analysis of (2S)-2-[(2-{[(2S)-1-hydroxybutan-2-yl]amino}ethyl)amino]butan-1-ol by density functional theory

    NASA Astrophysics Data System (ADS)

    Rajalakshmi, K.; Gunasekaran, S.; Kumaresan, S.

    2014-09-01

    The FTIR and FT-Raman spectra of (2S)-2-[(2-{[(2S)-1-hydroxybutan-2-yl]amino}ethyl)amino]butan-1-ol have been recorded in the region 4000-400 cm-1and 4000-100 cm-1 respectively. Utilizing the observed FTIR and FT-Raman data, a complete vibrational assignment and analysis of the fundamental vibrational modes of the compound were carried out. The optimized molecular geometry, harmonic vibrational frequencies, infrared intensities and Raman scattering were calculated by HF and density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) quantum chemical method with 6-31G(d,p), 6-31+G(d,p), 6-31++G(d,p) basis sets. The theoretical and optimized geometric parameters and vibrational frequencies have been found in good agreement with the corresponding experimental data and results in the literature. Ultraviolet-visible spectrum of the title molecule was recorded and has been calculated using TD-DFT method. The first-order hyperpolarizability (βo) and other related properties (μ, αo) of the compound are calculated using DFT method on a finite field approach. The most stable geometry of the compound under investigation has been determined from the potential energy scan. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital analysis (NBO). Besides, molecular electrostatic potential (MESP), HOMO and LUMO analysis, Mulliken population analysis and several other thermodynamic properties were performed by HF and DFT method.

  4. Vibrational assignment, HOMO-LUMO and NBO analysis of (2S)-2-[(2-{[(2S)-1-hydroxybutan-2-yl]amino}ethyl)amino]butan-1-ol by density functional theory.

    PubMed

    Rajalakshmi, K; Gunasekaran, S; Kumaresan, S

    2014-09-15

    The FTIR and FT-Raman spectra of (2S)-2-[(2-{[(2S)-1-hydroxybutan-2-yl]amino}ethyl)amino]butan-1-ol have been recorded in the region 4000-400 cm(-1)and 4000-100 cm(-1) respectively. Utilizing the observed FTIR and FT-Raman data, a complete vibrational assignment and analysis of the fundamental vibrational modes of the compound were carried out. The optimized molecular geometry, harmonic vibrational frequencies, infrared intensities and Raman scattering were calculated by HF and density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) quantum chemical method with 6-31G(d,p), 6-31+G(d,p), 6-31++G(d,p) basis sets. The theoretical and optimized geometric parameters and vibrational frequencies have been found in good agreement with the corresponding experimental data and results in the literature. Ultraviolet-visible spectrum of the title molecule was recorded and has been calculated using TD-DFT method. The first-order hyperpolarizability (βo) and other related properties (μ, αo) of the compound are calculated using DFT method on a finite field approach. The most stable geometry of the compound under investigation has been determined from the potential energy scan. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital analysis (NBO). Besides, molecular electrostatic potential (MESP), HOMO and LUMO analysis, Mulliken population analysis and several other thermodynamic properties were performed by HF and DFT method. PMID:24813275

  5. MAN or FA from n-butane

    SciTech Connect

    Di Cio, A.; Verde, L.

    1985-08-01

    Unsaturated polyester resins were first produced mostly from fumaric acid (FA) rather than from maleic anhydride (MAN). This is perfectly understandable if we consider that, using fumaric acid as raw material, polycondensates with a more homogeneous (less branched) structure are obtained, thus producing resins characterized by a more uniform and reproducible chemical and mechanical properties. Presently, for economical reasons, fumaric acid is used marginally as a MAN substitute in the production of polyester resins. These resins account for a major share (50%) of the overall MAN consumption in the U.S. and in Western Europe.

  6. (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.

  7. Magnetic investigations of a two-dimensional coordination polymer with a three-dimensional supramolecular framework: poly[[bis[μ2-1,4-bis(1,2,4-triazol-1-yl)butane]bis(thiocyanato-κN)cobalt(II)] dihydrate].

    PubMed

    Tao, Jian-Qing; Mao, Dan; Wang, Jun

    2013-06-01

    In the title mixed-ligand metal-organic polymeric complex, {[Co(NCS)2(C8H12N6)2]·2H2O}n, the asymmetric unit contains a divalent Co(II) cation, which sits on an inversion centre, two halves of two crystallographically distinct and centrosymmetric 1,4-bis(1,2,4-triazol-1-yl)butane (BTB) ligands, one N-bound thiocyanate ligand and one solvent water molecule. The Co(II) atom possesses a distorted {CoN6} octahedral geometry, with the equatorial positions taken up by triazole N atoms from four different BTB ligands. The axial positions are filled by thiocyanate N atoms. In the crystal, each Co(II) atom is linked covalently to four others through the distal donors of the tethering BTB ligands, forming a neutral (4,4)-topology two-dimensional rhomboid grid layer motif, which is coincident with the (121) crystal planes. Magnetic investigations show that weak antiferromagnetic coupling exists between Co(II) atoms in the complex. PMID:23744375

  8. Quantitative Measurements of HO2 and other products of n-butane oxidation (H2O2, H2O, CH2O, and C2H4) at elevated temperatures by direct coupling of a jet-stirred reactor with sampling nozzle and cavity ring-down spectroscopy (cw-CRDS).

    PubMed

    Djehiche, Mokhtar; Le Tan, Ngoc Linh; Jain, Chaithanya D; Dayma, Guillaume; Dagaut, Philippe; Chauveau, Christian; Pillier, Laure; Tomas, Alexandre

    2014-11-26

    For the first time quantitative measurements of the hydroperoxyl radical (HO2) in a jet-stirred reactor were performed thanks to a new experimental setup involving fast sampling and near-infrared cavity ring-down spectroscopy at low pressure. The experiments were performed at atmospheric pressure and over a range of temperatures (550-900 K) with n-butane, the simplest hydrocarbon fuel exhibiting cool flame oxidation chemistry which represents a key process for the auto-ignition in internal combustion engines. The same technique was also used to measure H2O2, H2O, CH2O, and C2H4 under the same conditions. This new setup brings new scientific horizons for characterizing complex reactive systems at elevated temperatures. Measuring HO2 formation from hydrocarbon oxidation is extremely important in determining the propensity of a fuel to follow chain-termination pathways from R + O2 compared to chain branching (leading to OH), helping to constrain and better validate detailed chemical kinetics models. PMID:25381864

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-11

    ... under the previously approved labeling until December 1, 2010, or a revised date if product labels with... of Unit II, once EPA has approved product labels reflecting the requested amendments to delete uses... of receipt for this action was published for comment on December 1, 2010 (75 FR 74714)...

  11. Crystal structure of catena-poly[[[tri-aqua-strontium]-di-μ2-glycinato] dibromide].

    PubMed

    Revathi, Palanisamy; Balakrishnan, Thangavelu; Ramamurthi, Kandasamy; Thamotharan, Subbiah

    2015-07-01

    In the title coordination polymer, {[Sr(C2H5NO2)2(H2O)3]Br2} n , the Sr(2+) ion and one of the water mol-ecules are located on twofold rotation axes. The alkaline earth ion is nine-coordinated by three water O atoms and six O atoms of the carboxyl-ate groups of four glycine ligands, two in a chelating mode and two in a monodentate mode. The glycine mol-ecule exists in a zwitterionic form and bridges the cations into chains parallel to [001]. The Br(-) counter-anions are located between the chains. Inter-molecular hydrogen bonds are formed between the amino and carboxyl-ate groups of neighbouring glycine ligands, generating a head-to-tail sequence. Adjacent head-to-tail sequences are further inter-connected by inter-molecular N-H⋯Br hydrogen-bonding inter-actions into sheets parallel to (100). O-H⋯Br and O-H⋯O hydrogen bonds involving the coordinating water mol-ecules are also present, consolidating the three-dimensional hydrogen-bonding network. PMID:26279890

  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

    ... general, and may be of interest to a wide range of stakeholders including environmental, human health, and... for malathion. The Agency will consider McFadden's comment as the human health risk assessment for... a class are too neurotoxic to be used safely in high human exposure applications, such as...

  13. Structural features of AgCaCdMg{sub 2}(PO{sub 4}){sub 3} and AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3}, two new compounds with the alluaudite-type structure, and their catalytic activity in butan-2-ol conversion

    SciTech Connect

    Kacimi, Mohammed; Ziyad, Mahfoud; Hatert, Frederic . E-mail: fhatert@ulg.ac.be

    2005-04-20

    AgCaCdMg{sub 2}(PO{sub 4}){sub 3} and AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3}, two new compounds with the alluaudite-type structure, were synthesized by a solid state reaction in air at 750 deg. C. The X-ray powder diffraction pattern of AgCaCdMg{sub 2}(PO{sub 4}){sub 3} indicates the presence of small amounts of (Ca, Mg){sub 3}(PO{sub 4}){sub 2} with the whitlockite structure, as impurity, whereas AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3} is constituted by pure alluaudite. The Rietveld refinements of the X-ray powder diffraction patterns indicate an ordered cationic distribution for AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3}, with Ag on A(2)', Cd on A(1) and M(1), and Mg on M(2), whereas a disordered distribution of Cd and Ca between the A(1) and M(1) sites is observed for AgCaCdMg{sub 2}(PO{sub 4}){sub 3}. The catalytic properties of these compounds has been measured in reaction of butan-2-ol dehydrogenation. In the absence of oxygen, both samples exhibit poor dehydrogenation activity. All samples displayed no dehydration activity. Introduction of oxygen into the feed changed totally the catalytic behavior of the catalysts. The production of methyl ethyl ketone increases with time on stream and the reaction temperature. AgCaCdMg{sub 2}(PO{sub 4}){sub 3} is more efficient than AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3}.

  14. Surface Charge Density Determines the Efficiency of Cationic Gemini Surfactant Based Lipofection

    PubMed Central

    Ryhänen, Samppa J.; Säily, Matti J.; Paukku, Tommi; Borocci, Stefano; Mancini, Giovanna; Holopainen, Juha M.; Kinnunen, Paavo K. J.

    2003-01-01

    The efficiencies of the binary liposomes composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine and cationic gemini surfactant, (2S,3R)-2,3-dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide as transfection vectors, were measured using the enhanced green fluorescent protein coding plasmid and COS-1 cells. Strong correlation between the transfection efficiency and lipid stoichiometry was observed. Accordingly, liposomes with XSR−1 ≥ 0.50 conveyed the enhanced green fluorescent protein coding plasmid effectively into cells. The condensation of DNA by liposomes with XSR−1 > 0.50 was indicated by static light scattering and ethidium bromide intercalation assay, whereas differential scanning calorimetry and fluorescence anisotropy of diphenylhexatriene revealed stoichiometry dependent reorganization in the headgroup region of the liposome bilayer, in alignment with our previous Langmuir-balance study. Surface charge density and the organization of positive charges appear to determine the mode of interaction of DNA with (2S,3R)-2,3-dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide/1,2-dimyristoyl-sn-glycero-3-phosphocholine liposomes, only resulting in DNA condensation when XSR−1 > 0.50. Condensation of DNA in turn seems to be required for efficient transfection. PMID:12524311

  15. 1,4-Dibromo-butane-2,3-dione.

    PubMed

    Zai, De-Xin

    2012-11-01

    The asymmetric unit of the title compound, C(4)H(4)Br(2)O(2), contains one half-mol-ecule, being located about a centre of inversion. In the crystal, there are no significant inter-molecular inter-actions. PMID:23284543

  16. Fueling Requirements for Steady State high butane current fraction discharges

    SciTech Connect

    R.Raman

    2003-10-08

    The CT injector originally used for injecting CTs into 1T toroidal field discharges in the TdeV tokamak was shipped PPPL from the Affiliated Customs Brokers storage facility in Montreal during November 2002. All components were transported safely, without damage, and are currently in storage at PPPL, waiting for further funding in order to begin advanced fueling experiments on NSTX. The components are currently insured through the University of Washington. Several technical presentations were made to investigate the feasibility of the CT injector installation on NSTX. These technical presentations, attached to this document, were: (1) Motivation for Compact Toroida Injection in NSTX; (2) Assessment of the Engineering Feasibility of Installing CTF-II on NSTX; (3) Assessment of the Cost for CT Installation on NSTX--A Peer Review; and (4) CT Fueling for NSTX FY 04-08 steady-state operation needs.

  17. 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].

  18. 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.

  19. 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.

  20. 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

    ... would terminate metam-sodium and metam- potassium soil fumigant uses (agricultural application) for... crop only) 1448-74 PNMDC Metam-potassium Soil fumigant uses (agricultural application) 1448-83 SNMDC Metam-sodium Soil fumigant uses (agricultural application) 1448-85 Busan 1020 Metam-sodium Soil...

  1. 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...

  2. Chemistry of Zerumbone. 1. Simplified Isolation, Conjugate Addition Reactions, and a Unique Ring Contracting Transannular Reaction of Its Dibromide.

    PubMed

    Kitayama, Takashi; Okamoto, Tadashi; Hill, Richard K.; Kawai, Yasushi; Takahashi, Sho; Yonemori, Shigetomo; Yamamoto, Yukio; Ohe, Kouichi; Uemura, Sakae; Sawada, Seiji

    1999-04-16

    Zerumbone (1) was isolated from fresh rhizomes of Zingiber zerumbet Smith in yields of 0.3-0.4% by simple steam distillation and recrystallization. 1 accepted 2 equiv of hydrogen cyanide at the C6 and C9 double bonds of the cross-conjugated dienone system to give a mixture of diastereomers 3a-d. In the presence of potassium cyanide, the dominant isomer 3a was isomerized to a mixture of 3a-d. Under controlled conditions, 1 added one mole of methanol regio- and stereoselectively at the C6 double bond to give adduct 4a. With potassium cyanide, 4a was transformed to the mixture of 3a-d. 1 took up one mole of bromine at C6 double bond to give a diastereomeric mixture of adducts 5a and 5b. Treatment of 5a with potassium cyanide gave a mixture of cyclopropanecarboxylic acid 6a and 6b. This unique ring-contracting cyclopropane formation is pictured as a sequential Favorskii type reaction. alpha-Cyclodextrin improved the selectivity and yields of the reactions conducted in an aqueous medium. PMID:11674334

  3. 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.

  4. 4-Oxo-2,4-diphenyl­butane­nitrile

    PubMed Central

    Abdel-Aziz, Alaa A.-M.; El-Azab, Adel S.; Ng, Seik Weng; Tiekink, Edward R. T.

    2012-01-01

    The title mol­ecule, C16H13NO, is twisted, the dihedral angle between the terminal phenyl rings being 68.40 (6)°. In the crystal, C—H⋯O and C—H⋯N inter­actions lead to supra­molecular layers in the bc plane. PMID:22412616

  5. Field pilot tests for tertiary recovery using butane and propane injection

    SciTech Connect

    Pacheco, E.F.; Garcia, A.I.

    1981-01-01

    This work describes a pilot project for tertiary recovery of liquid hydrocarbons through LPG injection in water-out sections of the Bolivar reservoir in La Pena Field, Santa Cruz, Boliva. The promising results obtained in the initial field miscibility tests, as well as the results from a mathematical model built to stimulate and evaluate the tertiary recovery project, directed subsequent work into a cyclic scheme for enhanced recovery. This scheme is explained and injection production data is presented. Field facilities built to handle both the injected LPG and the produced oil-LPG mixture are described. The oil/LPG ratio and the LPG recovered/injected fraction are the main factors measured in this to make further considerations for a full scale project.

  6. Thermolysis of some transition metal nitrate complexes with 1,4-diamino butane ligand.

    PubMed

    Singh, Gurdip; Singh, Chandra Prakash; Mannan, S M

    2005-06-30

    Four complexes are prepared and characterized having molecular formula [Zn(dab)(2)](NO(3))(2), [Cu(dab)(2)](NO(3))(2).H(2)O, [Ni(dab)(2)](NO(3))(2).2H(2)O and [Mn(dab)(2)](NO(3))(2), where dab: 1,4-diaminobutane. Thermolyses of these complexes were investigated by simultaneous thermogravimetry (TG), derivatives thermogravimetry (DTG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The kinetics of the thermolysis at early stages is investigated using isothermal TG by applying model-fitting and isoconversional method. Thermolytic process is slow in inert (N(2)) and is fast in air atmosphere due to oxidative nature. To investigate the response of these complexes under the condition of rapid heating, ignition delay (D(i)) has been measured. Thermal stability of the complexes was found to increase in the order Mn < Cu < Ni < Zn. PMID:15943933

  7. 4-[(4-Methyl­phen­yl)sulfan­yl]butan-2-one

    PubMed Central

    Novaković, Sladjana B.; Leka, Zorica; Stevanović, Dragana; Muškinja, Jovana; Bogdanović, Goran A.

    2013-01-01

    In the title compound, C11H14OS, all non-H atoms are essentially coplanar, with a mean deviation of 0.023 Å. In the crystal, centrosymmetrically related mol­ecules are weakly connected into dimers by pairs of C—H⋯O inter­actions. The dimers are further linked along the a axis by weak C—H⋯π and C—H⋯S inter­actions. PMID:24454074

  8. (2E,3E)-3-(Pyrazin-2-yloxyimino)butan-2-one oxime

    PubMed Central

    Chen, Ju Na; Yang, Lin Yan

    2008-01-01

    In the title compound, C8H10N4O2, all non-H atoms are nearly coplanar [maximum deviation 0.1256 (16) Å for the methyl C furthest from the ring]. Inter­molecular O—H⋯N hydrogen bonds link adjacent mol­ecules into a one-dimensional zigzag chain along the c axis. There is also a weak π–π stacking inter­action between neighbouring pyrazine rings, with a centroid–centroid distance of 4.0432 (15) Å. PMID:21201831

  9. 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.

  10. PERFORMANCE AND EFFICIENCY EVALUATIONS OF NEW FLUORINATED ETHERS, PROPANES, AND BUTANES

    EPA Science Inventory

    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. n gen...

  11. Optical characteristics and parameters of the plasma of a barrier discharge excited in a mixture of mercury dibromide vapor with nitrogen and helium

    NASA Astrophysics Data System (ADS)

    Malinina, A. A.; Guivan, N. N.; Shimon, L. L.; Shuaibov, A. K.

    2010-09-01

    Results are presented from experimental and theoretical studies of the optical characteristics and parameters of the plasma of an atmospheric-pressure barrier discharge excited in a HgBr2: N2: He mixture, which was used as the working medium of a small-size (with a radiation area of 8 cm2) exciplex gas-discharge radiation source. The mean radiation power of 87 mW was achieved at the radiation wavelength λmax = 502 nm. The electron energy distribution function, the transport characteristics, the specific energy lost in the processes involving electrons, the electron temperature and density, and the rate constants of elastic and inelastic electron scattering by the components of the working mixture were calculated as functions of the reduced field E/ N. The plasma of a discharge excited in a HgBr2: N2: He mixture can be used as the working medium of a small-size blue-green radiation source. Such a source can find application in biotechnology, photonics, and medicine and can also be used to manufacture gas-discharge display panels.

  12. (2R,2′S)-2,2′-Bi­piperidine-1,1′-diium dibromide

    PubMed Central

    Yang, Guang; Noll, Bruce C.; Rybak-Akimova, Elena V.

    2013-01-01

    The title compound, C10H22N2 2+·2Br−, was synthesized via reduction of 2,2′-dipyridyl with Ni–Al alloy/KOH, followed by separation of diastereoisomers (meso and rac) by recrystallization from ethanol. Although the two bridging C atoms are optically active, these two chiral centers adopt an (S,R) configuration; thus, the title compound contains an achiral meso form of 2,2′-bi­piperidine. Both of the piperidinium rings adopt chair conformations, and the two N atoms are trans to each other; an inversion center is located in the mid-point of the central C—C bond. The conformation of the organic moiety resembles that of 1,1′-bi(cyclo­hexa­ne). The organic di­ammonium cations are linked to each other through hydrogen bonding with bromide counter-ions, each of which forms two hydrogen bonds (N—H⋯Br) with two adjacent organic cations, thus linking the latter together in sheets parallel to (100). PMID:24454135

  13. Optical characteristics and parameters of the plasma of a barrier discharge excited in a mixture of mercury dibromide vapor with nitrogen and helium

    SciTech Connect

    Malinina, A. A.; Guivan, N. N.; Shimon, L. L.; Shuaibov, A. K.

    2010-09-15

    Results are presented from experimental and theoretical studies of the optical characteristics and parameters of the plasma of an atmospheric-pressure barrier discharge excited in a HgBr{sub 2}: N{sub 2}: He mixture, which was used as the working medium of a small-size (with a radiation area of 8 cm{sup 2}) exciplex gas-discharge radiation source. The mean radiation power of 87 mW was achieved at the radiation wavelength {lambda}{sub max} = 502 nm. The electron energy distribution function, the transport characteristics, the specific energy lost in the processes involving electrons, the electron temperature and density, and the rate constants of elastic and inelastic electron scattering by the components of the working mixture were calculated as functions of the reduced field E/N. The plasma of a discharge excited in a HgBr{sub 2}: N{sub 2}: He mixture can be used as the working medium of a small-size blue-green radiation source. Such a source can find application in biotechnology, photonics, and medicine and can also be used to manufacture gas-discharge display panels.

  14. 40 CFR 180.226 - Diquat; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the dibromide salt and calculated as the cation in or on the following food commodities... the cation) derived from the application of the dibromide salt to ponds, lakes, reservoirs, marshes...'-c)pyrazinediium) derived from application of the dibromide salt and calculated as the cation in...

  15. N,N,N-Tri-butyl-butan-1-aminium (T-4)-(cyano-κC)tri-hydro-borate.

    PubMed

    Maris, Thierry

    2013-10-26

    In the crystal structure of the title salt, C16H36N(+)·CH3BN(-), the tetra-n-butyl-ammonium cations and [BH3(CN)](-) anions are connected via weak C-H⋯N inter-actions, forming chains along the b-axis direction. The anion is almost linear with an N-C-B angle of 178.7 (2)°. The C-N-C angle values at the core of the tetra-n-butyl-ammonium cation range from 105.74 (11) to 111.35 (11)° with an average of 109.49 (11)°, close to the ideal tetra-hedral value. PMID:24454137

  16. 2-(4-Meth­oxy­phen­yl)-4-oxo-4-phenyl­butane­nitrile

    PubMed Central

    Abdel-Aziz, Alaa A.-M.; El-Azab, Adel S.; Ng, Seik Weng; Tiekink, Edward R. T.

    2012-01-01

    The title mol­ecule, C17H15NO2, is twisted, the dihedral angle between the terminal benzene rings being 63.30 (6)°. In the crystal, C—H⋯O and C—H⋯N inter­actions lead to supra­molecular layers in the ab plane. These are connected along the c axis via C—H⋯π inter­actions. PMID:22412617

  17. 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. PMID:21978552

  18. THE EFFECTS OF EQUIVALENCE RATIO ON THE FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND SOOT IN PREMIXED BUTANE FLAMES. (R826730)

    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...

  19. 3-Oxocyclo­butane­carboxylic acid: hydrogen bonding in a small-ring γ-keto acid

    PubMed Central

    Efthimiopoulos, Georgia; Thompson, Hugh W.; Lalancette, Roger A.

    2009-01-01

    The title ketocarboxylic acid, C5H6O3, is the smallest carboxy­cyclanone to have its crystal structure determined. It adopts a chiral conformation, by rotation of its carboxyl O atoms away from the plane of skeletal symmetry that passes through the carboxyl carbon and both atoms of the ketone carbonyl. The four-membered ring is non-planar, with a shallow fold of 14.3 (1)° along a line connecting the two α-carbons of the ketone group. In the crystal, the molecules are linked by centrosymmetric hydrogen-bond pairing of ordered carboxylic acid groups [O⋯O = 2.6392 (12) Å and O—H⋯O = 175.74 (15)°], yielding two different sets of dimers, related by by a 21 screw axis in c, in the cell. A C—H⋯O interaction is also present. PMID:21582158

  20. 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 workbooks…

  1. An investigation of active and selective oxygen in vanadium phosphorus oxide catalysts for n-butane conversion to maleic anhydride

    SciTech Connect

    Lashier, M.E.

    1990-01-01

    The role of lattice oxygens in two model catalysts, {beta}-VOPO{sub 4} and (VO){sub 2}P{sub 2}O{sub 7}, was investigated for the selective and nonselective oxidation of C{sub 4} hydrocarbons to maleic anhydride and combustion products. Specific catalytic oxygen sites in each model catalyst were labeled with specific amounts of {sup 18}O. Labeled sites were identified by laser Raman spectroscopy and Fourier transform infrared spectroscopy. The level of {sup 18}O enrichment in each site was estimated from the laser Raman spectra and the stoichiometry of reactions involved in the synthesis of the labeled catalysts. Products of the anaerobic C{sub 4} hydrocarbon oxidation and, in the case of (VO){sub 2}P{sub 2}O{sub 7}, alternating pulses of oxygen with pulses of hydrocarbon, over labeled catalysts were monitored by quadrupole mass spectrometry. 146 refs., 51 figs., 7 tabs.

  2. Effect of Mo on the active sites of VPO catalysts upon the selective oxidation of n-butane

    SciTech Connect

    Irusta, S.; Boix, A.; Pierini, B.; Caspani, C.; Petunchi, J.

    1999-10-25

    The effect of the addition of Mo to VPO formulations on the physiochemical and catalytic properties of VPO solids was studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Laser Raman spectroscopy (LRS), temperature-programmed reduction, and a flow reactor system. The addition of Mo to the oxides increases the activity and selectivity of the VPO catalysts. The promoting effect is a function of both the Mo loading and the way such cation was added to the VPO matrix. The best catalyst was obtained when 1% Mo was impregnated on the NOHPO{sub 4}-0.5H{sub 2}O phase. At 400 C 36% of molar yield to maleic anhydride was obtained in this catalyst against 12% of the unpromoted catalysts and only 3% of the solids where Mo was added during the phosphatation step. The impregnated 1% Mo catalyst achieved a molar yield of 50% after 700 h under reaction stream (equilibrated catalysts). (VO){sub 2}P{sub 2}O{sub 7} was the only phase detected by XRD and LRS in all the catalysts studied. They showed comparable BET surface areas and crystallinity after 400 h under reaction conditions. A local order distortion of the O{sub 3}-P-O-P-O{sub 3} structure was detected by LRS in the impregnated Mo VPO catalysts. After 400 h on stream, both promoted and unpromoted solids only showed V{sup IV} on the surface layer. The main effect on the addition of Mo by impregnation to VPO oxides was enhanced by the very strong Lewis acid sites and the liability of the oxygen of (VO){sub 2}P{sub 2}O{sub 7}. This suggests that the promoting effect is more electronic in nature than structural. Polymeric MO{sub 3} species were detected neither by TPR nor by LRS. All the promoted catalysts presented a surface molybdenum enrichment but whereas the coprecipitated Mo VPO solid only shows surface Mo{sup VI}, both Mo{sup VI} coexist in the impregnated catalyst.

  3. Spectroscopy of the tilde A state of NO-alkane complexes (alkane = methane, ethane, propane, and n-butane)

    NASA Astrophysics Data System (ADS)

    Tamé-Reyes, Victor M.; Gardner, Adrian M.; Harris, Joe P.; McDaniel, Jodie; Wright, Timothy G.

    2012-12-01

    We have recorded (1+1) resonance-enhanced multiphoton ionization spectra of complexes formed between NO and the alkanes: CH4, C2H6, C3H8, and n-C4H10. The spectra correspond to the tilde A ← tilde X transition, which is a NO-localized 3s ← 2pπ* transition. In line with previous work, the spectrum for NO-CH4 has well-defined structure, but this is only partially resolved for the other complexes. The spectra recorded in the NO+-alkane mass channels all show a slowly rising onset, followed by a sharp offset, which is associated with dissociation of NO-alkane, from which binding energies in the tilde X and tilde A states are deduced. Beyond this sharp offset, there is a further rise in signal, which is attributed to fragmentation of higher complexes, NO-(alkane)n. Analysis of these features allows binding energies for (NO-alkane) ... alkane to be estimated, and these suggest that in the NO-(alkane)2 complexes, the second alkane molecule is bound to the first, rather than to NO. Calculated structures for the 1:1 complexes are reported, as well as binding energies.

  4. (E,E)-N-[3-(Biphenyl-2-ylimino)butan-2-yl­idene]-2-phenyl­aniline

    PubMed Central

    Zou, Hao; Hou, Yubang; Yong, Xuejian; Cen, Yunbin; Bao, Feng

    2008-01-01

    The two C=N double bonds in the structure of the title compound, C28H24N2, lie in the same plane with a bond length of 1.269 (2) Å. The mol­ecule is positioned on a centre of symmetry. PMID:21201910

  5. 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

  6. 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 19

  7. 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. PMID:26870507

  8. 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...

  9. 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. PMID:23744390

  10. (E,E)-N 1,N 4-Bis(2,6-difluoro­benzyl­idene)butane-1,4-diamine

    PubMed Central

    Khaledi Sardashti, Mohammad; Kia, Reza; Clegg, William; Harrington, Ross W.

    2011-01-01

    The asymmetric unit of the title compound, C18H16F4N2, comprises two half crystallographically independent potentially bidentate Schiff base ligands, with an inversion centre located at the mid-point of the central C—C bond. The crystal packing is stabilized by inter­molecular C—H⋯F and π–π inter­actions [centroid–centroid distance = 3.8283 (11) Å]. PMID:22220111

  11. 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

  12. Design and synthesis of 4-(2,4,5-trifluorophenyl)butane-1,3-diamines as dipeptidyl peptidase IV inhibitors.

    PubMed

    Zhu, Linrong; Li, Yuanyuan; Qiu, Ling; Su, Mingbo; Wang, Xin; Xia, Chunmei; Qu, Yi; Li, Jingya; Li, Jia; Xiong, Bing; Shen, Jingkang

    2013-07-01

    The worldwide prevalence of diabetes has spurred numerous studies on the development of new antidiabetic medicines. As a result, dipeptidyl peptidase IV (DPP4) has been recognized as a validated target. In our efforts to discover new DPP4 inhibitors, we analyzed the complexed structures of DPP4 available in Protein Data Bank and designed a series of triazole compounds. After enzyme activity assays and crystallographic verification of the binding interaction patterns, we found that the triazole compounds can inhibit DPP4 with micromolar IC50 values. Liver microsome stability and cytochrome P450 metabolic tests were performed on this series, revealing undesirable pharmacokinetic profiles for the triazole compounds. To overcome this liability, we substituted the triazole ring with an amide or urea group to produce a new series of DPP4 inhibitors. Based on its enzyme activity, metabolic stability, and selectivity over DPP8 and DPP9, we selected compound 21 r for further study of its in vivo effects in mice using an oral glucose tolerance test (OGTT). The results show that 21 r has efficacy similar to that of sitagliptin at a dose of 3 mg kg(-1) . The crystal structure of 21 r bound to DPP4 also reveals that the trifluoromethyl group is directed toward a subpocket different from the subsite bound by sitagliptin, providing clues for the design of new DPP4 inhibitors. PMID:23671024

  13. Characterization of mixed monolayers of phosphatidylcholine and a dicationic gemini surfactant SS-1 with a langmuir balance: effects of DNA.

    PubMed Central

    Matti, V; Säily, J; Ryhänen, S J; Holopainen, J M; Borocci, S; Mancini, G; Kinnunen, P K

    2001-01-01

    Monolayers of a cationic gemini surfactant, 2,3-dimethoxy-1,4-bis(N-hexadecyl-N;N-dimethyl-ammonium)butane dibromide (abbreviated as SS-1) and its mixtures with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were studied using a Langmuir balance. More specifically, we measured the force-area (pi-A) curves and determined the elastic area compressibility modulus (C) as a function of lateral packing pressure and the mole fraction of the cationic lipid (X(SS-1)), with and without DNA in the subphase. Both SS-1 and POPC exhibited smooth compression isotherms, indicating their monolayers to be in the liquid expanded state. Even low contents (X(SS-1) < 0.05) of SS-1 in a POPC monolayer condensed the film dramatically, up to 20% at 30 mN/m. This effect is suggested to reflect reorientation of the P(-)-N(+) dipole of the POPC headgroup. Accordingly, the magnitude of the condensing effect diminishes with X(SS-1) and is not observed for mixed films of dioleoylglycerol and SS-1. Reorientation of the P(-)-N(+) dipole is further supported by the pronounced increase in monolayer dipole potential psi due to SS-1. The presence of DNA in the subphase affected the mixed POPC/SS-1 monolayers differently depending on the constituent lipid stoichiometry as well as on the DNA/SS-1 charge ratio. At a DNA concentration of 0.63 microM (in base pairs) condensation of neat POPC monolayers was evident, and this effect remained up to X(SS-1) < 0.5, corresponding to DNA/SS-1 charge ratio of 1.25. An expansion due to DNA, evident as an increase in DeltaA/molecule, was observed at X(SS-1) > 0.5. At a higher concentration of DNA (1.88 microM base pairs) in the subphase corresponding to DNA/SS-1 charge ratio of 3.75 at X(SS-1) = 0.5, condensation was observed at all values of X(SS-1). PMID:11566784

  14. 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

  15. EVALUATION OF EMISSION TEST METHODS FOR HALOGENATED HYDROCARBONS. VOLUME II. CH2CL2, CH3CCL3, CF2CLCFCL2, AND CH2BRCH2BR

    EPA Science Inventory

    A test method for halogenated hydrocarbons has been evaluated and information is provided for the user. Four compounds were investigated, methylene chloride, methyl chloroform, Freon 113 and ethylene dibromide. Cylinder gases used for calibration and auditing were tested for stab...

  16. 49 CFR 180.209 - Requirements for requalification of specification cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... for methyl bromide, liquid; mixtures of methyl bromide and ethylene dibromide, liquid; mixtures of methyl bromide and chlorpicrin, liquid; mixtures of methyl bromide and petroleum solvents, liquid; or methyl bromide and nonflammable, nonliquefied compressed gas mixtures, liquid; commercially free...

  17. 49 CFR 180.209 - Requirements for requalification of specification cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... for methyl bromide, liquid; mixtures of methyl bromide and ethylene dibromide, liquid; mixtures of methyl bromide and chlorpicrin, liquid; mixtures of methyl bromide and petroleum solvents, liquid; or methyl bromide and nonflammable, nonliquefied compressed gas mixtures, liquid; commercially free...

  18. 49 CFR 180.209 - Requirements for requalification of specification cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... for methyl bromide, liquid; mixtures of methyl bromide and ethylene dibromide, liquid; mixtures of methyl bromide and chlorpicrin, liquid; mixtures of methyl bromide and petroleum solvents, liquid; or methyl bromide and nonflammable, nonliquefied compressed gas mixtures, liquid; commercially free...

  19. Poly[[(4,4′-bipyridine-κN)[μ3-(S)-2-hy­droxy­butane­dioato-κ4 O 1,O 2:O 4:O 4′]zinc] dihydrate

    PubMed Central

    Lu, Yu-Kun; Liu, Jian; Diao, Cheng-Lin; Lü, Ren-Qing; Liu, Yun-Qi

    2011-01-01

    In the title compound, {[Zn(C4H4O5)(C10H8N2)]·2H2O}n, the ZnII ion displays a distorted tetra­gonal–pyramidal coordination environment with one hy­droxy O and three carboxyl­ate O atoms from three malate anions, and the one remaining position occupied by an N atom from a 4,4′-bipyridine ligand. The pyridine rings of the 4,4′-bipyridine ligand are twisted with respect to each other by a dihedral angle of 35.8 (2)°. The uncoordinated water mol­ecules are linked to the complex mol­ecules by O—H⋯O hydrogen bonds. Each malate anion forms four coordination bonds with three Zn atoms, establishing a layer structure parallel to the ac plane. Adjacent layers are further linked via O—H⋯N hydrogen bonding. π–π stacking between the pyridine rings [face-to-face distance = 3.651 (3) Å] occurs in the crystal structure. PMID:22199502

  20. Structural and spectral studies of an iron(III) complex [Fe(Pranthas) 2][FeCl 4] derived from 2-acetylpyridine- N(4), N(4)-(butane-1, 4-diyl) thiosemicarbazone (HPranthas)

    NASA Astrophysics Data System (ADS)

    Sreekanth, A.; Fun, Hoong-Kun; Prathapachandra Kurup, M. R.

    2005-02-01

    A novel iron(III) complex of 2-acetylpyridine N(4), N(4)-(butyl-1, 4-diyl) thiosemicarbazone (HPranthas), [Fe(Pranthas) 2]FeCl 4 was synthesized and physico-chemically characterized by means of partial elemental analysis, magnetic measurements (polycrystalline state), UV-Vis and IR spectroscopies. The presence of spin-paired iron(III) cation with dxz2dyz2dxy1 ground state is revealed by the EPR and Mössbauer spectral data. Structure of the free ligand HPranthas and the complex [Fe(Pranthas) 2]FeCl 4 were solved by single crystal X-ray diffraction. The framework of iron(III) complex consists of a discrete monomeric cationic entity containing low spin iron(III) in a slightly distorted octahedral environment. The metal ion is bonded to one sulfur and two nitrogens of each thiosemicarbazone molecule. The tetrachloroferrate(III) ion acts as counterion.

  1. Crystal structure of [butane-2,3-dione bis­(4-methyl­thio­semicarbazonato)-κ4 S,N 1,N 1′,S′](pyridine-κN)zinc(II)

    PubMed Central

    Brown, Oliver C.; Tocher, Derek A.; Blower, Philip J.; Went, Michael J.

    2015-01-01

    In the structure of the title complex, [Zn(C8H14N6S2)(C5H5N)], the ZnII ion has a pseudo-square-pyramidal coordination environment and is displaced by 0.490 Å from the plane of best fit defined by the bis­(thio­semicarbazonate) N2S2 donor atoms. Chains sustained by intermolecular N—H⋯N and N—H⋯S hydrogen-bonding interactions extend parallel to [10-1]. PMID:26594508

  2. Crystal structure of [butane-2,3-dione bis-(4-methyl-thio-semicarbazonato)-κ(4) S,N (1),N (1'),S'](pyridine-κN)zinc(II).

    PubMed

    Brown, Oliver C; Tocher, Derek A; Blower, Philip J; Went, Michael J

    2015-11-01

    In the structure of the title complex, [Zn(C8H14N6S2)(C5H5N)], the Zn(II) ion has a pseudo-square-pyramidal coordination environment and is displaced by 0.490 Å from the plane of best fit defined by the bis-(thio-semicarbazonate) N2S2 donor atoms. Chains sustained by intermolecular N-H⋯N and N-H⋯S hydrogen-bonding interactions extend parallel to [10-1]. PMID:26594508

  3. (Z)-3-Chloro-N-[(Z)-3-(3-chloro-2-methyl­phenyl­imino)­butan-2-yl­idene]-2-methyl­aniline

    PubMed Central

    Yuan, Jianchao; Xu, Weibing; Mei, Tongjian; Liu, Yufeng; Wang, Xuehu

    2012-01-01

    In the title compound, C18H18Cl2N2, the complete molecule is generated by the application of C 2 symmetry. The C=N bond has an E configuration. The dihedral angle between the benzene ring and the 1,4-diaza­butadiene plane is 66.81 (9)°. PMID:22259563

  4. Isotopic splitting patterns in the (13) C NMR spectra of some partially deuterated 1-aryl-2-(phenyldiazenyl)butane-1,3-dione and 4-hydroxy-3-(phenyldiazenyl)-2H-chromen-2-one: evidence for elucidation of tautomeric forms.

    PubMed

    Noroozi Pesyan, Nader; Rashidnejad, Hamid

    2016-05-01

    Nuclear magnetic resonance spectra of synthesized azo dyes derived from aniline derivatives in reaction with benzoylacetone and 4-hydroxycoumarin were studied in both CDCl3 and (CD3 )2 SO (two drops of D2 O were added into solutions of dyes). All dyes showed intramolecular hydrogen bonding. Dyes derived from o-nitro aniline in the reaction with benzoylacetone, and 4-hydroxycoumarin showed bifurcated intramolecular hydrogen bonds. The solvent-substrate proton exchange of dyes derived from benzoylacetone and 4-hydroxycoumarin was examined in the presence of two drops of D2 O. Among ten dye samples, two dyes derived from benzoylacetone did not show deuteration, three dyes showed partial deuteration and five dyes showed full deuteration under similar conditions. For the partially deuterated dyes the β-isotope effect in (13) C splitting was investigated and was used for the determination of the predominant tautomeric form. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26776053

  5. Spectrophotometric Procedure for Fast Reactor Advanced Coolant Manufacture Control

    NASA Astrophysics Data System (ADS)

    Andrienko, O. S.; Egorov, N. B.; Zherin, I. I.; Indyk, D. V.

    2016-01-01

    The paper describes a spectrophotometric procedure for fast reactor advanced coolant manufacture control. The molar absorption coefficient of dimethyllead dibromide with dithizone was defined as equal to 68864 ± 795 l·mole-1·cm-1, limit of detection as equal to 0.583 · 10-6 g/ml. The spectrophotometric procedure application range was found to be equal to 37.88 - 196.3 g. of dimethyllead dibromide in the sample. The procedure was used within the framework of the development of the method of synthesis of the advanced coolant for fast reactors.

  6. Synthesis and antimicrobial studies on novel chloro-fluorine containing hydroxy pyrazolines.

    PubMed

    Karthikeyan, Mari Sithambaram; Holla, Bantwal Shivarama; Kumari, Nalilu Suchetha

    2007-01-01

    A series of chloro-fluorine containing chalcones (3) were prepared by Claisen-Schmidt condensation. Chalcone dibromides (4) were obtained by the bromination of chalcones at room temperature. Treatment of chalcone dibromides (4) with aryloxy acid hydrazides (5) in the presence of triethylamine gave chloro-fluorine containing hydroxy pyrazolines (7) rather than the expected 1-aryloxy-3-aryl-5-aryl pyrazoles (6). The structures of the newly synthesized compounds were confirmed by IR, NMR, mass and elemental analysis. All the compounds were tested for their antibacterial and antifungal activities. Some compounds showed very good antibacterial activity and antifungal activity. PMID:17007964

  7. Nonlinear optical properties of new organotellurium compounds containing azomethine and azo groups under CW laser illumination

    NASA Astrophysics Data System (ADS)

    Saadon, H. L.; Ali, Basil; Al-Fregi, Adil A.

    2014-06-01

    Two new organotellurium compounds containing azomethine and azo groups, [2-(2-hydroxynaphthylazo)phenyl][2-(2-methoxybenzylideneamino)-5-methylphenyl]tellurium dibromide (P1) and [2-(2-hydroxynaphthylazo)-5-nitrophenyl][2-(2-methoxy benzylideneamino)-5-methyl phenyl]tellurium dibromide (P2) were synthesized and doped in polyvinylprodidone (PVP) matrix. The nonlinear optical (NLO) properties of these compounds and doped polymer were studied using Z-scan technique at 532 nm. The Z-scan results reveal that the sample solutions and films exhibit self-defocusing nonlinearity. The P2/PVP solutions investigated here exhibit good optical power limiting.

  8. 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.

  9. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... carbohydrates or by organic synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived from ethylene, liquid phase oxidation of butane, and reaction of carbon monoxide...

  10. 21 CFR 184.1005 - Acetic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... carbohydrates or by organic synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived from ethylene, liquid phase oxidation of butane, and reaction of carbon monoxide...

  11. 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

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

    PubMed

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

    1975-04-01

    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

  13. SOC REJECTION BY NANOFILTRATION

    EPA Science Inventory

    A study was conducted to evaluate the rejection of six synthetic organic compounds (SOCs) from a potable water source by a nanofiltration membrane process. The S0Cs were ethylene dibromide (EDB), dibromochloropropane (DBCP), chlordane, heptachlor, methoxychlor and alachlor. To in...

  14. 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...

  15. 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...

  16. 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 ...

  17. 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...

  18. EFFECT OF A SUBSURFACE SEDIMENT ON HYDROLYSIS OF HALOALKANES AND EPOXIDES

    EPA Science Inventory

    Neutral and base-catalyzed hydrolyses of isopropyl bromide, 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane, and ethylene dibromide were studied in pure water and in barely saturated subsurface sediment at 25-60 deg C. No significant differences in the kinetics or products were ...

  19. Couplings of benzylic halides mediated by titanocene chloride: synthesis of bibenzyl derivatives.

    PubMed

    Barrero, Alejandro F; Herrador, M Mar; del Moral, José F Quílez; Arteaga, Pilar; Akssira, Mohammed; El Hanbali, Fadwa; Arteaga, Jesús F; Diéguez, Horacio R; Sánchez, Elena M

    2007-03-16

    Titanocene monochloride catalyzes the homocoupling of benzylic halides and benzylic gem-dibromides to give the corresponding bibenzyl and stilbenyl systems. Exposure of benzylic bromides to Ti(III) in the presence of aldehydes gave rise to the Barbier-type products. Examples of the utility of the herein described processes are included. PMID:17309310

  20. INFLUENCE OF INORGANIC AND ORGANIC NUTRIENTS ON AEROBIC BIODEGRADATION AND ON THE ADAPTATION RESPONSE OF SUBSURFACE MICROBIAL COMMUNITIES

    EPA Science Inventory

    The influence of inorganic and organic amendments on the mineralization of ethylene dibromide, p-nitrophenol, phenol, and toluene was examined in subsurface soil samples from a pristine aquifer near Lula, Okla. The responses indicate that the metabolic abilities and nutrient requ...

  1. Disinfestation by Fumigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter by Neil Heather and Guy Hallman, in “Pest Management and Phytosanitary Trade Barriers,” CABI Press, covers gaseous chemical treatments. Fumigants have been the mainstays of phytosanitary treatments for decades, but the loss of one key fumigant, ethylene dibromide, in the mid-1980’...

  2. A novel cationic conjugated polymer for homogeneous fluorescence-based DNA detection.

    PubMed

    Peng, Hui; Soeller, Christian; Travas-Sejdic, Jadranka

    2006-09-21

    A novel water-soluble cationic conjugated polymer, poly({2,5-bis[3-(N,N-diethylamino)-1-oxapropyl]-para-phenylenevinylene}-alt-para-phenylenevinylene) dibromide, was synthesized and used to develop a simple label-free DNA detection essay. PMID:17047828

  3. 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.

  4. Crystal structures of 1-(4-chloro­phen­yl)-2-(di­phenyl­phosphor­yl)ethan-1-one and 1-(di­phenyl­phosphor­yl)-3,3-di­methyl­butan-2-one

    PubMed Central

    Leach, Erin G.; Kulesza, Alyssa A.; Staples, Richard J.; Biros, Shannon M.

    2015-01-01

    The title compounds, C20H16ClO2P, (I), and C18H21O2P, (II), were synthesized via an Arbuzov reaction between an α-bromo­ketone and isopropoxydi­phenyl­phosphane. In the crystals of both compounds, mol­ecules are linked via bifurcated C—H⋯(O,O) hydrogen bonds, forming chains propagating along [100] for (I) and along [010] for (II). The chains are linked via C—H⋯π inter­actions, leading to the formation of sheets lying parallel to (010) for (I) and (001) for (II). The absolute structure of compound (II) was determined by resonant scattering [Flack parameter = 0.088 (14)]. PMID:25995871

  5. Di-tert-butyl (2R,3R)-2-{[(2E)-3-(4-acet­yloxy-3-meth­oxy­phen­yl)prop-2-eno­yl]­oxy}-3-hy­droxy­butane­dioate

    PubMed Central

    Hixson, Josh L.; Taylor, Dennis K.; Ng, Seik Weng; Tiekink, Edward R. T.

    2012-01-01

    In the title mol­ecule, C24H32O10, one tert-butyl ester group is folded towards the central benzene ring while the other is directed away. The acetyl group is almost perpendicular to the benzene ring to which it is connected [C—C—O—C torsion angle = 90.4 (12)°]. The conformation about the ethene bond [1.313 (7) Å] is E. The atoms of the benzene ring and its attached ester group and part of the hy­droxy tert-butyl ester side chain are disordered over two sets of sites in a 50:50 ratio. Linear supra­molecular chains along the a axis mediated by hy­droxy–carbonyl O—H⋯O hydrogen bonds feature in the crystal packing. The same H atom also partakes in an intra­molecular O—H⋯O inter­action. PMID:22412486

  6. 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

  7. Comparison of storm intensity and application timing on modeled transport and fate of six contaminants.

    PubMed

    Chiovarou, Erica D; Siewicki, Thomas C

    2008-01-15

    Hundreds, if not thousands, of fish kills and kills of other aquatic organisms occur following storms in the US each year, but they are difficult to quantify, investigate, or manage due to the transient nature of major storms and the other priorities following them. Methods are needed to better understand the causes of these kills. The Pesticide Root Zone Model and the Exposure Analysis Modeling System were used to compare risk to resident biota in estuarine headwaters in two locations under various conditions. Contaminants were selected using a landuse-based preliminary risk assessment approach. Atrazine, fipronil, and imidacloprid were compared for potential impacts on important prey species, including copepods and grass shrimp, in Lake Bethel in Volusia County, Florida. Carbaryl, diquat dibromide, and fluoranthene were compared for potential impacts on salmon and other aquatic species in Johnson Creek, near Portland, Oregon. Predictions of contaminant concentrations in groundwater runoff, surface water, benthic sediments, and pelagic biota tissue were obtained based upon watershed characteristics, storm types, and contaminant chemistry and application. For all six contaminants, the simulated concentrations were highest following the 100-yr storms and lowest following the 2-yr storms. Aqueous concentrations ranged between 84 and 2100% higher in 100-yr compared to two-yr storms. Most atrazine and carbaryl concentrations were highest if applied one day before the storm while fipronil, imidacloprid, and diquat dibromide were highest if applied 16 days prior to the storm. Carbaryl and fluoranthene concentrations were highest in the forested segment of the watershed while diquat dibromide concentrations were highest in the agricultural segment. In Florida simulations, groundwater and surface water concentrations generally were highest for atrazine, followed by imidacloprid, and then fipronil. Atrazine poses the highest risk to algae and copepods due to its mobility

  8. 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.

  9. 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.

  10. Renal failure and corrosive airway and gastrointestinal injury after ingestion of diluted diquat solution.

    PubMed

    Tanen, D A; Curry, S C; Laney, R F

    1999-10-01

    A 66-year-old man ingested 200 mL of Dexol Industries Weed and Grass Killer Concentrate (Torrance, CA), which contains 1.84% diquat dibromide, a herbicide structurally similar to paraquat. He remained asymptomatic for 8 hours, and then a sore throat and vomiting developed. Twenty hours after ingestion, esophagitis, mucositis, epiglottitis, and acute renal failure developed, from which he slowly recovered. This is the first report of systemic diquat toxicity from ingestion of a diluted diquat solution. PMID:10499956

  11. Chemistry of zerumbone. 2. Regulation of ring bond cleavage and unique antibacterial activities of zerumbone derivatives.

    PubMed

    Kitayama, T; Yamamoto, K; Utsumi, R; Takatani, M; Hill, R K; Kawai, Y; Sawada, S; Okamoto, T

    2001-10-01

    Further investigation of the chemistry of the eleven-membered cyclic sesquiterpene, zerumbone, the major component of the wild ginger, Zingiber zerumbet Smith, has revealed a new selective epoxidation process, a further example of a novel Favorskii-initiated double ring contraction, and a regiospecific fragmentation of zerumbone dibromide derivatives. Several zerumbone derivatives were found to be selective inhibitors of the growth of gram-positive bacteria. PMID:11758909

  12. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-Dichloroethylene 0.07 (10) 78-87-5 1,2-Dichloropropane 0.005 (11) 100-41-4 Ethylbenzene 0.7 (12) 108-90-7... Endrin X 100-41-4 Ethylbenzene X X 106-93-4 Ethylene Dibromide (EDB) X X 1071-83-6 Gylphosate X 76-44-8... X 58-89-9 Lindane X 72-43-5 Methoxychlor X 108-90-7 Monochlorobenzene X X 23135-22-0 Oxamyl...

  13. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Dichloroethylene 0.07 (10) 78-87-5 1,2-Dichloropropane 0.005 (11) 100-41-4 Ethylbenzene 0.7 (12) 108-90-7... Endrin X 100-41-4 Ethylbenzene X X 106-93-4 Ethylene Dibromide (EDB) X X 1071-83-6 Gylphosate X 76-44-8... X 58-89-9 Lindane X 72-43-5 Methoxychlor X 108-90-7 Monochlorobenzene X X 23135-22-0 Oxamyl...

  14. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Dichloroethylene 0.07 (10) 78-87-5 1,2-Dichloropropane 0.005 (11) 100-41-4 Ethylbenzene 0.7 (12) 108-90-7... Endrin X 100-41-4 Ethylbenzene X X 106-93-4 Ethylene Dibromide (EDB) X X 1071-83-6 Gylphosate X 76-44-8... X 58-89-9 Lindane X 72-43-5 Methoxychlor X 108-90-7 Monochlorobenzene X X 23135-22-0 Oxamyl...

  15. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Dichloroethylene 0.07 (10) 78-87-5 1,2-Dichloropropane 0.005 (11) 100-41-4 Ethylbenzene 0.7 (12) 108-90-7... Endrin X 100-41-4 Ethylbenzene X X 106-93-4 Ethylene Dibromide (EDB) X X 1071-83-6 Gylphosate X 76-44-8... X 58-89-9 Lindane X 72-43-5 Methoxychlor X 108-90-7 Monochlorobenzene X X 23135-22-0 Oxamyl...

  16. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Dichloroethylene 0.07 (10) 78-87-5 1,2-Dichloropropane 0.005 (11) 100-41-4 Ethylbenzene 0.7 (12) 108-90-7... Endrin X 100-41-4 Ethylbenzene X X 106-93-4 Ethylene Dibromide (EDB) X X 1071-83-6 Gylphosate X 76-44-8... X 58-89-9 Lindane X 72-43-5 Methoxychlor X 108-90-7 Monochlorobenzene X X 23135-22-0 Oxamyl...

  17. 40 CFR Appendix A to Subpart Q of... - NPDWR Violations and Other Situations Requiring Public Notice 1

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... In addition to §§ 1415 and 1416 of the Safe Drinking Water Act, 40 CFR 142.307 specifies the items... of a waterborne disease outbreak given in 40 CFR 141.2 but that still have the potential to have... 141.24(h) 17. Ethylene dibromide 2 141.61(c) 3 141.24(h) 18. Glyphosate 2 141.61(c) 3 141.24(h)...

  18. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51...) Editorial Note: For Federal Register citations affecting § 141.24, see the List of CFR Sections Affected... 37. Endrin 508, 525.2, 508.1, 505, 551.1 38. Ethylene dibromide (EDB) 504.1, 551.1 39. Glyphosate...

  19. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51...) Editorial Note: For Federal Register citations affecting § 141.24, see the List of CFR Sections Affected... 37. Endrin 508, 525.2, 508.1, 505, 551.1 38. Ethylene dibromide (EDB) 504.1, 551.1 39. Glyphosate...

  20. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51...) Editorial Note: For Federal Register citations affecting § 141.24, see the List of CFR Sections Affected... 37. Endrin 508, 525.2, 508.1, 505, 551.1 38. Ethylene dibromide (EDB) 504.1, 551.1 39. Glyphosate...

  1. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51...) Editorial Note: For Federal Register citations affecting § 141.24, see the List of CFR Sections Affected... 37. Endrin 508, 525.2, 508.1, 505, 551.1 38. Ethylene dibromide (EDB) 504.1, 551.1 39. Glyphosate...

  2. 40 CFR 141.24 - Organic chemicals, sampling and analytical requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51...) Editorial Note: For Federal Register citations affecting § 141.24, see the List of CFR Sections Affected... 37. Endrin 508, 525.2, 508.1, 505, 551.1 38. Ethylene dibromide (EDB) 504.1, 551.1 39. Glyphosate...

  3. 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.

  4. 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)

  5. 40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... *Alkylates *Alpha-Olefins Butane (all forms) *C-4 Hydrocarbons (Unsaturated) Calcium Stearate Caprolactam...-Ethylbutyraldehyde 2,2,4-Trimethyl-1,3-Pentanediol (b) Amine and Amide Organic Chemicals 2,4-Diaminotoluene...

  6. Nitrogen limiation and nitrogen fixation during alkane biodegradation in a sandy soil

    SciTech Connect

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

    1993-09-01

    Leaking underground storage tanks are a significant source of petroleum hydrocarbon contamination in soils and ground water. Hydrocarbon biodegradation studies have been conducted in both ground water and topsoil regions, but few studies have been done on the unsaturated zone between these two. This study examines the effects of Nitrogen on propane and butane biodegradiations in an unsaturated sandy soil. Results indicate that nitrogen additions initially stimulated both propane and butane oxidizing organisms in the soil, but that propane-amended soil became N limited whereas butane-amended soil eventually overcame its N limitations by fixing Nitrogen and that nitrogen fixing organisms grew in butane amended but not in propane amended soil. 27 refs., 6 figs.

  7. 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.

  8. 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.

  9. 40 CFR 63.11100 - What definitions apply to this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... means a thermal oxidation system using an open (without enclosure) flame. Gasoline means any petroleum... reservoirs; (3) Oil/water separators and sumps, including butane blending sample recovery tanks, used...

  10. 40 CFR 63.11100 - What definitions apply to this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... means a thermal oxidation system using an open (without enclosure) flame. Gasoline means any petroleum... reservoirs; (3) Oil/water separators and sumps, including butane blending sample recovery tanks, used...

  11. 40 CFR 63.11100 - What definitions apply to this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... means a thermal oxidation system using an open (without enclosure) flame. Gasoline means any petroleum... reservoirs; (3) Oil/water separators and sumps, including butane blending sample recovery tanks, used...

  12. Lighter fluid poisoning

    MedlinePlus

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

  13. 21 CFR 173.360 - Octafluorocyclobutane.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Octafluorocyclobutane. The food additive octafluorocyclo-butane may be safely used as a propellant and aerating agent in... one or more of the following substances: Carbon dioxide, nitrous oxide, and propane, as a...

  14. Clean-air legislation will buoy U. S. gas processing

    SciTech Connect

    Haun, R.R.; Ellington, E.E.; Otto, K.W. )

    1991-07-22

    This paper reports on the effects of recent U.S. clean-air legislation on NGL demand and pricing. Demand for all NGL products will be firm throughout the 1990s. Increased requirements for butane as methyl tertiary butyl ether (MTBE) feedstock will strengthen butane prices. Higher base-load requirements for propane in new NGL-based olefin plants will also have a positive impact on propane prices.

  15. [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. PMID:25739197

  16. Impact of molecular structure on the lubricant squeeze-out between curved surfaces with long range elasticity.

    PubMed

    Tartaglino, U; Sivebaek, I M; Persson, B N J; Tosatti, E

    2006-07-01

    The properties of butane (C4H10) lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and elastic properties of the solid surfaces. We consider the linear n-butane and the branched isobutane. For the linear molecule, well defined molecular layers develop in the lubricant film when the width is of the order of a few atomic diameters. The branched isobutane forms more disordered structures which permit it to stay liquidlike at smaller surface separations. During squeezing the solvation forces show oscillations corresponding to the width of a molecule. At low speeds (<0.1 ms) the last layers of isobutane are squeezed out before those of n-butane. Since the (interfacial) squeezing velocity in most practical applications is very low when the lubricant layer has molecular thickness, one expects n-butane to be a better boundary lubricant than isobutane. With n-butane possessing a slightly lower viscosity at high pressures, our result refutes the view that squeeze-out should be harder for higher viscosities; on the other hand our results are consistent with wear experiments in which n-butane were shown to protect steel surfaces better than isobutane. PMID:16863321

  17. In situ studies of fuel oxidation in solid oxide fuel cells.

    PubMed

    Pomfret, Michael B; Owrutsky, Jeffrey C; Walker, Robert A

    2007-03-15

    Existing electrochemical experiments and models of fuel oxidation postulate about the importance of different oxidation pathways and relative fuel conversion efficiencies, but specific information is often lacking. Experiments described below present the first direct, in situ measurements of relevant chemical species formed on solid oxide fuel cell (SOFC) cermet anodes operating with both butane and CO fuel feeds. Raman spectroscopy is used to acquire vibrational spectra from SOFC anodes at 715 degrees C during operation. Both C4H10 and CO form graphitic intermediates. In the limit of a large oxide flux, excess butane forms ordered graphite but only transiently. At higher cell potentials (e.g., less current being drawn) ordered and disordered graphite form on the Ni cermet anode following exposure to butane, and under open circuit voltage (OCV) conditions the graphite persists indefinitely. The chemistry of CO oxidation is such that ordered graphite and a Ni-COO intermediate form only at intermediate cell potentials. Concurrent voltammetry studies show that the formation of graphite with butane at OCV leads first to decreased cell performance after exposure to 25 cm3 butane, then recovered performance after 75 cm3. CO voltammetry data show that at lower potentials the oxide flux through the YSZ electrolyte is sufficient to oxidize the Ni in the anode especially near the interface with the electrolyte. PMID:17295449

  18. Two distinct monooxygenases for alkane oxidation in Nocardioides sp. strain CF8.

    PubMed

    Hamamura, N; Yeager, C M; Arp, D J

    2001-11-01

    Alkane monooxygenases in Nocardioides sp. strain CF8 were examined at the physiological and genetic levels. Strain CF8 can utilize alkanes ranging in chain length from C(2) to C(16). Butane degradation by butane-grown cells was strongly inhibited by allylthiourea, a copper-selective chelator, while hexane-, octane-, and decane-grown cells showed detectable butane degradation activity in the presence of allylthiourea. Growth on butane and hexane was strongly inhibited by 1-hexyne, while 1-hexyne did not affect growth on octane or decane. A specific 30-kDa acetylene-binding polypeptide was observed for butane-, hexane-, octane-, and decane-grown cells but was absent from cells grown with octane or decane in the presence of 1-hexyne. These results suggest the presence of two monooxygenases in strain CF8. Degenerate primers designed for PCR amplification of genes related to the binuclear-iron-containing alkane hydroxylase from Pseudomonas oleovorans were used to clone a related gene from strain CF8. Reverse transcription-PCR and Northern blot analysis showed that this gene encoding a binuclear-iron-containing alkane hydroxylase was expressed in cells grown on alkanes above C(6). These results indicate the presence of two distinct monooxygenases for alkane oxidation in Nocardioides sp. strain CF8. PMID:11679317

  19. 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.

  20. Vanadium-phosphorus-oxygen industrial catalysts for C/sub 4/ hydrocarbon selective oxidation to maleic anhydride

    SciTech Connect

    Wenig, R.W.

    1987-06-01

    The selective oxidation of n-butane to maleic anhydride by vanadium-phosphorus-oxygen (V-P-O) industrial catalysts varying in P-to-V ratio has been studied in a fixed bed integral reactor system. Catalyst characterization studies including x-ray diffraction, laser Raman spectroscopy, infrared spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, x-ray energy dispersive spectroscopy, and BET surface area measurements were used. A strong effect of P-to-V synthesis ratio on catalyst structure, catalyst morphology, vanadium oxidation state, and reactivity in n-butane selective oxidation was observed. A slight ''excess'' of catalyst phosphorus (P/V = 1.1 catalyst) was found to stabilize an active and selective (VO)/sub 2/P/sub 2/O/sub 7/ phase. The mechanism of n-butane selective oxidation to maleic anhydride was studied by in situ infrared spectroscopy using n-butane, 1-butene, 1,3-butadiene, crotyl alcohol, maleic acid, crotonic acid, and maleic anhydride feeds. During paraffin selective oxidation, highly reactive olefin species and maleic acid were observed on the surfaces of V-P-O catalysts. Further evidence in support of conjugated or possibly strained olefin and maleic acid reaction intermediates in n-butane and 1-butene partial oxidation to maleic anhydride was gathered.

  1. 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.

  2. Tritiated chiral alkanes as substrates for soluble methane monooxygenase from Methylococcus capsulatus (Bath): Probes for the mechanism of hydroxylation

    SciTech Connect

    Valentine, A.M.; Liu, K.E.; Komar-Panicucci, S.; Lippard, S.J.; Wilkinson, B.; Priestley, N.D.; Floss, H.G.; Williams, P.G.; Morimoto, Hiromi

    1997-02-26

    The tritiated chiral alkanes (S)-[1-{sup 2}H{sub 1}, 1-{sup 3}H]ethane, (R)-[1-{sup 2}H{sub 1},1-{sup 3}H]ethane, (S)-[1-{sup 2}H{sub 1},1-{sup 3}H]butane, (R)-[1-{sup 2}H{sub 1}, 1-{sup 3}H]butane, (S)-[2-{sup 3}H]butane, (R)-[2-{sup 3}H]butane, and racemic [2-{sup 3}H]butane were oxidized by soluble methane monooxygenase (sMMO) from Methylococcus capsulatus (Bath), and the absolute stereochemistry of the resulting product alcohols was determined in order to probe the mechanism of substrate hydroxylation. When the hydroxylations were performed with purified hydroxylase but only a partially purified cellular extract for the coupling and reductase proteins, different product distributions were observed. These apparently anomalous results could be explained by invoking exchange of hydrogen atoms at the {alpha} carbon of the product alcohols. The characteristics of this exchange reaction are discussed. Together with the mechanistic information available from a range of substrate probes, the results are best accounted for by a nonsynchronous concerted process involving attack on the C-H bond by one or more of several pathways discussed in the text. 65 refs., 5 figs., 3 tabs.

  3. 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.

  4. Liquid crystal catalytic surfactant films for decomposing and sensing pollutants by electrolysis

    SciTech Connect

    Rusling, J.F.; Howe, D.J.; Nassar, A.E.

    1993-12-31

    Living organisms utilize protein biocatalysts incorporated in lipid bilayer membranes. Some synthetic lipid-like surfactant molecules can be self assembled into bilayer structures resembling biomembranes. Films composed of stacks of bilayers were prepared by casting solutions of insoluble surfactants onto solid electrodes. Catalysts were incorporated either after or before casting. In their liquid crystal forms, films containing metal phthalocyanine tetrasulfonates or the redox protein myoglobin were excellent, stable electrochemical catalysts for dehalogenation of pollutants such as trichloracetic acid and ethylene dibromide. Electrons are transported to reactions sites via the incorporated catalysts, and the films also preconcentrate the organohalides to enhance reaction rates. Characterization and applications of these films will be discussed.

  5. Testimony presented to the Massachusetts Department of Public Health, March 19, 1984, Jamaica Plain, Massachusetts

    SciTech Connect

    Griesemer, R.A.

    1984-03-19

    The testimony relates the witness' experience as Director of the Carcinogenesis Bioassay Program at the National Cancer Institute relating to experiments performed with ethylene dibromide (EDB). NCI conducted carcinogenicity bioassays of EDB in rats and mice by both the oral and inhalation routes of exposure. EDB produced multiple kinds of cancer at multiple body sites, in three strains of rats and two strains of mice, in both sexes, at high incidences, with short latent periods, and by three routes of exposure (oral, inhalation, and skin application). (ACR)

  6. 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).

  7. Near-UV phosphorescent emitters: N-heterocyclic platinum(ii) tetracarbene complexes.

    PubMed

    Unger, Yvonne; Zeller, Alexander; Taige, Maria A; Strassner, Thomas

    2009-06-28

    Although examples of nickel(ii), palladium(ii) and platinum(ii) N-heterocyclic tetracarbene complexes are known in the literature, particularly platinum(ii) tetracarbene complexes are rare. We developed a new synthetic route via biscarbene acetate complexes, which make homoleptic as well as heteroleptic platinum(ii) tetracarbene complexes accessible. The reported photoluminescence data show that these complexes have good quantum yields and photostability and are a promising class of emitters for PhOLEDs. Characterization of the compounds includes a solid-state structure of the homoleptic complex bis(1,1'-diisopropyl-3,3'-methylenediimidazoline-2,2'-diylidene)platinum(ii) dibromide. PMID:19513490

  8. Novel gemini cationic surfactants based on N, N-dimethyl fatty hydrazide and 1,3-dibromopropane: synthesis, evaluation of surface and antimicrobial properties.

    PubMed

    Badr, E E; Kandeel, E M; El-Sadek, B M

    2010-01-01

    A fatty hydrazide based cationic gemini surfactants, 1,3-bis (N'-acyl-N,N-dimethylhydrazinium) propane dibromide which possess hydrolyzable amido moieties in the lipophilic portions, were prepared by reacting 1,3-bromopropane with N,N-dimethyl fatty hydrazide. The surface properties were explained and discussed based on the effect of their chemical structures. The micelle-forming ability, foaming ability, and foam stability were evaluated. The prepared surfactants also showed some antimicrobial activity against gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) but they were not active against gram negative bacteria (Escherichia coli, P. aeruginosa), yeast (Candida albicans), and molds (Aspergillus niger). PMID:21099142

  9. Effect of palladium on gas sensing properties of Sn(Sb2O3)O2 nanoparticles synthesized by sonochemical processing at room temperature

    NASA Astrophysics Data System (ADS)

    Majumdar, Sanhita

    2016-07-01

    Palladium catalyzed Sn(Sb2O3)O2 nanoparticles prepared by the sonication assisted method exhibited a Pd dependent selectivity to butane as well as methane. Attempts have been made to correlate powder properties such as surface area, particle size, crystallite size and rate of agglomeration with sensor properties like resistance, percent sensitivity, response and recovery times. Sample with 3 wt% Pd exhibited the lowest rate of agglomeration amongst the prepared samples and around 70% sensitivity towards butane at 400 °C operating temperature. 5 wt% Pd loaded sample, on the other hand, exhibited about 98% methane sensitivity at 350 °C operating temperature. Results confirmed that either by varying the amount of palladium or by changing the operating temperature, it was possible to tune the selective sensitivity of the fabricated sensors towards either butane or methane.

  10. Tailoring the Transport Properties of Zeolitic Imidazolate Frameworks by Post-Synthetic Thermal Modification.

    PubMed

    Zhang, Chen; Koros, William J

    2015-10-28

    Understanding how to control transport properties of zeolitic imidazolate frameworks (ZIFs) is critical to extend ZIF-based membranes and adsorbents to a wide spectrum of gas and vapor separations. In this work, we report a facile post-synthetic thermal modification (PSTM) technique to tailor ZIFs' transport properties by balancing diffusivity and diffusion selectivity. With controllable dissociation of framework methyl groups from a precursor ZIF (ZIF-8), we have prepared thermally modified ZIFs showing substantially increased n-butane diffusivity and attractive n/iso-butane diffusion selectivity. Hybrid ZIF/polymer mixed-matrix membranes formed using these thermally modified ZIFs are expected to deliver attractive butane isomer separation performance. Membranes based on such materials can potentially be used to retrofit refinery alkylation units for producing premium gasoline blending stocks. PMID:26451850

  11. Adsorption properties of biomass-based activated carbon prepared with spent coffee grounds and pomelo skin by phosphoric acid activation

    NASA Astrophysics Data System (ADS)

    Ma, Xiaodong; Ouyang, Feng

    2013-03-01

    Activated carbon prepared from spent coffee grounds and pomelo skin by phosphoric acid activation had been employed as the adsorbent for ethylene and n-butane at room temperature. Prepared activated carbon was characterized by means of nitrogen adsorption-desorption, X-ray powder diffraction, scanning electron microscope and Fourier transform infrared spectroscope. It was confirmed that pore structure played an important role during the adsorption testes. Adsorption isotherms of ethylene and n-butane fitted well with Langmuir equation. The prepared samples owned better adsorption capacity for n-butane than commercial activated carbon. Isosteric heats of adsorptions at different coverage were calculated through Clausius-Clapeyron equation. Micropore filling effect was explained in a thermodynamic way.

  12. In situ fourier transform infrared study of crotyl alcohol, maleic acid, crotonic acid, and maleic anhydride oxidation on a V-P-O industrial catalyst

    SciTech Connect

    Wenig, R.W.; Schrader, G.L.

    1987-10-22

    Crotyl alcohol, maleic acid, crotonic (2-butenoic) acid, and maleic anhydride were fed to an in situ infrared cell at 300/sup 0/C containing a P/V = 1.1 vanadium-phosphorous-oxide (V-P-O) catalyst used for the selective oxidation of n-butane. Crotyl alcohol was used as a mechanistic probe for the formation of reactive olefin species observed during previous n-butane and 1-butene studies. Crotonic acid, maleic acid, and maleic anhydride were fed as probes for the existence of other possible adsorbed intermediates. Olefin species and maleic acid are proposed as possible reaction intermediates in n-butane selective oxidation to maleic anhydride. The involvement of peroxide species in the oxidation of butadiene to maleic acid is also discussed.

  13. Laboratory Studies of Hydrocarbon Nucleation on Tholin Particles and Thin Organic Films: Application to Titan's Atmosphere

    NASA Technical Reports Server (NTRS)

    Curtis, Daniel B.; Glandorf, David L.; Toon, Owen B.; Tolbert, Margaret A.; McKay, Christopher P.; Khare, Bishun N.

    2001-01-01

    Titan, Saturn's largest satellite, has a thick nitrogen/methane atmosphere. In Titan's lower atmosphere, methane is saturated or supersaturated with respect to nucleation and may form clouds. To better characterize the properties of Titan's methane clouds we have measured the saturation ratio required to obtain butane nucleation, S (sub crit), on Titan tholin material and organic films. We find a critical saturation ratio for butane on tholin particles of S (sub crit) = 1.40, suggesting high supersaturations are required for nucleation. If methane is similar to butane, we expect high supersaturations of methane as well. This could favor the formation of a small number of large particles, consistent with recent measurements of methane rain on Titan.

  14. Tungsta and platinum-tungsta supported on zirconia catalysts for alkane isomerization

    SciTech Connect

    Larsen, G.; Lotero, E.; Parra, R.D.

    1996-12-31

    Tungsta- and platinum-tungsta supported on zirconia catalysts (WZ and PtWZ) were tested for isomerization of n-butane with hydrogen at 573 K. The catalysts reduction kinetics and the chemical state of tungsten were studied by X-ray absorption near-edge spectroscopy (XANES) and conventional temperature-programmed (TPR) techniques. Platinum was found to catalyze the reduction of the support and the tungsta co-catalyst. An effective n-butane isomerization catalyst results from the combination of high-temperature calcination and low-temperature reduction. Pyridine adsorption, as monitored by diffuse reflectance infrared spectroscopy (DRIFTS), indicates that water of reduction generates Bronsted acid sites.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Enhanced metabolism of halogenated hydrocarbons in transgenic plants containing mammalian cytochrome P450 2E1

    PubMed Central

    Doty, Sharon Lafferty; Shang, Tanya Q.; Wilson, Angela M.; Tangen, Jeff; Westergreen, Aram D.; Newman, Lee A.; Strand, Stuart E.; Gordon, Milton P.

    2000-01-01

    Chlorinated solvents, especially trichloroethylene (TCE), are the most widespread groundwater contaminants in the United States. Existing methods of pumping and treating are expensive and laborious. Phytoremediation, the use of plants for remediation of soil and groundwater pollution, is less expensive and has low maintenance; however, it requires large land areas and there are a limited number of suitable plants that are known to combine adaptation to a particular environment with efficient metabolism of the contaminant. In this work, we have engineered plants with a profound increase in metabolism of the most common contaminant, TCE, by introducing the mammalian cytochrome P450 2E1. This enzyme oxidizes a wide range of important pollutants, including TCE, ethylene dibromide, carbon tetrachloride, chloroform, and vinyl chloride. The transgenic plants had a dramatic enhancement in metabolism of TCE of up to 640-fold as compared with null vector control plants. The transgenic plants also showed an increased uptake and debromination of ethylene dibromide. Therefore, transgenic plants with this enzyme could be used for more efficient remediation of many sites contaminated with halogenated hydrocarbons. PMID:10841534

  20. Probing endocytosis from the enterocyte brush border using fluorescent lipophilic dyes: lipid sorting at the apical cell surface.

    PubMed

    Danielsen, E Michael

    2015-05-01

    The small intestinal brush border is a specialized cell membrane that needs to withstand the solubilizing effect of bile salts during assimilation of dietary nutrients and to achieve detergent resistance; it is highly enriched in glycolipids organized in lipid raft microdomains. In the present work, the fluorescent lipophilic probes FM 1-43 (N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl)pyridinium dibromide), FM 4-64 (N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino) phenyl)hexatrienyl)pyridinium dibromide), TMA-DPH (1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene p-toluenesulfonate), and CellMask Orange plasma membrane stain were used to study endocytosis from the enterocyte brush border of organ-cultured porcine mucosal explants. All the dyes readily incorporated into the brush border but were not detectably endocytosed by 5 min, indicating a slow uptake compared with other cell types. At later time points, FM 1-43 clearly appeared in distinct punctae in the terminal web region, previously shown to represent early endosomes (TWEEs). In contrast, the other dyes were relatively "endocytosis resistant" to varying degrees for periods up to 2 h, indicating an active sorting of lipids in the brush border prior to internalization. For some of the dyes, a diphenylhexatriene motif in the lipophilic tail seemed to confer the relative endocytosis resistance. Lipid sorting by selective endocytosis therefore may be a process in the enterocytes aimed to generate and maintain a unique lipid composition in the brush border. PMID:25526697

  1. Parahydrogen induced polarization and the oxidative addition of hydrogen to iridium tribromostannyl carbonylate anions.

    PubMed

    Permin, Alexei; Eisenberg, Richard

    2002-05-01

    Activation of dihydrogen by a system composed of (Bu(4)N)[IrBr(2)(CO)(2)] (1) and tin dibromide in varying ratios was studied using parahydrogen induced polarization (PHIP) which allows the detection of transient dihydrides not observable in conventional (1)H NMR spectra. While the oxidative addition of dihydrogen to neutral and cationic Ir(I) species is common, there are only a few examples of H(2) addition to anionic complexes. Tin dibromide reacts with iridium(I) complex 1 in acetone forming equilibrium mixtures of cis- and trans-tribromostannyl derivatives [IrBr(n)()(SnBr(3))(2)(-)(n)()(CO)(2)](-), n = 0,1, the existence of which is inferred from the stereochemistries of the dihydrogen addition products determined using PHIP. The sigma-donating effect of the SnBr(3)(-) ligand facilitates the oxidative addition to the iridium center. The structures of the dihydrides formed upon addition of dihydrogen are assigned on the basis of hydride chemical shifts and values of (2)J((1)H-(117,119)Sn). The only dihydride observed in conventional (1)H NMR spectra is cis-trans-cis-[IrH(2)(SnBr(3))(2)(CO)(2)](-), the identity of which was confirmed using the (13)C labeled Ir(I) precursor. Both [IrBr(2)(CO)(2)](-) and its tribromostannyl derivatives catalyze cis-pairwise addition of dihydrogen to phenylacetylene. PMID:11978112

  2. RATE CONSTANTS FOR THE GAS-PHASE REACTIONS OF A SERIES OF C3-C6 ALDEHYDES WITH OH AND NO3 RADICALS. (R825252)

    EPA Science Inventory

    By using relative rate methods, rate constants for the gas-phase reactions of OH and NO3 radicals with propanal, butanal, pentanal, and hexanal have been measured at 296 ? 2 K and atmospheric pressure of air. By using methyl vinyl ketone as the reference compound, the ...

  3. ENANTIOSELECTIVE IN VITRO METABOLISM OF THE TRIAZOLE FUNGICIDES BROMUCONAZOLE AND TRIADIMEFON USING RAT HEPATIC MICROSOMES

    EPA Science Inventory

    We report on the in vitro metabolism of the enantiomers of two triazole fungicides: triadimefon [two enantiomers; 1-(4-chlorophneoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one] and bromuconazole {two diastereomers, each having two enantiomers; 1-[(2RS,4RS:2RS,4SR)-4-brom...

  4. Carbonaceous deposits in direct utilization hydrocarbon SOFC anode

    NASA Astrophysics Data System (ADS)

    He, Hongpeng; Vohs, John M.; Gorte, Raymond J.

    Carbonaceous deposits formed in Cu-based SOFC anode compartment by exposing porous YSZ anodes to n-butane at elevated temperatures were studied using a combination of V- I curves, impedance spectroscopy, SEM, and TPO measurements. While short-term exposure of a porous YSZ matrix to n-butane at 973 K resulted in the deposition of electronically conducting carbonaceous film and therefore to enhance the fuel cell performance, the power density decays quickly in n-butane at temperature 1073 K or higher for long-term operation. SEM results indicate that the carbonaceous deposits arising from gas phase reaction have different morphology, and a dense layer composed of poly-aromatic rings has been formed on the porous anode surface. The dense layer could block the penetration of fuels to the anode and ions transfer to the three-phase boundaries where electrochemical reactions occur, resulting in the drop of the power density. TPO measurements revealed that the amount of carbonaceous deposits increased and the type of deposits changed with exposure time to n-butane. The stability of deposits increased with extending the exposure time according to the increased oxidation temperature. Steam can remove the carbonaceous deposits from the porous YSZ anode, but the reaction temperature was severely elevated compared to that of oxygen. The carbonaceous deposits can also be removed at 973 K by steam but the deposition of carbon will be controlled by the speed of removal and formation from the gas phase reaction.

  5. 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...

  6. 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…

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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…

  12. 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...

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. Tetra-tert-butyl 13,14-dioxapenta­cyclo­[8.2.1.14,7.02,9.03,8]tetra­deca-5,11-diene-5,6,11,12-tetra­carboxyl­ate

    PubMed Central

    Lough, Alan J.; Jack, Kelsey; Tam, William

    2012-01-01

    The stereochemistry of the title compound, C32H44O10, at the cyclo­butane ring is cis-anti-cis. The mol­ecule lies across an inversion center. In the crystal, weak C—H⋯O hydrogen bonds connect mol­ecules into chains along [100], forming R 2 2(6) rings. PMID:23125744

  18. Roaming radical pathways for the decomposition of alkanes.

    SciTech Connect

    Harding, L. B.; Klippenstein, S. J.

    2010-01-01

    CASPT2 calculations predict the existence of roaming radical pathways for the decomposition of propane, n-butane, isobutane and neopentane. The roaming radical paths lead to the formation of an alkane and an alkene instead of the expected radical products. The predicted barriers for the roaming radical paths lie {approx}1 kcal/mol below the corresponding radical asymptotes.

  19. Abiotic formation of volatile organic compounds from plant biomass and its dependence on temperature and UV radiation

    NASA Astrophysics Data System (ADS)

    Derendorp, L.; Holzinger, R.; Röckmann, T.

    2009-04-01

    The emissions of volatile organic compounds (VOCs) from living vegetation are measured for many different plant species. However, almost no research has been performed on the VOC emissions from plant litter and senescent leaves. The few studies that are done on plant litter indicate that the VOC emissions from this material can be significant for atmospheric chemistry and the global budgets of those VOCs. Recently, research showed that methane is emitted from dead and senescent leaves, and that the emission rates are influenced by temperature and ultraviolet (UV) radiation. It is also observed that not only methane, but also ethane and ethylene were emitted from leaf material under the influence of UV radiation. In this study, the emissions of ethane, ethylene, acetylene, propane, propylene, i-butane, n-butane and methyl chloride are measured with a gas chromatograph with a flame ionization detector. The effect of temperature and UV radiation on the emission rates of the different VOCs is measured for leaves of several plant species. The emission rates of ethane, ethylene, propane, propylene, and methylchloride increased exponentially with increasing temperature for all measured plant species, while a linear increase of the emission rates was observed for increasing intensity of the UV radiation. Emissions of acetylene, i-butane, and n-butane were not observed.

  20. 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.

  1. Engineering development of advanced physical fine coal cleaning for premium fuel applications: Subtask 3.3 - dewatering studies

    SciTech Connect

    Yoon, R. H.; Phillips, D. I.; Sohn, S. M.; Luttrell, G. H.

    1996-10-01

    If successful, the novel Hydrophobic Dewatering (HD) process being developed in this project will be capable of efficiently removing moisture from fine coal without the expense and other related drawbacks associated with mechanical dewatering or thermal drying. In the HD process, a hydrophobic substance is added to a coal-water slurry to displace water from the surface of coal, while the spent hydrophobic substance is recovered for recycling. For this process to have commercialization potential, the amount of butane lost during the process must be small. Earlier testing revealed the ability of the hydrophobic dewatering process to reduce the moisture content of fine coal to a very low amount as well as the determination of potential butane losses by the adsorption of butane onto the coal surface. Work performed in this quarter showed that the state of oxidation affects the amount of butane adsorbed onto the surface of the coal and also affects the final moisture content. the remaining work will involve a preliminary flowsheet of a continuous bench-scale unit and a review of the economics of the system. 1 tab.

  2. Molecular Mechanics: Illustrations of Its Application.

    ERIC Educational Resources Information Center

    Cox, Philip J.

    1982-01-01

    The application of molecular mechanics (a nonquantum mechanical method for solving problems concerning molecular geometries) to calculate force fields for n-butane and cyclohexane is discussed. Implications regarding the stable conformations of the example molecules are also discussed. (Author/SK)

  3. In situ vibrational spectroscopic investigation of C{sub 4} hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    SciTech Connect

    Xue, Z.Y.

    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.

  4. Calculating Thermophysical Properties Of 12 Fluids

    NASA Technical Reports Server (NTRS)

    Cleghorn, T. F.; Mccarty, R. D.

    1991-01-01

    MIPROPS is set of computer programs giving thermophysical and transport properties of selected fluids. Calculates properties of fluids in both liquid and vapor states over wide range of temperatures and pressures. Fluids included: helium, hydrogen, nitrogen, oxygen, argon, nitrogen trifluoride, methane, ethylene, ethane, propane, isobutane, and normal butane. All programs except helium program incorporate same equation of state. Written in FORTRAN 77.

  5. 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…

  6. Selective ruthenium-catalyzed transfer hydrogenations of nitriles to amines with 2-butanol.

    PubMed

    Werkmeister, Svenja; Bornschein, Christoph; Junge, Kathrin; Beller, Matthias

    2013-04-01

    Transfer your hydrogen: Fast and general transfer hydrogenation of nitriles to form primary amines is possible with a homogeneous Ru/1,4-bis(diphenylphosphino)butane (DPPB) catalyst (see scheme). The use of 2-butanol as the hydrogen-transfer reagent is essential for the selective reduction of aromatic, heteroaromatic, and aliphatic nitriles with this system. PMID:23450803

  7. 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.

  8. 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...

  9. 40 CFR 63.11100 - What definitions apply to this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reservoirs; (3) Oil/water separators and sumps, including butane blending sample recovery tanks, used to... distribution facility that receives gasoline by pipeline, ship or barge, or cargo tank, and subsequently loads the gasoline into gasoline cargo tanks for transport to gasoline dispensing facilities, and has...

  10. 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...

  11. 29 CFR 779.361 - Classification of other fuel oil sales.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Sales of fuel oil (as differentiated from sales of butane and propane gases) are classified as retail.... 4, No. 5, and No. 6 fuel oil as these heavy oils are “special purpose” goods to which the retail... 29 Labor 3 2011-07-01 2011-07-01 false Classification of other fuel oil sales. 779.361 Section...

  12. 29 CFR 779.361 - Classification of other fuel oil sales.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Sales of fuel oil (as differentiated from sales of butane and propane gases) are classified as retail.... 4, No. 5, and No. 6 fuel oil as these heavy oils are “special purpose” goods to which the retail... 29 Labor 3 2010-07-01 2010-07-01 false Classification of other fuel oil sales. 779.361 Section...

  13. Ventilation of liquefied petroleum gas components from the Valley of Mexico

    SciTech Connect

    Elliott, S.; Blake, D.R.; Sherwood Rowland, F.; Lu, R.; Brown, M.J.; Williams, M.D.; Russell, A.G.; Bossert, J.E.; Streit, G.E.; Santoyo, M.R.; Guzman, F.; Porch, W.M.; McNair, L.A.; Keyantash, J.; Kao, C.J.; Turco, R.P.; Eichinger, W.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 chromatographic 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{percent} 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.{copyright} 1997 American Geophysical Union

  14. 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.

  15. Physics of the multi-functionality of lanthanum ferrite ceramics

    NASA Astrophysics Data System (ADS)

    Bhargav, K. K.; Ram, S.; Majumder, S. B.

    2014-05-01

    In the present work, we have illustrated the physics of the multifunctional characteristics of nano-crystalline LaFeO3 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 LaFeO3 exhibits dielectric maxima similar to that observed in ferroelectric ceramics with non-centrosymmetric point group. The dielectric relaxation of LaFeO3 correlates well with small polaron conduction. The occurrence of polarization hysteresis in LaFeO3 (with centro-symmetric Pnma space group) is thought to be spin current induced type. The canting of the Fe3+ spins induce weak ferromagnetism in nano-crystalline LaFeO3. Room temperature saturation magnetization of pure LaFeO3 is reported to be 3.0 emu/g. Due to the presence of both ferromagnetic as well as polarization ordering, LaFeO3 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 LaFeO3 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 LaFeO3 surface. Surface adsorbed oxygen species play major role in their low temperature butane sensing. Finally, we have hypothesized that the desorbed H2O and O2 (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.

  16. 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.

  17. 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

    2015-06-01

    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

  18. Fluorescent sensor based on a novel conjugated polyfluorene derivative

    NASA Astrophysics Data System (ADS)

    Gao, Weiqiang; Yan, Mei; Ge, Shenguang; Liu, Xiaoxia; Yu, Jinghua

    2012-09-01

    A novel water-soluble polyfluorene derivative, poly[(9,9-bis(3'-((N,N-dimethylamino)N-ethylammonium)propyl)-2,7-fluorene)-alt-2,7-(9,9-p-divinylbenzene)]dibromide (P-2) was synthesized by the palladium-catalyzed Suzuki coupling reaction and it's quaternized ammonium polyelectrolyte derivatives was obtained through a postpolymerization treatment on the terminal amino groups. The electrochemical and optical properties of the copolymers was fully investigated. The results showed that the new polyfluorene derivative had high electronic conductivity and strong fluorescence, therefore it had good potential to be used in chemical and biological sensors, as shown in optical sensing of bovine albumin (BSA) in this study.

  19. 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. PMID:25966390

  20. 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.

  1. Intense photo- and tribo-luminescence of three tetrahedral manganese(II) dihalides with chelating bidentate phosphine oxide ligand.

    PubMed

    Chen, Jun; Zhang, Qing; Zheng, Fa-Kun; Liu, Zhi-Fa; Wang, Shuai-Hua; Wu, A-Qing; Guo, Guo-Cong

    2015-02-21

    Three air-stable tetrahedral manganese(ii) dihalide complexes [MnX2(DPEPO)] (DPEPO = bis[2-(diphenylphosphino)phenyl]ether oxide; X = Cl, Br and I) were prepared. All of the obtained compounds were structurally characterized by single-crystal X-ray diffraction analyses, which reveal that they crystallize in centrosymmetric space groups and feature an isolated mononuclear structure with Mn(2+) in a tetrahedral environment. Interestingly, these complexes show excellent photoluminescent performance in neat solid form, with the highest total quantum yield (Φtotal) of up to 70% recorded for the dibromide complex. Intense green flashes of light could be observed by the naked eye when rubbing the manganese(ii) complexes. PMID:25597698

  2. Optical characteristics of a HgBr excilamp

    NASA Astrophysics Data System (ADS)

    Malinina, A. A.; Malinin, A. N.; Shuaibov, A. K.

    2013-08-01

    Optical characteristics of a coaxial HgBr excilamp on multicomponent mercury dibromide vapour mixtures with helium, nitrogen and sulfur hexafluoride are investigated under pumping by a pulse-periodic barrier discharge. Stable excilamp operation was demonstrated at a pump pulse repetition rate of 3 - 9 kHz. The component composition of the working system was determined, which provides a maximal average and pulsed specific radiation power of 48.8 mW cm-3 and 40.6 W cm-3, respectively, at the efficiency of 7.3 % in the blue-green spectral range with the maximal radiation intensity at the wavelength of 502 nm. The reduction in the radiation power after 2.5 × 106 shots is 5 %. Interpretation is given for the results of optimisation of excilamp characteristics.

  3. Reproductive toxins and alligator abnormalities at Lake Apopka, Florida.

    PubMed Central

    Semenza, J C; Tolbert, P E; Rubin, C H; Guillette, L J; Jackson, R J

    1997-01-01

    The alligator population at Lake Apopka in central Florida declined dramatically between 1980 and 1987. Endocrine-disrupting chemicals and specifically DDT metabolites have been implicated in the alligators' reproductive failure. The DDT metabolite hypothesis is based largely on the observation of elevated concentrations of p,p-DDE and p,p-DDD in alligator eggs obtained from Lake Apopka in 1984 and 1985. In the following commentary, we draw attention to two nematocides that are established reproductive toxins in humans, dibromochloropropane (DBCP) and ethylene dibromide (EDB), which could also have played a role in the reproductive failure observed in alligators from Lake Apopka in the early 1980s. Images Figure 1. PMID:9349835

  4. Innovative technology for expedited site remediation of extensive surface and subsurface contamination

    SciTech Connect

    Audibert, J.M.E.; Lew, L.R.

    1994-12-31

    Large scale surface and subsurface contamination resulted from numerous releases of feed stock, process streams, waste streams, and final product at a major chemical plant. Soil and groundwater was contaminated by numerous compounds including lead, tetraethyl lead, ethylene dibromide, ethylene dichloride, and toluene. The state administrative order dictated that the site be investigated fully, that remedial alternative be evaluated, and that the site be remediated within a year period. Because of the acute toxicity and extreme volatility of tetraethyl lead and other organic compounds present at the site and the short time frame ordered by the regulators, innovative approaches were needed to carry out the remediation while protecting plant workers, remediation workers, and the public.

  5. Public health assessment for Frontier Fertilizer, Davis, Yolo County, California, Region 9. Cerclis No. CAD071530380. Final report

    SciTech Connect

    1995-11-27

    The Frontier Fertilizer site is located near the eastern boundary of the City of Davis, in Yolo County, California. Two separate pesticide sales companies operated at the site from 1971 and 1987. Disposal of waste water and unused agricultural chemicals by these companies into an unlined basin on the property from approximately 1972 until 1983 have caused soils and groundwater contamination. In the area beneath the unlined basin, the principal contaminants of concern include dibromochloropropane (DBCP), 1,2-dichloropropane (1,2-DCP), and ethylene dibromide (EDB). Another contaminant of concern is carbon tetrahchloride, however, the source of contamination is unknown. Although much of the soil contamination was removed from the site in 1985, sampling since then indicates that substantial subsurface soil contamination still exists. An interim groundwater extraction and treatment system has been in operation at the site since January 1994.

  6. Soil Fumigation: Principles and Application Technology

    PubMed Central

    Lembright, H. W.

    1990-01-01

    The principal soil fumigants and their order of discovery are carbon disulfide, chloropicrin, methyl bromide, 1,3-dichloropropene, ethylene dibromide, 1,2-dibromo-3-chloropropane, and methyl isothiocyanate. Biological activity of soil fumigants ranges from limited to broad spectrum. Fumigants diffuse through the continuous soil air space as gases. Physical and chemical characteristics determine diffusion rates, distribution between the soil air and moisture, and sorption onto and into the soil particles. The principal soil factors affecting the efficacy of each treatment are the size and continuity of air space, moisture, temperature, organic matter, and depth of placement. Application can be made overall with tractor injection or plow-sole, or as a row or bed treatment. Treatment for trees is best made in conjunction with tree site backhoeing. PMID:19287772

  7. 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. PMID:27483397

  8. Optical characteristics of a HgBr excilamp

    SciTech Connect

    Malinina, A A; Malinin, A N; Shuaibov, A K

    2013-08-31

    Optical characteristics of a coaxial HgBr excilamp on multicomponent mercury dibromide vapour mixtures with helium, nitrogen and sulfur hexafluoride are investigated under pumping by a pulse-periodic barrier discharge. Stable excilamp operation was demonstrated at a pump pulse repetition rate of 3 – 9 kHz. The component composition of the working system was determined, which provides a maximal average and pulsed specific radiation power of 48.8 mW cm{sup -3} and 40.6 W cm{sup -3}, respectively, at the efficiency of 7.3 % in the blue-green spectral range with the maximal radiation intensity at the wavelength of 502 nm. The reduction in the radiation power after 2.5 × 10{sup 6} shots is 5 %. Interpretation is given for the results of optimisation of excilamp characteristics. (optical radiation sources)

  9. Influence of inorganic and organic nutrients on aerobic biodegradation and on the adaptation response of subsurface microbial communities.

    PubMed

    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, p-nitrophenol, phenol, and toluene was examined in subsurface soil samples from a pristine aquifer near Lula, Okla. The responses indicate that the metabolic abilities and nutrient requirements of groundwater 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. PMID:3125792

  10. Review of epidemiologic study results of vinyl chloride-related compounds.

    PubMed Central

    Apfeldorf, R; Infante, P F

    1981-01-01

    Epidemiologic study results addressing the carcinogenicity of six compounds related to vinyl chloride (vinylidene chloride, trichloroethylene, perchloroethylene, carbon tetrachloride, ethylene dibromide and epichlorohydrin) are reviewed. The study results suggest an increased carcinogenic risk among workers exposed to epichlorohydrin and to dry cleaning and degreasing solvents. Although several studies report no significant excess of cancer mortality, an evaluation of the design of these investigations demonstrates that these negative cohort studies consisted of populations of insufficient sample size and latency to permit any meaningful conclusions regarding carcinogenic risk. Therefore, experimental studies must be relied upon to determine whether several of these substances pose a potential carcinogenic risk to humans. Available evidence indicates that all of these substances have demonstrated a carcinogenic response in experimental animals and most are mutagenic in experimental test systems. PMID:7333239

  11. 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.

  12. Full spin-coated multilayer structure hybrid light-emitting devices

    NASA Astrophysics Data System (ADS)

    Cheng, Gang; Mazzeo, Marco; Carallo, Sonia; Wang, Huiping; Ma, Yuguang; Gigli, Giuseppe

    2010-09-01

    We report on a multilayer structure hybrid light-emitting device (HLED) using a water/alcohol-soluble polymer poly(9,9-bis{30-[(N,N-dimethyl)-N-ethylammonium}-propyl]-2,7-fluorene dibromide) as an electron-transporting layer and a close-packed quantum dot-layer (QD-layer) as an emitting layer. The device was realized by full spin-coating technology without thermal evaporation process for the deposition of organic layers. The QD-layer was a mixture of QDs with two different sizes, in which large size QD-emitters were dispersed in small size QDs to weaken the concentration quenching. The device achieved a maximum power efficiency of 0.58 lm/W, which nearly quadrupled that of the HLED with a plain large size QD-EML.

  13. 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. PMID:25746409

  14. Ultrasound assisted the preparation of 1-butoxy-4-nitrobenzene under a new multi-site phase-transfer catalyst--kinetic study.

    PubMed

    Harikumar, Kuppuswamy; Rajendran, Venugopal

    2014-01-01

    In the present research work deals with the preparation of 1-butoxy-4-nitrobenzene was successfully carried out by 4-nitrophenol with n-butyl bromide using aqueous potassium carbonate and catalyzed by a new multi-site phase-transfer catalyst (MPTC) viz., N(1),N(4)-diethyl-N(1),N(1),N(4),N(4)-tetraisopropylbutane-1,4-diammonium dibromide, under ultrasonic (40 kHz, 300 W) assisted organic solvent condition. The pseudo first-order kinetic equation was applied to describe the overall reaction. Under ultrasound irradiation (40 kHz, 300 W) in a batch reactor, it shows that the overall reaction greatly enhanced with ultrasound irradiation than without ultrasound. The present study provides a method to synthesize nitro aromatic ethers by ultrasound assisted liquid-liquid multi-site phase-transfer catalysis condition. PMID:23948491

  15. Postharvest-applied agrochemicals and their residues in fresh fruits and vegetables.

    PubMed

    Papadopoulou-Mourkidou, E

    1991-01-01

    Many agrochemicals are applied postharvest on fruits and vegetables to extend their lives and preserve quality during storage, transport, and marketing. Persistence and distribution of residues on the edible portions of produce have been reported for citrus fruits, pome fruits, stone fruits, mangos, strawberries, bananas, kiwi fruits, avocados, some minor fruit commodities, and bell peppers and tomatoes. Data on the persistance and residues of the fungicides benomyl, biphenyl, sec-butylamine, captan, carbendazim, dicloran, fosetyl-aluminum, guazatine, imazalli, iprodione, metalaxyl, o-phenylphenol, prochloraz, thiabendazole, thiophanate-methyl, triadimeton, and vinclozolin, the fumigants ethylene dibromide, methyl bromide, and sulfur dioxide, the insecticides dimethoate and fenthion, the antiscald compounds diphenylamine and ethoxyquin, and the growth regulators 2,4-D and daminozide are presented and discussed. PMID:1783584

  16. 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.

  17. 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). PMID:21754422

  18. Evaluation of possible inhibition of human liver drug metabolizing cytochromes P450 by two new acetylcholinesterase oxime-type reactivators.

    PubMed

    Spicakova, Alena; Anzenbacher, Pavel; Liskova, Barbora; Kuca, Kamil; Fusek, Josef; Anzenbacherova, Eva

    2016-02-01

    Two non-symmetric bispyridine oxime - based reactivators of acetylcholinesterase enzyme (AChE), labeled as K027 (1-(4-carbamoylpyridinium)-3-(4-hydroxyiminomethylpyridinium)-propane dibromide) and K203 ((E)-1-(4- carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide) were tested for their potential to inhibit activities of human liver microsomal cytochromes P450 (CYP). Both oximes are very potent reactivators of organophosphate-inhibited AChE. An interaction of both compounds with CYP in human liver microsomal preparation was detected using difference spectroscopy. The compounds were shown to bind to CYP enzymes with spectral binding constants of 5.04 ± 1.79 nM (K027) and 5.2 ± 2.6 nM (K203). Enzymology studies were subsequently performed aimed at determining which of the nine most important CYP involved in drug is affected by this interaction. The results have shown no prominent inhibition of individual CYP activities with either compounds except in the case of CYP2E1 and K203. Diagnostic Dixon plot revealed that K203 acted as an uncompetitive inhibitor of CYP2E1. Inhibition of this activity however is not as prominent as to make a potent drug interaction likely. Hence, the interaction of K027 and K203 oxime-type AChE reactivators with human liver microsomal CYP enzymes does not seem to be of prominent clinical importance and both compounds could be safely used in this respect as antidotes with low risk of drug interactions. PMID:26747974

  19. Ultraviolet photoinitiated on-fiber copolymerization of ionic liquid sorbent coatings for headspace and direct immersion solid-phase microextraction.

    PubMed

    Ho, Tien D; Yu, Honglian; Cole, William T S; Anderson, Jared L

    2012-11-01

    A high-throughput method for the production of solid-phase microextraction (SPME) sorbent coatings via ultraviolet (UV) photoinitiated copolymerization of ionic liquid (IL) monomers on a fused silica support is described. The copolymerization of monocationic and dicationic IL cross-linkers was performed "on-fiber" using UV initiated free radical polymerization. Mixtures composed of various amounts of the IL cross-linker, UV initiator (DAROCUR 1173), and IL monomer were dip-coated onto an etched and derivatized fused silica support and placed in a high-capacity UV reactor. The method requires no organic dispersive solvent and is much more rapid compared to traditional methods in which polymeric ionic liquid (PIL) sorbent coatings are prepared by 2,2'-azobis(2-methylpropionitrile) (AIBN)-initiated polymerization. Two ionic liquid-based cross-linkers, namely, 1,8-di (3-vinylimidazolium) octane dibromide ([(VIM)(2)C(8)] 2[Br]) and 1,12-di (3-vinylimidazolium) dodecane dibromide ([(VIM)(2)C(12)] 2[Br]), were copolymerized with an ionic liquid monomer, 1-vinyl-3-hexylimidazolium chloride ([VHIM][Cl]), to produce polar cross-linked PIL-based SPME sorbent coatings. The cross-linking and immobilization of these coatings make them particularly applicable in direct immersion SPME. The coatings were applied in the extraction of polar analytes, including alcohols, aldehydes, and esters, from aqueous solutions using headspace and direct immersion SPME gas chromatography mass spectrometry (GC/MS). Compared to linear PIL-based sorbent coatings containing the same anions, the cross-linked PIL-based coatings exhibited higher thermal stability and lower bleed, making them ideal for GC/MS. Recovery experiments were performed in deionized, well, and river water. The structural integrity of the sorbent coatings, as well as their analytical precision, was not diminished after 90 extractions from complex samples using headspace and direct immersion SPME. PMID:22991947

  20. 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. PMID:18293029

  1. 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

  2. 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.

  3. The efficient use of natural gas in transportation

    SciTech Connect

    Stodolsky, F.; Santini, D.J.

    1992-04-01

    Concerns over air quality and greenhouse gas emissions have prompted discussion as well as action on alternative fuels and energy efficiency. Natural gas and natural gas derived fuels and fuel additives are prime alternative fuel candidates for the transportation sector. In this study, we reexamine and add to past work on energy efficiency and greenhouse gas emissions of natural gas fuels for transportation (DeLuchi 1991, Santini et a. 1989, Ho and Renner 1990, Unnasch et al. 1989). We add to past work by looking at Methyl tertiary butyl ether (from natural gas and butane component of natural gas), alkylate (from natural gas butanes), and gasoline from natural gas. We also reexamine compressed natural gas, liquified natural gas, liquified petroleum gas, and methanol based on our analysis of vehicle efficiency potential. We compare the results against nonoxygenated gasoline.

  4. The efficient use of natural gas in transportation

    SciTech Connect

    Stodolsky, F.; Santini, D.J.

    1992-01-01

    Concerns over air quality and greenhouse gas emissions have prompted discussion as well as action on alternative fuels and energy efficiency. Natural gas and natural gas derived fuels and fuel additives are prime alternative fuel candidates for the transportation sector. In this study, we reexamine and add to past work on energy efficiency and greenhouse gas emissions of natural gas fuels for transportation (DeLuchi 1991, Santini et a. 1989, Ho and Renner 1990, Unnasch et al. 1989). We add to past work by looking at Methyl tertiary butyl ether (from natural gas and butane component of natural gas), alkylate (from natural gas butanes), and gasoline from natural gas. We also reexamine compressed natural gas, liquified natural gas, liquified petroleum gas, and methanol based on our analysis of vehicle efficiency potential. We compare the results against nonoxygenated gasoline.

  5. 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.

  6. Process for the manufacture of catalysts for the production of maleic anhydride

    SciTech Connect

    Edwards, R.C.

    1987-10-13

    A process is described for the manufacture of a phosphorus-vanadium oxide catalyst suitable for use in the manufacture of maleic anhydride from butane. The process comprises reacting at a temperature of about 0/sup 0/C to about 200/sup 0/C a vanadium compound in an organic ether solvent having from about 2 to about 10 carbon atoms, with a phosphoryl halide in the presence of water or an aliphatic alcohol having from about 1 to about 8 carbon atoms, eliminating the solvent and activating the catalyst by the addition of butane, benzene or another C/sub 4/ hydrocarbon feedstock and water and a phosphorus compound at a temperature of about 300/sup 0/C to about 500/sup 0/C wherein the amount of water added is about 1000 parts per million to about 40,000 parts per million by weight of the reactor feed gas stream.

  7. Solvothermal synthesis of vanadium phosphates in the form of xerogels, aerogels and mesostructures

    SciTech Connect

    Sydorchuk, V.; Zazhigalov, V.; Khalameida, S.; Diyuk, E.; Skubiszewska-Zieba, J.; Leboda, R.; Kuznetsova, L.

    2010-09-15

    Regularities and peculiarities of physicochemical changes, first of all phase transformations, during solvothermal treatment (with conventional and microwave heating) of the vanadium pentoxide and orthophosphoric acid mixture in organic solvents in the presence of reducing agents have been studied. Hemihydrate of vanadium hydrophosphate - the precursor of vanadium pyrophosphate, the active phase for n-butane to maleic anhydride oxidation, and ion exchanger with variable physicochemical characteristics, i.e. crystal structure, specific surface area, crystallite size and acidic properties - has been synthesized in the temperature range 170-200 {sup o}C. The obtained phases were examined using XRD, DTA-TG, SEM, FTIR spectroscopy, nitrogen adsorption as well as gas chromatographic determination of acidity through organic bases adsorption. The catalytic activity of prepared samples for n-butane oxidation has been investigated.

  8. A Study on the Base–Catalyzed Reverse Vinylogous Aldol Reaction of (4aβ,5β)-4,4a,5,6,7,8-Hexahydro-5-hydroxy-1,4a-dimethylnaphthalen-2(3H)-one under Robinson Annulation Conditions

    PubMed Central

    Payette, Joshua N.; Honda, Tadashi; Yoshizawa, Hidenori; Favaloro, Frank G.; Gribble, Gordon W.

    2008-01-01

    We have proposed a pathway of the base–catalyzed reverse vinylogous aldol reaction of (−)-(4aβ,5β)-4,4a,5,6,7,8-hexahydro-5-hydroxy-1,4a-dimethylnaphthalen-2(3H)-one ((−)-8) under Robinson annulation conditions. For confirmation, 4-(2,6-dimethyl-3-oxocyclohex-1-enyl)butanal (11) and 4-(2,6-dimethyl-5-oxocyclohex-1-enyl)butanal (12), both of which potentially produce enolate I, were synthesized regioselectively. Unexpectedly, 11 gave a complex mixture including only a trace amount of (±)-8 (less than 5% yield) under these basic conditions. To the contrary, 12 cleanly afforded (±)-8 in 66% yield. This result provides evidence for our proposed mechanism of the above reaction. PMID:16388674

  9. A Small-Volume Apparatus for the Measurement of Phase Equilibria

    PubMed Central

    Outcalt, Stephanie L.; Lee, Byung-Chul

    2004-01-01

    An apparatus has been designed and constructed for the measurement of vapor-liquid equilibrium properties. The main components of the apparatus consist of an equilibrium cell and a vapor circulation pump. The cell and all of the system valves are housed inside a temperature controlled, insulated aluminum block. The temperature range of the apparatus is 260 K to 380 K to pressures of 6 MPa. The uncertainty of the temperature measurement is 0.03 K, and the uncertainty in the pressure measurement is 9.8 × 10−4 MPa. An automated data acquisition system is used to measure temperature and pressure at equilibrium. The apparatus has been performance tested by measuring the vapor pressures of propane, butane, and a standard mixture of propane + butane. PMID:27366631

  10. Open-Pore Two-Dimensional MFI Zeolite Nanosheets for the Fabrication of Hydrocarbon-Isomer-Selective Membranes on Porous Polymer Supports.

    PubMed

    Zhang, Han; Xiao, Qiang; Guo, Xianghai; Li, Najun; Kumar, Prashant; Rangnekar, Neel; Jeon, Mi Young; Al-Thabaiti, Shaeel; Narasimharao, Katabathini; Basahel, Sulaiman Nasir; Topuz, Berna; Onorato, Frank J; Macosko, Christopher W; Mkhoyan, K Andre; Tsapatsis, Michael

    2016-06-13

    Two-dimensional zeolite nanosheets that do not contain any organic structure-directing agents were prepared from a multilamellar MFI (ML-MFI) zeolite. ML-MFI was first exfoliated by melt compounding and then detemplated by treatment with a mixture of H2 SO4 and H2 O2 (piranha solution). The obtained OSDA-free MFI nanosheets disperse well in water and can be used for coating applications. Deposits made on porous polybenzimidazole (PBI) supports by simple filtration of these suspensions exhibit an n-butane/isobutane selectivity of 5.4, with an n-butane permeance of 3.5×10(-7)  mol m(-2)  s(-1)  Pa(-1) (ca. 1000 GPU). PMID:27101318

  11. 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.

  12. 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

  13. Regioselective Alkoxycarbonylation of Allyl Phenyl Ethers Catalyzed by Pd/dppb Under Syngas Conditions.

    PubMed

    Amézquita-Valencia, Manuel; Alper, Howard

    2016-05-01

    A simple and regioselective synthesis of phenoxy esters and phenylthio esters is reported. The products are obtained by selective alkoxycarbonylation catalyzed by Pd2(dba)3, 1,4-bis(diphenylphisphino)butane (dppb), and syngas (CO/H2) in chloroform/alcohol. This methodology affords bifunctional products in good yield with excellent n-selectivity and without the need to use additives. PMID:27075974

  14. 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.

  15. 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

  16. Worldwide gas processing: Capacities as of January 1, 1996, and average production

    SciTech Connect

    1996-07-01

    Data are presented for gas plant capacities and production by country, by companies within each country, and by state or province within larger countries. Data are presented for total capacity as well as for average production of ethane, propane, isobutane, butane, LP-gas mixtures, raw NGL mixtures, natural gasoline, and other products. Processes are absorption, refrigerated absorption, refrigeration, compression, adsorption, cryogenic-Joule-Thomson, cryogenic-expander, and H{sub 2}S removal.

  17. 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. PMID:26529563

  18. Modeling of simulated photochemical smog with kinetic mechanisms. Volume 2. Chemk: a computer modeling scheme for chemical kinetics. Final report, July 1978-September 1979

    SciTech Connect

    Whitten, G.Z.; Hogo, H.

    1980-02-01

    Mechanisms that describe the formation of photochemical smog are developed using a computer modeling technique directed toward the simulation of data collected in two smog chambers: an indoor chamber and a dual outdoor chamber. Individual compounds for which specific experiments were simulated and mechanisms developed include the following: formaldehyde, acetaldehyde, ethylene, propylene, butane, and toluene. Volume 2 contains the user's manual and coding for a chemical kinetics computer program, CHEMK.

  19. 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.

  20. Synthesis, structure, and magnetic properties of iron and nickel nanoparticles encapsulated into carbon

    NASA Astrophysics Data System (ADS)

    Tsurin, V. A.; Yermakov, A. Ye.; Uimin, M. A.; Mysik, A. A.; Shchegoleva, N. N.; Gaviko, V. S.; Maikov, V. V.

    2014-02-01

    Nanocomposites based on iron and nickel particles encapsulated into carbon (Fe@C and Ni@C), with an average size of the metal core in the range from 5 to 20 nm and a carbon shell thickness of approximately 2 nm, have been prepared by the gas-phase synthesis method in a mixture of argon and butane. It has been found using X-ray diffraction, transmission electron microscopy, and Mössbauer spectroscopy that iron nanocomposites prepared in butane, apart from the carbon shell, contain the following phases: iron carbide (cementite), α-Fe, and γ-Fe. The phase composition of the Fe@C nanocomposite correlates with the magnetization of approximately 100 emu/g at room temperature. The replacement of butane by methane as a carbon source leads to another state of nanoparticles: no carbon coating is formed, and upon subsequent contact with air, the Fe3O4 oxide shell is formed on the surface of nanoparticles. Nickel-based nanocomposites prepared in butane, apart from pure nickel in the metal core, contain the supersaturated metastable solid solution Ni(C) and carbon coating. The Ni(C) solid solution can decompose both during the synthesis and upon the subsequent annealing. The completeness and degree of decomposition depend on the synthesis regime and the size of nickel nanoparticles: the smaller is the size of nanoparticles, the higher is the degree of decomposition into pure nickel and carbon. The magnetization of the Ni@C nanocomposites is determined by several contributions, for example, the contribution of the magnetic solid solution Ni(C) and the contribution of the nonmagnetic carbon coating; moreover, some contribution to the magnetization can be caused by the superparamagnetic behavior of nanoparticles.

  1. Hexamethyl 13,14-dioxapenta­cyclo­[8.2.1.14,7.02,9.03,8]tetra­deca-5,11-diene-1,4,5,6,11,12-hexa­carboxyl­ate

    PubMed Central

    Lough, Alan J.; Jack, Kelsey; Tam, William

    2012-01-01

    In the title compound, C24H24O14, the stereochemistry at the cyclo­butane ring is cis-anti-cis and the –COOMe groups in the bicyclic rings are syn to each other. The mol­ecule lies on a twofold rotation axis. In the crystal, weak C—H⋯O hydrogen bonds connect mol­ecules into chains along [001], forming R 2 2(10) rings. PMID:23125745

  2. Maleic anhydride catalysts and process for their manufacture

    SciTech Connect

    Haddad, M.S.; Meyers, B.L.; Eryman, W.S.

    1990-06-12

    This patent describes a catalyst for the production of maleic anhydride by the oxidation of a member of the group consisting of benzene, butane, butene and butadiene. It comprises a phosphorus-vanadium-mixed oxide and exists in the form of geometric shapes, the shapes having been heated in an inert atmosphere at a temperature of about 650{degrees} to about 1300{degrees} F. prior to being exposed to an oxygen-containing gas at an elevated temperature.

  3. Synthesis of graphene-like materials by pyrolysis of hydrocarbons in thermal plasma and their properties

    NASA Astrophysics Data System (ADS)

    Amirov, R. Kh; Atamanuk, I. N.; Vorobieva, N. A.; Isakaev, E. H.; Shavelkina, M. B.; Shkolnikov, E. I.

    2015-11-01

    A method to synthesize graphene-like materials using dc high current divergent anode-channel plasma torch has been developed. Carbon atoms are generated by decomposition of propane-butane and methane in a thermal plasma jet. Products of synthesis are characterized by electron microscopy, thermogravimetry, Raman spectroscopy and porosimetry. Effect of experimental conditions on the morphology, phase composition and porosity of the products of synthesis are investigated. The optimal conditions have been found.

  4. 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.

  5. A new hydronaphthalenone from the mangrove-derived Daldinia eschscholtzii PSU-STD57.

    PubMed

    Kongyen, Wipapan; Rukachaisirikul, Vatcharin; Phongpaichit, Souwalak; Sakayaroj, Jariya

    2015-01-01

    One new hydronaphthalenone derivative (1) was isolated from the broth extract of the endophytic fungus Daldinia eschscholtzii PSU-STD57 together with five known compounds, isosclerone (2), 8-methoxy-1-naphthol, 1,8-dimethoxynaphthalene, 2,6-dihydroxyphenyl-1-butan-1-one and tyrosol. The structures were assigned by spectroscopic methods. All the compounds were tested for antimicrobial activity against Staphylococcus aureus, methicillin-resistant S. aureus and Microsporum gypseum. PMID:25776658

  6. Measurements on thermodiffusion in ternary hydrocarbon mixtures at high pressure

    NASA Astrophysics Data System (ADS)

    Srinivasan, S.; Saghir, M. Z.

    2009-09-01

    Experimental investigations on thermodiffusion have been conducted for five different ternary mixtures of methane, n-butane, and n-dodecane at a high temperature and pressure. While the mole fraction of methane was fixed at 0.2 the mole fraction of n-dodecane was varied from 0.7 to 0.2. The experiments were performed in a microgravity environment on board the satellite FOTON-M3. It was found that in all mixtures, n-dodecane separated to the cold side whereas methane segregated to the hot side. n-butane, the species with an intermediate density, showed a change in sign as its mole fraction was increased. At low concentrations it collected on the cold side but moved in the opposite direction with an increase in its mole fraction. The role of the relative density coupled with the species concentrations has been used to explain the thermodiffusion factor in each mixture. Computational investigations showed a similar behavior. However, the theoretical model was not able to capture the sign change of n-butane accurately. The inadequate representation of the significance of the relative densities and the mole fraction of the species has been found as the reason for this.

  7. 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. PMID:25528241

  8. Photolytic formation of free radicals and their effect on hydrocarbon pyrolysis chemistry in a concentrated solar environment

    SciTech Connect

    Hunjan, M.S.; Mok, W.S.L.; Antal, M.J. Jr. . Dept. of Mechanical Engineering)

    1989-08-01

    High-energy photons present in concentrated sunlight can be used to photolytically dissociate certain vapor-phase compounds known to be sources of free radicals. These free radicals can subsequently initiate or influence pyrolysis reactions involving hydrocarbons. Experiments were conducted in a vapor-phase, tubular flow reactor placed at the focus of a 1-kW arc image furnace, which acted as a source of simulated concentrated sunlight. Experimentally observed rates of acetone photolysis were in close agreement with the values predicted by employing the Beer-Lambert law. By the use of acetone as a photosensitizing agent, the photosensitized pyrolysis chemistry of n-butane, at 350{sup 0}C, was studied. Without photosensitization, no pyrolysis was observed. With photosensitization, a modest (2-4%) conversion of n-butane to butane, hexene, propene, and other hydrocarbons was achieved. Numerical simulations of the photosensitized pyrolysis behavior provided results similar to the experimental observations. The results of numerical simulations at higher temperatures lead the authors to conclude that major photosensitization effects may be observed at temperatures between 400 and 500{sup 0}C.

  9. Superacid catalysis of light hydrocarbon conversion. Tenth quarterly report, January 1, 1996--March 31, 1996

    SciTech Connect

    Gates, B.C.

    1996-09-01

    Transition metal promoters markedly increase the activity of sulfated zirconia for isomerization of butane. Data presented here demonstrate the effects of the promoters zinc, iron, and manganese; none of these is as effective as the iron/manganese combination. The effects of feed impurities (olefins and/or isobutane in n-butane) are consistent with those described in the preceding quarterly report: they lead to an improvement in catalytic activity. These observations are inferred to be of practical importance; they indicate the benefit of the impurities in increasing butane conversion. The product distribution data show that reactions accompanying isomerization and disproportionation are more important with some promoters (e.g., iron) than others (e.g., zinc). The data demonstrate that the iron- and manganese-promoted catalyst can be regenerated at least sever times with negligible loss of activity (within the experimental error). To apply this catalyst or a related catalyst industrially, it seems very likely to be necessary to reduce the rate of deactivation substantially and/or to regenerate the catalyst through many cycles.

  10. 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. PMID:17694375

  11. 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.

  12. New trends in the kitchen: propellants assessment of edible food aerosol sprays used on food.

    PubMed

    Varlet, V; Smith, F; Augsburger, M

    2014-01-01

    New products available for food creations include a wide variety of "supposed" food grade aerosol sprays. However, the gas propellants used cannot be considered as safe. The different legislations available did not rule any maximum residue limits, even though these compounds have some limits when used for other food purposes. This study shows a preliminary monitoring of propane, butane and dimethyl ether residues, in cakes and chocolate after spraying, when these gases are used as propellants in food aerosol sprays. Release kinetics of propane, butane and dimethyl ether were measured over one day with sprayed food, left at room temperature or in the fridge after spraying. The alkanes and dimethyl ether analyses were performed by headspace-gas chromatography-mass spectrometry/thermal conductivity detection, using monodeuterated propane and butane generated in situ as internal standards. According to the obtained results and regardingthe extrapolations of the maximum residue limits existing for these substances, different delays should be respected according to the storage conditions and the gas propellant to consume safely the sprayed food. PMID:24001847

  13. Propene concentration sensing for combustion gases using quantum-cascade laser absorption near 11 μm

    NASA Astrophysics Data System (ADS)

    Chrystie, Robin S. M.; Nasir, Ehson F.; Farooq, Aamir

    2015-08-01

    We report on a strategy to measure, in situ, the concentration of propene (C3H6) in combustion gases using laser absorption spectroscopy. Pyrolysis of n-butane was conducted in a shock tube, in which the resultant gases were probed using an extended cavity quantum-cascade laser. A differential absorption approach using online and offline wavelengths near λ = 10.9 μm enabled discrimination of propene, cancelling the effects of spectral interference from the simultaneous presence of intermediate hydrocarbon species during combustion. Such interference-free measurements were facilitated by exploiting the =C-H bending mode characteristic to alkenes (olefins). It was confirmed, for intermediate species present during pyrolysis of n-butane, that their absorption cross sections were the same magnitude for both online and offline wavelengths. Hence, this allowed time profiles of propene concentration to be measured during pyrolysis of n-butane in a shock tube. Time profiles of propene subsequent to a passing shock wave exhibit trends similar to that predicted by the well-established JetSurF 1.0 chemical kinetic mechanism, albeit lower by a factor of two. Such a laser diagnostic is a first step to experimentally determining propene in real time with sufficient time resolution, thus aiding the refinement and development of chemical kinetic models for combustion.

  14. 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.

  15. 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.

  16. 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.

  17. The idiosyncrasies of (BBIM-alkane)DB30C10 MIMs

    NASA Astrophysics Data System (ADS)

    Ghosh, Sabari; Chaudhuri, Tandrima; Padmanaban, E.; Mukhopadhyay, Chhanda

    2015-10-01

    In this present study we explore the mechanically interlocked molecules (MIMs) resulting from the combination of the BBIM(bis-benzimidazolium)-alkane systems with DB30C10 (Dibenzo-30-crown-10) in solvent acetonitrile. The (BBIM-alkane)DB30C10 systems chosen for the study are (BBIM)DB30C10, (BBIM-methane)DB30C10, (BBIM-ethane)DB30C10, (BBIM-propane)DB30C10 and (BBIM-butane)DB30C10. 1H NMR, 2D-NMR (COSY and NOESY), Monte Carlo calculations and HRMS have been done on the studied assemblies. Even though (BBIM)DB30C10 and (BBIM-methane)DB30C10 form normal threaded structures, in (BBIM-ethane)DB30C10, (BBIM-propane)DB30C10 and (BBIM-butane)DB30C10 systems the respective axles are cradled inside the crown ether. That is, the axles BBIM-ethane, BBIM-propane and BBIM-butane are cradled inside the boat-like cavity of DB30C10.

  18. 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. PMID:26241651

  19. Measurements on thermodiffusion in ternary hydrocarbon mixtures at high pressure.

    PubMed

    Srinivasan, S; Saghir, M Z

    2009-09-28

    Experimental investigations on thermodiffusion have been conducted for five different ternary mixtures of methane, n-butane, and n-dodecane at a high temperature and pressure. While the mole fraction of methane was fixed at 0.2 the mole fraction of n-dodecane was varied from 0.7 to 0.2. The experiments were performed in a microgravity environment on board the satellite FOTON-M3. It was found that in all mixtures, n-dodecane separated to the cold side whereas methane segregated to the hot side. n-butane, the species with an intermediate density, showed a change in sign as its mole fraction was increased. At low concentrations it collected on the cold side but moved in the opposite direction with an increase in its mole fraction. The role of the relative density coupled with the species concentrations has been used to explain the thermodiffusion factor in each mixture. Computational investigations showed a similar behavior. However, the theoretical model was not able to capture the sign change of n-butane accurately. The inadequate representation of the significance of the relative densities and the mole fraction of the species has been found as the reason for this. PMID:19791895

  20. 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

  1. Ecotoxicity and biodegradability of antielectrostatic dicephalic cationic surfactants.

    PubMed

    Piętka-Ottlik, Magdalena; Frąckowiak, Renata; Maliszewska, Irena; Kołwzan, Barbara; Wilk, Kazimiera A

    2012-11-01

    Four series of dicephalic cationic surfactants, considered as new antielectrostatic agents have been investigated in order to establish their toxicity and biodegradability. Among them N,N-bis[3,3'-(dimethylamine)propyl]alkylamides, N,N-bis[3,3'-(dimethylamine)propyl]alkylamide dihydrochlorides, N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dibromides and N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dimethylsulphates with different hydrophobic chain length (n-C(9)H(19) to n-C(15)H(31)) and type of counterion (chloride, bromide and methylsulfate) have been studied. The inhibitory effect against microorganisms has been examined using model gram-positive and gram-negative bacteria, and yeasts. None of the tested surfactants have shown antimicrobial activity against gram-negative bacteria (Escherichia coli, Pseudomonas putida) and yeasts (Saccharomyces cerevisiae, Rhodotorula glutinis) at a concentration below 1000 μg mL(-1), however some of them were moderately active against gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis). The Microtox® test was successfully applied to measure EC(50) values of the studied dicephalic cationic surfactants. Their toxicity to Vibrio fischeri depended upon the alkanoyl chain length with the EC(50) values in a range of 2.6-980 mg L(-1). N,N-bis[3,3'-(dimethylamine)propyl]alkylamide dihydrochlorides 2a-b and N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dibromides 3a-b comprising n-decanoyl and n-dodecanoyl hydrophobic tails appeared to be the least toxic. Furthermore, the biodegradability under aerobic conditions of 2a-b, 3a-b was evaluated using OECD Method 301F. According to the obtained results 2a, 3a-3b can be considered as almost readily biodegradable and they are not expected to be persistent in the environment. Additionally, partial biodegradation was observed for 2b, indicating its possible biodegradation in wastewater treatment systems. PMID:22743183

  2. Selone-stabilized aryltellurenyl cations.

    PubMed

    Yadav, Sangeeta; Raju, Saravanan; Singh, Harkesh B; Butcher, Ray J

    2016-05-28

    Controlled bromination of a diarylditelluride, R2Te2 (R = 2,6-dimethylphenyl) (6) in dichloromethane led to the formation of a Te(II)-Te(IV) mixed-valent tellurenyl bromide, RBr2TeTeR (7). A further reaction of 7 with 1,3-dibutylbenzimidazolin-2-selone, C15H22N2Se (L) (9), produced the first selone adduct of the 2,6-dimethylphenyltellurenyl cation with the 2,6-dimethylphenyltellurium dibromide anion, [(2,6-Me2C6H3)Te(L)](+)[(2,6-Me2C6H3)TeBr2](-) (10). The red colored cationic adduct 10 is not stable in acetonitrile and disproportionated to give the selone adduct of 2,6-dimethylphenyltellurenyl bromide, [(2,6-Me2C6H3)Te(L)Br] (11b) and bis(2,6-dimethylphenyl)tellurium dibromide, [(2,6-Me2C6H3)2TeBr2], (13). The metathesis reaction of 11b with AgBF4 produced a stable dark red colored selone adduct of the 2,6-dimethylphenyltellurenyl cation with the BF4(-) anion, [(2,6-Me2C6H3)Te(L)](+)BF4(-) (15). The selone adducts of aryltellurenyl halides, i.e. [(2,6-Me2C6H3)Te(L)X] (X = Cl, Br, I) (11a-11c), have been synthesized by a one-pot reaction of 6 with an equimolar mixture of 9 and 1,3-dibutylbenzimidazolin-2-dihaloselones, C15H22N2SeX2 (14a-14c). Triphenylphosphine (PPh3), when treated with [(2,6-Me2C6H3)Te(L)X] (11a-11c), substitutes selone from the adduct to afford the triphenylphosphine adducts of aryltellurenyl halides, [(2,6-Me2C6H3)Te(PPh3)X] (16a-16c). PMID:27111528

  3. 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. PMID:27128188

  4. Enhancing Attraction of African Malaria Vectors to a Synthetic Odor Blend.

    PubMed

    Mweresa, Collins K; Mukabana, Wolfgang R; Omusula, Philemon; Otieno, Bruno; Van Loon, Joop J A; Takken, Willem

    2016-06-01

    The deployment of odor-baited tools for sampling and controlling malaria vectors is limited by a lack of potent synthetic mosquito attractants. A synthetic mixture of chemical compounds referred to as "the Mbita blend" (MB) was shown to attract as many host-seeking malaria mosquitoes as attracted to human subjects. We hypothesized that this effect could be enhanced by adding one or more attractive compounds to the blend. We tested changes in the capability of MB (ammonia + L-lactic acid + tetradecanoic acid +3-methyl-1-butanol + carbon dioxide) to attract host-seeking malaria mosquitoes by addition of selected dilutions of butyl-2-methylbutanoate (1:10,000), 2-pentadecanone (1:100), 1-dodecanol (1:10,000), and butan-1-amine (1:10,000,000). The experiments were conducted in semi-field enclosures and in a village in western Kenya. In semi-field enclosures, the attraction of Anopheles gambiae sensu stricto females to MB-baited traps was not enhanced by adding butyl-2-methylbutanoate. There was, however, an increase in the proportion of An. gambiae caught in traps containing MB augmented with the selected dilutions of butan-1-amine, 2-pentadecanone, and 1-dodecanol. When tested in the village, addition of butan-1-amine to MB enhanced catches of female An. gambiae sensu lato, An. funestus, and Culex mosquitoes. 1-Dodecanol increased attraction of An. gambiae s.l. to the MB, while addition of 2-pentadecanone improved trap catches of An. funestus and Culex mosquitoes. This study demonstrates the possibility of enhancing synthetic odor blends for trapping the malarial mosquitoes An. gambiae s.l. and An. funestus, as well as some culicine species. The findings provide promising results for the optimization and utilization of synthetic attractants for sampling and controlling major disease vectors. PMID:27349651

  5. Relative contribution of oxygenated hydrocarbons to the total biogenic VOC emissions of selected mid-European agricultural and natural plant species

    NASA Astrophysics Data System (ADS)

    König, Georg; Brunda, Monika; Puxbaum, Hans; Hewitt, C. Nicholas; Duckham, S. Craig; Rudolph, Jochen

    Emission rates of more than 50 individual VOCs were determined for eight plant species and three different types of grass land typical for natural deciduous and agricultural vegetation in Austria. In addition to the emissions of isoprene and monoterpenes, 33 biogenic oxygenated volatile organic compounds (BOVOCs) were detected. Of these, 2-methyl-l-propanol, 1-butanal, 2-butanal, 1-pentanol, 3-pentanol, 1-hexanol, 6-methyl-5-hepten-2-one, butanal and ethylhexylacetate were observed for the first time as plant emissions. In terms of prevalence of one of the groups of emitted VOCs (isoprene, terpenes, BOVOCs) the grain plants wheat and rye, grape, oilseed rape and the decidous trees hombeam and birch could be classified as "BOVOC"-emitters. For the grass plots examined, BOVOCs and terpenes appear to be of equal importance. The emission rates of the total assigned organic plant emissions ranged from 0.01 μ g -1 h -1 for wheat to 0.8 μg g -1 h -1 for oak (based on dry leaf weight). Intercomparison with available data from other studies show that our emission rates are rather at the lower end of reported ranges. The influence of the stage of growth was examined for rye, rape (comparing emissions of blossoming and nonblossoming plants) and for grape (with and without fruit). Emission rate differences for different stages of growth varied from nondetectable for blossoming and nonblossoming rye to a factor of six for the grape with fruits vs grape without fruits (emission rate based on dry leaf weight). The major decidous tree in Austria (beech) is a terpene emitter, with the contribution of BOVOCs below 5% of the total assigned emissions of 0.2 μg g -1 h -1 for the investigations of 20°C.

  6. 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.

  7. Reactivity of molybdovanadophosphoric acids: Influence of the presence of vanadium in the primary and secondary structure

    SciTech Connect

    Casarini, D.; Centi, G.; Lena, V.; Tvaruzkova, Z. ); Jiru, P. )

    1993-10-01

    The catalytic behavior in butadiene and n-butane oxidation of molybdovanadophosphoric acids with vanadium localized inside the primary (oxoanion) and/or the secondary structure is reported. The samples are characterized by infrared, [sup 31]P-NMR, [sup 51]V-NMR, and UV-visible diffuse reflectance spectroscopies in order to obtain information on the nature and localization of vanadium in the samples before reaction and the possible changes occurring during the course of the catalytic reaction. In particular, it is shown that vanadium localized initially in the secondary structure can exchange with the molybdenum atoms of the oxoanion during the catalytic reaction. Introduction of vanadium in the molybdophosphoric acid structure enhances the selective formation of maleic anhydride from the butadiene when vanadium is present both inside the oxoanion or localized in the secondary structure (before the catalytic tests), but the maximum in catalytic performance is found for different amounts of vanadium, depending on where the vanadium is localized initially. However, when present in the secondary structure, vanadium also has a negative influence on the activity of the heteropoly acid. On the contrary, in n-butane oxidation, the presence of vanadium enhances the rate of alkane activation due to the different rate-determining step. The presence of V ions also affects the maximum selectivity and yield to maleic anhydride from butane. V ions in the secondary structure are more selective at low conversion, while V ions inside the oxoanion are more selective at higher conversions and thus allow better maximum yields to maleic anhydride. 40 refs., 11 figs., 2 tabs.

  8. Probing the hydrophobic pocket of the active site in the particulate methane monooxygenase (pMMO) from Methylococcus capsulatus (Bath) by variable stereoselective alkane hydroxylation and olefin epoxidation.

    PubMed

    Ng, Kok-Yaoh; Tu, Li-Chun; Wang, Yane-Shih; Chan, Sunney I; Yu, Steve S-F

    2008-05-01

    pMMO from M. capsulatus (Bath) oxidizes straight-chain C1-C5 alkanes and alkenes to form their corresponding 2-alcohols and epoxides. According to experiments performed with cryptically chiral ethane and D,L-[2-(2)H(1),3-(2)H(1)]butane, the reactions proceed through the concerted O-atom insertion mechanism. However, when propene and but-1-ene are used as epoxidation substrates, the enantiomeric excesses (ees) of the enzymatic products are only 18 and 37 %, respectively. This relatively poor stereoselectivity in the enzymatic epoxidation presumably reflects low stereochemical differentiation between the re and si faces in the hydrophobic pocket of the active site. Further insights into the reaction mechanism are now provided by studies on trans-but-2-ene, which reveal only the D,L-2,3-dimethyloxirane products, and on cis-but-2-ene, which yield only the meso product. These observations indicate that the enzymatic epoxidation indeed proceeds through electrophilic syn addition. To achieve better facial selectivity, we have also used 3,3,3-trifluoroprop-1-ene as the substrate. The products obtained are 90 % (2S)-oxirane. When 1,1,1-trifluoropropane is the substrate, the hydroxylation at the 2-carbon exhibits an inverse chiral selectivity relative to that seen with normal butane, if we consider the size of the CF(3) group in the fluorinated propane to be comparable to one of the ethyl groups in butane. These experiments are beginning to delineate the factors that influence the orientations of various substrates in the hydrophobic cavity of the active site in the enzyme. PMID:18383583

  9. 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

  10. 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.

  11. 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.

  12. Natural Gas

    NASA Astrophysics Data System (ADS)

    Maddox, Robert N.; Moshfeghian, Mahmood; Ldol, James D.; Johannes, Arland H.

    Natural gas is a naturally occurring mixture of simple hydrocarbons and nonhydrocarbons that exists as a gas at ordinary pressures and temperatures. In the raw state, as produced from the earth, natural gas consists principally of methane (CH4) and ethane (C2H4), with fractional amounts of propane (C3H8), butane (C4H10), and other hydrocarbons, pentane (C5H12) and heavier. Occasionally, small traces of light aromatic hydrocarbons such as benzene and toluene may also be present.

  13. 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.

  14. Saudi ethylene plants move toward more feed flexibility

    SciTech Connect

    Lee, A.K.K.; Aitani, A.M. )

    1990-09-10

    Demand for basic petrochemicals, such as propylene, butenes, and aromatics, is increasing in Saudi Arabia. This paper discusses how increased demand for these materials will require a change to heavier feedstocks, such as butanes, naphtha, and gas oil, for the next generation of Saudi Arabian ethylene plants. Changing to heavier ethylene plant feedstocks would also take pressure off of limited ethane supplies in the region. Ethylene production in Saudi Arabia currently has the advantages of low-cost feedstock, cheap energy, and low-cost capital loans. The existing ethylene plants are designed to crack ethane and produce, primarily, ethylene.

  15. Pyrolysis: theory and industrial practice

    SciTech Connect

    Albright, L.F.; Crynes, B.L.; Corcoran, W.H.

    1983-01-01

    This book is useful for the study of pyrolysis from two perspectives: theory and industrial practice. Topics included are thermal decompositions and reactions of methane pyrolysis of ethane and propane, pyrolysis of n-butane, thermal reaction of olefins and diolefins, pyrolysis of heavy hydrocarbons, formation of aromatics, hydrogenolysis of toluene, mathematical modeling of hydrocarbon pyrolysis reactions, nonpetroleum feedstocks, formation and gasification of coke, surface reactions in pyrolysis units, pyrolysis furnace design, laboratory reactors for pyrolysis, and economic considerations in the design and operation of conventional pyrolysis furnaces.

  16. 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

  17. Emission characteristics of nonmethane hydrocarbons from private cars and taxis at different driving speeds in Hong Kong

    NASA Astrophysics Data System (ADS)

    Guo, H.; Zou, S. C.; Tsai, W. Y.; Chan, L. Y.; Blake, D. R.

    2011-05-01

    Vehicular emissions are the major sources of a number of air pollutants including nonmethane hydrocarbons (NMHCs) in urban area. The emission composition and emission factors of NMHCs from vehicles are currently lacking in Hong Kong. In this study, speciation and emission factors of NMHCs emitted from gasoline-fuelled private cars and liquefied petroleum gas (LPG)-fuelled taxis at different driving speeds were constructed using a chassis dynamometer. Large variations in the contributions of individual NMHC species to total emission were observed for different private cars at different driving speeds. The variations of individual NMHC emissions were relatively smaller for taxis due to their relatively homogeneous year of manufacture and mileages. Incomplete combustion products like ethane, ethene and propene were the major component of both types of vehicles, while unburned fuel component was also abundant in the exhausts of private cars and taxis (i.e. i-pentane and toluene for private car, and propane and butanes for taxi). Emission factors of major NMHCs emitted from private cars and taxis were estimated. High emission factors of ethane, n-butane, i/ n-pentanes, methylpentanes, trimethylpentanes, ethene, propene, i-butene, benzene, toluene and xylenes were found for private cars, whereas propane and i/ n-butanes had the highest values for taxis. By evaluating the effect of vehicular emissions on the ozone formation potential (OFP), it was found that the contributions of olefinic and aromatic hydrocarbons to OFP were higher than that from paraffinic hydrocarbons for private car, whereas the contributions of propane and i/ n-butanes were the highest for taxis. The total OFP value was higher at lower speeds (≤50 km h -1) for private cars while a minimum value at driving speed of 100 km h -1 was found for taxis. At the steady driving speeds, the total contribution of NMHCs emitted from LPG-fuelled taxis to the OFP was much lower than that from gasoline

  18. Regioselective alkane hydroxylation with a mutant CYP153A6 enzyme

    DOEpatents

    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.

  19. Amorphous Insulator Films With Controllable Properties

    NASA Technical Reports Server (NTRS)

    Alterovitz, Samuel A.; Warner, Joseph D.; Liu, David C.; Pouch, John J.

    1987-01-01

    In experiments described in report, amorphous hydrogenated carbon films grown at room temperature by low-frequency plasma deposition, using methane or butane gas. Films have unique array of useful properties; (a) adhere to wide variety of materials; (b) contain only carbon and hydrogen; (c) smooth and free of pinholes; (d) resistant to attack by moisture and chemicals; and (e) have high electric-breakdown strength and electrical resistivity. Two of optical properties and hardness of this film controlled by deposition conditions. Amorphous a-C:H and BN films used for hermetic sealing and protection of optical, electronic, magnetic, or delicate mechanical systems, and for semiconductor field dielectrics.

  20. Towards reproducible, scalable lateral molecular electronic devices

    NASA Astrophysics Data System (ADS)

    Durkan, Colm; Zhang, Qian

    2014-08-01

    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.

  1. Neural network modeling of distillation columns

    SciTech Connect

    Baratti, R.; Vacca, G.; Servida, A.

    1995-06-01

    Neural network modeling (NNM) was implemented for monitoring and control applications on two actual distillation columns: the butane splitter tower and the gasoline stabilizer. The two distillation columns are in operation at the SARAS refinery. Results show that with proper implementation techniques NNM can significantly improve column operation. The common belief that neural networks can be used as black-box process models is not completely true. Effective implementation always requires a minimum degree of process knowledge to identify the relevant inputs to the net. After background and generalities on neural network modeling, the paper describes efforts on the development of neural networks for the two distillation units.

  2. Plasma deposition of amorphous hydrogenated carbon films on III-V semiconductors

    NASA Technical Reports Server (NTRS)

    Pouch, John J.; Warner, Joseph D.; Liu, David C.; Alterovitz, Samuel A.

    1988-01-01

    Amorphous hydrogenated carbon films were grown on GaAs, InP and fused silica substrates using plasmas generated from hydrocarbon gases. Methane and n-butane sources were utilized. The effects of flow rate and power density on film growth were investigated. Carbon was the major constituent in the films. The degree of asymmetry at the carbon-semiconductor interface was approximately independent of the power density. Different H-C bonding configurations were detected by the technique of secondary-ion mass spectrometry. Band gaps up to 3 eV were obtained from optical absorption studies. Breakdown strengths as high as 600 MV/m were measured.

  3. Structural elucidation, optical, magnetic and nonlinear optical properties of oxystyryl dyes.

    PubMed

    Koleva, Bojidarka B; Stoyanov, Stanimir; Kolev, Tsonko; Petkov, Ivan; Spiteller, Michael

    2009-01-01

    Structure, magnetic and optical properties of tetraphenylborate salts of 2,5-[1-methyl-4-[2-(4-hydroxyphenyl)ethenyl]piridinium]-propane and butane are performed in gas and condense phase by means of solution and solid-state conventional and linear-polarized IR-spectroscopy of oriented colloids in nematic liquid crystal suspension, UV-vis and fluorescence methods, HPLC tandem ESI mess spectrometry (MS/MS), (1)H, (13)C and (1)H-(1)H COSY NMR, TGV and DSC methods. Quantum chemical DFT calculations are used for performing of the structures, optical and nonlinear optical properties of the studied compounds. PMID:18722806

  4. 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.

  5. 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

  6. 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).

  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. Experimental investigation of the effect of magnetic field on temperature and temperature profile of diffusion flame using circular grating Talbot interferometer

    NASA Astrophysics Data System (ADS)

    Agarwal, Shilpi; Kumar, Manoj; Shakher, Chandra

    2015-05-01

    The effect of magnetic field on temperature and temperature profile of diffusion flame is investigated by using circular grating Talbot interferometer. Talbot interferometric fringes are recorded for diffusion flame generated by butane torch burner, in the absence of magnetic field, in the presence of uniform magnetic field, upward-decreasing and upward-increasing magnetic field. Analysis of recorded interferogram reveals that the temperature of the flame is increased under the influence of the upward-decreasing magnetic field and flame temperature is decreased under the influence of upward-increasing magnetic field. Uniform magnetic field has a negligible effect on temperature of the flame.

  9. 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

    2014-02-01

    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. PMID:23838574

  10. Quantification of hydrogen peroxide during the low-temperature oxidation of alkanes

    PubMed Central

    Bahrini, Chiheb; Herbinet, Olivier; Glaude, Pierre-Alexandre; Schoemaecker, Coralie; Fittschen, Christa; Battin-Leclerc, Frédérique

    2013-01-01

    The first reliable quantification of hydrogen peroxide (H2O2) formed during the low temperature oxidation of an organic compound has been achieved thanks to a new system that couples a jet stirred reactor to a detection by continuous wave cavity ring-down spectroscopy (cw-CRDS) in the near infrared. The quantification of this key compound for hydrocarbon low-temperature oxidation regime has been obtained under conditions close to those actually observed before the autoignition. The studied hydrocarbon was n-butane, the smallest alkane which has an oxidation behaviour close to that of the species present in gasoline and diesel fuels. PMID:22746212

  11. Adsorption and dissociation kinetics of alkanes on CaO(100)

    NASA Astrophysics Data System (ADS)

    Chakradhar, A.; Liu, Y.; Schmidt, J.; Kadossov, E.; Burghaus, U.

    2011-08-01

    The adsorption kinetics of ethane, butane, pentane, and hexane on CaO(100) have been studied by multi-mass thermal desorption (TDS) spectroscopy. The sample cleanliness was checked by Auger electron spectroscopy. A molecular and dissociative adsorption pathway was evident for the alkanes, except for ethane, which does not undergo bond activation. Two TDS peaks appeared when recording the parent mass, which are assigned to different adsorption sites/configurations of the molecularly adsorbed alkanes. Bond activation leads to desorption of hydrogen and several alkane fragments assigned to methane and ethylene formation. Only one TDS feature is seen in this case. Formation of carbon residuals was absent.

  12. Tetra­methyl 1,4-dimethyl-13,14-dioxa­penta­cyclo­[8.2.1.14,7.02,9.03,8]tetra­deca-5,11-diene-5,6,11,12-tetra­carboxyl­ate

    PubMed Central

    Lough, Alan J.; Jack, Kelsey; Tam, William

    2012-01-01

    In the title compound, C22H24O14, the relative stereochemistry at the cyclo­butane ring is cis-anti-cis and the methyl groups in the bicyclic rings are syn to each other. The two carboxyl­ate groups attached to the same —C=C— bond are disordered over two sets of sites in a 0.603 (2):0.397 (2) ratio. In the crystal, weak C—H⋯O hydrogen bonds connect mol­ecules into C(12) chains along [001] incorporating R 2 2 2(10) rings. PMID:23125743

  13. 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

  14. Olefins by catalytic oxidation of alkanes in fluidized bed reactors

    SciTech Connect

    Bharadwaj, S.S.; Schmidt, L.D.

    1995-09-01

    The production of ethylene or syngas from ethane and olefins from propane, n-butane, and isobutane in the presence of air or O{sub 2} at atmospheric pressure has been examined over 100 {mu}m {alpha}-Al{sub 2}O{sub 3} beads coated with noble metals in a static fluidized bed reactor at contact times from 0.05 to 0.2 s. Variations in feed composition, preheating temperature, and flow rate were examined. 21 refs., 5 figs., 1 tab.

  15. Synthesis and characterization of segmented polyurethanes based on amphiphilic polyether diols.

    PubMed

    Lan, P N; Corneillie, S; Schacht, E; Davies, M; Shard, A

    1996-12-01

    Segmented polyurethanes (SPUs) based on polyethylene glycol (PEG), polypropylene glycol (PPG) and a series of Pluronics with different ethylene oxide/propylene oxide ratios (EO/PO) and molecular weights were prepared. Different diisocyanates were used for making SPUs: 4,4-diphenylmethane diisocyanate (MDI), 4,4-dicyclohexylmethane diisocyanate (MDCI), hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI). 1,4-Butane diol (BD) and ethylene diamine (ED) were used as chain extenders. The polymers obtained were characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). The microphase morphology (phase separation and phase mixing) is discussed in more detail. PMID:8968523

  16. Butanediol via maleic anhydride

    SciTech Connect

    Harris, N.; Tuck, M.W. )

    1990-05-01

    A new butanediol process offers the opportunity for new producers to enter a growth market previously dominated by a very few major companies. Butanediol (BDO) and its derivatives compete with alternative products on a cost basis in their end use applications. The ability of the new route to produce BDO at a lower cost than established technology will lead to further market penetration and an expansion of the uses for the product. The feedstock, n-butane, is widely available and likely to fall in cost relative to the cost of the feedstocks used by competing processes. The process is environmentally acceptable and less hazardous than competing technologies.

  17. Potential energy surfaces for chemical reactions. Progress report, March 15, 1988--1989

    SciTech Connect

    Schaefer, H.F. III

    1995-01-01

    The crystal structure of two esters, both coupled bicyclo[1.1.0] butane derivatives, are found to have extremely short carbon-carbon central bonds (1.440-1.445 angstroms). The phenomena is tested by quantum mechanical methods since chemical experiments are not currently possible. Theoretical models employed were the minimum basis set (MBS), the standard double zeta(DZ), the double zeta plus d(DZ+d), the double zeta plus polarization(DZ+P), along with the self-consistent field method provide predictions for intra-cyclic bond lengths and angles including the central bond length.

  18. 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. PMID:26471445

  19. 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.

  20. Bio-butanol: Combustion properties and detailed chemical kinetic model

    SciTech Connect

    Black, G.; Curran, H.J.; Pichon, S.; Simmie, J.M.; Zhukov, V.

    2010-02-15

    Autoignition delay time measurements were performed at equivalence ratios of 0.5, 1 and 2 for butan-1-ol at reflected shock pressures of 1, 2.6 and 8 atm at temperatures from 1100 to 1800 K. High-level ab initio calculations were used to determine enthalpies of formation and consequently bond dissociation energies for each bond in the alcohol. A detailed chemical kinetic model consisting of 1399 reactions involving 234 species was constructed and tested against the delay times and also against recent jet-stirred reactor speciation data with encouraging results. The importance of enol chemistry is highlighted. (author)

  1. A New and Efficient Approach to the Synthesis of Nicotine and Anabasine Analogues

    PubMed Central

    Huang, Kun; Ortiz-Marciales, Margarita; De Jesús, Melvin; Stepanenko, Viatcheslav

    2010-01-01

    A straightforward and practical approach was established for the synthesis of nicotine and anabasine analogues by the cyclization of mesylated 1-(3-pyridinyl)-1,4, and 1,5-diol derivatives to form the pyrrolidino or piperidino fragments. Nicotine analogue (S)-15 was prepared with good enantioselectivity using the developed azacyclization procedure of nonracemic (R)-1-pyridin-3-yl-butane-1,4-diol, which was obtained by the borane-mediated reduction of ketone 12 in the presence of the spiroborate ester derived from diphenyl prolinol and ethylene glycol. PMID:20161612

  2. Gas and hydrocarbon vapor permeation in poly(1-trimethylsilyl-1-propyne)/poly(1-phenyl-1-propyne) blends

    SciTech Connect

    Morisato, A.; Shen, H.C.; Toy, L.G.

    1996-12-31

    Permeation properties of phase-separated blends prepared from glassy poly(1-trimethylsilyl-1-propyne) (PTMSP) and poly(1-phenyl-1-propyne) (PPP) were determined as a function of blend composition with pure hydrogen, nitrogen, oxygen, carbon dioxide, and butane. Blend permeabilities decrease significantly with increasing PPP concentration and suggest the occurrence of a phase inversion at low PPP content (5 to 20 wt%). Based on TEM analysis high-aspect-ratio (extended) PPP ellipsoidal dispersions are found in a PTMSP matrix, indicating that the phase inversion is closely related to dispersed-phase connectivity in the blends.

  3. 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)

  4. Structural elucidation, optical, magnetic and nonlinear optical properties of oxystyryl dyes

    NASA Astrophysics Data System (ADS)

    Koleva, Bojidarka B.; Stoyanov, Stanimir; Kolev, Tsonko; Petkov, Ivan; Spiteller, Michael

    2009-01-01

    Structure, magnetic and optical properties of tetraphenylborate salts of 2,5-[1-methyl-4-[2-(4-hydroxyphenyl)ethenyl]piridinium]-propane and butane are performed in gas and condense phase by means of solution and solid-state conventional and linear-polarized IR-spectroscopy of oriented colloids in nematic liquid crystal suspension, UV-vis and fluorescence methods, HPLC tandem ESI mess spectrometry (MS/MS), 1H, 13C and 1H- 1H COSY NMR, TGV and DSC methods. Quantum chemical DFT calculations are used for performing of the structures, optical and nonlinear optical properties of the studied compounds.

  5. 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.

  6. 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.

  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. 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.

  9. 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.

  10. 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.

  11. 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

  12. Unconventional olefin processes

    SciTech Connect

    Hu, Y.C.

    1982-11-01

    Ethylene and coproducts are produced from steam cracking of hydrocarbons such as ethane, propane, butane, naphtha and gas oil in tubular reactor coils installed in externally fired heaters. Due to increasing costs of raw materials and uncertainty of supply, there were flurries of research and development for alternative feedstocks and processes. Alternative processes include crude or residual oil cracking processes, ethanol dehydration processes and syngas based processes. In this series of articles the state-of-the-art for these processes is reviewed and they are assessed for their potential for commercialization.

  13. Silicon-based elementary particle tracking system: Materials science and mechanical engineering design

    SciTech Connect

    Miller, W.O.; Gamble, M.T.; Thompson, T.C.; Hanlon, J.A.

    1993-01-01

    Research and development of the mechanical, cooling, and structural design aspects of a silicon detector-based elementary particle tracking system has been performed. Achieving stringent system precision, stability, and mass requirements necessitated the use of graphite fiber-reinforced cyanate-ester (C-E) resins. Mechanical test results of the effects of butane, ionizing radiation, and a combination of both on the mechanical properties of these materials are presented, as well as progress on developing compression molding of an ultralightweight graphite composite ring structure and TV holography-based noninvasive evaluation.

  14. Silicon-based elementary particle tracking system: Materials science and mechanical engineering design

    SciTech Connect

    Miller, W.O.; Gamble, M.T.; Thompson, T.C.; Hanlon, J.A.

    1993-05-01

    Research and development of the mechanical, cooling, and structural design aspects of a silicon detector-based elementary particle tracking system has been performed. Achieving stringent system precision, stability, and mass requirements necessitated the use of graphite fiber-reinforced cyanate-ester (C-E) resins. Mechanical test results of the effects of butane, ionizing radiation, and a combination of both on the mechanical properties of these materials are presented, as well as progress on developing compression molding of an ultralightweight graphite composite ring structure and TV holography-based noninvasive evaluation.

  15. 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.

  16. Laboratory Studies on the Irradiation of Solid Ethane Analog Ices and Implications to Titan's Chemistry

    NASA Astrophysics Data System (ADS)

    Kim, Y. S.; Bennett, C. J.; Chen, Li-Hsieh; O'Brien, K.; Kaiser, R. I.

    2010-03-01

    Pure ethane ices (C2H6) 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 (CH4), acetylene (C2H2), ethylene (C2H4), and the ethyl radical (C2H5), together with n-butane (C4H10) and butene (C4H8), 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 atmosphere. Finally, we discuss to what extent the n-butane could be the

  17. Turbulence effects on volatilization rates of liquids and solutes

    USGS Publications Warehouse

    Lee, J.-F.; Chao, H.-P.; Chiou, C.T.; Manes, M.

    2004-01-01

    Volatilization rates of neat liquids (benzene, toluene, fluorobenzene, bromobenzene, ethylbenzene, m-xylene, o-xylene, o-dichlorobenzene, and 1-methylnaphthalene) and of solutes (phenol, m-cresol, benzene, toluene, ethylbenzene, o-xylene, and ethylene dibromide) from dilute water solutions have been measured in the laboratory over a wide range of air speeds and water-stirring rates. The overall transfer coefficients (KL) for individual solutes are independent of whether they are in single- or multi-solute solutions. The gas-film transfer coefficients (kG) for solutes in the two-film model, which have hitherto been estimated by extrapolation from reference coefficients, can now be determined directly from the volatilization rates of neatliquids through anew algorithm. The associated liquid-film transfer coefficients (KL) can then be obtained from measured KL and kG values and solute Henry law constants (H). This approach provides a novel means for checking the precision of any kL and kG estimation methods for ultimate prediction of KL. The improved kG estimation enables accurate K L predictions for low-volatility (i.e., low-H) solutes where K L and kGH are essentially equal. In addition, the prediction of KL values for high-volatility (i.e., high-H) solutes, where KL ??? kL, is also improved by using appropriate reference kL values.

  18. Photochemical approach to functionalized benzobicyclo[3.2.1]octene structures via fused oxazoline derivatives from 4- and 5-(o-vinylstyryl)oxazoles

    PubMed Central

    Šagud, Ivana; Božić, Simona; Marinić, Željko

    2014-01-01

    Summary Novel cis/trans-4- and cis/trans-5-(2-vinylstyryl)oxazoles have been synthesized by Wittig reactions from the diphosphonium salt of α,α’-o-xylene dibromide, formaldehyde and 4- and 5-oxazolecarbaldehydes, respectively. In contrast, trans-5-(2-vinylstyryl)oxazole has been synthesized by the van Leusen reaction from trans-3-(2-vinylphenyl)acrylaldehyde which is prepared from o-vinylbenzaldehyde and (formylmethylene)triphenylphosphorane. The 4- and 5-(2-vinylstyryl)oxazoles afford, by photochemical intramolecular cycloaddition, diverse fused oxazoline-benzobicyclo[3.2.1]octadienes, which are identified and characterized by spectroscopic methods. The photoproducts formed are relatively unstable and spontaneously or on silica gel undergo oxazoline ring opening followed by formation of formiato- or formamido-benzobicyclo[3.2.1]octenone derivatives. On irradiation of 4-(2-vinylstyryl)oxazole small quantities of electrocyclization product, 4-(1,2-dihydronaphthalen-2-yl)oxazole, are isolated and spectroscopically characterized. PMID:25246981

  19. Sonication effect on the reaction of 4-bromo-1-methylbenzene with sodium sulfide in liquid-liquid multi-site phase-transfer catalysis condition - kinetic study.

    PubMed

    Abimannan, Pachaiyappan; Selvaraj, Varathan; Rajendran, Venugopal

    2015-03-01

    The synthesis of di-p-tolylsulfane from the reaction of 4-bromo-1-methylbenzene (BMB) with sodium sulfide was carried out using a multi-site phase-transfer catalyst (MPTC) viz., 1,4-dihexyl-1,4-diazoniabicyclo[2.2.2]octanium dibromide and ultrasonic irradiation in a liquid-liquid reaction condition. The overall reaction rate is greatly enhanced when catalyzed by multi-site phase-transfer catalyst (MPTC) combined with sonication (40 kHz, 300 W) in a batch reactor than catalyzed by MPTC without sonication. Effects on the reaction due to various operating conditions, such as agitation speed, different ultrasound frequencies, different phase-transfer catalysts, different organic solvents, the amount of MPTC, temperature, amount of sodium sulfide, effect of sodium hydroxide, volume of n-hexane and the concentration of 4-bromo-1-methylbenzene. The reaction obeys a pseudo first-order rate law and a suitable mechanism was proposed based on the experimental observation. PMID:25199442

  20. Experimental and theoretical characterization of a multi-wavelength DBD-driven exciplex lamp operated with mercury bromide/rare gas mixtures

    NASA Astrophysics Data System (ADS)

    Guivan, Mykola M.; Malinina, Antonina A.; Brablec, Antonin

    2011-06-01

    Emission spectra from an atmospheric-pressure dielectric barrier discharge (DBD) with HgBr2/He or HgBr2/Xe/Kr mixtures, as well as the electrical characteristics, were investigated at repetition frequencies of sinusoidal voltage pulses up to 125 kHz. In the spectra, the study revealed radiation from HgBr(B-X, C-X) exciplex molecules, atomic lines of mercury and rare gases, and in mixtures with xenon, radiation of XeBr(B-X, B-A) exciplex molecules. Regularities in the spectral characteristics of the radiation from the gas-discharge plasma were discussed. The electron energy distribution function, the specific energy lost in the processes involving electrons, the electron temperature and density, and the rate constants of elastic and inelastic electron scattering by the components of the working mixture were calculated as functions of the reduced field E/N. The high-frequency atmospheric-pressure barrier discharge in mixtures of mercury dibromide with gases can be used in multi-wavelength exciplex lamps, operating in the UV and visible regions.

  1. Cysteine-mediated aggregation of Au nanoparticles: the development of a H2O2 sensor and oxidase-based biosensors.

    PubMed

    Wang, Fuan; Liu, Xiaoqing; Lu, Chun-Hua; Willner, Itamar

    2013-08-27

    The cysteine-stimulated aggregation of Au nanoparticles (Au NPs) is used as an auxiliary reporting system for the optical detection of H2O2, for optical probing of the glucose oxidase (GOx) and the catalyzed oxidation of glucose, for probing the biocatalytic cascade composed of acetylcholine esterase/choline oxidase (AChE/ChOx), and for following the inhibition of AChE. The analytical paradigm is based on the I(-)-catalyzed oxidation of cysteine by H2O2 to cystine, a process that prohibits the cysteine-triggered aggregation of the Au NPs. The system enabled the analysis of H2O2 with a detection limit of 2 μM. As the GOx-biocatalyzed oxidation of glucose yields H2O2, and the AChE/ChOx cascade leads to the formation of H2O2, the two biocatalytic processes could be probed by the cysteine-stimulated aggregation of the Au NPs. Since AChE is inhibited by 1,5-bis(4-allyldimethylammonium phenyl)pentane-3-one dibromide, the biocatalytic AChE/ChOx cascade is inhibited by the inhibitor, thus leading to the enhanced cysteine-mediated aggregation of the NPs. The results suggest the potential implementation of the cysteine-mediated aggregation of Au NPs in the presence of AChE/ChOx as a sensing platform for the optical detection of chemical warfare agents. PMID:23829431

  2. Hitching a ride on vesicles: cauliflower mosaic virus movement protein trafficking in the endomembrane system.

    PubMed

    Carluccio, Anna Vittoria; Zicca, Stefania; Stavolone, Livia

    2014-03-01

    The transport of a viral genome from cell to cell is enabled by movement proteins (MPs) targeting the cell periphery to mediate the gating of plasmodesmata. Given their essential role in the development of viral infection, understanding the regulation of MPs is of great importance. Here, we show that cauliflower mosaic virus (CaMV) MP contains three tyrosine-based sorting signals that interact with an Arabidopsis (Arabidopsis thaliana) μA-adaptin subunit. Fluorophore-tagged MP is incorporated into vesicles labeled with the endocytic tracer N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)pyridinium dibromide. The presence of at least one of the three endocytosis motifs is essential for internalization of the protein from the plasma membrane to early endosomes, for tubule formation, and for CaMV infection. In addition, we show that MP colocalizes in vesicles with the Rab GTPase AtRAB-F2b, which is resident in prevacuolar late endosomal compartments that deliver proteins to the vacuole for degradation. Altogether, these results demonstrate that CaMV MP traffics in the endocytic pathway and that virus viability depends on functional host endomembranes. PMID:24477592

  3. Validation of biological markers for quantitative risk assessment.

    PubMed Central

    Schulte, P; Mazzuckelli, L F

    1991-01-01

    The evaluation of biological markers is recognized as necessary to the future of toxicology, epidemiology, and quantitative risk assessment. For biological markers to become widely accepted, their validity must be ascertained. This paper explores the range of considerations that compose the concept of validity as it applies to the evaluation of biological markers. Three broad categories of validity (measurement, internal study, and external) are discussed in the context of evaluating data for use in quantitative risk assessment. Particular attention is given to the importance of measurement validity in the consideration of whether to use biological markers in epidemiologic studies. The concepts developed in this presentation are applied to examples derived from the occupational environment. In the first example, measurement of bromine release as a marker of ethylene dibromide toxicity is shown to be of limited use in constructing an accurate quantitative assessment of the risk of developing cancer as a result of long-term, low-level exposure. This example is compared to data obtained from studies of ethylene oxide, in which hemoglobin alkylation is shown to be a valid marker of both exposure and effect. PMID:2050067

  4. Application of SOS umu-test for the detection of genotoxic volatile chemicals and air pollutants

    SciTech Connect

    Ong, T.M.; Stewart, J.; Wen, Y.F.; Whong, W.Z.

    1987-01-01

    The SOS umu-test has been used for the detection of DNA-damaging agents. In this system the plasmid pSK1002 carrying a fused gene umuC-lacZ was introduced into Salmonella typhimurium TA1535. The SOS function induced by genotoxic agents is detected by a colorimetric measurement of beta-galactosidase activity encoded by the lacZ gene, which is regulated by the Umu operon. This system was used with modifications to study the SOS function inducibility of volatile chemicals (propylene oxide, methyl bromide, and ethylene dibromide) and air pollutants (diesel emission, welding fumes, and cigarette smoke). Tester cells were exposed directly to the test material. The enzyme activity of the treated cells was measured according to the established procedure. Results of the study showed that all chemicals and pollutants tested induced SOS function in a dose-related manner. These results indicate that the SOS umu-test is potentially useful for the in situ detection of genotoxic agents in occupational settings.

  5. Efficient gene transfection using novel cationic polymers poly(hydroxyalkylene imines).

    PubMed

    Zaliauskiene, Lolita; Bernadisiute, Ula; Vareikis, Ausvydas; Makuska, Ricardas; Volungeviciene, Ieva; Petuskaite, Agne; Riauba, Laurynas; Lagunavicius, Arunas; Zigmantas, Sarunas

    2010-09-15

    A series of novel cationic polymers poly(hydroxyalkylene imines) were synthesized and tested for their ability to transfect cells in vitro and in vivo. Poly(hydroxyalkylene imines), in particular, poly(2-hydroxypropylene imine) (pHP), poly(2-hydroxypropylene imine ethylene imine) (pHPE), and poly(hydroxypropylene imine propylene imine) (pHPP) were synthesized by polycondensation reaction from 1,3-diamino-2-propanol and the appropriate dibromide. Electron microscopic examination demonstrated that the resulting polymers condensed DNA into toroid shape complexes of 100-150 nm in size. Transfection studies showed that all three polymers were able to deliver genetic material into the cell, with pHP being superior to pHPP and pHPE. pHP acted as an efficient gene delivery agent in a variety of different cell lines and outcompeted most of the widely used polymer or lipid based transfection reagents. Intravenous administration of pHP-DNA polyplexes in mice followed by the reporter gene analysis showed that the reagent was suitable for in vivo applications. In summary, the results indicate that pHP is a new efficient reagent for gene delivery in vitro and in vivo. PMID:20695432

  6. Ranking the potential carcinogenic hazards to workers from exposures to chemicals that are tumorigenic in rodents

    SciTech Connect

    Gold, L.S.; Backman, G.M.; Hooper, N.K.; Peto, R.

    1987-12-01

    For 41 chemicals there exist both reasonable data on carcinogenic potency in experimental animals and also a defined Permissible Exposure Level (PEL), which is the upper limit of legally permissible chronic occupational exposure for US workers. These 41 agents are ranked by an index that compares the permitted chronic human exposure to the chronic dose rate that induces tumors in 50% of laboratory animals. This index, the Permitted Exposure/Rodent Potency index, or PERP, does not estimate absolute risks directly, but rather suggests the relative hazards that such substances may pose. The PERP values for these 41 substances differ by more than 100,000-fold from each other. The PERP does not take into account the actual level of exposure or the number of exposed workers. Nevertheless, it might be reasonable to give priority attention to the reduction of allowable worker exposures to substances that appear most hazardous by this index and that some workers may be exposed to full-time near the PEL. Ranked by PERP, these chemicals are: ethylene dibromide, ethylene dichloride, 1,3-butadiene, tetrachloroethylene, propylene oxide, chloroform, formaldehyde, methylene chloride, dioxane, and benzene.

  7. Utilization of water/alcohol-soluble polyelectrolyte as an electron injection layer for fabrication of high-efficiency multilayer saturated red-phosphorescence polymer light-emitting diodes by solution processing

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Liang, Bo; Huang, Fei; Peng, Junbiao; Cao, Yong

    2006-10-01

    Highly efficient multilayer red polymer light-emitting diodes were fabricated by solution process-ing from iridium complex, bis(1-(3-(9,9-dimethyl-fluorene-2-yl)phenyl)isoquinoline-C2,N ') iridium(III)acetylacetonate, doped into polyfluorene as a host and with a water/alcohol-soluble polymer, poly[(9,9-bis(3'-((N ,N-dimethyl)-N-ethylammonium)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)-4,7-(2,1,3-benzoselenadiazole)]dibromide (PFN) as electron injection layer. The device with the structure ITO /PEDOT-PSS(50nm)/PVK(40nm)/PFO:PBD:Ir(DMFPQ)2acac(2%,75nm)/PFN(20nm)/Ba(4.5nm)/Al(150nm) showed an external quantum efficiency of 18.0% and luminance efficiency of 9.8Cd/A at a current density of 1.1mA/cm2, a peak emission at λmax=636nm, and Commission International de I'Eclairage coordinates of (0.665, 0.319). The efficiency remained as high as QE =11.1%, and LE =6.0cd/A, at a current density of 100mA/cm2, and a luminance of 6140cd/m2.

  8. Opposing effects of oxidative challenge and carotenoids on antioxidant status and condition-dependent sexual signalling

    PubMed Central

    Tomášek, Oldřich; Gabrielová, Barbora; Kačer, Petr; Maršík, Petr; Svobodová, Jana; Syslová, Kamila; Vinkler, Michal; Albrecht, Tomáš

    2016-01-01

    Several recent hypotheses consider oxidative stress to be a primary constraint ensuring honesty of condition-dependent carotenoid-based signalling. The key testable difference between these hypotheses is the assumed importance of carotenoids for redox homeostasis, with carotenoids being either antioxidant, pro-oxidant or unimportant. We tested the role of carotenoids in redox balance and sexual signalling by exposing adult male zebra finches (Taeniopygia guttata) to oxidative challenge (diquat dibromide) and manipulating carotenoid intake. As the current controversy over the importance of carotenoids as antioxidants could stem from the hydrophilic basis of commonly-used antioxidant assays, we used the novel measure of in vivo lipophilic antioxidant capacity. Oxidative challenge reduced beak pigmentation but elicited an increase in antioxidant capacity suggesting resource reallocation from signalling to redox homeostasis. Carotenoids counteracted the effect of oxidative challenge on lipophilic (but not hydrophilic) antioxidant capacity, thereby supporting carotenoid antioxidant function in vivo. This is inconsistent with hypotheses proposing that signalling honesty is maintained through either ROS-induced carotenoid degradation or the pro-oxidant effect of high levels of carotenoid-cleavage products acting as a physiological handicap. Our data further suggest that assessment of lipophilic antioxidant capacity is necessary to fully understand the role of redox processes in ecology and evolution. PMID:27000655

  9. Electrochemistry and electrocatalysis with vitamin B sub 12 in an AOT water-in-oil microemulsion

    SciTech Connect

    Owlia, Azita; Wang, Zhenghao; Rusling, J.F. )

    1989-07-05

    Vitamin B{sub 12a} solubilized in water pools of highly resistive water-in-oil (w/o) microemulsions of 0.2 M Aerosol OT (AOT, bis(2-ethylhexyl) sulfosuccinate)/4 M water/isooctane gave separate reductions of base-on cob(III)alamine to base-on cob(II)alamine (E{sub 1/2} = {minus}0.03 V vs SCE) and base-on cob(II)alamine to base-off cob(I)alamine (E{sub 1/2} = {minus} 0.87 V). Diffusion coefficients suggested that vitamin B{sub 12} induces the formation of surfactant aggregates in w/o microemulsions that are larger than in solute-free systems. Relative reactivities toward reductions of three oil-soluble alkyl vicinal dihalides by electrochemically generated cob(I) alamine were modified in the microemulsion compared to isotropic water-acetonitrile. Changes in relative reactivity are not explained by simple partition of vicinal dibromides between isooctane and water and suggest specific interactions with surfactant aggregates or significant reaction in the bulk isooctane phase.

  10. Occupational cancer in Spain.

    PubMed Central

    González, C A; Agudo, A

    1999-01-01

    The knowledge of specific problems of occupational cancer in Spain is scarce. The environment of the workplace has improved over the last few years after a long period distinguished by bad working conditions, incomplete legislation, and insufficient safety measures and control. It has been estimated that 3,083,479 workers (25.4% of employees) were exposed to carcinogens. The most common occupational exposures to carcinogenic agents were solar radiation, environmental tobacco smoke, silica, and wood dust. The highest number of employees were exposed to silica crystalline (404,729), diesel engine exhaust (274,321), rubber products (99,804), benzene (89,932), ethylene dibromide (81,336), agents used in furniture and cabinet making (72,068), and formaldehyde (71,189). The percentage of total cancer deaths attributed to occupational exposure was 4% (6% in men, 0.9% in women). Compared with other European countries, the incidence of lung cancer and leukemia in Spain are one of the lowest, but it is rapidly increasing. The incidence of urinary bladder and larynx cancer, on the contrary, are one of the highest. Few studies on occupational cancer have been conducted in Spain. The main problems are the availability of death certificates and the quality of the information on occupation in mortality of statistics. It is necessary to improve methods of assessment of exposures using expert hygienists and biologic markers of exposure and diseases. Reduction of cancer by limiting or avoiding exposure to known occupational carcinogens is still necessary. PMID:10350510

  11. Effects and Carry-Over Benefits of Nematicides in Soil Planted to a Sweet Corn-Squash-Vetch Cropping System

    PubMed Central

    Johnson, A. W.; Leonard, R. A.

    1995-01-01

    The effects of irrigation on the efficacy of nematicides on Meloidogyne incognita race 1 population densities, yield of sweet corn, and the carry-over of nematicidal effect in the squash crop were determined in a sweet corn-squash-vetch cropping system for 3 years. Fenamiphos 15G and aldicarb 15G were applied at 6.7 kg a.i./ha and incorporated 15 cm deep with a tractor-mounted rototiller. Ethylene dibromide (EDB) was injected at 18 kg a.i./ha on each side of the sweet corn rows (total 36 kg a.i./ha) at planting for nematode control. Supplemental sprinkler irrigation (1.52-4.45 cm), applied in addition to natural rainfall (4.60-10.80 cm) within l0 days after application of nematicides, did not affect nematicide efficacy against M. incognita or yield of sweet corn. Soil treatment with fenamiphos, EDB, and aldicarb increased the number and total weight of sweet corn ears and the weight per ear each year over untreated controls (P ≤ 0.05). All nematicides provided some control of M. incognita on squash planted after sweet corn, but yields were consistently greater and root-gall indices lower on squash following sweet corn treated with fenamiphos than other nematicides. PMID:19277323

  12. Effects and carry-over benefits of nematicides in soil planted to a sweet corn-squash-vetch cropping system.

    PubMed

    Johnson, A W; Leonard, R A

    1995-12-01

    The effects of irrigation on the efficacy of nematicides on Meloidogyne incognita race 1 population densities, yield of sweet corn, and the carry-over of nematicidal effect in the squash crop were determined in a sweet corn-squash-vetch cropping system for 3 years. Fenamiphos 15G and aldicarb 15G were applied at 6.7 kg a.i./ha and incorporated 15 cm deep with a tractor-mounted rototiller. Ethylene dibromide (EDB) was injected at 18 kg a.i./ha on each side of the sweet corn rows (total 36 kg a.i./ha) at planting for nematode control. Supplemental sprinkler irrigation (1.52-4.45 cm), applied in addition to natural rainfall (4.60-10.80 cm) within l0 days after application of nematicides, did not affect nematicide efficacy against M. incognita or yield of sweet corn. Soil treatment with fenamiphos, EDB, and aldicarb increased the number and total weight of sweet corn ears and the weight per ear each year over untreated controls (P

  13. Hydroxyl radical substitution in halogenated carbonyls: oxalic acid formation.

    PubMed

    Christiansen, Carrie J; Dalal, Shakeel S; Francisco, Joseph S; Mebel, Alexander M; Gaffney, Jeffrey S

    2010-03-01

    An ab initio study of OH radical substitution reactions in halogenated carbonyls is conducted. Hydroxyl radical substitution into oxalyl dichloride [ClC(O)C(O)Cl] and oxalyl dibromide [BrC(O)C(O)Br], resulting in the formation of oxalic acid, is presented. Analogous substitution reactions in formyl chloride [ClCH(O)], acetyl chloride [ClC(O)CH(3)], formyl bromide [BrCH(O)], and acetyl bromide [BrC(O)CH(3)] are considered. Energetics of competing hydrogen abstraction reactions for all applicable species are computed for comparison. Geometry optimizations and frequency computations are performed using the second-order Møller-Plesset perturbation theory (MP2) and the 6-31G(d) basis set for all minimum species and transition states. Single point energy computations are performed using fourth-order Møller-Plesset perturbation theory (MP4) and coupled cluster theory [CCSD(T)]. Potential energy surfaces, including activation energies and enthalpies, are determined from the computations. These potential energy surfaces show that OH substitution into ClC(O)C(O)Cl and BrC(O)C(O)Br, resulting in the formation of oxalic acid and other minor products, is energetically favorable. Energetics of analogous reactions with ClCH(O), BrCH(O), ClC(O)CH(3), and BrC(O)CH(3) are also computed. PMID:20131850

  14. Reduction of 1,2-dibromoethane in the presence of zero-valent iron

    SciTech Connect

    Rajagopal, V.K.; Burris, D.R.

    1999-08-01

    The degradation reaction of 1,2-dibromoethane (ethylene dibromide or EDB) in water was studied in the presence of zero-valent iron (acid-cleaned, cast iron) in well-mixed batch aqueous systems. The observed products were ethylene and bromide ions. Carbon and bromine mass recoveries of >95% were obtained. Bromoethane and vinyl bromide were not observed. The reduction rates of bromoethane and vinyl bromide with iron indicate that they should have been observed if they were significant reaction intermediates for EDB. The results indicate that reductive {beta}-elimination may be the dominant reaction pathway. Reaction kinetics are rapid and pseudo-first order. The activation energy was determined to be 50 kJ/mol, indicating that the reaction rate may not be aqueous phase diffusion controlled but rather controlled by the chemical reaction rate on the iron surface. Metallic iron may be a suitable treatment approach for EDB-contaminated groundwater in above-ground, as well as in situ applications, due to rapid kinetics and nontoxic products.

  15. Manganese powder promoted highly efficient and selective synthesis of fullerene mono- and biscycloadducts at room temperature

    PubMed Central

    Si, Weili; Zhang, Xuan; Lu, Shirong; Yasuda, Takeshi; Asao, Naoki; Han, Liyuan; Yamamoto, Yoshinori; Jin, Tienan

    2015-01-01

    Discovery of an efficient, practical, and flexible synthetic method to produce various important electron acceptors for low-cost organic photovoltaics (OPVs) is highly desirable. Although the most commonly used acceptor materials, such as PC61BM, PC71BM, IC60BA, bisPC61BM have been proved to be promising for the OPVs, they are still very expensive mainly due to their low production yields and limited synthetic methods. Herein, we report an unprecedented and innovative synthetic method of a variety of fullerene mono- and biscycloadducts by using manganese powder as a promotor. The reaction of fullerenes with various dibromides proceeds efficiently and selectively under very mild conditions to give the corresponding cycloadducts in good to excellent yields. The combination of manganese power with DMSO additive is crucial for the successful implementation of the present cycloaddition. Notably, the standard OPV acceptors, such as PCBMs, have been obtained in extraordinarily high yields, which cannot be achieved under the previously reported methods. PMID:26349427

  16. Rayleigh, Ramsay, Rutherford and Raman--their connections with, and contributions to, the discovery of the Raman effect.

    PubMed

    Clark, Robin J H

    2013-02-21

    The key contributions of the four great Nobel Laureates - Lord Rayleigh, Sir William Ramsay, Lord Rutherford and Sir Chandrasekhara Raman - to the understanding of light scattering, to the identification and classification of the rare gases, and to the discovery in 1928 of the Raman effect are outlined. The interactions between these scientists are explored, in particular those of Rayleigh with Ramsay (in establishing the physics and chemistry of the rare gases), Ramsay with Rutherford (on studies of the radioactivity of radium dibromide and on the discovery of radon and its position in the periodic table), and Rutherford with Raman (in supporting Raman's career via the Royal Society and as a nominee for the Nobel Prize). The resilience and dedication of these scientific pioneers is emphasised, noting in particular that Rutherford and Raman emerged with success from unlikely backgrounds and from countries far removed from the then centres of scientific excellence. Key developments from 1928 onwards in the light sources used for the excitation of Raman spectra and in the detectors of Raman scattered radiation are outlined. Attention is drawn to the mounting number of scientific areas which continue to be opened up by Raman microscopy and many other derived techniques such as SERS, TERS, etc. PMID:23236600

  17. Protonation process of conjugated polyelectrolytes on enhanced power conversion efficiency in the inverted polymer solar cells

    NASA Astrophysics Data System (ADS)

    Yi, Chao; Hu, Rong; Ren, He; Hu, Xiaowen; Wang, Shu; Gong, Xiong; Cao, Yong

    2014-01-01

    In this study, two conjugated polyelectrolytes, polythiophene derivative (PTP) and poly[(9,9-bis [6‧-N, N, N-trimethylammonium] hexyl)-fluorenylene-phenylene] dibromide (PFP), are utilized to modify the surface properties of ZnO electron extraction layer (EEL) in the inverted polymer solar cells (PSCs). Both higher short-circuit current densities and larger open-circuit voltages were observed from the inverted PSCs with ZnO/PFP or ZnO/PTP as compared with those only with ZnO EEL. The protonation process for PTP and PFP in solution is distinguished. Overall, more than 40% enhanced power conversion efficiency (PCE) from the inverted PSCs with ZnO/PFP, in which the PFP could be fully ionized in deionized water, and more than 30% enhanced PCE from the inverted PSCs with ZnO/PTP, as the case that the PTP could not be fully ionized in deionized water, as compared with the inverted PSCs with ZnO EEL were observed, respectively. These results demonstrate that the conjugated polyelectrolytes play an important role in enhancement of device performance of inverted PSCs and that the protonation process of the conjugated polyelectrolytes is critical to the modification for EEL in PSCs.

  18. Hitching a Ride on Vesicles: Cauliflower Mosaic Virus Movement Protein Trafficking in the Endomembrane System1[W][OPEN

    PubMed Central

    Carluccio, Anna Vittoria; Zicca, Stefania; Stavolone, Livia

    2014-01-01

    The transport of a viral genome from cell to cell is enabled by movement proteins (MPs) targeting the cell periphery to mediate the gating of plasmodesmata. Given their essential role in the development of viral infection, understanding the regulation of MPs is of great importance. Here, we show that cauliflower mosaic virus (CaMV) MP contains three tyrosine-based sorting signals that interact with an Arabidopsis (Arabidopsis thaliana) μA-adaptin subunit. Fluorophore-tagged MP is incorporated into vesicles labeled with the endocytic tracer N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)pyridinium dibromide. The presence of at least one of the three endocytosis motifs is essential for internalization of the protein from the plasma membrane to early endosomes, for tubule formation, and for CaMV infection. In addition, we show that MP colocalizes in vesicles with the Rab GTPase AtRAB-F2b, which is resident in prevacuolar late endosomal compartments that deliver proteins to the vacuole for degradation. Altogether, these results demonstrate that CaMV MP traffics in the endocytic pathway and that virus viability depends on functional host endomembranes. PMID:24477592

  19. Dietary administration of diquat for 13 weeks does not result in a loss of dopaminergic neurons in the substantia nigra of C57BL/6J mice.

    PubMed

    Minnema, Daniel J; Travis, Kim Z; Breckenridge, Charles B; Sturgess, Nicholas C; Butt, Mark; Wolf, Jeffrey C; Zadory, Dan; Herberth, Mark T; Watson, Scott L; Cook, Andrew R; Botham, Philip A

    2016-03-01

    Male and female C57BL/6J mice were administered diquat dibromide (DQ∙Br2) in their diets at concentrations of 0 (control), 12.5 and 62.5 ppm for 13 weeks to assess the potential effects of DQ on the nigrostriatal dopaminergic system. Achieved dose levels at 62.5 ppm were 6.4 and 7.6 mg DQ (ion)/kg bw/day for males and females, respectively. A separate group of mice was administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) ip as a positive control. The comparative effects of DQ and MPTP on the substantia nigra pars compacta (SNpc) and/or striatum were assessed using neurochemical, neuropathological and stereological endpoints. Morphological and stereological assessments were performed by investigators who were "blinded" to dose group. DQ had no effect on striatal dopamine concentration or dopamine turnover. There was no evidence of neuronal degeneration, astrocytic or microglial activation, or a reduction in the number of tyrosine hydroxylase positive (TH(+)) neurons in the SNpc or neuronal processes in the striatum of DQ-treated mice. These results are consistent with the rapid clearance of DQ from the brain following a single dose of radiolabeled DQ. In contrast, MPTP-treated mice exhibited decreased striatal dopamine concentration, reduced numbers of TH(+) neurons in the SNpc, and neuropathological changes, including neuronal necrosis, as well as astrocytic and microglial activation in the striatum and SNpc. PMID:26683030

  20. The role of linear accelerators in industry

    NASA Astrophysics Data System (ADS)

    Sivinski, Jacek S.; Sloan, Daniel P.

    1985-05-01

    The short-term demand for ionizing energy will increase rapidly due to developing irradiation markets in sludge irradiation, medical product sterilization, biological toxic waste sterilization, exhaust gas treatment, and the much larger area of food disinfestation. Incentives for the increase are due not only to inherent positive characteristics of ionizing radiation, but to the worldwide concern and increased awareness of currently used fumigants, such as methyl bromide, ethylene dibromide, and ethylene oxide. Cobalt-60 is a gamma-emitting isotope, produced primarily by the Atomic Energy of Canada Limited, which can help satisfy these developing market demands. As an alternative to cobalt-60, the US Department of Energy is promoting cesium-137, a gamma emitter obtained from reprocessed nuclear waste. However, the supply of these two isotopes is limited and unable to meet the projected ionizing energy demands. Utilization of accelerator technology is therefore critical to the development of various product irradiation programs. It will not only meet the demand which is in excess of that covered by the isotopes, but it will also release the limited quantities of isotope for better use in roles for which they are especially suited. The accelerator and isotope roles in the irradiation markets need to be more finely focused in the future to benefit the growth of both systems.