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

  1. Volatilization of ethylene dibromide from water

    USGS Publications Warehouse

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

    1987-01-01

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

  2. Normal butane/iso-butane separation

    SciTech Connect

    Volles, W.K.; Cusher, N.A.

    1986-08-26

    This patent describes an improved pressure swing adsorption process for the separation of iso-butane from normal butane in an adsorption system having at least three adsorbent beds, each bed of which undergoes, on a cyclic basis and a processing sequence comprising: introducing a feed gas mixture of iso-butane and normal butane at an upper adsorption pressure to the feed end of the bed capable of selectively adsorbing normal butane as the more selectivity adsorbable component of the gas mixture. The iso-butane as the less readily adsorbable component passes through the bed and is discharged from the discharge end. The feed gas introduction is continued as a normal butane adsorption front is formed in the bed and passes through the bed from the feed end and breaks through at the discharge end of the bed, a portion of the iso-butane effluent stream thus discharged being diverted for passage as purge gas to another bed in the system; and countercurrently depressurizing the bed with release of gas from the feed end.

  3. Here's butane hydrates equilibria

    SciTech Connect

    Peettman, F.H.

    1984-06-01

    In 1961 McLeod and Campbell studied hydrates formation for binary mixtures of methane with ethane through butane at pressures up to 10,000 psia. Their data showed that butane lowered the pressure of hydrate formation for methane up to pressures ranging from 1,500 to 2,000 psia. At pressures above this range methane-n-butane mixtures generally followed the curve for pure methane or were slightly above it. McLeod and Campbell conclude that the crystal lattice is deformed at higher pressures (above 6,000 psia) and that hydrate composition on a water-free basis is the same as the gas.

  4. 76 FR 27317 - Ziram, Diquat Dibromide, and Chloropicrin; Order for Amendments To Terminate Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-11

    ... of receipt for this action was published for comment on December 1, 2010 (75 FR 74714) (FRL-8854-3......... Sorghum and soybean. Herbicide. 2749-530 Diquat Dibromide 37.3% Diquat Dibromide...... Sorghum and soybean (seed SL AG. crop only). 2749-531 Diquat Manufacturing Diquat Dibromide...... Sorghum and soybean...

  5. 40 CFR 80.82 - Butane blending.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... results demonstrate that the butane is 95% pure and has the following properties: olefins≤1.0 vol... results demonstrate the butane has the following properties: olefins≤10.0 vol% aromatics≤2.0 vol%...

  6. 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...

  7. 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...

  8. Cardiac arrest following butane inhalation

    PubMed Central

    Sen, Ahmet; Erdivanli, Basar

    2015-01-01

    Butane is a commonly misused volatile agent, and a cause of intoxication. We present a case, who had a syncope and persistent ventricular fibrillation during the course of resuscitation. We discussed the management of this case in the intensive care unit and the accompanying difficulties in the light of the current literature. PMID:26417144

  9. Cardiac arrest following butane inhalation.

    PubMed

    Sen, Ahmet; Erdivanli, Basar

    2015-01-01

    Butane is a commonly misused volatile agent, and a cause of intoxication. We present a case, who had a syncope and persistent ventricular fibrillation during the course of resuscitation. We discussed the management of this case in the intensive care unit and the accompanying difficulties in the light of the current literature. PMID:26417144

  10. Emissions with butane/propane blends

    SciTech Connect

    1996-11-01

    This article reports on various aspects of exhaust emissions from a light-duty car converted to operate on liquefied petroleum gas and equipped with an electrically heated catalyst. Butane and butane/propane blends have recently received attention as potentially useful alternative fuels. Butane has a road octane number of 92, a high blending vapor pressure, and has been used to upgrade octane levels of gasoline blends and improve winter cold starts. Due to reformulated gasoline requirements for fuel vapor pressure, however, industry has had to remove increasing amounts of butane form the gasoline pool. Paradoxically, butane is one of the cleanest burning components of gasoline.

  11. 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

  12. Quantitative determination of n-butane metabolites in three cases of butane sniffing death.

    PubMed

    Sasao, Ako; Yonemitsu, Kosei; Ohtsu, Yuki; Mishima, Satoko; Nishitani, Yoko

    2015-09-01

    Butane is an addictive volatile substance like toluene. We report three forensic autopsy cases of sudden death that occurred while sniffing n-butane and isobutane from portable gas cartridges. n-Butane and isobutane were detected in all three cases. In cases 1-3, n-butane concentrations in heart blood were 54.3, 25.5, and 30.7μg/mL, respectively. These concentrations were considered fatal according to the previous reports. In addition, n-butane metabolites (2-butanol and 2-butanone) were detected in cases 1 and 3 but not in case 2. Blood levels of 2-butanol and 2-butanone were 6.5 and 1.8μg/mL, respectively, in case 1, and 6.3 and 5.6μg/mL, respectively, in case 3. According to the police investigation, the decedent in case 1 had misused butane gas for more than 6 months in the period leading up to death. The decedent in case 3 also had a history of chronic misuse of butane gas. There was no history of chronic misuse of butane gas by the decedent in case 2. It was suspected that he attempted suicide via inhalation of butane gas using a plastic bag, leading to a rapid death. The presence or absence of n-butane metabolites might reflect the way of butane inhalation, such as the frequency and duration. Although additional experimental and case studies are necessary to establish the forensic applications of n-butane metabolite detection, it may be a useful method to understand the decedents' pattern of butane sniffing before death. PMID:26247128

  13. 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.

  14. 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.

  15. 75 FR 6658 - Malathion, Diquat Dibromide, Metam-potassium and Metam-sodium; Notice of Receipt of Requests to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

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

  16. Effects of the bipyridylium herbicides diquat dibromide and paraquat dichloride on growth and development of Neobellieria bullata (Diptera: Sarcophagidae) larvae.

    PubMed

    Darvas, B; Zdárek, J; Timár, T; el-Din, M H

    1990-12-01

    Diet containing diquat dibromide (1,000 or 2,000 ppm) caused an extension of the first-instar stadium of Neobellieria bullata (Parker); the first molt was primarily disturbed. Pupariation was delayed when early-wandering larvae had been injected with diquat dibromide (18 micrograms/larva; approximately to 150 ppm). This effect of diquat dibromide was eliminated by simultaneous injection of 20-OH ecdysone (0.02 micrograms/larva). After larvae in the red spiracle stage were injected with diquat dibromide (5 micrograms/larva; approximately 42 ppm), evagination of the pupal head was inhibited. Paraquat dichloride was less active than diquat dibromide and appears to be a safer herbicide for use around decomposer fly species.

  17. 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

  18. 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,...

  19. 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...

  20. Environmental chemistry of ethylene dibromide in soil and ground water.

    PubMed

    Pignatello, J J; Cohen, S Z

    1990-01-01

    Ethylene dibromide is a ground water pollutant principally as a result of its use as a soil pesticide and secondarily from spills or leaks of leaded gasoline in which it is an additive. The compound has been found in over 1900 wells in 4 countries: Japan, Israel, Australia, and the United States (10 states), typically at concentrations of 0.04-4 micrograms/L. The overall rate of detections in suspected areas is about 13%. Its use as a soil fumigant was banned in the US in 1983 because of its carcinogenicity. Concern over gasoline as a source should diminish as leaded fuels all but disappear from the market in many countries. The voluminous research and regulatory attention devoted to EDB has generated a picture, if not an entirely clear one, of how EDB behaves in the environment and what we can expect for the future. EDB is volatile, moderately water soluble, and has only weak equilibrium sorptive affinity for soil. Transport to ground water occurs by both vapor-phase diffusion and by advection with infiltrating water, depending on soil properties and precipitation and irrigation patterns. Models describing these processes have been developed and validated in part by laboratory experiments, but the complexity and heterogeneity of the field makes predictions difficult there. As with other pesticides, experience indicates that areas with permeable soils and shallow water tables are most vulnerable. However, EDB seems to have penetrated many tens of meters of unsaturated zone in some cases to reach the water table. Transport in ground water occurs with bulk water flow, subject to hydrodynamic dispersion effects common to all solutes, and subject to sorptive retardation. From equilibrium sorption partition coefficients, plume migration is likely to be a factor of 2-4 slower than bulk water flow. Hydrolysis is the most important abiotic reaction. The reaction is independent of pH in the range 4-9 and is probably uncatalyzed by particle surfaces. Both SN1 and SN2

  1. New butane isomerization unit is unvieled by Andrews Petroleum

    SciTech Connect

    McWilliams, H.

    1990-06-01

    This article discusses the development of a butane isomerization unit which will help reduce butane surplus by fractionating it into other LPG products. Other features of this California project increase on-site storage.

  2. 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.

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

    PubMed

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

    2016-01-01

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

  4. 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...

  5. 40 CFR 80.835 - What requirements apply to butane blenders?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 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...

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

    NASA Astrophysics Data System (ADS)

    Hamidi, Nurkholis; Wijayanti, Widya; Widhiyanuriyawan, Denny

    2016-03-01

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

  7. 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.

  8. Synthesis, growth and characterization of a novel semiorganic NLO crystal: Triglycine calcium dibromide

    NASA Astrophysics Data System (ADS)

    Esthaku Peter, M.; Ramasamy, P.

    2010-06-01

    Triglycine calcium dibromide, a new semiorganic nonlinear optical material, has been grown by slow solvent evaporation technique for the first time. The size of the grown crystal is up to the dimension of 20×12×4 mm 3. They were characterized by single crystal X-ray diffraction for confirming the coordination formed and FTIR spectral analysis for identifying the functional groups present in the compound. Optical behavior such as UV-vis-NIR transmission spectrum and second-harmonic generation were investigated to explore the NLO characteristics of the material. Thermal analysis was carried out to determine the melting point and the thermal stability of the grown crystal. Dielectric constant and dielectric loss measurements were carried out at different temperatures and frequencies. Mechanical studies were carried out on the as-grown crystal to find Vicker's microhardness and yield strength. Laser damage threshold studies were also performed on the as-grown crystal.

  9. 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

  10. 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.

  11. Association of ethylene dibromide (EDB) with mature cranberry (Vaccinium macrocarpon) fruit.

    PubMed

    Xia, K; Rice, C W

    2001-03-01

    Ethylene dibromide (EDB), a potential carcinogen, has been used in gasoline mixtures to avoid the accumulation of metallic lead in engines. Ethylene dibromide is present in the environment and in groundwater. Previous analysis has shown that EDB levels have reached up to 16 microg L-1 in the groundwater at two fuel spill plumes in the vicinity of the Massachusetts Military Reservation (MMR) Base and up to 1.69 microg L-1 in the Coonamessett and Quashnet Rivers in Cape Cod, MA (U.S. Air Force IRP, Fact Sheet #98-10, 1998). Groundwater and river water from this area are used to flood some local cranberry bogs for irrigation and harvesting of cranberry fruits. The potential sorption of EDB by cranberry fruits during harvest has caused concern but information regarding its occurrence is not available. In this study, low levels of EDB (0.04-0.15 microg kg-1) were found to be associated with cranberry fruits that were exposed to EDB at levels ranging from 3 to 12 microg L-1 at 10, 20, and 30 degrees C for up to 7 days. Rinsing EDB-exposed cranberry fruits twice with deionized water or once with 0.01 M NaCl solution reduced the amount of EDB associated with the cranberry fruits by 65-72% to a level of 0.02 microg kg-1. Therefore, the EDB most likely is associated with the water residue on the surface of the cranberry fruit rather than being absorbed into the flesh of the fruit during the EDB exposure.

  12. Magnesium molybdate catalyst for oxidation of butane

    SciTech Connect

    Khazai, B.; Vrieland, G.E.; Murchison, C.B.

    1993-12-31

    Magnesia supported molybdenum oxide has been shown to exhibit catalytic activity in the partial oxidation of butane to 1,3-butadiene. This reaction is carried out in the absence of gaseous oxygen and the catalyst is regenerated by contacting with air in a separate step. The authors have been investigating the use of transport bed technology for this reaction as the relatively short time intervals involved between regenerations (order of seconds) require rapid cycling of the reaction/reoxidation steps for a continuous process. To meet the attrition criteria the authors have developed a multiphase catalyst system based on a dispersion of molybdenum oxide on a magnesia/magnesium aluminate substrate. Hardness is provided by a gamma alumina matrix which displays Davison attrition numbers of 1-5. The catalyst which shows conversions of 35-40% and selectivities to C4 olefins of approximately 80% in a pulsed reactor has been characterized by a variety of techniques. This paper will present data on the catalyst properties and will discuss phase development during synthesis.

  13. 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.)

  14. 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.

  15. Butane extraction of model organic pollutants from water.

    PubMed

    Yang, Chun; Teo, Khay Chuan; Xu, Yan Rong

    2004-04-30

    In this study, n-butane (n-C(4)H(10)), a by-product of the oil refining process, was used as the extractant to remove various model organic pollutants including halogenated hydrocarbons, phenols and aromatic compounds from aqueous matrices. The presence of salt, inorganic acid and dissolved organic materials in the aqueous matrix were found to have little influence on the removal efficiency. High removal efficiencies are readily achievable for a great number of organic pollutants. The removal efficiencies for hydrophobic pollutants were greater than 90% for a single stripping stage for pollutants with a distribution constants (K(D)) greater than 45 and for a n-butane to aqueous phase ratio of 1-5. Results were also reported for the removal of residual butane in treated effluent by combinations of depressurization, air stripping and elevating operating temperature.

  16. Gas phase infrared contour simulation of isolated CH stretches in butane-d 9

    NASA Astrophysics Data System (ADS)

    Van der Veken, B. J.; Odeurs, R. O.; Brown, A.; McKean, D. C.; Morrisson, A. R.

    1986-09-01

    n-Butane-d 9 was synthesized with the hydrogen atom located in one of the methyl groupings. Both CH stretches of the trans conformer and two of the three CH stretches of the gauche conformer were assigned to transitions observed in the gas phase infrared spectrum, using the harmonic rigid rotor approximation. The simulation lends support to the more recent literature values of the trans—gauche relative populations. The assignments agree with those obtained by other authors using different techniques, and, when compared to ν isCH values in propane, lead to γ substitution effects of methyl which are very small, except perhaps on the op *g (out-of-plane gauche) bond, where steric interaction is likely.

  17. 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.

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

    PubMed

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

    2016-09-20

    The present study investigated dual carbon-bromine isotope fractionation of the common groundwater contaminant ethylene dibromide (EDB) during chemical and biological transformations, including aerobic and anaerobic biodegradation, alkaline hydrolysis, Fenton-like degradation, debromination by Zn(0) and reduced corrinoids. Significantly different correlation of carbon and bromine isotope fractionation (ΛC/Br) was observed not only for the processes following different transformation pathways, but also for abiotic and biotic processes with, the presumed, same formal chemical degradation mechanism. The studied processes resulted in a wide range of ΛC/Br values: ΛC/Br = 30.1 was observed for hydrolysis of EDB in alkaline solution; ΛC/Br between 4.2 and 5.3 were determined for dibromoelimination pathway with reduced corrinoids and Zn(0) particles; EDB biodegradation by Ancylobacter aquaticus and Sulfurospirillum multivorans resulted in ΛC/Br = 10.7 and 2.4, respectively; Fenton-like degradation resulted in carbon isotope fractionation only, leading to ΛC/Br ∞. Calculated carbon apparent kinetic isotope effects ((13)C-AKIE) fell with 1.005 to 1.035 within expected ranges according to the theoretical KIE, however, biotic transformations resulted in weaker carbon isotope effects than respective abiotic transformations. Relatively large bromine isotope effects with (81)Br-AKIE of 1.0012-1.002 and 1.0021-1.004 were observed for nucleophilic substitution and dibromoelimination, respectively, and reveal so far underestimated strong bromine isotope effects. PMID:27526716

  19. A physiologically-based pharmacokinetic(PB-PK) model for ethylene dibromide: relevance of extrahepatic metabolism.

    PubMed

    Hissink, A M; Wormhoudt, L W; Sherratt, P J; Hayes, J D; Commandeur, J N; Vermeulen, N P; van Bladeren, P J

    2000-08-01

    A physiologically-based pharmacokinetic (PB-PK) model was developed for ethylene dibromide (1,2-dibromoethane, EDB) for rats and humans, partly based on previously published in vitro data (Ploemen et al., 1997). In the present study, this PB-PK model has been validated for the rat. In addition, new data were used for the human class ThetaGST T1-1. Validation experiments are described in order to test the predictive value of kinetics to describe "whole-body" metabolism. For the validation experiments, groups of cannulated rats were dosed orally or intravenously with different doses of EDB. Obtained blood concentration-time curves of EDB for all dosing groups were compared to model predictions. It appeared that metabolism, which previously was assumed to be restricted to the liver, was underestimated. Therefore, we extended the PB-PK model to include all the extrahepatic organs, in which the enzymes involved in EDB metabolism have been detected and quantified. With this extended model, the blood concentrations were much more accurately described compared to the predictions of the "liver-model". Therefore, extrahepatic metabolism was also included in the human model. The present study illustrates the potential application of in vitro metabolic parameters in risk assessment, as well as the use of PB-PK modelling as a tool to understand and predict in vivo data.

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

    PubMed

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

    2016-09-20

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

  1. 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.

  2. Butane segregated by fluorides, olefins content at Texas terminals

    SciTech Connect

    Not Available

    1993-03-22

    Texas Eastern Products Pipeline Co., Houston (Teppco), this month has begun segregating butane streams at the company's Mont Belvieu and Baytown, Texas terminals according to fluoride and olefin contents. Streams containing fluoride or an olefin content greater than 1 ppm (or both) currently flow into Teppco's south Mont Belvieu terminal. Those fluoride-free streams with less than 1 ppm of olefins flow to its north Mont Belvieu terminal. Butane processed through an isomerization unit yields isobutane, a key component in MTBE. But high-fluoride butane from crude-oil refineries using hydrofluoric (HF) acid alkylation units cannot be used to produce MTBE because fluoride will damage isomerization units' process catalysts. Olefins also affect the efficiency of isomerization units, but less critically than fluorides. Their presence is higher in refinery product than in fractionated NGL. To extend the life of their process catalysts and to maximize yields, producers (including MTBE and isomerization unit operators) are specifying low-fluoride butanes developed from natural-gas fractionators or from refineries that do not use an HF process.

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

    USGS Publications Warehouse

    McConnell, J.B.

    1987-01-01

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

  4. 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).

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Improving fractionation lowers butane sulfur level at Saudi gas plant

    SciTech Connect

    Harruff, L.G.; Martinie, G.D.; Rahman, A.

    1998-10-12

    Increasing the debutanizer reflux/feed ratio to improve fractionation at an eastern Saudi Arabian NGL plant reduced high sulfur in the butane product. The sulfur resulted from dimethyl sulfide (DMS) contamination in the feed stream from an offshore crude-oil reservoir in the northern Arabian Gulf. The contamination is limited to two northeastern offshore gas-oil separation plants operated by Saudi Arabian Oil Co. (Saudi Aramco) and, therefore, cannot be transported to facilities outside the Eastern Province. Two technically acceptable solutions for removing this contaminant were investigated: 13X molecular-sieve adsorption of the DMS and increased fractionation efficiency. The latter would force DMS into the debutanizer bottoms.

  13. 40 CFR 721.1920 - 1,4-Bis(3-hydroxy-4-benzoylphenoxy)butane.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 1,4-Bis(3-hydroxy-4-benzoylphenoxy)butane. 721.1920 Section 721.1920 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.1920 1,4-Bis(3-hydroxy-4-benzoylphenoxy)butane. (a) Chemical...

  14. 40 CFR 721.1920 - 1,4-Bis(3-hydroxy-4-benzoylphenoxy)butane.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1,4-Bis(3-hydroxy-4-benzoylphenoxy)butane. 721.1920 Section 721.1920 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.1920 1,4-Bis(3-hydroxy-4-benzoylphenoxy)butane. (a) Chemical...

  15. Availability of Canadian imports to meet U.S. demand for ethane, propane and butane

    SciTech Connect

    Hawkins, D.J.

    1996-12-31

    Historically, Canada has had a surplus of ethane, propane and butane. Almost all of the available propane and butane in Canadian natural gas streams is recovered. While there is significant ethane recovery in Canada, ethane that cannot be economically sold is left in the gas streams. All of the surplus Canadian ethane and most of the Canadian surplus propane and butane is exported to the US. Some volumes of Canadian propane and butane have been moved offshore by marine exports to the Asia-Pacific region or South America, or directly to Mexico by rail. Essentially all of the Canadian ethane, 86% of the propane and 74% of the butane are recovered by gas processing. Canadian natural gas production has increased significantly over the last 10 years. Canadian gas resources in the Western Canadian Sedimentary Basin should permit further expansion of gas exports, and several gas pipeline projects are pending to expand the markets for Canadian gas in the US. The prospective increase in Canadian gas production will yield higher volumes of ethane, propane and butane. While there is a potential to expand domestic markets for ethane, propane and butane, a significant part of the incremental production will move to export markets. This paper provides a forecast of the expected level of ethane, propane and butane exports from Canada and discusses the supply, demand and logistical developments which may affect export availability from Canada.

  16. Hydrate equilibria for binary and ternary mixtures of methane, propane, isobutane, and n-butane; Effect of salinity

    SciTech Connect

    Paranjpe, S.G. ); Kamath, V.A.; Patil, S.L. ); Godpole, S.P. )

    1989-11-01

    This paper provides new experimental data on the phase behavior of gas hydrates for several binary and ternary mixtures of methane, propane, isobutane, and n-butane. After the molecular Kihara parameters for n-butane in the thermodynamic model were tuned, the predictions were in good agreement with the experimental data. The role of n-butane formation is explained, and the effect of salinity on the phase behavior of binary mixtures of propane/n-butane is determined.

  17. 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.

  18. Infrared spectroscopy and phase behavior of n-butane aerosols and thin films at cryogenic temperatures.

    PubMed

    Lang, E Kathrin; Knox, Kerry J; Momose, Takamasa; Signorell, Ruth

    2013-11-21

    Spectroscopic studies of two phase transitions of solid n-butane aerosol droplets performed under conditions representative of those in the lower atmosphere of Titan are presented. Pure n-butane aerosols and mixed ensembles of n-butane/acetylene, n-butane/carbon dioxide and n-butane/water aerosols were generated in a bath gas cooling cell at 78 K and their phase transition dynamics monitored using infrared extinction spectroscopy. For pure n-butane aerosols the volume and surface nucleation constants were found to range from JV = 10(12) -10(14) cm(-3) s(-1) and JS = 10(13) -10(15) cm(-2) s(-1), respectively, for the first observed transition, and JV = 10(9) -10(11) cm(-3) s(-1) and JS = 10(11) -10(13) cm(-2) s(-1) for the second observed transition. The phases of the n-butane aerosols were determined by comparing their spectroscopic signatures with spectra collected from thin films of liquid and solid n-butane. The first observed transition was from an amorphous-annealed phase into the metastable crystalline phase II of n-butane. The second transition was from the metastable crystalline phase II into the crystalline phase III. The effect of the presence of a second aerosol substance (acetylene, carbon dioxide or water) was examined; while this accelerated the first phase transition, it did not directly influence the rate of the second phase transition. The kinetic studies might be important for the understanding of cloud formation on Titan, while the spectral data provided, which include the first reported spectrum of liquid n-butane close to the melting point, are expected to be of use for remote sensing applications. PMID:23668828

  19. Ethylene dibromide: biochemical effects and environmental concerns. January 1978-September 1988 (Citations from the Life Sciences Collection data base). Report for January 1978-September 1988

    SciTech Connect

    Not Available

    1988-10-01

    This 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. (This updated bibliography contains 193 citations, 51 of which are new entries to the previous edition.)

  20. Ionization of ethane, butane, and octane in strong laser fields

    SciTech Connect

    Palaniyappan, Sasi; Mitchell, Rob; Ekanayake, N.; Watts, A. M.; White, S. L.; Sauer, Rob; Howard, L. E.; Videtto, M.; Mancuso, C.; Wells, S. J.; Stanev, T.; Wen, B. L.; Decamp, M. F.; Walker, B. C.

    2010-10-15

    Strong-field photoionization of ethane, butane, and octane are reported at intensities from 10{sup 14} to 10{sup 17} W/cm{sup 2}. The molecular fragment ions, C{sup +} and C{sup 2+}, are created in an intensity window from 10{sup 14} to 10{sup 15} W/cm{sup 2} and have intensity-dependent yields similar to the molecular fragments C{sub m}H{sub n}{sup +} and C{sub m}H{sub n}{sup 2+}. In the case of C{sup +}, the yield is independent of the molecular parent chain length. The ionization of more tightly bound valence electrons in carbon (C{sup 3+} and C{sup 4+}) has at least two contributing mechanisms, one influenced by the parent molecule size and one resulting from the tunneling ionization of the carbon ion.

  1. Laboratory studies of butane nucleation on organic haze particles: application to Titan's clouds.

    PubMed

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

    2005-02-24

    Titan, Saturn's largest satellite, has a thick nitrogen/methane atmosphere with various hydrocarbons present in minor amounts. Recent observations suggest that CH4 may condense to form clouds near the moon's tropopause. Titan's methane cloud formation is probably triggered by a sequential nucleation of hydrocarbons onto Titan's haze material as tropospheric convection occurs due to differential heating of the surface or as the haze settles through the lower stratosphere. To better constrain Titan's cloud formation mechanism, investigations of the nucleation of several hydrocarbons will be necessary. Butane was chosen for this study because it has a relatively high freezing point and is estimated to be present at 200 part per billion levels. If this amount of butane were to condense on each haze particle, a visible cloud would be observed. Laboratory measurements at T = 125 K were performed to determine the relative ease of solid butane nucleation onto laboratory-produced tholin particles having an elemental composition of C5H5N, and solid films of hexane and acetonitrile. We find that butane nucleation onto the haze particles requires a relatively high saturation ratio of S > 1.30. Because butane nucleation is difficult, it may occur on only a very small subset of the total haze particles available. Such selective nucleation of butane would lead to those particles becoming coated with significant amounts of butane. Requiring a high saturation ratio for butane nucleation will reduce the optical depth of butane clouds by a factor of 100 because the particles will be fewer in number for a given condensed mass.

  2. 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.

  3. Metabolism of the soil and groundwater contaminants, ethylene dibromide and trichloroethylene, by the tropical leguminous tree, Leuceana leucocephala.

    PubMed

    Doty, Sharon Lafferty; Shang, Tanya Qing; Wilson, Angela M; Moore, Allison Leigh; Newman, Lee A; Strand, Stuart Edward; Gordon, Milton Paul

    2003-01-01

    Ethylene dibromide (EDB; dibromoethane) and trichloroethylene (TCE) are hazardous environmental pollutants. The use of plants to treat polluted sites and groundwater, termed phytoremediation, requires plants that can both effectively remove the pollutant as well as grow in the climatic region of the site. In this paper, we report that the tropical leguminous tree, Leuceana leucocephala var. K636, is able to take up and metabolize EDB and TCE. The plants were grown in sterile hydroponic solution without its symbiont, Rhizobium. EDB and TCE were both metabolized by the plant, as indicated by the formation of bromide ion from EDB and trichloroethanol from TCE. Each plant organ was independently capable of debromination of EDB. L. leucocephala is being used to treat perched groundwater as part of a remedial alternative to address an accidental EDB spill in Hawaii. Bromide levels of plant tissues from the trees grown in the phytoremediation treatment cells at the Hawaii Site were elevated, indicating uptake and degradation of brominated compounds in the trees. This report is the first evidence of a tropical tree effectively metabolizing these common organic pollutants.

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

    PubMed

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

    2011-01-01

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

  5. 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...

  6. Syntrophic Interactions Within a Butane-Oxidizing Bacterial Consortium Isolated from Puguang Gas Field in China.

    PubMed

    Zhang, Ying; Deng, Chun-Ping; Shen, Bin; Yang, Jin-Shui; Wang, En-Tao; Yuan, Hong-Li

    2016-10-01

    Butane oxidation by the hydrocarbon degradation bacteria has long been described, but little is known about the microbial interaction in this process. To investigate this interaction, the efficiency of butane oxidation was estimated in monocultures and co-cultures of six strains of butane-oxidizing bacteria (BOB) and a butanol-oxidizing strain. Results showed that the butane degradation velocity was at least 26 times higher in the co-culture of the seven strains (228.50 nmol h(-1)) than in the six individual monocultures (8.71 nmol h(-1)). Gas chromatographic analysis of metabolites in the cultures revealed the accumulation of butanol in the monocultures of BOB strains but not in the co-culture with the butanol-oxidizing strain. These results evidenced a novel syntrophic association between BOB and butanol-oxidizing bacteria in the butane oxidation. The BOB strains oxidized butane into butanol, but this activity was inhibited by the accumulated butanol in monocultures, whereas the removal of butanol by the butanol-oxidizing strain in co-culture could eliminate the suppression and improve the butane degradation efficiency. In the co-culture, both BOB and butanol-oxidizing bacteria could grow and the time needed for butane complete removal was shortened from more than 192 h to less than 4 h. The unsuppressed effect of the co-culture was also consistent with the results of reverse transcription quantitative real-time PCR (RT-qPCR) of bmoX gene because increased expression of this gene was detected during the syntrophic growth compared with that in monoculture, pointing to the upregulation of bmoX in the syntrophic interaction. PMID:27324653

  7. 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.

  8. 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.

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

    USGS Publications Warehouse

    McConnell, J.B.

    1988-01-01

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

  10. Low temperature n-butane oxidation skeletal mechanism, based on multilevel approach

    SciTech Connect

    Strelkova, M.I.; Sukhanov, L.P.; Kirillov, I.A.; Safonov, A.A.; Umanskiy, S.Ya.; Potapkin, B.V.; Pasman, H.J.; Tentner, A.M.

    2010-04-15

    In order to reconcile an increasingly large deviation (order of magnitude) of the ignition delay time at decreasing initial temperature, computed using the prior art kinetic schemes, with the available experimental values, a new skeletal mechanism (54 species, 94 reactions) for low-temperature (500-800 K) ignition of n- butane in air based on ab initio calculations is developed. The skeletal mechanism obtained accurately reproduces n-butane combustion kinetics for the practically important ranges of pressure, temperature and fuel-air equivalence ratio, especially in the low-temperature range. The elaborated first principal skeletal chemical kinetic mechanism of n-butane oxidation was validated against available experimental results for normal and elevated initial pressure (1-15 atm) using the Chemical Work Bench code. A good agreement with experiments was shown. (author)

  11. 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.

  12. Thermal diffusion and partial molar enthalpy variations of n-butane in silicalite-1.

    PubMed

    Inzoli, I; Simon, J M; Bedeaux, D; Kjelstrup, S

    2008-11-27

    We report for the first time the heat of transfer and the Soret coefficient for n-butane in silicalite-1. The heat of transfer was typically 10 kJ/mol. The Soret coefficient was typically 0.006 K(-1) at 360 K. Both varied with the temperature and the concentration. The thermal conductivity of the crystal with butane adsorbed was 1.46 +/- 0.07 W/m K. Literature values of the isosteric enthalpy of adsorption, the concentration at saturation, and the diffusion coefficients were reproduced. Nonequilibrium molecular dynamics simulations were used to find these results, and a modified heat-exchange algorithm, Soft-HEX, was developed for the purpose. Enthalpies of butane were also determined. We use these results to give numerical proof for a recently proposed relation, that the heat of transfer plus the partial molar enthalpy of butane is constant at a given temperature. The proof is offered for a regime where the partial molar enthalpy can be approximated by the molar internal energy. This result may add to the understanding of the sign of the Soret coefficient. The technical importance of the heat of transfer is discussed.

  13. Propane and butane emission sources to ambient air of Mexico City metropolitan area.

    PubMed

    Jaimes, L; Sandoval, J

    2002-04-22

    Samples of volatile organic compounds (VOCs) were collected in a smog chamber in order to determine whether automotive exhausts or LP Gas emissions play a greater role in the source of propane and butane, which affect ozone formation and other pollutants in the ambient air of the Mexico City metropolitan area (MCMA). These samples were collected in April 1995 during mornings and evenings. The testing methodology used for measuring exhaust emission were FTP or EPA-74 tests, and SHED type tests were also conducted in order to evaluate evaporative emissions. The finding from analysis of the VOCs collected in the morning demonstrate that in the atmosphere, propane concentrations are higher than that of butane but the reverse in evaporative and exhaust emissions, with the concentration of propane lower than that of butane. Our conclusion is that most of C3 and C4 in the ambient air comes from LP gas and not vehicle exhaust or evaporative emission, due to the higher levels of propane than butane in its formulation. The analysis of VOCs also indicates that although the conversion (in the smog chamber) of alkanes is low during the day, due to the high initial concentration, their contribution in the reaction mechanism to produce ozone can be appreciable.

  14. 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...

  15. 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...

  16. Selective oxidation of n-butane and butenes over vanadium-containing catalysts

    SciTech Connect

    Nieto, J.M.L.; Concepcion, P.; Dejoz, A.; Knoezinger, H.; Melo, F.; Vazquez, M.I.

    2000-01-01

    The oxidative dehydrogenation (OXDH) of n-butane, 1-butene, and trans-2-butene on different vanadia catalysts has been compared. MgO, alumina, and Mg-Al mixed oxides with Mg/(Al + Mg) ratios of 0.25 and 0.75 were used as supports. The catalytic data indicate that the higher the acid character of catalysts the lower is both the selectivity to C{sub 4}-olefins from n-butane and the selectivity to butadiene from both 1-butene or trans-2-butene. Thus, OXDH reactions are mainly observed from n-butane and butenes on basic catalysts. The different catalytic performance of both types of catalysts is a consequence of the isomerization of olefins on acid sites, which appears to be a competitive reaction with the selective way, i.e., the oxydehydrogenation process by a redox mechanism. Infrared spectroscopy data of 1-butene adsorbed on supported vanadium oxide catalysts suggest the presence of different adsorbed species. O-containing species (carbonyl and alkoxide species) are observed on catalysts with acid sites while adsorbed butadiene species are observed on catalysts with basic sites. According to these results a reaction network for the oxydehydrogenation of n-butane is proposed with parallel and consecutive reactions.

  17. 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.

  18. 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.

  19. Bubble point measurements of the system butane + octylbenzene in the temperature range 290--450 K

    SciTech Connect

    Leeuw, V.V. de; Poot, W.; Loos, T.W. de; Swaan Arons, J. de . Lab. of Applied Thermodynamics and Phase Equilibria)

    1994-01-01

    As a part of research on nitrogen displacement in light-oil reservoirs, the phase behavior of mixtures of a model oil and nitrogen is studied. The model oil consists of methane, butane, and tetradecane or octylbenzene. For reliable phase behavior calculations in the multicomponent system at reservoir conditions -- about 370 K and 50 MPa in the North Sea -- measurements are needed of at least the binary sub-systems in the temperature and pressure range of interest, in order to determine binary interaction coefficients. Bubble points of butane + octylbenzene at eight different mole fractions have been determined at 290--440 K using the synthetic method. The raw experimental data have been fitted using the Peng-Robinson and the Soave-Redlich-Kwong equations of state in combination with a number of different mixing rules.

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

    PubMed

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

    1989-12-01

    We reported 2 cases of patients who abused butane gas, toluene-based solvent and marihuana. They showed different signs in the each substance, respectively. Butane gas was easier to make visual hallucinations and distorted perception of body form, and was less potent and addictive than toluene-based solvent. Spontaneous laughter and the most amotivational state were characterized by marihuana intoxication. Alteration of auditory perception that simple music sounded wonderful was also experienced. Furthermore, the above symptoms were thought to change by the order of taking the substance. Therefore, it is needed to examine the order of the use of drugs and clarify differences of symptoms in abuse among drugs, respectively. PMID:2627172

  1. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  3. Aromatic and polycyclic aromatic hydrocarbon formation in a laminar premixed n-butane flame

    SciTech Connect

    Marinov, N.M.; Pitz, W.J.; Westbrook, C.K.; Vincitore, A.M.; Castaldi, M.J.; Senkan, S.M.; Melius, C.F.

    1998-07-01

    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 stabilized flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.6 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer technique. Measurements were made in the main reaction and post-reaction zones for a number of low molecular weight species, aliphatics, aromatics, and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-fused aromatic rings. Reaction flux and sensitivity analysis were used to help identify the important reaction sequences leading to aromatic and PAH growth and destruction in the n-butane flame. Reaction flux analysis showed the propargyl recombination reaction was the dominant pathway to benzene formation. The consumption of propargyl by H atoms was shown to limit propargyl, benzene, and naphthalene formation in flames as exhibited by the large negative sensitivity coefficients. Naphthalene and phenanthrene production was shown to be plausibly formed through reactions involving resonantly stabilized cyclopentadienyl and indenyl radicals. Many of the low molecular weight aliphatics, combustion by-products, aromatics, branched aromatics, and PAHs were fairly well simulated by the model. Additional work is required to understand the formation mechanisms of phenyl acetylene, pyrene, and fluoranthene in the n-butane flame. 73 refs.

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

    PubMed

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

    2015-04-21

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

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

    PubMed

    Saha, Rumpa; Ghosh, Aniruddha; Saha, Bidyut

    2014-04-24

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

  6. 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.

  7. Effect of Pt and H{sub 2} on n-butane isomerization over Fe and Mn promoted sulfated zirconia

    SciTech Connect

    Song, Xuemin; Reddy, K.R.; Sayari, A.

    1996-06-01

    The activity of a 0.4 wt% Pt-containing Fe and Mn promoted sulfated zirconia (PtSFMZ) catalyst in n-butane isomerization at 35{degrees}C was compared to that of a Pt-free catalyst (SFMZ). The maximum rate of n-butane conversion observed in helium over PtSFMZ was found to be 2.5 times higher than that over the SFMZ catalyst under the same conditions. It is believed that n-butane isomerization proceeds via a bimolecular mechanism in which the formation of hydrogen-deficient intermediates (carbenium ions and butenes), is necessary and the presence of transition metals such as Pt, Fe, and Mn on sulfated zirconia facilitates the formation/accumulation of these intermediates and increases their stability on the catalyst surface. The presence of H{sub 2} had a strong negative effect on n-butane conversion over PtSFMZ, but had no effect over SFMZ. The negative effect of H{sub 2} on PtSFMZ catalyst in n-butane isomerization reaction was attributed to the decreased concentration of butenes in the presence of hydrogen atoms which are formed by the dissociation of H{sub 2} on Pt. The ability of calcined Pt-containing catalysts to activate hydrogen at 35{degrees}C was demonstrated. Reduced SFMZ with or without Pt was not active at 35{degrees}C regardless of the nature of the carrier gas. 42 refs., 5 figs.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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)

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

    SciTech Connect

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

    1992-02-01

    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.

  17. 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

  18. 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

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

    PubMed

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

    1971-10-01

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

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

    SciTech Connect

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

    2012-01-01

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

  1. 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

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

    PubMed Central

    Gabriel, M. A.; Jabara, Haifa; Al-Khalidi, U. A. S.

    1971-01-01

    1. [14C]Acetoin was enzymically synthesized from [14C]pyruvate with a pyruvate decarboxylase preparation. Its optical activity was [α]20d−78°. 2. Large amounts (1000-fold higher than physiological concentrations) of acetoin were incubated with rat liver mince. Acetoin disappeared but very little 14CO2 was evolved. A compound accumulated, which was purified and identified as butane-2,3-diol. Chromatography on borate-impregnated paper indicated the presence of both the erythro and threo forms. 3. Liver extracts capable of interconverting biacetyl, acetoin and butane-2,3-diol were obtained. These interconversions were catalysed by two different enzymes: acetoin dehydrogenase (EC 1.1.1.5) and butane-2,3-diol dehydrogenase (EC 1.1.1.4), previously identified in bacteria. Both required NAD+ or NADP+ as cofactors and were different from alcohol dehydrogenase. The equilibrium in both cases favoured the more reduced compound. 4. The activity of butane-2,3-diol dehydrogenase was decreased by dialysis against EDTA: the addition of Co2+, Cu2+, Zn2+ and other bivalent metal ions restored activity. 5. Biacetyl reductase was resolved into multiple forms by CM-Sephadex chromatography and electrophoresis. PMID:4399820

  3. 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.

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

    PubMed

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

    2009-06-01

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

  5. Kinetic characterization of the soluble butane monooxygenase from Thauera butanivorans, formerly ‘Pseudomonas butanovora’

    PubMed Central

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

    2009-01-01

    Soluble butane monooxygenase (sBMO), a three-component di-iron monooxygenase complex expressed by the C2–C9 alkane-utilizing bacterium Thauera butanivorans, was kinetically characterized by measuring substrate specificities for C1–C5 alkanes and product inhibition profiles. sBMO has high sequence homology with soluble methane monooxygenase (sMMO) and shares a similar substrate range, including gaseous and liquid alkanes, aromatics, alkenes and halogenated xenobiotics. Results indicated that butane was the preferred substrate (defined by kcat : Km ratios). Relative rates of oxidation for C1–C5 alkanes differed minimally, implying that substrate specificity is heavily influenced by differences in substrate Km values. The low micromolar Km for linear C2–C5 alkanes and the millimolar Km for methane demonstrate that sBMO is two to three orders of magnitude more specific for physiologically relevant substrates of T. butanivorans. Methanol, the product of methane oxidation and also a substrate itself, was found to have similar Km and kcat values to those of methane. This inability to kinetically discriminate between the C1 alkane and C1 alcohol is observed as a steady-state concentration of methanol during the two-step oxidation of methane to formaldehyde by sBMO. Unlike methanol, alcohols with chain length C2–C5 do not compete effectively with their respective alkane substrates. Results from product inhibition experiments suggest that the geometry of the active site is optimized for linear molecules four to five carbons in length and is influenced by the regulatory protein component B (butane monooxygenase regulatory component; BMOB). The data suggest that alkane oxidation by sBMO is highly specialized for the turnover of C3–C5 alkanes and the release of their respective alcohol products. Additionally, sBMO is particularly efficient at preventing methane oxidation during growth on linear alkanes ≥C2, despite its high sequence homology with sMMO. These

  6. 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

  7. Three cases of sudden death due to butane or propane gas inhalation: analysis of tissues for gas components.

    PubMed

    Sugie, Hideaki; Sasaki, Chizuko; Hashimoto, Chikako; Takeshita, Hiroshi; Nagai, Tomonori; Nakamura, Shigeki; Furukawa, Masataka; Nishikawa, Takashi; Kurihara, Katsuyoshi

    2004-07-16

    We report three cases of sudden death due to inhalation of portable cooking stove fuel (case 1), cigarette lighter fuel (case 2), and liquefied petroleum gas (LPG) (case 3). Specimens of blood, urine, stomach contents, brain, heart, lung, liver, kidney, and fat were collected and analyzed for propylene, propane, isobutane, and n-butane by headspace gas chromatography. n-Butane was the major substance among the volatiles found in the tissues of cases 1 and 2, and propane was the major substance in case 3. A combination of the autopsy findings and the gas analysis results revealed that the cause of death was ventricular fibrillation induced by hard muscle exercise after gas inhalation in cases 1 and 2, and that the cause of death in case 3 might be hypoxia. It is possible that the victim in case 3 was under anesthetic toxicity of accumulated isobutane which is a minor component of liquefied petroleum gas.

  8. 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

  9. Synthesis and evaluation of inhaled [11C]butane and intravenously injected [11C]acetone as potential radiotracers for studying inhalant abuse.

    PubMed

    Gerasimov, Madina R; Ferrieri, Richard A; Pareto, Deborah; Logan, Jean; Alexoff, David; Ding, Yu-Shin

    2005-02-01

    The phenomenon of inhalant abuse is a growing problem in the US and many countries around the world. Yet, relatively little is known about the pharmacokinetic properties of inhalants that underlie their abuse potential. While the synthesis of 11C-labeled toluene, acetone and butane has been proposed in the literature, none of these compounds has been developed as radiotracers for PET studies. In the present report we extend our previous studies with [11C]toluene to include [11C]acetone and [11C]butane with the goal of comparing the pharmacokinetic profiles of these three volatile abused substances. Both [11C]toluene and [11C]acetone were administered intravenously and [11C]butane was administered via inhalation to anesthesized baboons. Rapid and efficient uptake of radiolabeled toluene and acetone into the brain was followed by fast clearance in the case of toluene and slower kinetics in the case of acetone. [11C]Butane was detected in the blood and brain following inhalation, but the levels of radioactivity in both tissues dropped to half of the maximal values over the period of less than a minute. To our knowledge, this is the first reported study of the in vivo brain pharmacokinetics of labeled acetone and butane in nonhuman primates. These data provide insight into the pharmacokinetic features possibly associated with the abuse liability of toluene, acetone and butane.

  10. 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.

  11. 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.

  12. Kinetic study of the oxidation of n-butane on vanadium oxide supported on Al/Mg mixed oxide

    SciTech Connect

    Dejoz, A.; Vazquez, I.; Nieto, J.M.L.; Melo, F.

    1997-07-01

    The reaction kinetics of the oxidative dehydrogenation (ODH) of n-butane over vanadia supported on a heat-treated Mg/Al hydrotalcite (37.3 wt % of V{sub 2}O{sub 5}) was investigated by both linear and nonlinear regression techniques. A reaction network including the formation of butenes (1-, 2-cis-, and 2-trans-butene), butadiene, and carbon oxides by parallel and consecutive reactions, at low and high n-butane conversions, has been proposed. Langmuir-Hinshelwood (LH) models can be used as suitable models which allows reproduction of the global kinetic behavior, although differences between oxydehydrogenation and deep oxidation reactions have been observed. Thus, the formation of oxydehydrogenation products can be described by a LH equation considering a dissociative adsorption of oxygen while the formation of carbon oxides is described by a LH equation with a nondissociative adsorption of oxygen. Two different mechanisms operate on the catalyst: (i) a redox mechanism responsible of the formation of olefins and diolefins and associated to vanadium species, which is initiated by a hydrogen abstraction; (ii) a radical mechanism responsible of the formation of carbon oxides from n-butane and butenes and associated to vanadium-free sites of the support. On the other hand, the selectivity to oxydehydrogenation products increases with the reaction temperature. This catalytic performance can be explained taking into account the low reducibility of V{sup 5+}-sites and the higher apparent activation energies of the oxydehydrogenation reactions with respect to deep oxidation reactions.

  13. Benchmarking Experimental and Computational Thermochemical Data: A Case Study of the Butane Conformers.

    PubMed

    Barna, Dóra; Nagy, Balázs; Csontos, József; Császár, Attila G; Tasi, Gyula

    2012-02-14

    Due to its crucial importance, numerous studies have been conducted to determine the enthalpy difference between the conformers of butane. However, it is shown here that the most reliable experimental values are biased due to the statistical model utilized during the evaluation of the raw experimental data. In this study, using the appropriate statistical model, both the experimental expectation values and the associated uncertainties are revised. For the 133-196 and 223-297 K temperature ranges, 668 ± 20 and 653 ± 125 cal mol(-1), respectively, are recommended as reference values. Furthermore, to show that present-day quantum chemistry is a favorable alternative to experimental techniques in the determination of enthalpy differences of conformers, a focal-point analysis, based on coupled-cluster electronic structure computations, has been performed that included contributions of up to perturbative quadruple excitations as well as small correction terms beyond the Born-Oppenheimer and nonrelativistic approximations. For the 133-196 and 223-297 K temperature ranges, in exceptional agreement with the corresponding revised experimental data, our computations yielded 668 ± 3 and 650 ± 6 cal mol(-1), respectively. The most reliable enthalpy difference values for 0 and 298.15 K are also provided by the computational approach, 680.9 ± 2.5 and 647.4 ± 7.0 cal mol(-1), respectively.

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

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

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

  15. 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

  16. 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+}).

  17. 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.

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

    PubMed

    Sironi, Luca; Amadasi, Alberto; Zoja, Riccardo

    2016-09-01

    The recreational use of inhalants is a fairly widespread habit among adolescents because of the ease of availability and methods of assumption. Their use is however not free of risks, both for direct toxicity on several target organs and for a mechanism of gas replacement with lack of oxygen. The first case concerns a 12-year-old boy who died suddenly after sniffing a mix of butane and propane contained in a can of air freshener. The second case concerns a 14-year-old boy who died by acute poisoning by the same mixture contained in a refill for lighters. High concentrations of the compounds were found in the tissues by analysis with gas chromatography-mass spectrometry. The compounds found in tissues and biological fluids were perfectly compatible with those contained in the containers used for the inhalation. The mechanisms of death were therefore assessed in a combination of the direct toxicity of the compound and oxygen replacement, thus highlighting the crucial help that toxicological analyses can provide in such cases. PMID:27282951

  19. A study of the kinetics and mechanism of the adsorption and anaerobic partial oxidation of n-butane over a vanadyl pyrophosphate catalyst

    SciTech Connect

    Sakakini, B.H.; Taufiq-Yap, Y.H.; Waugh, K.C.

    2000-01-25

    The interaction of n-butane with a ((VO){sub 2}P{sub 2}O{sub 7}) catalyst has been investigated by temperature-programmed desorption and anaerobic temperature-programmed reaction. n-Butane has been shown to adsorb on the (VO){sub 2}P{sub 2}O{sub 7} to as a butyl-hydroxyl pair. When adsorption is carried out at 223 K, upon temperature programming some of the butyl-hydroxyl species recombine resulting in butane desorption at 260 K. However, when adsorption is carried out at 423 K, the hydroxyl species of the butyl-hydroxyl pair migrate away from the butyl species during the adsorption, forming water which is detected in the gas phase. Butane therefore is not observed to desorb at 260 K after the authors lowered the temperature to 223 K under the butane/helium from the adsorption temperature of 423 K prior to temperature programming from that temperature to 1100 K under a helium stream. Anaerobic temperature-programmed oxidation of n-butane produces butene and butadiene at a peak maximum temperature of 1000 K; this is exactly the temperature at which, upon temperature programming, oxygen evolves from the lattice and desorbs as O{sub 2}. This, and the fact that the amount of oxygen desorbing from the (VO){sub 2}P{sub 2}O{sub 7} at {approximately}1000 K is the same as that required for the oxidation of the n-butane to butene and butadiene, strongly suggests (1) that lattice oxygen as it emerges at the surface is the selective oxidant and (2) that its appearance at the surface is the rate-determining step in the selective oxidation of n-butane. The surface of the (VO){sub 2}P{sub 2}O{sub 7} catalyst on which this selective oxidation takes place has had approximately two monolayers of oxygen removed from it by unselective oxidation of the n-butane to CO, CO{sub 2}, and H{sub 2}O between 550 and 950 K and has had approximately one monolayer of carbon deposited on it at {approximately}1000 K. It is apparent, therefore, that the original crystallography of the (VO){sub 2}P

  20. Ignition of ethane, propane, and butane in counterflow jets of cold fuel versus hot air under variable pressures

    SciTech Connect

    Fotache, C.G.; Wang, H.; Law, C.K.

    1999-06-01

    This study investigates experimentally the nonpremixed ignition of ethane, propane, n-butane, and isobutane in a configuration of opposed fuel versus heated air jets. For each of these fuels the authors explore the effects of inert dilution, system pressure, and flow strain rate, for fuel concentrations ranging between 3--100% by volume, pressures between 0.2 and 8 atm, and strain rates of 100--600 s{sup {minus}1}. Qualitatively, these fuels share a number of characteristics. First, flame ignition typically occurs after an interval of mild oxidation, characterized by minimal heat release, fuel conversion, and weak light emission. The temperature extent of this regime decreases with increasing the fuel concentration, the ambient pressure, or the flow residence time. Second, the response to strain rate, pressure, and fuel concentration is similar for all investigated fuels, in that the ignition temperatures monotonically decrease with increasing fuel content, decreasing flow strain, and increasing ambient pressure. The C{sub 4} alkanes, however, exhibit three distinct p-T ignition regimes, similar to the homogeneous explosion limits. Finally, at 1 atm, 100% fuel, and a fixed flow strain rate the ignition temperature increases in the order of ethane < propane < n-butane < i-butane. Numerical simulation was conducted for ethane ignition using detailed reaction kinetics and transport descriptions. The modeling results suggest that ignition for all fuels studied at pressures below 5 atm is initiated by fuel oxidation following the high-temperature mechanism of radical chain branching and with little contribution by low-to-intermediate temperature chemistry.

  1. Microbial oxidation of methane, ethane, propane, and butane in marine gas seeps

    NASA Astrophysics Data System (ADS)

    Kinnaman, F. S.; Valentine, D. L.; Tyler, S.

    2005-12-01

    The microbial consumption of methane (C1), ethane (C2), propane (C3) and n-butane (nC4) in marine gas seeps was investigated using a stable isotope approach. Sediment samples were collected from the shallow hydrocarbon seeps at Coal Oil Point, Santa Barbara, CA and were used to quantify the natural distributions of C1-C4 hydrocarbons (concentrations and 13C) and as inoculum for laboratory experiments designed to quantify stable isotope fractionation associated with microbial C1-C4 consumption. Stable carbon isotope analyses of C1-C4 dissolved in pore fluids display significant enrichments in the 13C content of C1-C4 compared to the seep gas, and are interpreted as an indication of microbial oxidation. Distributions of sulfate in the sediment pore fluids indicate significant advection of pore fluids into the sediments likely driven by bubble flux. The advective flux of seawater into the sediments presumably expands the oxic zone and creates a habitat suitable for the aerobic oxidation of C1-C4. The maximum extent of oxidation was observed at a distance of 4-8 cm from individual gas vents, and at a depth of 6-10cm. Laboratory incubations of seep sediment demonstrate microbial consumption of C1-C4 hydrocarbons. Carbon and hydrogen isotope fractionation factors (ɛc and ɛh) for the aerobic oxidation of C1-C4 were determined as follows: ɛc was -31.4‰ ±1.6 for C1, -8.8‰ ±1.8 for C2, -5.4‰ ±0.7 for C3, and -3.1‰ ±0.7 for nC4; ɛh was -201.9‰ ±33.7, -62.7‰ ±7.4 for C2, and -16.3‰ ±2.0 for C3. Preferential oxidation of higher molecular weight hydrocarbons was noted in mixed gas incubations, along with possible inhibition of methane oxidation by the presence of C2-C4 gases. Application of the isotopic enrichment factors to observed pore water values indicates that as much as 75% of the dissolved hydrocarbons are consumed in the sediment.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. [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

  7. Dynamics of Vapor Explosions: Rapid Evaporation and Instability of Butane Droplets Exploding at the Superheat Limit.

    NASA Astrophysics Data System (ADS)

    Shepherd, Joseph Emmett

    A preliminary experimental investigation of the vapor explosion of a single droplet ((TURN) 1 mm diameter) of liquid butane at the superheat limit has been completed. These experiments provided the first detailed look at rapid evaporation taking place under conditions such that departures from equilibrium, evaporative fluxes and fluid accelerations are orders of magnitude larger than observed under ordinary circumstances. Single short-exposure photographs and fast -response pressure measurements were used to obtain a description of the complete explosion process within a superheated drop immersed in a bubble-column apparatus. Emphasis was placed on the early (microsecond-time-scale) evaporative stage. Despite the apparant simplicity of the vapor explosion of a single superheated droplet, the present experiments revealed a wide range of phenomina of varying complexity occurring at different stages of the explosion. The explosion is initiated by the spontaneous formation within the drop of a single vapor bubble, which grows until the drop liquid is completely evaporated. The resulting vapor bubble undergoes volume oscillations and eventually breaks up via Taylor instability. Several new and unusual features of the early evaporative stage of the explosion have been observed, three of which are remarkably repeatable. First, photographs of the evaporative surface show a highly roughened and disturbed interface for most of the evaporative stage. At the earliest observed times (8 (mu)sec) the roughening appears to begin as a rather regular pattern on an otherwise spherical surface, suggestive of a fundamental instability due to evaporative mass flux. Second, due to the asymmetric location of the initial nucleus within the drop, a portion of the evaporating surface contacts the surrounding fluid first and becomes nonevaporating. As the bubble grows, a unique, axisymmetric structure of circumferential waves terminated by a spherical cap appears on this nonevaporating

  8. 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.

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

    ERIC Educational Resources Information Center

    Bodner, George M.; Magginnis, Lenard J.

    1985-01-01

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

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. Highly sensitive and fast detection of propane-butane using a 3 μm quantum cascade laser.

    PubMed

    Jágerská, Jana; Tuzson, Béla; Looser, Herbert; Bismuto, Alfredo; Faist, Jérôme; Prinz, Heino; Emmenegger, Lukas

    2013-07-01

    A mid-IR optical analyzer based on a 3 μm Fabry-Perot quantum cascade laser has been developed for ultrafast detection of aerosol propellants, such as propane and butane. Given the laser emission bandwidth of 35 cm(-1), the system is spectrally well-matched to the C-H vibrational band of hydrocarbons, it is insusceptible to water interference, and stable enough to operate without wavelength scanning. Thus, it offers both high sensitivity and speed, reaching 1 ppm precision within a measurement time of 10 ms. The performance of the instrument is evaluated with an industrial demonstrator for aerosol cans leak testing, confirming that, in compliance with international directives, it can detect leaks of 1.2×10(-4) slpm at a rate of 500 cans per minute.

  15. 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

  16. 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

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

    SciTech Connect

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

    1993-01-01

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

  18. 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

  19. Solvent vapor recovery by pressure swing adsorption. 3: Comparison of simulation with experiment for the butane-activated carbon system

    SciTech Connect

    Liu, J.; Holland, C.E.; Ritter, J.A.

    1999-06-01

    A fully predictive (no adjustable parameters), nonisothermal, multicomponent mathematical model was developed and used to simulate a pressure swing adsorption (PSA) process designed for the separation and recovery of concentrated butane vapor from nitrogen using BAX activated carbon. Nearly quantitative agreement with experiment was realized with this model over a wide range of process conditions, and for both the transient and periodic state process dynamics and the periodic state process performance. The model also verified some unique characteristics of this PSA process, and it revealed some of the subtleties associated with accurately simulating a PSA-solvent vapor recovery (SVR) process. These subtleties included the need to account for the adsorbate heat capacity and the temperature dependence of the gas-phase physical properties. No PSA models in the literature have included both of these features, which were critical to the accurate prediction of the heat effects in this PSA-SVR process.

  20. Density and virial coefficients of gaseous butane from 265 to 450 K at pressures to 3.3 MPa

    SciTech Connect

    Gupta, D.; Eubank, P.T.

    1997-09-01

    The Burnett-isochoric (B-I) method has been used to measure gas densities and virial coefficients for butane from 265 to 450 K. Two independent B-I runs were performed but both with a base isotherm of 450 K, which is well above the critical temperature of 425 K. Significant physical adsorption of butane molecules onto the highly-polished, stainless steel cell walls was found below 75 K in agreement with conclusions reached by Ewing and associates in comparing their sonic-velocity-based density virial coefficients with those from the P-V-T literature. The data below 375 K were then corrected for adsorption errors by previously published procedures developed by this laboratory for highly polar gases. Using statistical weighting of two B-I runs, recommended density second virial coefficients B(T) are reported from 265 to 450 K whereas third virial coefficients C(T) are reported only from 325 to 450 K as values below 325 K are too uncertain due to the vapor pressure dropping under 300 kPa. However, then the virial equation of state truncated after B(T) is sufficient to represent the gas densities. At the lower temperatures of this investigation, B(T) values lie between those from sonic velocities and the more negative values from the P-V-T literature, which are uncorrected for adsorption errors; the authors are closer to the values from sonic velocities and about 1/4 of the way between the two sets. At the higher temperatures, the authors agree very closely with the better P-V-T measurements whereas the sonic-velocity-based values become increasingly more negative.

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

    PubMed

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

    2011-11-01

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

  2. A novel two-dimensional CuSCN network templated by 2,2'-dimethyl-1,1'-(butane-1,4-diyl)bis(1H-imidazol-3-ium) cations.

    PubMed

    Liu, Shan-Shan; Yuan, Shuai; Lu, Hai-Feng; Xu, Meng-Zhen; Sun, Di

    2013-06-01

    The cation-templated self-assembly of 1,4-bis(2-methyl-1H-imidazol-1-yl)butane (bmimb) with CuSCN gives rise to a novel two-dimensional network, namely catena-poly[2,2'-dimethyl-1,1'-(butane-1,4-diyl)bis(1H-imidazol-3-ium) [tetra-μ2-thiocyanato-κ(4)S:S;κ(4)S:N-dicopper(I)

  3. 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.

  4. 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.

  5. Catalytic asymmetric synthesis of butane diacetal-protected (4S,5S)-dihydroxycyclohexen-1-one and use in natural product synthesis.

    PubMed

    Burns, David J; Hachisu, Shuji; O'Brien, Peter; Taylor, Richard J K

    2012-10-14

    Due to the lack of availability of unnatural (+)-quinic acid as a starting material, a 6-step synthesis of butane diacetal-protected (4S,5S)-dihydroxycyclohexen-1-one (formally derived from (+)-quinic acid) has been devised. The key catalytic asymmetric step involves a chiral Co-salen-catalysed epoxide ring-opening reaction. (4S,5S)-Dihydroxycyclohexen-1-one was utilised in the synthesis of two cyclohexenone natural products isolated from the mycelia of Lasiodiplodia theobromae. PMID:22930235

  6. Carbon and hydrogen stable isotope fractionation associated with the anaerobic degradation of propane and butane by marine sulfate-reducing bacteria.

    PubMed

    Jaekel, Ulrike; Vogt, Carsten; Fischer, Anko; Richnow, Hans-Hermann; Musat, Florin

    2014-01-01

    The anaerobic degradation of propane and butane is typically initiated by activation via addition to fumarate. Here we investigated the mechanism of activation under sulfate-reducing conditions by one pure culture (strain BuS5) and three enrichment cultures employing stable isotope analysis. Stable isotope fractionation was compared for cultures incubated with or without substrate diffusion limitation. Bulk enrichment factors were significantly higher in mixed vs. static incubations. Two dimensional factors, given by the correlation of stable isotope fractionation of both carbon and hydrogen at their reactive positions (Lambda reactive position, Λrp), were compared to analyse the activation mechanisms. A characteristic reactive position isotope fractionation pattern was observed, distinct from aerobic degradation. Λrp values ranged from 10.5 to 11.8 for propane and from 7.8 to 9.4 for butane. Incubations of strain BuS5 with deuterium-labelled n-alkanes indicated that butane was activated solely at the subterminal C atom. In contrast, propane was activated mainly at the subterminal C atom but also significantly at the terminal C atoms. A conservative estimate suggests that about 70% of the propane activation events occurred at the subterminal C atom and about 30% at the terminal C atoms.

  7. Initial activity of reduced chromia/alumina catalyst in n-butane dehydrogenation monitored by on-line FT-IR gas analysis

    SciTech Connect

    Hakuli, A. |; Kytoekivi, A.; Suntola, T.

    1996-06-01

    The initial activity of chromia/alumina catalyst (13 wt% Cr) in n-butane dehydrogenation was studied in a flow reactor at 853 K. The initial activity was determined by on-line FT-IR gas analysis, which enabled sampling of the gaseous product mixture at a time resolution of seconds. The catalysts were processed in repeated cycles of oxidation, reduction, and dehydrogenation using n-butane, methane, hydrogen, or carbon monoxide as reducing agents. With n-butane, methane, and hydrogen and dehydrogenation activity was associated with Cr{sup 3+} species apparently formed in the reduction of high-valence Cr species. The catalyst reduced with carbon monoxide at 853 K showed poor initial selectivity for butenes and, relative to the other catalysts. Simultaneous data relating the initial activity, coke content, and some of the physicochemical properties of the catalyst indicated that the surfaces of all catalysts were modified to some extent by the successive reaction cycles. 33 refs., 7 figs., 2 tabs.

  8. 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

  9. Role of metal-support interactions on the activity of Pt and Rh catalysts for reforming methane and butane.

    SciTech Connect

    Rossignol, C.; Krause, T.; Krumpelt, M.

    2002-01-11

    For residential fuel cell systems, reforming of natural gas is one option being considered for providing the H{sub 2} necessary for the fuel cell to operate. Industrially, natural gas is reformed using Ni-based catalysts supported on an alumina substrate, which has been modified to inhibit coke formation. At Argonne National Laboratory, we have developed a new family of catalysts derived from solid oxide fuel cell technology for reforming hydrocarbon fuels to generate H{sub 2}. These catalysts consist of a transition metal supported on an oxide-ion-conducting substrate, such as ceria, that has been doped with a small amount of a non-reducible element, such as gadolinium, samarium, or zirconium. Unlike alumina, the oxide-ion-conducting substrate has been shown to induce strong metal-support interactions. Metal-support interactions are known to play an important role in influencing the catalytic activity of many metals supported on oxide supports. Based on results from temperature-programmed reduction/oxidation and kinetic reaction studies, this paper discusses the role of the metal and the substrate in the metal-support interactions, and how these interactions influence the activity and the selectivity of the catalyst in reforming methane and butane to hydrogen for use in fuel cell power systems.

  10. Effects of butane-2,3-dione thiosemicarbazone oxime on testicular damage induced by cadmium in mice.

    PubMed

    de Freitas, Mayara Lutchemeyer; Dalmolin, Laíza; Oliveira, Lia Pavelacki; da Rosa Moreira, Laís; Roman, Silvane Souza; Soares, Félix Alexandre Antunes; Bresolin, Leandro; Duarte, Marta Maria Medeiros Frescura; Brandão, Ricardo

    2012-01-01

    Our group of studies investigated the action of butane-2,3-dione thiosemicarbazone oxime against the testicular damage caused by cadmium chloride (CdCl(2)) in mice. Mice received a single injection of CdCl(2 )(5 mg/kg, intraperitoneally) and, after thirty minutes, the oxime (10 mg/kg, subcutaneously) was administered. Twenty four hours after the last administration, the animals were killed by cervical dislocation and the testes and serum were removed for analysis. The parameters determined were δ-aminolevulinate dehydratase (δ-ALA-D), myeloperoxidase (MPO), glutathione-S-transferase (GST) and glutathione peroxidase (GPx) activities. The levels of thiobarbituric acid-reactive substances (TBARS), nonprotein thiols (NPSH), ascorbic acid, cadmium and testosterone were also determined. In addition, histological analysis and cytokines quantification (IL-1, IL-6, IL-10, TNF-α and IFN-γ) were performed. Our results demonstrated that the oxime was effective in restoring the inhibition in δ-ALA-D activity induced by CdCl(2). The activation of MPO and increase in IL-1, IL-6, TNF-α and IFN-γ levels induced by CdCl(2) were also reduced by oxime. IL-10, which was reduced by cadmium, was restored by oxime administration. In addition, the oxime was effective in restoring the increase in TBARS levels and the reduction on NPSH levels induced by CdCl(2). Our results demonstrated that oxime was effective in containing the histological alterations induced by CdCl(2). In addition, oxime was able to increase the testosterone levels, reduced by cadmium exposure. In conclusion, the oxime tested was effective in reducing the testicular damage induced by CdCl(2) in mice. The beneficial effects of this oxime are related to its antioxidant and anti-inflammatory action. PMID:23038000

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

    PubMed

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

    2016-04-13

    The effects of zeolite structure on the kinetics of n-butane monomolecular cracking and dehydrogenation are investigated for eight zeolites differing in the topology of channels and cages. Monte Carlo simulations are used to calculate enthalpy and entropy changes for adsorption (ΔHads-H+ and ΔSads-H+) of gas-phase alkanes onto Brønsted protons. These parameters are used to extract intrinsic activation enthalpies (ΔHint‡), entropies (ΔSint‡), and rate coefficients (kint) from measured data. As ΔSads-H+ decreases (i.e., as confinement increases), ΔHint‡ and ΔSint‡ for terminal cracking and dehydrogenation decrease for a given channel topology. These results, together with positive values observed for ΔSint‡, indicate that the transition states for these reactions resemble products. For central cracking (an earlier transition state), ΔHint‡ is relatively constant, while ΔSint‡ increases as ΔSads-H+ decreases because less entropy is lost upon protonation of the alkane. Concurrently, selectivities to terminal cracking and dehydrogenation decrease relative to central cracking because ΔSint‡ decreases for the former reactions. Depending on channel topology, changes in the measured rate coefficients (kapp) with confinement are driven by changes in kint or by changes in the adsorption equilibrium constant (Kads-H+). Values of ΔSint‡ and ΔHint‡ are positively correlated, consistent with weaker interactions between the zeolite and transition state and with the greater freedom of movement of product fragments within more spacious pores. These results differ from earlier reports that ΔHint‡ and ΔSint‡ are structure-insensitive and that kapp is dominated by Kads-H+. They also suggest that ΔSads-H+ is a meaningful descriptor of confinement for zeolites having similar channel topologies. PMID:26909765

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

    NASA Astrophysics Data System (ADS)

    Chin, Chih-Hao; Lee, Shih-Huang

    2012-01-01

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

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

    SciTech Connect

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

    2007-02-15

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

  14. 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).

  15. Volumetric Properties of the Mixture Butan-2-one C4H8O + C14H30 Tetradecane (VMSD1111, LB3218_V)

    NASA Astrophysics Data System (ADS)

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

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-2-one C4H8O + C14H30 Tetradecane (VMSD1111, LB3218_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  16. Volumetric Properties of the Mixture Butan-2-one C4H8O + C14H30 Tetradecane (VMSD1212, LB3212_V)

    NASA Astrophysics Data System (ADS)

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

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Butan-2-one C4H8O + C14H30 Tetradecane (VMSD1212, LB3212_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-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).

  18. 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.

  19. 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.

  20. 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).

  1. 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).

  2. 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.

  3. 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

  4. 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

  5. 75 FR 29435 - Diquat Dibromide; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... not limited to those engaged in the following activities: Crop production (NAICS code 111). Animal production (NAICS code 112). Food manufacturing (NAICS code 311). Pesticide manufacturing (NAICS code 32532...) 305-5805. II. Summary of Petitioned-For Tolerance In the Federal Register of February 4, 2010 (75...

  6. 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

  7. 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.

  8. (1-Ferrocenyl-4,4,4-trifluoro­butane-1,3-dionato-κ2 O,O)bis­(triphenyl­phosphane)copper(I)

    PubMed Central

    Rüffer, Tobias; Joubert, Chris C.; Buitendach, Blenerhassit E.; Swarts, Jannie C.; Jakob, Alexander; Lang, Heinrich

    2011-01-01

    In the title mononuclear coordination complex, [CuFe(C5H5)(C9H5F3O2)(C18H15P)2], the CuI ion is coordinated by the chelating β-diketonate 1-ferrocenyl-4,4,4-trifluoro­butane-1,3-dione ligand through two O atoms and the two datively bonded triphenyl­phosphane ligands resulting in a distorted tetra­hedral coordination sphere. The CuI ion, together with its chelating butane-1,3-dione group, is mutually coplanar [greatest displacement of an atom from this plane = 0.037 (1) Å], and the CuI ion lies slightly above [0.013 (1) Å] the plane. The overall geometry, including the bond distances and angles within the complex, corresponds to those of other reported copper(I) β-diketon­ates featuring organic groups at the β-diketonate ligand. PMID:21522889

  9. 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

  10. A Fatal Case of Acute Butane-Propane Poisoning in a Prisoner Under Psychiatric Treatment: Do These 2 Factors Have an Arrhythmogenic Interaction, Thus Increasing the Cardiovascular Risk Profile?

    PubMed

    Gioia, Sara; Lancia, Massimo; Bacci, Mauro; Suadoni, Fabio

    2015-12-01

    Sudden death due to inhalation of aliphatic hydrocarbons such as butane and propane is well described in the literature. The main mechanism involved is the induction of a fatal cardiac arrhythmia. This phenomenon is frequently associated with prisoners who accidentally die while sniffing these volatile substances with an abuse purpose. Furthermore, such prisoners are often under psychiatric treatment; specific drugs belonging to this pharmacological class lead to a drug-related QT interval prolongation, setting the stage for torsade de pointes. In this article, we present the case of a prisoner died after sniffing a butane-propane gas mixture from a prefilled camping stove gas canister. The man was under psychiatric drugs due to mental disorders. He was constantly subjected to electrocardiogram to monitor the QTc (corrected QT interval), which was 460 milliseconds long. Toxicological analysis on cadaveric samples was performed by means of gas chromatography (head space) and revealed the presence of butane and propane at low levels. The aim of this article was to discuss a possible arrhythmogenic interaction of QT interval prolongation induced by psychiatric drugs and butane-propane inhalations, increasing the cardiovascular risk profile. In other words, evidence may suggest that prisoners, under these circumstances, are more likely to experience cardiovascular adverse effects. We believe that this study underlines the need to take this hypothesis into account to reduce death risk in prison and any medical-related responsibilities. Further studies are needed to validate the hypothesis.

  11. A Fatal Case of Acute Butane-Propane Poisoning in a Prisoner Under Psychiatric Treatment: Do These 2 Factors Have an Arrhythmogenic Interaction, Thus Increasing the Cardiovascular Risk Profile?

    PubMed

    Gioia, Sara; Lancia, Massimo; Bacci, Mauro; Suadoni, Fabio

    2015-12-01

    Sudden death due to inhalation of aliphatic hydrocarbons such as butane and propane is well described in the literature. The main mechanism involved is the induction of a fatal cardiac arrhythmia. This phenomenon is frequently associated with prisoners who accidentally die while sniffing these volatile substances with an abuse purpose. Furthermore, such prisoners are often under psychiatric treatment; specific drugs belonging to this pharmacological class lead to a drug-related QT interval prolongation, setting the stage for torsade de pointes. In this article, we present the case of a prisoner died after sniffing a butane-propane gas mixture from a prefilled camping stove gas canister. The man was under psychiatric drugs due to mental disorders. He was constantly subjected to electrocardiogram to monitor the QTc (corrected QT interval), which was 460 milliseconds long. Toxicological analysis on cadaveric samples was performed by means of gas chromatography (head space) and revealed the presence of butane and propane at low levels. The aim of this article was to discuss a possible arrhythmogenic interaction of QT interval prolongation induced by psychiatric drugs and butane-propane inhalations, increasing the cardiovascular risk profile. In other words, evidence may suggest that prisoners, under these circumstances, are more likely to experience cardiovascular adverse effects. We believe that this study underlines the need to take this hypothesis into account to reduce death risk in prison and any medical-related responsibilities. Further studies are needed to validate the hypothesis. PMID:26332645

  12. 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.

  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. 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.

  15. 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.

  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. 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

  19. Experimental and modeling study of the oxidation of n-butane in a jet stirred reactor using cw-CRDS measurements.

    PubMed

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

    2013-12-01

    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 its 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 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) ↔ 2OH (+M) has been updated to the value recently proposed by Troe (Combust. Flame, 2011, 158, 594-601) and (b) a temperature dependent 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 the 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

  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. 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.

  2. Poly(vinyl) chloride membrane copper-selective electrode based on 1-phenyl-2-(2-hydroxyphenylhydrazo)butane-1,3-dione.

    PubMed

    Kopylovich, Maximilian N; Mahmudov, Kamran T; Pombeiro, Armando J L

    2011-02-28

    1-Phenyl-2-(2-hydroxyphenylhydrazo)butane-1,3-dione (H(2)L) was used as an effective ionophore for copper-selective poly(vinyl) chloride (PVC) membrane electrodes. Optimization of the composition of the membrane and of the conditions of the analysis was performed, and under the optimized conditions the electrode has a detection limit of 6.30×10(-7) M Cu(II) at pH 4.0 with response time 10s and displays a linear EMF versus log[Cu(2+)] response over the concentration range 2.0×10(-6) to 5.0×10(-3) M Cu(II) with a Nernstian slope of 28.80±0.11 mV/decade over the pH range of 3.0-8.0. The sensor is stable for 9 weeks and exhibits good selectivity with respect to alkali, alkali earth and transition metal ions (e.g. Na(+), K(+), Ba(2+), Ca(2+), Zn(2+), Cd(2+), Co(2+), Mn(2+), Ni(2+), Fe(2+), Al(3+)) in the 3.0-8.0 pH range. It was successfully applied for the direct determination of copper(II) in zinc, aluminum and nickel based alloys, in soils polluted by oil, and as an indicator electrode for potentiometric titration of copper ions with EDTA. PMID:21177026

  3. 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.

  4. Experimental and theoretical studies of (FT-IR, FT-Raman, UV-Visible and DFT) 4-(6-methoxynaphthalen-2-yl) butan-2-one.

    PubMed

    Govindasamy, P; Gunasekaran, S

    2015-01-01

    In this work, the vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 4000-50 cm(-1) and 4000-450 cm(-1) respectively for 4-(6-methoxynaphthalen-2-yl) butan-2-one (abbreviated as 4MNBO) molecule. Theoretical calculations were performed by density functional theory (DFT/B3LYP) method using 6-311G(d,p) and 6-311++G(d,p) basis sets. The difference between the observed and calculated wavenumber value of most of the fundamentals were very small. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The UV-Vis spectrum was recorded in the methanol solution. The energy, wavelength and oscillator's strength were calculated by Time Dependent Density Functional Theory (TD-DFT) and matched to the experimental findings. The intramolecular contacts have been interpreted using natural bond orbital (NBO) and natural localized molecular orbital (NLMO) analysis. Thermodynamic properties of 4MNBO at different temperature have been calculated. The molecular electrostatic potential surface (MESP) and Frontier molecular orbital's (FMO's) analysis were investigated using theoretical calculations.

  5. (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

  6. 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.

  7. 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

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

    PubMed

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

    2013-04-21

    We report the synthesis and characterization of new V2O5/Al2O3-MgO catalysts and their application in oxidative dehydrogenation and epoxidation reactions. The materials were prepared by wet impregnation under excess acid conditions. Anchoring of the desired species on the support occurs via an exchange reaction between the vanadium complex and surface hydroxyl groups. The IR and UV-Vis spectra of these catalysts indicate the presence of monomeric vanadium species at 5 wt% V2O5 loading, along with small amounts of polymeric species at 5 and 10 wt% V2O5 loadings. Electron paramagnetic resonance (EPR) spectroscopy reveals the presence of ferromagnetic VO(2+) dimers following calcination at 773 K. The catalysts were then tested in two reactions, namely the gas phase oxidative dehydrogenation of n-butane under flow conditions at 773 K and the liquid phase epoxidation of limonene with H2O2. The dehydrogenation reaction gave butenes and 1,3-butadiene in moderate selectivity at 8-10% conversion. The epoxidation of limonene was less successful, giving 50-70% selectivity to the 1,2-epoxide at 10-20% conversion. PMID:23426160

  9. 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.

  10. Bis(pyridine-κN)bis-[4,4,4-trifluoro-1-(4-fluoro-phen-yl)butane-1,3-dionato-κO,O']cobalt(II).

    PubMed

    Fan, Ling; Wang, Dunjia; Peng, Lihong; Ke, Xiaocui

    2008-01-16

    In the structure of the title compound, [Co(C(10)H(5)F(4)O(2))(2)(C(5)H(5)N)(2)], cobalt(II) forms a complex with two 4,4,4-trifluoro-1-(4-fluoro-phen-yl)butane-1,3-dionate anions and two pyridine mol-ecules in an octa-hedral coordination environment, where the two dionate ligands are in equatorial positions and the two pyridine mol-ecules in axial positions. The complex is located on a crystallographic inversion centre.

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

    PubMed

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

    2016-02-01

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

  12. 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

  13. Role of Conformational Structures and Torsional Anharmonicity in Controlling Chemical Reaction Rates and Relative Yields. Butanal + HO2 Reactions

    SciTech Connect

    Zheng, Jingjing; Seal, Prasenjit; Truhlar, Donald G.

    2012-09-24

    Aldehyde–radical reactions are important in atmospheric and combustion chemistry, and the reactions studied here also serve more generally to illustrate a fundamental aspect of chemical kinetics that has been relatively unexplored from a quantitative point of view, in particular the roles of multiple structures and torsional anharmonicity in determining the rate constants and branching ratios (product yields). We consider hydrogen abstraction from four carbon sites of butanal (carbonyl-C, a-C, b-C and g-C) by hydroperoxyl radical. We employed multi-structural variational transition state theory for studying the first three channels; this uses a multi-faceted dividing surface and allows us to include the contributions of multiple structures of both reacting species and transition states. Multiconfigurational Shepard interpolation (MCSI) was used to obtain the geometries and energies of the potential energy surface along the minimum-energy paths, with gradients and Hessians calculated by the M08-HX/maug-cc-pVTZ method. We find the numbers of structures obtained for the transition states are 46, 60, 72 and 76respectively for the H abstraction at the carbonyl C, the a position, the b position and the g position. Our results show that neglecting the factors arising from multiple structures and torsional anharmonicity would lead to errors at 300, 1000 and 2400 K of factors of 8, 11 and 10 for abstraction at the carbonyl-O, 2, 11 and 25 at the a-C position, 2, 23 and 47 at the b-C position, and 0.6, 8 and 18 at the g-C position. The errors would be even larger at high temperature for the reverse of the H abstraction at the b-C. Relative yields are changed as much as a factor of 7.0 at 200 K, a factor of 5.0 at 298 K, and a factor of 3.7 in the other direction at 2400 K. The strong dependence of the product ratios on the multi-structural anharmonicity factors shows that such factors play an important role in controlling branching ratios in reaction mechanism networks.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1991-07-01

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

  16. Maleic anhydride from normal butane

    SciTech Connect

    Cooley, S.D.; Doshi, B.

    1987-01-01

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

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

    PubMed

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

    2012-07-01

    Vanadium-magnesium oxide catalysts supported on nano-structured MgO and ZrO2 (Mg3(VO4)2/MgO/ZrO2) were prepared by a wet impregnation method with a variation of Mg:Zr ratio (8:1, 4:1, 2:1, and 1:1). For comparison, Mg3(VO4)2/MgO and Mg3(VO4)2/ZrO2 catalysts were also prepared by a wet impregnation method. The prepared catalysts were applied to the oxidative dehydrogenation of n-butane in a continuous flow fixed-bed reactor. Mg3(VO4)2/MgO/ZrO2 (Mg:Zr = 4:1, 2:1, and 1:1) and Mg3(VO4)2/ZrO2 catalysts showed a stable catalytic activity during the whole reaction time, while Mg3(VO4)2/MgO/ZrO2 (8:1) and Mg3(VO4)2/MgO catalysts experienced a severe catalyst deactivation. Deactivation of Mg3(VO4)2/MgO/ZrO2 (8:1) and Mg3(VO4)2/MgO catalysts was due to their low oxygen mobility. Effect of oxygen capacity (the amount of oxygen in the catalyst involved in the reaction) of the supported Mg3(V04)2 catalysts on the catalytic performance in the oxidative dehydrogenation of n-butane was investigated. Experimental results revealed that oxygen capacity of the catalyst was closely related to the catalytic activity in the oxidative dehydrogenation of n-butane. A large oxygen capacity of the catalyst was favorable for obtaining a high catalytic activity in this reaction. Among the catalysts tested, Mg3(VO4)2/MgO/ZrO2 (4:1) catalyst with the largest oxygen capacity showed the best catalytic performance. PMID:22966706

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

    SciTech Connect

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

    2014-03-07

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

  19. Oxidation of butane and butene on the (100) face of (VO) sub 2 P sub 2 O sub 7 : A dynamic view in terms of the crystallochemical model of active sites

    SciTech Connect

    Ziolkowski, J. ); Bordes, E.; Courtine, P. )

    1990-03-01

    The structure of the (100) face of (VO){sub 2}P{sub 2}O{sub 7} and its performance in the oxidation of n-butane and butenes to maleic anhydride have been analyzed in terms of the crystallochemical model of active sites (CMAS). Analysis involves the heats of adsorption of oxygen, hydrogen (as a component of OH), and water as well as the heats of their movement along the surface, which allows determination of the energetically easiest pathways of elementary steps and gives insight into the reaction dynamics. The catalyst (100) (VO){sub 2}P{sub 2}O{sub 7} is found to work in a surface-oxidized state, all cations being covered with oxygen. The active site for the direct oxidation of n-butane to maleic anhydride is found to be situated between four protruding, undersaturated oxygens (2 {times} V-O, 2 {times} P-O). The reaction is thought to be initiated by H bonding at both terminal carbons. The desorption of water and migration of surface oxygen (which produces the pairs of adjacent vacancies to be filled by O{sub 2} molecules) that constitute a substep of the concerted reoxidation seem to be rate determining. Oxidation of butenes on (100) (VO){sub 2}P{sub 2}O{sub 7} is thought to be initiated by adsorption of C{double bond}C over unsaturated oxygens. In view of the surface structure, this adsorption limits the number of active oxygens with which the hydrocarbon may interact and favors a mild and nonselective oxidation to epoxybutanes, crotonaldehyde, hydrofuran, furan, and acetaldehyde. Minor yields are expected due to difficult reoxidation and competitive adsorption. Theoretical predictions are shown to agree with experimental data.

  20. 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.

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

    PubMed

    Frenzel, Peter; Korb, Marcus; Lang, Heinrich

    2016-02-01

    The mol-ecular structure of the tetra-kis(tri-phenyl-phosphan-yl)disilver salt of butane-1,1,4,4-tetra-carb-oxy-lic acid, [Ag2(C8H8O8)(C18H15P)4]·3CH2Cl2, crystallizes with one and a half mol-ecules of di-chloro-methane in the asymmetric unit. The coordination complex exhibits an inversion centre through the central CH2-CH2 bond. The Ag(I) atom has a distorted trigonal-planar P2O coordination environment. The packing is characterized by inter-molecular T-shaped π-π inter-actions between the phenyl rings of the PPh3 substituents in neighbouring mol-ecules, forming a ladder-type superstructure parallel to [010]. These ladders are arranged in layers parallel to (101). Intra-molecular hydrogen bonds between the OH group and one O atom of the Ag-bonded carboxyl-ate group results in an asymmetric bidendate coordination of the carboxyl-ate moiety to the Ag(I) ion. PMID:26958391

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

    PubMed Central

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

    2015-01-01

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

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

    SciTech Connect

    Lobo Lapidus, R.; Gates, B

    2009-01-01

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

  4. (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

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

    NASA Astrophysics Data System (ADS)

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

    2010-09-01

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

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

    PubMed

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

    2010-09-01

    Cr(3+), ZrO(2+), HfO(2+) and UO(2)(2+) complexes of oxalohydrazide (H(2)L(1)) and oxalyl bis(diacetylmonoxime hydrazone) [its IUPAC name is oxalyl bis(3-hydroxyimino)butan-2-ylidene)oxalohydrazide] (H(4)L(2)) have been synthesized and characterized by partial elemental analysis, spectral (IR; electronic), thermal and magnetic measurements. [Cr(L(1))(H(2)O)(3)(Cl)].H(2)O, [ZrO(HL(1))(2)].C(2)H(5)OH, [UO(2)(L(1))(H(2)O)(2)] [ZrO(H(3)L(2))(Cl)](2).2H(2)O, [HfO(H(3)L(2))(Cl)](2).2H(2)O and [UO(2)(H(2)L(2))].2H(2)O have been suggested. H(2)L(1) behaves as a monobasic or dibasic bidentate ligand while H(4)L(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(2)L(1) and H(4)L(2) as well as their complexes revealed that direct contact of [ZrO(H(3)L(2))(Cl)](2).2H(2)O or [HfO(H(3)L(2))(Cl)](2).2H(2)O 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.

  7. Controlling the framework formation of silver(I) coordination polymers with 1,4-bis(phenylthio)butane by varying the solvents, metal-to-ligand ratio, and counteranions.

    PubMed

    Bu, Xian-He; Chen, Wei; Hou, Wen-Feng; Du, Miao; Zhang, Ruo-Hua; Brisse, Francois

    2002-07-01

    The reactions of 1,4-bis(phenylthio)butane (L) with Ag(I) salts in varied conditions (varying the solvents, metal-to-ligand ratios, and counteranions) lead to the formation of four new two-dimensional (2D) coordination polymers with different network structures: [Ag(2)L(3)(ClO(4))(2)](infinity) 1, [Ag(2)L(3)(ClO(4))(2) x CH(3)OH](infinity) 2, [[AgL(2)](ClO(4))](infinity) 3, and [AgLNO(3)](infinity) 4. All the structures were established by single-crystal X-ray diffraction analysis. Crystal data for 1: triclinic, P-1, a = 11.0253(9) A, b = 11.3455(9) A, c = 11.5231(9) A, alpha = 93.931(2) degrees, beta = 92.689(2) degrees, gamma = 112.9810(10) degrees, Z = 2. 2: triclinic, P-1, a = 11.9147(13) A, b = 16.1534(17) A, c = 16.2259(17) A, alpha = 74.977(2) degrees, beta = 69.030(2) degrees, gamma = 69.986(2) degrees, Z = 2. 3: triclinic, P-1, a = 12.1617(9) A, b = 12.5054(10) A, c = 13.1547(10) A, alpha = 64.3370(10) degrees, beta =85.938 (2) degrees, gamma = 69.3010(10) degrees, Z = 2. 4: monoclinic, P2(1)/c, a = 5.4032(17) A, b = 16.974(6) A, c = 19.489(6) A, beta = 94.234(6) degrees, Z = 4. In all four complexes, each Ag(I) center has a tetracoordination geometry, and the 2D networks consist of fused large macrometallacyclic ring systems. The "hexagonal" 42-membered rings, Ag(6)L(6), observed in 1 and 2 are nearly identical, which could be considered as unique examples of self-sustaining noninterpenetrated frameworks formed with flexible ligands. The repeating rectangular 28-membered macrometallacycle, Ag(4)L(4), is the basis for the network of 3, in which the perchlorate anions occupy the voids to prevent the ring from collapsing. In 4, columns of the fused rectangular 22-membered rings, Ag(4)L(2)(NO(3))(2), are cross-linked through the L ligands to form a unique 2D network consisting of two types of 22-membered repeating units.

  8. 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.

  9. 40 CFR 80.82 - Butane blending.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., 2005 through December 31, 2016; ≤10 ppm beginning January 1, 2017 and thereafter. (d) Non-commercial... properties: (1) Olefins ≤10.0 vol%. (2) Aromatics ≤2.0 vol%. (3) Benzene ≤0.03 vol%. (4) Sulfur ≤30 ppm beginning January 1, 2005 through December 31, 2016; ≤10 ppm beginning January 1, 2017 and thereafter....

  10. (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.

  11. DIVERSITY IN BUTANE MONOOXYGENASES AMONG BUTANE-GROWN BACTERIA. (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...

  12. 21 CFR 184.1165 - n-Butane and iso-butane.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ingredients are used in food with no limitations other than current good manufacturing practice. The affirmation of these ingredients as generally recognized as safe (GRAS) as direct human food ingredients is... ingredients are used in food at levels not to exceed current good manufacturing practice. (d) Prior...

  13. 21 CFR 184.1165 - n-Butane and iso-butane.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ingredients are used in food with no limitations other than current good manufacturing practice. The affirmation of these ingredients as generally recognized as safe (GRAS) as direct human food ingredients is... ingredients are used in food at levels not to exceed current good manufacturing practice. (d) Prior...

  14. 21 CFR 184.1165 - n-Butane and iso-butane.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... their intended use. (c) In accordance with § 184.1(b)(1), these ingredients are used in food with no... recognized as safe (GRAS) as direct human food ingredients is based upon the following current good... gases as defined in § 170.3(o)(25) of this chapter. (2) The ingredients are used in food at levels...

  15. 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

  16. 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

  17. Crystal structure of catena-poly[[[tri­aqua­strontium]-di-μ2-glycinato] dibromide

    PubMed Central

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

    2015-01-01

    In the title coordination polymer, {[Sr(C2H5NO2)2(H2O)3]Br2}n, the Sr2+ ion and one of the water mol­ecules are located on twofold rotation axes. The alkaline earth ion is nine-coordinated by three water O atoms and six O atoms of the carboxyl­ate groups of four glycine ligands, two in a chelating mode and two in a monodentate mode. The glycine mol­ecule exists in a zwitterionic form and bridges the cations into chains parallel to [001]. The Br− counter-anions are located between the chains. Inter­molecular hydrogen bonds are formed between the amino and carboxyl­ate groups of neighbouring glycine ligands, generating a head-to-tail sequence. Adjacent head-to-tail sequences are further inter­connected by inter­molecular N—H⋯Br hydrogen-bonding inter­actions into sheets parallel to (100). O—H⋯Br and O—H⋯O hydrogen bonds involving the coordinating water mol­ecules are also present, consolidating the three-dimensional hydrogen-bonding network. PMID:26279890

  18. 75 FR 17712 - Malathion and Diquat Dibromide; Cancellation Order for Amendments to Terminate Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-07

    ... Herbicide only) Soybean (seed crop only) 4787-46 Atrapa 8E Malathion Animal premise and barns used for dairy and livestock 67760-40 Fyfanon 57% EC Malathion Animal premise and barns used for dairy and livestock... Table 1 of this unit, in sequence by EPA company number. Table 2.--Registrants of Amended Products...

  19. 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}.

  20. Demonstration that 1-trans-epoxysuccinyl-L-leucylamido-(4-guanidino) butane (E-64) is one of the most effective low Mr inhibitors of trypsin-catalysed hydrolysis. Characterization by kinetic analysis and by energy minimization and molecular dynamics simulation of the E-64-beta-trypsin complex.

    PubMed Central

    Sreedharan, S K; Verma, C; Caves, L S; Brocklehurst, S M; Gharbia, S E; Shah, H N; Brocklehurst, K

    1996-01-01

    1-trans-Epoxysuccinyl-L-leucylamido(4-guanidino)butane (E-64) was shown to inhibit beta-trypsin by a reversible competitive mechanism; this contrasts with the widely held view that E-64 is a class-specific inhibitor of the cysteine proteinases and reports in the literature that it does not inhibit a number of other enzymes including, notably, trypsin. The K1, value (3 x 10(-5) M) determined by kinetic analysis of the hydrolysis of N alpha-benzoyl-L-arginine 4-nitroanilide in Tris/HCl buffer, pH 7.4, at 25 degrees C, I = 0.1, catalysed by beta-trypsin is comparable with those for the inhibition of trypsin by benzamidine and 4-aminobenzamidine, which are widely regarded as the most effective low Mr inhibitors of this enzyme. Computer modelling of the beta-trypsin-E64 adsorptive complex, by energy minimization, molecular dynamics simulation and Poisson-Boltzmann electrostatic-potential calculations, was used to define the probable binding mode of E-64; the ligand lies parallel to the active-centre cleft, anchored principally by the dominant electrostatic interaction of the guanidinium cation at one end of the E-64 molecule with the carboxylate anion of Asp-171 (beta-trypsin numbering from Ile-1) in the S1-subsite, and by the interaction of the carboxylate substituent on C-2 of the epoxide ring at the other end of the molecule with Lys-43; the epoxide ring of E-64 is remote from the catalytic site serine hydroxy group. The possibility that E-64 might bind to the cysteine proteinases clostripain (from Clostridium histolyticum) and alpha-gingivain (one of the extracellular enzymes from phyromonas gingivalis) in a manner analogous to that deduced for the beta-trypsin-E-64 complex is discussed. PMID:8670152

  1. Demonstration that 1-trans-epoxysuccinyl-L-leucylamido-(4-guanidino) butane (E-64) is one of the most effective low Mr inhibitors of trypsin-catalysed hydrolysis. Characterization by kinetic analysis and by energy minimization and molecular dynamics simulation of the E-64-beta-trypsin complex.

    PubMed

    Sreedharan, S K; Verma, C; Caves, L S; Brocklehurst, S M; Gharbia, S E; Shah, H N; Brocklehurst, K

    1996-06-15

    1-trans-Epoxysuccinyl-L-leucylamido(4-guanidino)butane (E-64) was shown to inhibit beta-trypsin by a reversible competitive mechanism; this contrasts with the widely held view that E-64 is a class-specific inhibitor of the cysteine proteinases and reports in the literature that it does not inhibit a number of other enzymes including, notably, trypsin. The K1, value (3 x 10(-5) M) determined by kinetic analysis of the hydrolysis of N alpha-benzoyl-L-arginine 4-nitroanilide in Tris/HCl buffer, pH 7.4, at 25 degrees C, I = 0.1, catalysed by beta-trypsin is comparable with those for the inhibition of trypsin by benzamidine and 4-aminobenzamidine, which are widely regarded as the most effective low Mr inhibitors of this enzyme. Computer modelling of the beta-trypsin-E64 adsorptive complex, by energy minimization, molecular dynamics simulation and Poisson-Boltzmann electrostatic-potential calculations, was used to define the probable binding mode of E-64; the ligand lies parallel to the active-centre cleft, anchored principally by the dominant electrostatic interaction of the guanidinium cation at one end of the E-64 molecule with the carboxylate anion of Asp-171 (beta-trypsin numbering from Ile-1) in the S1-subsite, and by the interaction of the carboxylate substituent on C-2 of the epoxide ring at the other end of the molecule with Lys-43; the epoxide ring of E-64 is remote from the catalytic site serine hydroxy group. The possibility that E-64 might bind to the cysteine proteinases clostripain (from Clostridium histolyticum) and alpha-gingivain (one of the extracellular enzymes from phyromonas gingivalis) in a manner analogous to that deduced for the beta-trypsin-E-64 complex is discussed. PMID:8670152

  2. Cis-[RuCl(BzCN)(N-N)(P-P)]PF6 complexes: Synthesis and in vitro antitumor activity: (BzCN=benzonitrile; N-N=2,2'-bipyridine; 1,10-phenanthroline; P-P=1,4-bis(diphenylphosphino) butane, 1,2-bis(diphenylphosphino)ethane, or 1,1'-(diphenylphosphino)ferrocene).

    PubMed

    Pereira, Flávia de C; Lima, Benedicto A V; de Lima, Aliny P; Pires, Wanessa C; Monteiro, Thallita; Magalhães, Lorena F; Costa, Wanderson; Graminha, Angélica E; Batista, Alzir A; Ellena, Javier; Siveira-Lacerda, Elisângela de P

    2015-08-01

    The motivation to use ruthenium complexes in cancer treatment has led our research group to synthesize complexes with this metal and test them against several types of tumor cells, yielding promising results. In this paper the results of biological tests, assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, were carried out on the complexes cis-[RuCl(BzCN)(bipy)(dppe)]PF6 (1), cis-[RuCl(BzCN)(bipy)(dppb)]PF6 (2), cis-[RuCl(BzCN)(bipy)(dppf)]PF6 (3) and cis-[RuCl(BzCN)(phen)(dppb)]PF6 (4) which are described [BzCN = b enzonitrile; bipy = 2,2'-bipyridine; phen = 1,10-phenanthroline; dppe = 1,2-bis(diphenylphosphino) ethane; dppb = 1,4-bis-(diphenylphosphino)butane; dppf = 1,1'-bis(diphenylphosphino)ferrocene]. The present study is focused on the cytotoxic activity of complexes (1)-(4) against four tumor cell lines and on the apoptosis and changes in the cell cycle and gene expression observed in the sarcoma 180 (S180) tumor cell line treated with complex (1). The results demonstrated that this complex inhibits S180 cell growth, with an IC50 of 17.02 ± 8.21 μM, while exhibiting lower cytotoxicity (IC50 = 53.73 ± 5.71 μM) towards lymphocytes (normal cells). Flow cytometry revealed that the complex inhibits the growth of tumor cells by inducing apoptosis as evidenced by an increase in the proportion of cells positive for annexin V staining and G0/G1 phase cell-cycle arrest. Further investigation showed that complex (1) induces a drop in the mitochondrial membrane potential and provokes a decrease in Bcl-2 protein expression and increase in caspase 3 activation, while the increased activation of caspase 8 caused a decrease in the gene expression in caspases 3 and 9. Increases in Tp53 and Bax expressions were also observed.

  3. 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.

  4. 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...

  5. Biodegradation of ethylene dibromide (1,2-dibromoethane [EDB]) in microcosms simulating in situ and biostimulated conditions.

    PubMed

    McKeever, Robert; Sheppard, Diane; Nüsslein, Klaus; Baek, Kyung-Hwa; Rieber, Khalil; Ergas, Sarina J; Forbes, Rose; Hilyard, Mark; Park, Chul

    2012-03-30

    Although 1,2-dibromoethane (EDB) is a common groundwater contaminant, there is the lack of knowledge surrounding EDB biodegradation, especially under aerobic conditions. We have performed an extensive microcosm study to investigate the biodegradation of EDB under simulated in situ and biostimulated conditions. The materials for soil microcosms were collected from an EDB-contaminated aquifer at the Massachusetts Military Reservation in Cape Cod, MA. This EDB plume has persisted for nearly 40 years in both aerobic and anaerobic EDB zones of the aquifer. Microcosms were constructed under environmentally relevant conditions (field EDB and DO concentrations; incubated at 12°C). The results showed that natural attenuation occurred under anaerobic conditions but not under aerobic conditions, explaining why aerobic EDB contamination is so persistent. EDB degradation rates were greater under biostimulated conditions for both the aerobic and anaerobic microcosms. Particularly for aerobic biostimulation, methane-amended microcosms degraded EDB, on average, at a first order rate eight times faster than unamended microcosms. The best performing replicate achieved an EDB degradation rate of 7.0 yr(-1) (half-life (t(1/2))=0.10 yr). Residual methane concentrations and the emergence of methanotrophic bacteria, measured by culture independent bacterial analysis, provided strong indications that EDB degradation in aerobic methane-amended microcosms occurred via cometabolic degradation. These results indicate the potential for enhanced natural attenuation of EDB and that methane could be considered co-substrate for EDB bioremediation for the EDB-contaminated groundwater in aerobic zone.

  6. Approach to vicinal t-Boc-amino dibromides via catalytic aminobromination of nitrostyrenes without using chromatography and recrystallization.

    PubMed

    Sun, Hao; Han, Jianlin; Kattamuri, Padmanabha V; Pan, Yi; Li, Guigen

    2013-02-01

    A 1.0 mol % amount of K(3)PO(4)·3H(2)O was found to catalyze aminohalogenation reaction of nitrostyrenes with N,N-dibromo-tert-butylcarbamate (t-Boc-NBr(2)) in a dichloroethane system. Good to excellent yields and complete regioselectivity have been achieved by taking advantage of the GAP workup without using traditional purification techniques such as column chromatography and recrystallization. Anew mechanism is proposed involving radical and ionic catalytic cycles and an intramolecular migration.

  7. Crystal structure of poly[[μ2-di­aqua-di­aqua-μ2-l-proline-κ2 O:O′-strontium] dibromide

    PubMed Central

    Sathiskumar, Selladurai; Balakrishnan, Thangavelu; Ramamurthi, Kandasamy; Thamotharan, Subbiah

    2015-01-01

    In the title coordination polymer, {[Sr(C5H9NO2)(H2O)4]Br2}n, the proline mol­ecule exists in a zwitterionic form with one of the ring C atoms disordered over two sites [site-occupancy factors = 0.57 (6):0.43 (6)]. The SrII ion is nine-coordinated by six water O atoms, two monodentate and two μ2-bridging, and three carboxyl­ate O atoms of the proline ligands, with two bridging [Sr—O range = 2.524 (4)–2.800 (5) Å]. In the crystal, there is no direct inter­action between the proline mol­ecules. However, the proline and water mol­ecules associate with the bromide counter-anions through a number of inter­molecular O—H⋯Br and N—H⋯Br hydrogen-bonding inter­actions, giving a three-dimensional supra­molecular structure. PMID:26594406

  8. Effect of Diquat (1,1′-Ethylene-2,2′-Dipyridylium Dibromide) on the Photosynthetic Growth of Rhodospirillum rubrum

    PubMed Central

    Kaneshiro, Tsuneo; Zweig, Gunter

    1965-01-01

    Diquat (2 × 10-4m) inhibited both aerobic and anaerobic growth of Rhodospirillum rubrum. With photosynthetic cultures, diquat affected the synthesis of bacteriochlorophyll more readily than cell mass (turbidity). Diquat retarded the synthesis of bacteriochlorophyll and some protein more readily than that of other cellular constituents such as ribonucleic acid, deoxyribonucleic acid, and cell mass. With cells deficient in phosphate, diquat inhibited the uptake-conversion of inorganic phosphate completely only when 3-(3,4-dichlorophenyl)-1,1′-dimethyl urea and ascorbate were also present. PMID:5866040

  9. (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

  10. 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.

  11. 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.

  12. CHLORINATED SOLVENT COMETABOLISM BY BUTANE-GROWN MIXED CULTURE. (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...

  13. DICHLOROETHYLENES AS SUBSTRATES AND INDUCERS OF BUTANE MONOOXYGENASE IN PSEUDOMONAS BUTANOVORA. (R828772)

    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...

  14. TCE DEGRADATION BY BUTANE-OXIDIZING BACTERIA CAUSES A SPECTRUM OF TOXIC EFFECTS. (R828772)

    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...

  15. 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

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

    PubMed

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

    1991-08-01

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

  17. 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.

  18. The separation process of methane-butane fraction from natural gas before transport

    NASA Astrophysics Data System (ADS)

    Galtseva, O. V.; Bordunov, S. V.

    2015-04-01

    A series of experiments of adsorption of vapor-air mixtures of some individual hydrocarbons on fibrous sorbents out of polyethylene and polypropylene is made. The calculated changes of concentrations of hydrocarbons in the vapor-air mixture base on experimental data. It is shown that concentration of hydrocarbons decreases after column by 1.4 times and that sorption capacity of fibers reaches 1 g of hydrocarbons on 1 g of a fibrous sorbent. This result was assumed as a basis of calculation of model of the separator for separation of hydrocarbons C1-4 from water and fractions C5-n, the degree of separation of the first stage gas of the Verkhne - Tarskoe's field was 98%.

  19. 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.

  20. 75 FR 60114 - Notice of Receipt of Requests for Amendments to Delete Uses in Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ... Ingredient Delete from Label 228-675 Nufarm Diquat SPC 2 L Diquat dibromide Soybeans and Sorghum Herbicide... Admiral Liquid Acid Blue 9 Fish Farms and Fish Hatcheries 82633-2 Sharda Diquat Diquat dibromide Sorghum (seed crop Concentrate only) and Soybean (seed crop only) 83529-13 Diquash Ag Diquat dibromide...

  1. Cationic lipid membranes—specific interactions with counter-ions

    NASA Astrophysics Data System (ADS)

    Ryhänen, Samppa J.; Säily, V. Matti J.; Kinnunen, Paavo K. J.

    2006-07-01

    Lipids bearing net electric charges in their hydrophilic headgroups are ubiquitous in biological membranes. Recently, the interest in cationic lipids has surged because of their potential as non-viral transfection vectors. In order to utilize cationic lipids in transfer of nucleic acids and to elucidate the role of charged lipids in cellular membranes in general, their complex interactions within the membrane and with the molecules in the surrounding media need to be thoroughly characterized. Yet, even interactions between monovalent counter-ions and charged lipids are inadequately understood. We studied the interactions of the cationic gemini surfactant (2R,3R)-2,3-dimethoxy-1,4- bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide (RR-1) with chloride, bromide, fluoride, and iodide as counter-ions by differential scanning calorimetry and Langmuir balance. Chloride interacts avidly with RR-1, efficiently condensing the monolayer, decreasing the collapse pressure, and elevating the main transition temperature. With bromide and iodide clearly different behaviour was observed, indicating specific interactions between RR-1 and these counter-ions. Moreover, with fluoride as a counter-ion and in pure water identical results were obtained, demonstrating inefficient electrostatic screening of the headgroups of RR-1 and suggesting fluoride being depleted on the surface of RR-1 membranes.

  2. 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.

  3. 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…

  4. 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.

  5. AEROBIC COMETABOLISM OF CHLOROFORM AND 1,1,1-TRICHLOROETHANE BY BUTANE GROWN MICROORGANISMS. (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...

  6. 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.

  7. 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.

  8. Absolute configuration of (2S)-4-(4-hy­droxy­phen­yl)butan-2-ol

    PubMed Central

    Yousuf, S.; Musharraf, S. G.; Khan, I.; Samiullah; Fun, Hoong-Kun

    2011-01-01

    The title compound, C10H14O2, was isolated from the chloro­form extract of Taxus wallichiana Zucc. In the crystal, mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds, forming sheets parallel to (100). There are weak inter­molecular C—H⋯π inter­actions between the sheets. PMID:21754218

  9. 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

  10. 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

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

    USGS Publications Warehouse

    Landmeyer, James E.; Campbell, Bruce G.

    2014-01-01

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

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

    PubMed

    Tiritiris, Ioannis; Kantlehner, Willi

    2015-12-01

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

  13. 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

  14. Crystal structure of 2-aza­niumyl-3-bromo-6-oxo-5,6-di­hydro­pyrido[1,2-a]quinoxalin-11-ium dibromide

    PubMed Central

    Faizi, Md. Serajul Haque; Sharkina, Natalia O.; Iskenderov, Turganbay S.

    2015-01-01

    The title salt, C12H10BrN3O2+·2Br−, was synthesized from the reaction of N 1,N 4-bis­(pyridin-2-yl­methyl­idene)benzene-1,4-di­amine and bromine in a methanol solution. All non-H atoms of the 2-aza­niumyl-3-bromo-6-oxo-5,6-di­hydro­pyrido[1,2-a]quinoxalin-11-ium cation are nearly coplanar, the maximum deviation being 0.114 (4) Å. In the crystal, the cations and anions are linked through N—H⋯Br hydrogen bonds and weak C—H⋯Br inter­actions, forming a three-dimensional supra­molecular architecture. A short Br⋯Br contact [3.3088 (9) Å] is observed in the crystal. PMID:25705482

  15. 1,1'-Methyl-enebis[3-(2,6-diiso-propyl-phen-yl)-3,4,5,6-tetra-hydro-pyrimidin-1-ium] dibromide ethanol monosolvate monohydrate.

    PubMed

    Bian, Huanyu; Yang, Liangru; Yuan, Jinwei; Mao, Pu; Xiao, Yongmei

    2013-01-01

    In the title methyl-ene-bridged di(tetra-hydro-pyrimidinium) salt, C33H50N4 (2+)·2Br(-)·C2H5OH·H2O, the two tetra-hydro-pyrimidinium rings have envelope conformations with the central CH2 C atom as the flap. Their mean planes are inclined to one another by 73.31 (13)° and the attached benzene rings are inclined to one another by 67.39 (15)°. The methylene-C-N bond lengths in the tetra-hydro-pyrimidinium rings are 1.314 (3) and 1.304 (3) Å, values typical for C=N double bonds. The distances between the methyl-ene-bridge C atom and the linked tetra-hydro-pyrimidinium N atom are 1.457 (3) and 1.465 (3) Å, values typical for C-N single bonds. The mol-ecules co-crystallized with H2O and EtOH mol-ecules from the solvent. In the crystal, there is a zigzag chain along [010] of water mol-ecules linked by one of the Br(-) anions via O-H⋯Br hydrogen bonds. The second Br(-) anion is hydrogen bonded (O-H⋯Br) to the ethanol solvent mol-ecule. There are also a number of C-H⋯Br and C-H⋯O hydrogen bonds present, leading to the formation of a two-dimensional network lying parallel to the bc plane. PMID:24427021

  16. 27 CFR 21.56 - Formula No. 29.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  17. 40 CFR 80.340 - What standards and requirements apply to refiners producing gasoline by blending blendstocks into...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... which the butane blender is supplied. (i) Testing for the sulfur content of the butane by the supplier... immediately before transfer of butane to the butane blender. (ii) The testing must be performed by the method specified in § 80.46(a)(2) or by the alternative method specified in § 80.46(a)(4). (iii) The butane...

  18. 40 CFR 80.340 - What standards and requirements apply to refiners producing gasoline by blending blendstocks into...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... which the butane blender is supplied. (i) Testing for the sulfur content of the butane by the supplier... immediately before transfer of butane to the butane blender. (ii) The testing must be performed by the method specified in § 80.46(a)(2) or by the alternative method specified in § 80.46(a)(4). (iii) The butane...

  19. 1-(4-Carb­oxy­butan-2-yl­idene)-4-phenyl­thio­semicarbazide

    PubMed Central

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

    2012-01-01

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

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

    PubMed

    Gainsford, Graeme J; Hinkley, Simon

    2013-06-01

    Levulinic acid derivatives are potential `green chemistry' renewably sourced molecules with utility in industrial coatings applications. Suitable single crystals of the centrosymmetric title compounds, C14H22O6 and C16H26O6, respectively, were obtained with difficulty. The data for the latter hexane-1,6-diyl compound were extracted from the major fragment of a three-component twinned crystal. Both compounds crystallize in similar-sized unit cells with identical symmetry, utilizing the same weak nonconventional attractive C-H···O(ketone) hydrogen bonds via C(4) and C(5) motifs, which expand to R(2)(2)(30) ring and C(2)(2)(14) chain motifs. Their different packing orientations in similar-sized unit cells suggest that crystal growth involving packing mixes could lead to intergrowths or twins. PMID:23744390

  1. 4-(4-{[(2-Phenyl­quinazolin-4-yl)­oxy]methyl}-1H-1,2,3-triazol-1-yl)butan-1-ol hemihydrate

    PubMed Central

    Ouahrouch, Abdelaaziz; Lazrek, Hassan B.; Taourirte, Moha; El Azhari, Mohamed; Saadi, Mohamed; El Ammari, Lahcen

    2011-01-01

    The title compound, C21H21N5O2·0.5H2O, has two fused six-membered rings linked to a benzene ring and to a triazole ring, which is connected to a butanol group. The quinazoline ring forms a dihedral angle of 7.88 (8)° with the benzene ring, while the triazole ring is approximately perpendicular to the benzene ring and to the quinazoline system, making dihedral angles of 84.38 (10) and 76.55 (8)°, respectively. The stereochemical arrangement of the butanol chain, with a C—C—C—C torsion angle of 178.34 (19)°, corresponds to an anti­periplanar conformation. However the position of the –OH group is split into two very close [O—O = 0.810(3) Å] positions of equal occupancy. The crystal structure features O—H⋯N and O—H⋯O hydrogen bonds, building an infinite three-dimensional network. The water molecule is located on a half-filled general position. PMID:22091058

  2. 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...

  3. Bis­(3,5-diamino-4H-1,2,4-triazol-1-ium) 3,4-dioxocyclo­butane-1,2-diolate

    PubMed Central

    Fun, Hoong-Kun; Loh, Wan-Sin; Johnson, Atim; Yousuf, Sammer; Eno, Ededet

    2013-01-01

    The asymmetric unit of the title compound, 2C2H6N5 +·C4O4 2−, contains two 3,5-diamino-4H-1,2,4-triazolium cations and one squarate dianion. The squaric acid mol­ecule donated one H atom to each of the two 3,5-diamino-1,2,4-triazole mol­ecules at their N atoms. The squaric acid dianion has four C—O bonds which are shorter than a normal single C—O bond (1.426 Å) and are slightly longer than a normal C=O bond (1.23 Å), which indicates the degree of electron delocalization in the dianion. In the crystal, the cations and dianions are linked by N—H⋯N and N—H⋯O hydrogen bonds into a three-dimensional network. PMID:23476545

  4. 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.

  5. 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

  6. Crystal structure of bis­{μ-4-methyl-N′-[3-(oxido­imino)­butan-2-yl­idene]benzene­sulfono­hydrazidato}bis­[(dimethyl sulfoxide-κO)copper(II)

    PubMed Central

    Siqueira, Diego Pereira; Siqueira, Maria Carolina Bulhosa; Gervini, Vanessa Carratu; Bresolin, Leandro; de Oliveira, Adriano Bof

    2014-01-01

    In the title compound, [Cu2(C11H13N3O3S)2(C2H6OS)2], the CuII cation is N,N′,O-chelated by a deprotonated hy­droxy­imino-tosyl­hydrazone ligand and coordinated by a dimethyl sulfoxide mol­ecule. One O atom from the adjacent hy­droxy­imino-tosyl­hydrazone ligand bridges the CuII cation, forming the centrosymmetric dimeric complex. The cation is in an overall distorted N2O3 square-pyramidal coordination environment. The methyl­benzene ring is twisted with respect to the hydrazine fragment, with a dihedral angle of 89.54 (9)° between the planes. An intra­molecular C—H⋯O hydrogen bond occurs. In the crystal, mol­ecules are linked by weak C—H⋯O and C—H⋯S inter­actions. Weak π–π stacking is also observed between parallel benzene rings of adjacent mol­ecules, the centroid–centroid distance being 3.9592 (17) Å. PMID:25309178

  7. A COMBINED METHOD FOR DETERMINING INHIBITON TYPE, KINETIC PARAMETERS, AND INHIBITION COEFFICIENTS FOR AEROBIC COMETABOLISM OF 1,1,1-TRICHLOROETHANE BY A BUTANE-GROWN MIXED CULTURE. (R828772C003)

    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...

  8. 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. (R828772)

    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. 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. (R828772C003)

    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...

  10. A COMBINED METHOD FOR DETERMINING INHIBITION TYPE, KINETIC PARAMETERS, AND INHIBITION COEFFICIENTS FOR AEROBIC COMETABOLISM OF 1,1,1-TRICHLOROETHANE BY A BUTANE-GROWN MIXED CULTURE. (R828772)

    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...

  11. (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

  12. 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

  13. 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

    ..., and butane blenders. 80.131 Section 80.131 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... gasoline used to produce gasoline, and butane blenders. (a) Attest procedures for GTAB. The following are... gasoline, and designations regarding VOC control). (d) Attest procedures for butane blenders. The...

  14. 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

    ..., and butane blenders. 80.131 Section 80.131 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... gasoline used to produce gasoline, and butane blenders. (a) Attest procedures for GTAB. The following are... gasoline, and designations regarding VOC control). (d) Attest procedures for butane blenders. The...

  15. 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.

  16. Characterization and permeation properties of ZSM-5 tubular membranes

    SciTech Connect

    Coronas, J.; Falconer, J.L.; Noble, R.D.

    1997-07-01

    ZSM-5 zeolite membranes with reproducible properties were prepared by in-situ synthesis on porous {alpha}- and {gamma}-alumina tubular supports and characterized by XRD, SEM and electron microprobe analysis. Single-gas permeances for H{sub 2}, CH{sub 4}, N{sub 2}, CO{sup 2}, n-butane, and i-butane increase over some temperature range, but some gases exhibit maxima or minima. The highest ideal selectivities at room temperature are 299 for N{sub 2}/SF{sub 6}, 392 for H{sup 2}/n-butane, and 2,820 for H{sub 2}/i-butane. These membranes can separate n-butane/i-butane, H{sub 2}/n-butane and H{sub 2}/i-butane mixtures. All n-butane/i-butane separation selectivities have maxima as a function of temperature and are higher than ideal selectivities because n-butane inhibits i-butane permeation. Thus, separation is not by size selectivity, but is due to pore blocking. Temperature dependencies of single-gas permeances and separation selectivities depend strongly on the location of zeolite crystals and the location is determined by preparation procedure. Ideal selectivities also depend strongly on the preparation procedure. When the zeolite forms a continuous layer on the inside surface of the support tubes, pure i-butane permeates faster than pure n-butane so that the single-gas permeances are not determined just by molecular size. The i-butane permeance also increases much more with temperature than the n-butane permeance. The permeation behavior may be the result of permeation through nonzeolitic pores in parallel with zeolite pores. When zeolite crystals are dispersed throughout the pores of {alpha}-alumina supports, permeances are lower and gas permeation and separation properties are quite different. Ideal selectivities are lower, pure n-butane permeates faster than i-butane, and the permeances increase much less with temperature. Separation selectivities are lower but can be maintained to higher temperatures.

  17. Potential hazards of fumigant residues.

    PubMed Central

    Fishbein, L

    1976-01-01

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

  18. 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

  19. 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...

  20. 27 CFR 21.33 - Formula No. 2-B.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., including resins. 031.Photographic film and emulsions. 032.Transparent sheeting. 033.Explosives. 311....Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572.Ethylene gas.... (3) Miscellaneous uses: 812.Product development and pilot plant uses (own use only). (c)...

  1. 27 CFR 21.33 - Formula No. 2-B.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., including resins. 031.Photographic film and emulsions. 032.Transparent sheeting. 033.Explosives. 311....Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572.Ethylene gas.... (3) Miscellaneous uses: 812.Product development and pilot plant uses (own use only). (c)...

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., including resins. 031.Photographic film and emulsions. 032.Transparent sheeting. 033.Explosives. 311....Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572.Ethylene gas.... (3) Miscellaneous uses: 812.Product development and pilot plant uses (own use only). (c)...

  3. 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

  4. 40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Dichlorobenzidine (3,3″-) 91941 Dichloroethane (1,2-) (Ethylene dichloride) (EDC) 107062 Dichloroethyl ether (Bis(2... Ethyl acrylate 140885 Ethylbenzene 100414 Ethyl chloride (Chloroethane) 75003 Ethylene dibromide (Dibromoethane) 106934 Ethylene glycol dimethyl ether 110714 Ethylene glycol monobutyl ether 111762...

  5. 40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Dichlorobenzidine (3,3″-) 91941 Dichloroethane (1,2-) (Ethylene dichloride) (EDC) 107062 Dichloroethyl ether (Bis(2... Ethyl acrylate 140885 Ethylbenzene 100414 Ethyl chloride (Chloroethane) 75003 Ethylene dibromide (Dibromoethane) 106934 Ethylene glycol dimethyl ether 110714 Ethylene glycol monobutyl ether 111762...

  6. 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.

  7. 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...

  8. 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...

  9. 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 ...

  10. 24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Hazardous Liquids Acetic Acid Acetic Anhydride Acetone Acrylonitrile Amyl Acetate Amyl Alcohol Benzene Butyl... Butane Ethene Ethylene Ethylene Oxide Hydrogen Liquefied Natural Gas (LNG) Liquefied Petroleum Gas...

  11. 24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Hazardous Liquids Acetic Acid Acetic Anhydride Acetone Acrylonitrile Amyl Acetate Amyl Alcohol Benzene Butyl... Butane Ethene Ethylene Ethylene Oxide Hydrogen Liquefied Natural Gas (LNG) Liquefied Petroleum Gas...

  12. 24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Ketone Naptha Pentane Propylene Oxide Toluene Vinyl Acetate Xylene Hazardous Gases Acetaldehyde Butadiene Butane Ethene Ethylene Ethylene Oxide Hydrogen Liquefied Natural Gas (LNG) Liquefied Petroleum Gas...

  13. 24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Ketone Naptha Pentane Propylene Oxide Toluene Vinyl Acetate Xylene Hazardous Gases Acetaldehyde Butadiene Butane Ethene Ethylene Ethylene Oxide Hydrogen Liquefied Natural Gas (LNG) Liquefied Petroleum Gas...

  14. 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.

  15. 10 CFR 205.13 - Where to file.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...; (3) The pricing of propane, butane and natural gasoline pursuant to part 212 of this chapter and the allocation of butane and natural gasoline pursuant to part 211 of this chapter; (4) The allocation and... this chapter, filed by electric utilities; (7) The allocation and pricing of naphtha and gas...

  16. 10 CFR 205.13 - Where to file.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...; (3) The pricing of propane, butane and natural gasoline pursuant to part 212 of this chapter and the allocation of butane and natural gasoline pursuant to part 211 of this chapter; (4) The allocation and... this chapter, filed by electric utilities; (7) The allocation and pricing of naphtha and gas...

  17. 29 CFR 779.359 - May qualify as exempt 13(a)(2) establishments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... Liquefied-petroleum-gas means butane, propane and mixtures of butane and propane gases. ... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.359 May qualify as exempt 13(a)(2) establishments. A liquefied-petroleum-gas or fuel oil dealer's establishment may qualify as an exempt retail...

  18. 10 CFR 205.13 - Where to file.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...; (3) The pricing of propane, butane and natural gasoline pursuant to part 212 of this chapter and the allocation of butane and natural gasoline pursuant to part 211 of this chapter; (4) The allocation and... this chapter, filed by electric utilities; (7) The allocation and pricing of naphtha and gas...

  19. 29 CFR 779.359 - May qualify as exempt 13(a)(2) establishments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Liquefied-petroleum-gas means butane, propane and mixtures of butane and propane gases. ... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.359 May qualify as exempt 13(a)(2) establishments. A liquefied-petroleum-gas or fuel oil dealer's establishment may qualify as an exempt retail...

  20. 29 CFR 779.359 - May qualify as exempt 13(a)(2) establishments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Liquefied-petroleum-gas means butane, propane and mixtures of butane and propane gases. ... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.359 May qualify as exempt 13(a)(2) establishments. A liquefied-petroleum-gas or fuel oil dealer's establishment may qualify as an exempt retail...

  1. 29 CFR 779.359 - May qualify as exempt 13(a)(2) establishments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Liquefied-petroleum-gas means butane, propane and mixtures of butane and propane gases. ... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.359 May qualify as exempt 13(a)(2) establishments. A liquefied-petroleum-gas or fuel oil dealer's establishment may qualify as an exempt retail...

  2. 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

  3. 2,2′-[2,4-Bis(naphthalen-1-yl)cyclo­butane-1,3-di­yl]bis­(1-methyl­pyridinium) bis­(4-chloro­benzene­sulfonate): thermal-induced [2 + 2] cyclo­addition reaction of a heterostilbene

    PubMed Central

    Chantrapromma, Suchada; Chanawanno, Kullapa; Boonnak, Nawong; Fun, Hoong-Kun

    2014-01-01

    The asymmetric unit of the title salt, C36H32N2 2+·2C6H4ClO3S−, consists of one anion and one half-cation, the other half being generated by inversion symmetry. The dihedral angle between the pyridinium ring and the napthalene ring system in the asymmetric unit is 42.86 (6)°. In the crystal, cations and anions are linked by weak C—H⋯O inter­actions into chains along [010]. Adjacent chains are further arranged in an anti­parallel manner into sheets parallel to the bc plane. π–π inter­actions are observed involving the cations, with centroid–centroid distances of 3.7664 (8) and 3.8553 (8) Å. PMID:24860326

  4. Density and viscosity of binary mixtures of ethyl acetate with methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, 2-methylpropan-1-ol, and 2-methylpropan-2-ol at (298.15, 303.15, and 308.15) K

    SciTech Connect

    Nikam, P.S.; Mahale, T.R.; Hasan, M.

    1996-09-01

    Densities and viscosities have been measured for the binary mixtures of ethyl acetate with linear and branched alkanols (C{sub 1}-C{sub 4}) at (298.15, 303.15, and 308.15) K. The experimental density ({zeta}) and viscosity ({eta}) values were used to calculate the excess molar volume (V{sup E}) and viscosity deviation ({Delta}{eta}). The V{sup E} and {Delta}{eta} values have been fitted to a Redlich-Kister polynomial.

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

    SciTech Connect

    Gates, B.C.

    1996-12-31

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

  6. 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.

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

    PubMed Central

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

    1990-01-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded. PMID:2339874

  8. Separation of vapour and gas mixtures using a thin zeolite MFI membrane

    SciTech Connect

    Vroon, Z.A.E.P.; Gilde, M.J.; Kiezer, K.

    1994-12-31

    Zeolite MFI composite membranes were prepared by in situ crystallisation. A very thin (L < 5 {mu}m) polycrystalline MFI layer was grown on a flat {alpha}-Al{sub 2}O{sub 3} support (pore radii 80 nm). XRD and SEM showed that the layer was built of small MFI particles ({+-}200 nm). The single gas flux of methane, n-butane and iso-butane are respectively 9.7, 2.7 and 0.032 10{sup -3} mol.m{sup -2}.s{sup -1} at 25{degrees}C and 100 kPa. The separation of n-butane/methane is reversible. At 25{degrees}C it is possible to separate n-butane from methane. At 200{degrees}C it is possible to separate methane from n-butane. The separation factor for 50 n-butane/50 iso-butane is 26 at 50{degrees}C. Experiments with large molecules showed that the zeolite MFI membrane contains no pores larger than inherent to the zeolite.

  9. Effect of operating conditions and membrane quality on the separation performance of composite silicalite-1 membranes

    SciTech Connect

    Graaf, J.M. van de; Bijl, E. van der; Stol, A.; Kapteijn, F.; Moulign, J.A.

    1998-10-01

    The separation capacity of silicalite-1 membranes for various hydrocarbon mixtures is determined as a function of membrane quality, operating conditions, and orientation of the composite membrane with respect to the feed side. The quality of the membranes is judged on the basis of the n-butane/i-butane permselectivity. Membranes with a different n-butane/i-butane permselectivity showed an identical separation capacity for ethane/methane mixtures, but the quality difference was affecting separation of hydrogen from the butane isomers. The selectivity of the membrane is significantly affected by the operating conditions, such as mixture composition, temperature, and absolute pressure. These effects are shown for ethane/methane, propene/ethene, and n-butane/i-butane mixtures. The selectivity for ethane in ethane/methane mixtures, found when the zeolite layer is facing the feed side, is completely lost when the orientation of the composite membrane is reversed, due to concentration polarization. Depending on the membrane orientation, the major resistance of the composite is in the support layer or in the zeolite layer.

  10. 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.

  11. 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.

  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. 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)

  14. 29 CFR 779.361 - Classification of other fuel oil sales.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.361 Classification of other fuel oil sales. (a) Sales of fuel oil (as differentiated from sales of butane and propane gases) are classified as...

  15. 40 CFR Table Nn-2 to Subpart Hh of... - Lookup Default Values for Calculation Methodology 2 of This Subpart

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Natural Gas Mscf 0.055 Propane Barrel 0.235 Normal butane Barrel 0.276 Ethane Barrel 0.253 Isobutane... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal...

  16. MTBE will be a boon to U. S. gas processors

    SciTech Connect

    Otto, K.W. )

    1993-01-11

    This paper reports that the advent of methyl tertiary butyl ether (MTBE) as the primary oxygenate blending component for oxygenated and reformulated motor fuels promises significant benefits for the U.S. gas-processing industry. Increased demand for isobutane as MTBE-plant feedstock will buoy both normal butane and isobutane pricing in U.S. gulf Coast during the 1990s. Elimination of the need to crack normal butane in U.S. olefin plants will also strengthen competitive feedstocks somewhat, including ethane and propane. And increased use of normal butane as isomerization feedstock will result in wider recognition of the premium quality of gas plant normal butane production compared to most refinery C[sub 4] production.

  17. 29 CFR 779.361 - Classification of other fuel oil sales.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.361 Classification of other fuel oil sales. (a) Sales of fuel oil (as differentiated from sales of butane and propane gases) are classified as...

  18. 29 CFR 779.361 - Classification of other fuel oil sales.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.361 Classification of other fuel oil sales. (a) Sales of fuel oil (as differentiated from sales of butane and propane gases) are classified as...

  19. 40 CFR Table Nn-2 to Subpart Hh of... - Lookup Default Values for Calculation Methodology 2 of This Subpart

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Natural Gas Mscf 0.055 Propane Barrel 0.235 Normal butane Barrel 0.276 Ethane Barrel 0.253 Isobutane... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal...

  20. 29 CFR 779.361 - Classification of other fuel oil sales.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.361 Classification of other fuel oil sales. (a) Sales of fuel oil (as differentiated from sales of butane and propane gases) are classified as...

  1. 40 CFR Table Nn-2 to Subpart Hh of... - Lookup Default Values for Calculation Methodology 2 of This Subpart

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Natural Gas Mscf 0.055 Propane Barrel 0.235 Normal butane Barrel 0.276 Ethane Barrel 0.253 Isobutane... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal...

  2. [Ventricular fibrillation following deodorant spray inhalation].

    PubMed

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

    2008-01-01

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

  3. Webb report adds support for choosing LPG as a motor fuel

    SciTech Connect

    Not Available

    1990-01-01

    This article discusses a study on choosing propane and butane as an alternate transportation fuel (ATF). According to this article, the results of the study indicate that propane and butane have met two of the challenges facing selection of an ATF: there is a ready supply of the product and conversion equipment is easily available. Primary goals identified by the study are presented and discussed.

  4. 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

  5. [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

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

    PubMed

    Albrecht, W N

    1987-01-01

    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).

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. Interactions of Molecules with cis and trans Double Bonds: A Theoretical Study of cis- and trans-2-Butene.

    PubMed

    Zarić, Milana M; Bugarski, Branko; Kijevčanin, Mirjana Lj

    2016-01-18

    Noncovalent interactions of cis- and trans-2-butene, as the smallest model systems of molecules with cis and trans double bonds, were studied to find potential differences in interactions of these molecules. The study was performed using quantum chemical methods including very accurate CCSD(T)/CBS method. We studied parallel and displaced parallel interactions in 2-butene dimers, in butane dimers, and between 2-butene and saturated butane. The results show the trend that interactions of 2-butene with butane are the strongest, followed by interactions in butane dimers, whereas the interaction in 2-butene dimers are the weakest. The strongest calculated interaction energy is between trans-2-butene and butane, with a CCSD(T)/CBS energy of -2.80 kcal mol(-1) . Interactions in cis-2-butene dimers are stronger than interactions in trans-2-butene dimers. Interestingly, some of the interactions involving 2-butene are as strong as interactions in a benzene dimer. These insights into interactions of cis- and trans-2-butene can improve understanding of the properties and processes that involve molecules with cis and trans double bonds, such as fatty acids and polymers.

  13. 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.

  14. Vapor-liquid equilibrium of near-critical binary alkane mixtures

    SciTech Connect

    Rainwater, J.C.; Williamson, F.R.; Hauley, H.J.M.; Cezairliyan, A.

    1986-01-01

    The modified Leung-Griffiths model of Rainwater and Moldover is used to correlate vapor-liquid equilibrium (VLE) surfaces in pressure, temperature, and density for binary mixtures in the near-critical region. The systems studied are butane-pentane, propane-isopentane, butane-hexane, and ethane-butane. The model, which has also successfully fit several other mixtures, is based on scalinglaw equations of state expressed in terms of field variables. It incorporates a variation of the principle of corresponding states as well as the coupling of density and composition change across the phase boundary. As the width of the dew-bubble curves increases, additional parameters are required to obtain successful VLE correlations.

  15. Vapor-liquid equilibrium of near-critical binary alkane mixtures

    NASA Astrophysics Data System (ADS)

    Rainwater, J. C.; Williamson, F. R.

    1986-01-01

    The modified Leung-Griffiths model of Rainwater and Moldover is used to correlate vapor-liquid equilibrium (VLE) surfaces in pressure, temperature, and density for binary mixtures in the near-critical region. The systems studied are butane-pentane, propane-isopentane, butane-hexane, and ethane-butane. The model, which has also successfully fit several other mixtures, is based on scaling-law equations of state expressed in terms of field variables. It incorporates a variation of the principle of corresponding states as well as the coupling of density and composition change across the phase boundary. As the width of the dew-bubble curves increases, additional parameters are required to obtain successful VLE correlations.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. Targeted LC–MS derivatization for aldehydes and carboxylic acids with a new derivatization agent 4-APEBA

    PubMed Central

    Eggink, Mark; Wijtmans, Maikel; Kretschmer, Ansgar; Kool, Jeroen; Lingeman, Henk; de Esch, Iwan J. P.; Irth, Hubertus

    2010-01-01

    Based on the template of a recently introduced derivatization reagent for aldehydes, 4-(2-(trimethylammonio)ethoxy)benzeneaminium dibromide (4-APC), a new derivatization agent was designed with additional features for the analysis and screening of biomarkers of lipid peroxidation. The new derivatization reagent, 4-(2-((4-bromophenethyl)dimethylammonio)ethoxy)benzenaminium dibromide (4-APEBA) contains a bromophenethyl group to incorporate an isotopic signature to the derivatives and to add additional fragmentation identifiers, collectively enhancing the abilities for detection and screening of unknown aldehydes. Derivatization can be achieved under mild conditions (pH 5.7, 10 °C). By changing the secondary reagent (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide instead of sodium cyanoborohydride), 4-APEBA is also applicable to the selective derivatization of carboxylic acids. Synthesis of the new label, exploration of the derivatization conditions, characterization of the fragmentation of the aldehyde and carboxylic acid derivatives in MS/MS, and preliminary applications of the labeling strategy for the analysis of aldehydes in urine and plasma are described. Figure Structure and MS/MS fragmentation spectrum of 4-APEBA reagents derivatized with octanoic acid Electronic supplementary material The online version of this article (doi:10.1007/s00216-010-3575-1) contains supplementary material, which is available to authorized users. PMID:20238107

  2. 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.

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

    PubMed

    Doty, S L; Shang, T Q; Wilson, A M; Tangen, J; Westergreen, A D; Newman, L A; Strand, S E; Gordon, M P

    2000-06-01

    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.

  4. 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.

  5. 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.

  6. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    DOEpatents

    Koch, Daniel J.; Arnold, Frances H.

    2012-11-13

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

  7. Polycyclic aromatic hydrocarbons profile of kitchen dusts.

    PubMed

    Iwegbue, Chukwujindu M A

    2011-03-01

    Concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) were determined in thirty dust samples collected from kitchens that use wood cook system (WCS), kerosene stove cook system (KSCS) and butane gas cook system (BGCS). The total PAHs concentrations ranged from 52 to 497, 39 to 96 and 37 to 155 μg kg(-1) for WCS, KSCS and BGCS respectively. The results indicate predominance of lower molecular weight (2-3 rings) over higher molecular weight PAHs and users of wood cook system are more exposed to higher levels of PAHs than the users of either kerosene cook system or butane gas cook system.

  8. The North American natural gas liquids markets are chaotic

    SciTech Connect

    Serletis, A.; Gogas, P. . Dept. of Economics)

    1999-01-01

    In this paper the authors test for deterministic chaos (i.e., nonlinear deterministic processes which look random) in seven Mont Belview, Texas hydrocarbon markets, using monthly data from 1985:1 to 1996:12--the markets are those of ethane, propane, normal butane, iso-butane, naptha, crude oil, and natural gas. In doing so, they use the Lyapunov exponent estimator of Nychka, Ellner, Gallant, and McCaffrey. They conclude that there is evidence consistent with a chaotic nonlinear generation process in all five natural gas liquids markets.

  9. Expanding Canadian natural gas production will strengthen growth of LP-gas industry

    SciTech Connect

    Hawkins, D.J. )

    1994-01-01

    In 1992, over 86% of Canadian propane and 70% of Canadian butane production originated in gas plants. Propane and butane production not recovered at gas plants is recovered in other processing facilities, primarily refineries and heavy oil upgraders. As a result, supplies of both products are largely tied to natural gas production, and the outlook for natural gas therefore provides the basis for any discussion on the outlook for gas processing and NGL industry infrastructure. The paper discusses gas processing, economies of scale, NGL supply, expected declines, industry structure and infrastructure, the two major centers of the Canadian NGL industry, new shippers, and required pipeline expansion.

  10. 40 CFR 86.1232-96 - Vehicle preconditioning.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and one, two or three driving cycles of the dynamometer driving schedule, as described in paragraph (c... follows each driving cycle. (f)(1) Gasoline- and methanol-fueled vehicles. After completion of the... percent nitrogen by volume at a rate of 15±2 grams butane per hour. If the canister loading at that...

  11. 40 CFR 710.46 - Chemical substances for which information is not required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Gases (petroleum), blend oil, hydrogen-nitrogen-rich 68477-69-0 Gases (petroleum), butane splitter... (petroleum), hydrogen-rich 68477-98-5 Gases (petroleum), hydrotreater blend oil recycle, hydrogen-nitrogen... copies of these responses in a public docket that will be established for each reporting cycle. (B)...

  12. 40 CFR 80.330 - What are the sampling and testing requirements for refiners and importers?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...(a) and 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials... alternative method is correlated to the method provided in § 80.46(a)(1). (d) Test method for sulfur in butane... alternative method is correlated to the method provided in § 80.46(a)(2). (e) Incorporations by...

  13. 40 CFR 80.330 - What are the sampling and testing requirements for refiners and importers?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...(a) and 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials... alternative method is correlated to the method provided in § 80.46(a)(1). (d) Test method for sulfur in butane... alternative method is correlated to the method provided in § 80.46(a)(2). (e) Incorporations by...

  14. 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.

  15. 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...

  16. Effects of glycerol monosterate on TPUs crystallization and its foaming behavior

    NASA Astrophysics Data System (ADS)

    Hossieny, N.; Nofar, M.; Shaayegan, V.; Park, C. B.

    2014-05-01

    Thermoplastic polyurethane (TPU) containing 0-2 wt% glycerol monosterate (GMS) were compounded by a twin screw compounder and then foamed using a batch process and n-butane. Differential scanning calorimetry (DSC) and high-pressure DSC were performed to evaluate the effects of GMS and pressurized butane on the crystallization kinetics of TPU. The results showed that the synergistic effect of GMS and high pressure butane significantly promoted hard segment (HS) crystallization in the TPU-GMS samples. The TPU-GMS samples showed significant increase in crystallinity over a wide range of saturation temperatures in the presence of butane compared to neat melt-compounded TPU (PR-TPU). Comparing the foam characteristics of PR-TPU and TPU-GMS samples, it was observed that both samples exhibited microcellular morphology with high cell density over a wide range of processing temperatures of 150°C - 170°C. However at a high foaming temperature (170°C), PR-TPU foams showed high cell coalescence compared to TPU-GMS. Furthermore, TPU-GMS samples showed a much higher expansion ratio compared to PR-TPU over a wide range of processing temperatures. The lubricating effect of GMS assisted the HS to stack together and form crystalline domains. These HS crystalline domains are present at high temperature acting both as a heterogeneous nucleating sites as well as reinforcement leading to the observed microcellular morphology with a high expansion ratio in TPU-GMS samples.

  17. 21 CFR 173.350 - Combustion product gas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Combustion product gas. 173.350 Section 173.350... Combustion product gas. The food additive combustion product gas may be safely used in the processing and... manufactured by the controlled combustion in air of butane, propane, or natural gas. The combustion...

  18. 26 CFR 48.4041-8 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (such as propane, butane, pentane, or mixtures of the same); (ii) Liquefied natural gas; or (iii) Benzol... of transporting a load over highways, whether or not also designed to perform other functions, but..., the term “transport” includes the term “tow”. A vehicle which is not a highway vehicle within...

  19. 30 CFR 256.40 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., production of crude oil, natural gas, or liquefied petroleum products and shall include, but not be limited... products means natural gas liquid products including the following: ethane, propane, butane, pentane, natural gasoline, and other natural gas products recovered by a process of absorption,...

  20. 49 CFR Appendix B to Part 195 - Risk-Based Alternative to Pressure Testing Older Hazardous Liquid and Carbon Dioxide Pipelines

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) (Propane, butane, Natural Gas Liquid (NGL), ammonia) Highly toxic (Benzene, high Hydrogen Sulfide content..., product transported, and the release volume potential. Tables 2-6 give definitions of risk classification... classification is determined based on the type of pipe involved, the facility's location, the product...

  1. 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.

  2. 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…

  3. 40 CFR 60.503 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...=number of testing intervals. i=emission testing interval of 5 minutes. K=density of calibration gas, 1.83... concentration (Cei) at each interval. The calibration gas shall be either propane or butane. The owner or...) A pressure measurement device (liquid manometer, magnehelic gauge, or equivalent...

  4. 40 CFR 60.503 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...=number of testing intervals. i=emission testing interval of 5 minutes. K=density of calibration gas, 1.83... concentration (Cei) at each interval. The calibration gas shall be either propane or butane. The owner or...) A pressure measurement device (liquid manometer, magnehelic gauge, or equivalent...

  5. 40 CFR 60.503 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...=number of testing intervals. i=emission testing interval of 5 minutes. K=density of calibration gas, 1.83... concentration (Cei) at each interval. The calibration gas shall be either propane or butane. The owner or...) A pressure measurement device (liquid manometer, magnehelic gauge, or equivalent...

  6. Liquid fuels of high octane values

    SciTech Connect

    Jessup, P.J.

    1989-03-14

    This patent describes an unleaded fuel composition having an octane rating of about 100 or more, the fuel comprising toluene and alkylate and at least two further components selected from the group consisting of methyl tertiary-butyl ether, isopentane, and n-butane. It also describes a specific composition consisting of toluene, isopentane, alkylate, and MTBE.

  7. 15 CFR Supplement No. 1 to Part 754 - Petroleum and Petroleum Products

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... more than 125 seconds. 2711.11.0000 Natural gas, methane and mixtures thereof (including liquefied natural gas and synthetic or substitute natural gas). 2 2711.14.0000 Ethane with a minimum purity of 95....0000 Butane with a minimum purity of 90 liquid volume percent. 2711.19.0000 Other natural...

  8. 15 CFR Supplement No. 1 to Part 754 - Petroleum and Petroleum Products

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... more than 125 seconds. 2711.11.0000 Natural gas, methane and mixtures thereof (including liquefied natural gas and synthetic or substitute natural gas). 2 2711.14.0000 Ethane with a minimum purity of 95....0000 Butane with a minimum purity of 90 liquid volume percent. 2711.19.0000 Other natural...

  9. 15 CFR Supplement No. 1 to Part 754 - Petroleum and Petroleum Products

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... more than 125 seconds. 2711.11.0000 Natural gas, methane and mixtures thereof (including liquefied natural gas and synthetic or substitute natural gas). 2 2711.14.0000 Ethane with a minimum purity of 95....0000 Butane with a minimum purity of 90 liquid volume percent. 2711.19.0000 Other natural...

  10. 15 CFR Supplement No. 1 to Part 754 - Petroleum and Petroleum Products

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... more than 125 seconds. 2711.11.0000 Natural gas, methane and mixtures thereof (including liquefied natural gas and synthetic or substitute natural gas). 2 2711.14.0000 Ethane with a minimum purity of 95....0000 Butane with a minimum purity of 90 liquid volume percent. 2711.19.0000 Other natural...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Classification of other fuel oil sales. 779.361 Section 779... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.361 Classification of other fuel oil sales. (a) Sales of fuel oil (as differentiated from sales of butane and propane gases) are classified as...

  12. 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…

  13. 40 CFR Table Nn-1 to Subpart Hh of... - Default Factors for Calculation Methodology 1 of This Subpart

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Calculation Methodology 1 of This Subpart Fuel Default high heating value factor Default CO2 emission factor (kg CO2/MMBtu) Natural Gas 1.028 MMBtu/Mscf 53.02 Propane 3.822 MMBtu/bbl 61.46 Normal butane...

  14. 40 CFR Table Nn-1 to Subpart Hh of... - Default Factors for Calculation Methodology 1 of This Subpart

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Calculation Methodology 1 of This Subpart Fuel Default high heating value factor Default CO2 emission factor (kg CO2/MMBtu) Natural Gas 1.028 MMBtu/Mscf 53.02 Propane 3.822 MMBtu/bbl 61.46 Normal butane...

  15. 40 CFR Table Nn-1 to Subpart Hh of... - Default Factors for Calculation Methodology 1 of This Subpart

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Calculation Methodology 1 of This Subpart Fuel Default high heating value factor Default CO2 emission factor (kg CO2/MMBtu) Natural Gas 1.028 MMBtu/Mscf 53.02 Propane 3.822 MMBtu/bbl 61.46 Normal butane...

  16. 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...

  17. 24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Butane Ethene Ethylene Ethylene Oxide Hydrogen Liquefied Natural Gas (LNG) Liquefied Petroleum Gas (LPG... list of specific petroleum products and chemicals defined to be hazardous substances under § 51.201... (Petroleum) Cumene Cyclohexane No. 2 Diesel Fuel Ethyl Acetate Ethyl Acrylate Ethyl Alcohol Ethyl...

  18. 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...

  19. 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...

  20. 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...

  1. Increased productivity of Clostridium acetobutylicum fermentation of acetone, butanol, and ethanol by pervaporation through supported ionic liquid membrane.

    PubMed

    Izák, Pavel; Schwarz, Katrin; Ruth, Wolfgang; Bahl, Hubert; Kragl, Udo

    2008-03-01

    Pervaporation proved to be one of the best methods to remove solvents out of a solvent producing Clostridium acetobutylicum culture. By using an ionic liquid (IL)-polydimethylsiloxane (PDMS) ultrafiltration membrane (pore size 60 nm), we could guarantee high stability and selectivity during all measurements carried out at 37 degrees C. Overall solvent productivity of fermentation connected with continuous product removal by pervaporation was 2.34 g l(-1) h(-1). The supported ionic liquid membrane (SILM) was impregnated with 15 wt% of a novel ionic liquid (tetrapropylammonium tetracyano-borate) and 85 wt% of polydimethylsiloxane. Pervaporation, accomplished with the optimized SILM, led to stable and efficient removal of the solvents butan-1-ol and acetone out of a C. acetobutylicum culture. By pervaporation through SILM, we removed more butan-1-ol than C. acetobutylicum was able to produce. Therefore, we added an extra dose of butan-1-ol to run fermentation on limiting values where the bacteria would still be able to survive its lethal concentration (15.82 g/l). After pervaporation was switched off, the bacteria died from high concentration of butan-1-ol, which they produced.

  2. 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.

  3. NEW CHEMICAL ALTERNATIVES FOR THE PROTECTION OF STRATOSPHERIC OZONE

    EPA Science Inventory

    The report gives results of a study that focused on the investigation of fluorinated derivatives of propane and butane to determine if synthesis routes of such compounds were feasible and economical and to measure the physical properties needed to evaluate the compounds as altern...

  4. Biotransformation of pinoresinol diglucoside to mammalian lignans by human intestinal microflora, and isolation of Enterococcus faecalis strain PDG-1 responsible for the transformation of (+)-pinoresinol to (+)-lariciresinol.

    PubMed

    Xie, Li-Hua; Akao, Teruaki; Hamasaki, Kenjiro; Deyama, Takeshi; Hattori, Masao

    2003-05-01

    By anaerobic incubation of pinoresinol diglucoside (1) from the bark of Eucommia ulmoides with a fecal suspension of humans, eleven metabolites were formed, and their structures were identified as (+)-pinoresinol (2), (+)-lariciresinol (3), 3'-demethyl-(+)-lariciresinol (4), (-)-secoisolariciresinol (5), (-)-3-(3", 4"-dihydroxybenzyl)-2-(4'-hydroxy-3'-methoxybenzyl)butane-1, 4-diol (6), 2-(3', 4'-dihydroxybenzyl)-3-(3", 4"-dihydroxybenzyl)butane-1, 4-diol (7), 3-(3"-hydroxybenzyl)-2-(4'-hydroxy-3'-methoxybenzyl)butane-1, 4-diol (8), 2-(3', 4'-dihydroxybenzyl)-3-(3"-hydroxybenzyl)butane-1, 4-diol (9), (-)-enterodiol (10), (-)-(2R, 3R)-3-(3", 4"-dihydroxybenzyl)-2-(4'-hydroxy-3'-methoxybenzyl)butyrolactone (11), (-)-(2R, 3R)-2-(3', 4'-dihydroxybenzyl)-3-(3", 4"-dihydroxybenzyl)butyrolactone (12), (-)-(2R, 3R)-3-(3"-hydroxybenzyl)-2-(4'-hydroxy-3'-methoxybenzyl)butyrolactone (13), 2-(3', 4'-dihydroxybenzyl)-3-(3"-hydroxybenzyl)butyrolactone (14), 2-(3'-hydroxybenzyl)-3-(3", 4"-dihydroxybenzyl)butyrolactone (15) and (-)-(2R, 3R)-enterolactone (16) by various spectroscopic means, including two dimensional (2D)-NMR, mass spectrometry and circular dichroism. A possible metabolic pathway was proposed on the basis of their structures and time course experiments monitored by thin-layer chromatography. Furthermore, a bacterial strain responsible for the transformation of (+)-pinoresinol to (+)-lariciresinol was isolated from a human fecal suspension and identified as Enterococcus faecalis strain PDG-1.

  5. 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.

  6. 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.

  7. 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.

  8. Methionine derivatives diminish sulphide damage to colonocytes--implications for ulcerative colitis.

    PubMed Central

    Roediger, W E; Babidge, W; Millard, S

    1996-01-01

    BACKGROUND: Bacterial production of anionic sulphide is increased in the colon of ulcerative colitis and sulphides can cause metabolic damage to colonocytes. AIMS: To assess the reversal of the damaging effect of sulphide to isolated colonocytes by methionine and methionine derivatives. METHODS AND SUBJECTS: Isolated colonocytes were prepared from rat colons and 12 human colectomy specimens. In cell suspensions 14CO2/acetoacetate generation was measured from [1-14C]-butyrate (5.0 mmol/l) in the presence of 0-2.0 mmol/l sodium hydrogen sulphide. The effect of 5.0 mmol/l L-methionine, S-adenosylmethionine 1,4 butane disulphonate and DL-methionine-S-methylsulphonium chloride on sulphide inhibited oxidation was observed. RESULTS: In rat colonocytes sodium hydrogen sulphide dose dependently reduced oxidative metabolite formation from n-butyrate, an action reversed in order of efficacy by S-adenosylmethionine 1,4 butane disulphonate > DLmethionine-S-methyl-sulphonium chloride > L-methionine. In human colonocytes S-adenosylmethionine 1,4 butane disulphonate most significantly improved 14CO2 production (p = < 0.005) suppressed by sodium hydrogen sulphide. CONCLUSION: Sulphide toxicity in colonocytes is reversible by methyl donors. The efficiency of sulphide detoxification may be an important factor in the pathogenesis and treatment of ulcerative colitis for which S-adenosylmethionine 1,4 butane disulphonate may be of therapeutic value. PMID:8881814

  9. 16 CFR 1210.5 - Findings.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... million in property damage, resulted from fires started by children under the age of 5. Fire-related... intended for use in lighting cigarettes and other smoking materials. Lighters may be gas- or liquid-fueled... are pocket refillable butane models. A small proportion of refillables is comprised of pocket...

  10. 40 CFR 80.126 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... to determine a product's properties. For laboratories using test methods that must be correlated to... importer by the independent lab. Where assumed properties used (e.g., for butane) the assumed properties may serve as the test results. (k) Non-finished-gasoline petroleum products means liquid...

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  12. 40 CFR 86.1231-96 - Vehicle preparation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Emission Test Procedures for New Gasoline-Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and... that involves loading the evaporative emission canister(s) with butane, provide valving or other means... or plugging all detectable sources of exhaust gas leaks. The exhaust system shall be tested...

  13. One-dimensional channels constructed from per-hydroxylated pillar[6]arene molecules for gas and vapour adsorption.

    PubMed

    Ogoshi, Tomoki; Sueto, Ryuta; Yoshikoshi, Kumiko; Yamagishi, Tada-aki

    2014-12-14

    Per-hydroxylated pillar[6]arene molecules formed highly ordered one-dimensional channels with a diameter of 6.7 Å. The channels can capture various gases, such as CO2, N2 and n-butane, and vapours of saturated hydrocarbons such as n-hexane and cyclohexane. PMID:25339195

  14. West Virginia sells LP-gas throughout the Northeast

    SciTech Connect

    Maslowski, A.

    1988-02-01

    The Mountain State of West Virginia is one of the few states in the Northeastern U.S. that produce and process natural gas liquids from local wells. Because customers in this heavily populated region are easy to come by, West Virginia remains a net exporter of propane and butane.

  15. 40 CFR 86.1231-96 - Vehicle preparation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Emission Test Procedures for New Gasoline-Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and... that involves loading the evaporative emission canister(s) with butane, provide valving or other means... or plugging all detectable sources of exhaust gas leaks. The exhaust system shall be tested...

  16. 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

  17. 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.

  18. 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.

  19. 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)

  20. Synthesis, antitumor, and antibacterial activity of bis[4,5-diarylimidazol-2-ylidene]methane derivatives.

    PubMed

    Liu, Wukun; Chen, Xiaohua; Gust, Ronald

    2012-07-01

    Cationic [bis(1,3-diethyl-4,5-diarylimidazol-2-ylidene)]Au(I) bromide complexes have demonstrated considerable potential as new antitumor agents. In order to investigate whether the gold is crucial for the antitumor activity, the imidazole ligands were connected by a methylene bridge. Biological evaluation revealed that bis[1,3-diethyl-4,5-diarylimidazol-2-ylidene]methane compounds exhibited growth inhibition effects against mammary (MCF-7 and MDA-MB 231) and colon (HT-29) carcinoma cell lines. In comparison with gold complexes, the methylene derivatives showed drastically reduced cell growth inhibitory properties. However, the growth of bacteria was significantly inhibited by bis[1,3-diethyl-4,5-bis(4-methoxyphenyl)imidazol-2-ylidene]methane dibromide (4) and opens a new application of this compound type.

  1. 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

  2. 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.

  3. Bridged ferrocenes. 12. Metalation and subsequent reactions of ferrocene derivatives with two or three trimethylene bridges

    SciTech Connect

    Hillman, M.; Austin, J.D.; Kvick, A.

    1985-01-01

    Reaction of 1,1',2,2'-bis(trimethylene)ferrocene, I, 1,1',3,3'-bis(trimethylene)ferrocene, II, and 1,1',2,2',4,4'-tris(trimethylene)ferrocene, III, with n-butyllithium (n-BuLi) and N,N,N',N'-tetramethyl-ethylenediamine (TMEDA) or potassium tert-butoxide (KO-t-Bu) gave metal derivatives which were converted to the corresponding mono- and dicarboxylic acids and their methyl esters and in the case of III to the 3,3'-dibromo derivative. With a few modifications due to the peculiarities of the individual compounds, the explanation for the selectivity of the metalation reactions is essentially that given for the metalation of 1,1'-trimethyleneferrocene, IV. The crystal structure of the dibromide was determined. 12 references, 2 figures, 2 tables.

  4. Public health assessment for petitioned public health assessment, Union Carbide (Byers Warehouse), St. Joseph, Buchanan County, Missouri, Region 7. Final report

    SciTech Connect

    Not Available

    1993-05-04

    In response to a petition from a St. Joseph, Missouri resident, the Agency for Toxic Substances and Disease Registry (ATSDR) conducted a public health assessment of the Union Carbide (Byers Warehouse) site in St. Joseph, Missouri. The basement of Byers Warehouse was used by Vulcan Chemicals to store ethylene dibromide (EDB), chloroform, and carbon tetrachloride (CCI4). The first and second floors were used by Union Carbide to store 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4,5-trichlorophenoxyproprionic acid (2,4,5-TP). The Byers Warehouse (Union Carbide) Petition site is not a current public health hazard. That conclusion is based on the complete removal of the toxic substances stored in the warehouse, and the lack of any current or future completed exposure pathways. Past storage of herbicides and other chemical products represented a public health hazard.

  5. 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.

  6. 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

  7. Synthesis and structure-activity relationship of di-(3, 8-diazabicyclo[3.2.1]octane) diquaternary ammonium salts as unique analgesics.

    PubMed

    Liu, Hong; Cheng, Tie-Ming; Zhang, Hong-Mei; Li, Run-Tao

    2003-11-01

    Based on the structure characteristics of the lead compounds, 1, 1' octanedioyl-4, 4'-dimethyl-4, 4'-dibenzyl dipiperazinium dibromide (2) and 3, 8-disubstituted-3, 8-diazabicyclo [3.2.1]octanes (DBO), di-(3, 8-diazabicyclo [3.2.1]octane) diquaternary ammonium salts 3 a-c were designed and synthesized through a highly practical procedure. Target compounds 3 a-c and the hydrochloride salts of their precursors 10 a-c were evaluated for their in vivo analgesic and sedative activities. Interestingly, the introduction of an endoethylenic bridge in the piperazine of lead compound 2 causes loss of the analgesic activity and increases the toxicity dramatically. This result shows that the flexible conformation of piperazine in compound 2 is favorable for interaction with the receptor, and the quaternization of compounds 10 a-c is the main reason for the toxicity increase.

  8. Methodological challenges in health risk assessment. Final report

    SciTech Connect

    Not Available

    1987-10-12

    Risk assessment, a major activity of both health and regulatory agencies, is subject to large and unavoidable uncertainties. Thus, different teams of knowledgeable experts can come to different conclusions about risks to human health from various sorts of hazards. This report examines and compares analyses by two or more agencies of ten health hazards or potential hazards: ethylene dibromide, formaldehyde, Tris, dioxin (limited to cancer risks of contaminated soil), lead (reproductive effects), cotton dust, noise (long-term hearing impairment), passive smoking, dietary fat (cancer risks), and the radiation hazards of mammography. Each set of risk assessments is analyzed in depth. The report then turns to cross-cutting analyses of such matters as setting priorities for risk assessment, approaches and methods used to evaluate different kinds of risks, and the relationships between risk assessment and risk management. Overall, the report found large differences among risk assessments of the same hazard, but these differences are often quite appropriate.

  9. Current Intelligence Bulletin reprints - Bulletins 31 through 47

    SciTech Connect

    Not Available

    1986-09-01

    Current Intelligence Bulletins 31 through 47 were reprinted. Topics included are the adverse effects of smoking and the occupational environment on worker health; poisoning in the workplace by arsine; health hazards from radiofrequency sealers and heaters; evidence of carcinogenicity from formaldehyde; ethylene-oxide; silicosis from silica flour; ethylene-dibromide; vibration syndrome resulting from the operating of hand held vibrating tools; problems resulting from glycol ethers including reproductive problems among female employees and embryotoxicity; 2,3,7,8-tetrachlorodibenzo-p-dioxin poisoning; 1,3-butadiene and health-related effects among workers including reproductive effects and carcinogenesis; cadmium carcinogenesis in the workplace; monohalomethane hazards including teratogenesis and carcinogenesis; health hazards due to the use of dinitrotoluenes including cancer and reproductive defects; electrical equipment fires and potential health hazards due to polychlorinated biphenyls; methylene chloride carcinogenesis; and the potential carcinogenicity of 4,4'-methylenedianiline. A cumulative list of NIOSH Current Intelligence Bulletins numbers 1 through 47 is also included.

  10. 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

  11. 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

  12. Degradation of low molecular weight volatile organic compounds by plants genetically modified with mammalian cytochrome P450 2E1.

    PubMed

    James, C Andrew; Xin, Gang; Doty, Sharon L; Strand, Stuart E

    2008-01-01

    Cytochrome P450 2E1 (CYP2E1) is a key enzyme in the mammalian metabolism of several low molecular weight volatile organic compounds (VOCs), such as trichloroethylene (TCE), vinyl chloride (VC), carbon tetrachloride (CT), benzene, chloroform, and bromodichloromethane (BDCM), which are all common environmental pollutants that pose risks to human health. We have developed a transgenic tobacco (Nicotiana tabacum cv. Xanthii) that expresses CYP2E1 with increased activity toward TCE and ethylene dibromide. In experiments with tobacco plant cuttings exposed to VOCs in small hydroponic vessels, the transgenic tobacco had greatly increased rates of removal of TCE, VC, CT, benzene, toluene, chloroform, and BDCM, compared to wild-type or vector control tobacco, but not of perchloroethylene or 1,1,1-trichloroethane.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Pb(3)Te(2)O(6)Br(2).

    PubMed

    Weil, Matthias; Stöger, Berthold

    2010-01-16

    Single crystals of the title compound, trilead(II) bis-[tellurate(IV)] dibromide, have been grown under hydro-thermal conditions. The structure is isotypic with that of the chloride analogue, Pb(3)Te(2)O(6)Cl(2), and consists of three Pb, two Te, two Br and four O atoms in the asymmetric unit. Except for two of the O atoms, all atoms are located on mirror planes. The Pb(3)Te(2)O(6)Br(2) structure can be described as being built up from (∞) (2)[Pb(3)Te(2)O(6)](2+) layers extending parallel to (20) and Br(-) anions between the layers. Cohesion of the structure is accomplished through Pb-Br contacts of two of the three lead atoms, leading to highly asymmetric coordination polyhedra. The lone-pair electrons of both Te(IV) and Pb(II) atoms are stereochemically active and point towards the anionic halide layers.

  18. 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

  19. 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

  20. 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.

  1. Fuel property effects on engine combustion processes. Final report

    SciTech Connect

    Cernansky, N.P.; Miller, D.L.

    1995-04-27

    A major obstacle to improving spark ignition engine efficiency is the limitations on compression ratio imposed by tendency of hydrocarbon fuels to knock (autoignite). A research program investigated the knock problem in spark ignition engines. Objective was to understand low and intermediate temperature chemistry of combustion processes relevant to autoignition and knock and to determine fuel property effects. Experiments were conducted in an optically and physically accessible research engine, static reactor, and an atmospheric pressure flow reactor (APFR). Chemical kinetic models were developed for prediction of species evolution and autoignition behavior. The work provided insight into low and intermediate temperature chemistry prior to autoignition of n-butane, iso-butane, n-pentane, 1-pentene, n-heptane, iso-octane and some binary blends. Study of effects of ethers (MTBE, ETBE, TAME and DIPE ) and alcohols (methanol and ethanol) on the oxidation and autoignition of primary reference fuel (PRF) blends.

  2. Studies on Pt{sub x}In{sub y} bimetallics in NaY. II. Further characterization results and catalytic properties

    SciTech Connect

    Meriaudeau, P.; Thangaraj, A.; Dutel, J.F.; Gelin, P.; Naccache, C.

    1996-10-01

    In a previous paper the preparation and the characterization PtNaY and PtInNaY were reported. Here, complementary characterization results obtained by studying the TPD of CO by mass spectrometry coupled with IR studies of the adsorbed CO phases indicated no apparent change in the electronic properties of Pt. Comparison of catalytic properties for n-butane hydrogenolysis between PtNaY and PtInNaY indicated that the hydrogenolysis is deeply affected by the addition of In to Pt; the kinetic parameters (apparent activation energy, relative order for butane and for hydrogen) are modified by In addition. These results are explained considering that In is acting more like a diluent of Pt atoms than as an electronic modifier of Pt. 16 refs., 10 figs., 1 tab.

  3. Synthesis of SnO{sub 2} Nanoparticles Using Ultrasonication

    SciTech Connect

    Majumdar, Sanhita; Devi, P. Sujatha

    2010-10-04

    The use of ultrasonic energy for chemical synthesis has recently become an interesting and growing area of research. Using this form of energy, we have synthesized nanoparticles of SnO{sub 2}(8-30 nm) at room temperature by a sonication assisted precipitation technique. In order to understand the effect of ultrasonic energy on particle size and their distribution, the precipitation time was varied during the preparation. A sonication time of 3 h was found to be optimum to produce SnO{sub 2} nanoparticles having size below 10 nm. We found that a gradual increase of the sonication time gradually decreases the particle size with interesting morphology and increased surface area. The butane sensing properties of the synthesized powders exhibited a direct influence of the sonication time on the sensing properties. A 3 h sonicated sample, exhibited a maximum response of around 98.88% towards 5000 ppm butane at 450 deg. C with a fast recovery time.

  4. 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

  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. Assembly of nanozeolite monolayers on the gold substrates of piezoelectric sensors.

    PubMed

    Biemmi, Enrica; Bein, Thomas

    2008-10-01

    Colloidal zeolites NaA (LTA structure type) and ZSM-5 (MFI-type) with crystal diameters of about 100 nm were synthesized as building blocks for the formation of microporous self-limiting monolayers on the piezo-active area (gold electrodes) of a quartz crystal microbalance (QCM). Two different coupling strategies were explored, concerning the modification of either the gold substrate or the external zeolite crystal surface with a bifunctional molecular interface. Diverse analytical methods were employed to fully characterize the materials (dynamic light scattering, X-ray diffraction, infrared and Raman spectroscopy, solid state 29Si NMR spectroscopy, N2 sorption) and to study the process of coupling the zeolite crystals to the gold surface (reflection-absorption IR spectroscopy, scanning electron microscopy). The molecularly selective sensing behavior of these zeolite-coated devices is demonstrated by measuring the full adsorption isotherms of n-butane and i-butane in the microporous films.

  7. 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.

  8. Enzymatic hydrolysis of esters containing a tetrazole ring.

    PubMed

    Łukowska-Chojnacka, Edyta; Mierzejewska, Jolanta

    2014-12-01

    The lipase-catalyzed enantioselective hydrolysis of acetates containing tetrazole moiety was studied. Among all tested lipases, Novozyme SP 435 allowed to obtain optically active 4-(5-aryl-2H-tetrazol-2yl)butan-2-ol and 1-(5-aryl-2H-tetrazol-2yl)-propan-2-ol and their acetates with the highest optical purities (ee = 95%-99%) and excellent enantioselectivity (E>100). Some of the synthesized tetrazole derivatives were screened for their antifungal activity. Racemic mixtures of 4-[5-(4-chlorophenyl)-2H-tetrazol-2-yl)butan-2-ol as well as pure enantiomers of this compound showed promising antifungal activity against F. sambucinum, F. oxysporum, C. coccodes, and A. niger.

  9. 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.

  10. 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.

  11. Monitoring breath during oral glucose tolerance tests.

    PubMed

    Ghimenti, S; Tabucchi, S; Lomonaco, T; Di Francesco, F; Fuoco, R; Onor, M; Lenzi, S; Trivella, M G

    2013-03-01

    The evolution of breath composition during oral glucose tolerance tests (OGTTs) was analysed by thermal desorption/gas chromatography/mass spectrometry in 16 subjects and correlated to blood glucose levels. The glucose tolerance tests classified five of the subjects as diabetics, eight as affected by impaired glucose tolerance and three as normoglycaemic. Acetone levels were generally higher in diabetics (average concentration values: diabetics, 300 ± 40 ppbv; impaired glucose tolerance, 350 ± 30 ppbv; normoglycaemic, 230 ± 20 ppbv) but the large inter-individual variability did not allow us to identify the three groups by this parameter alone. The exhalation of 3-hydroxy-butan-2-one and butane-2,3-dione, likely due to the metabolization of glucose by bacteria in the mouth, was also observed. Future work will involve the extension of the analyses to other volatile compounds by attempting to improve the level of discrimination between the various classes of subjects. PMID:23446273

  12. Probing the low temperature initiation sites in Fe-, Mn-promoted sulfated zirconia via CO and H{sub 2} adsorption

    SciTech Connect

    Sayari, A.; Yang, Y.

    1999-10-01

    Exposure of freshly activated Fe-, Mn-promoted sulfated zirconia (SFMZ) to carbon monoxide at temperatures up to 50 C induced permanent loss of activity, while the addition of CO after the beginning of the reaction had a reversible effect, regardless of whether the butane flow has been interrupted or not. Similar experiments using dissociated hydrogen instead of CO led to irreversible poisoning in all cases. These findings were interpreted based on (1) the occurrence of initiation sites that are consumed stoichiometrically and very rapidly upon exposure to butane, (2) such initiation sites which are also consumed by CO or dissociated hydrogen, (3) CO which competes effectively for adsorption sites without affecting accumulated reaction intermediates, and (4) such intermediates that are removed in the presence of dissociated hydrogen.

  13. Characterization of different precursors and activated vanadium phosphate catalysts by [sup 31]P NMR spin echo mapping

    SciTech Connect

    Sananes, M.T. Univ. of Liverpool ); Tuel, A.; Volta, J.C. ); Hutchings, G.J. )

    1994-07-01

    In a previous publication, the authors emphasized the use of the spin echo mapping technique applied to [sup 31]P NMR to obtain information on the valence state of vanadium in different environments of phosphorus for several VPO reference structures. In this paper, the authors describe the use of this technique, combined with knowledge of reference phases, to study VPO catalysts prepared from different precursors and used for the oxidation of n-butane into maleic anhydride. 9 refs., 2 figs., 1 tab.

  14. Amines in the marking fluid and anal sac secretion of the tiger, Panthera tigris.

    PubMed

    Banks, G R; Buglass, A J; Waterhouse, J S

    1992-01-01

    Analysis of the marking fluid of two tigers (one Bengal and one Sumatran) by GC using an amine-specific column and a nitrogen-specific detector has shown the presence of the following amines: ammonia, methylamine, dimethylamine, trimethylamine, triethylamine, propylamine, and butane-1,4-diamine (putrescine). In contrast to previously published reports, we were unable to detect 2-phenylethylamine. The anal sac secretion was found to have a similar amine content.

  15. Metabolism of Diethyl Ether and Cometabolism of Methyl tert-Butyl Ether by a Filamentous Fungus, a Graphium sp

    PubMed Central

    Hardison, L. K.; Curry, S. S.; Ciuffetti, L. M.; Hyman, M. R.

    1997-01-01

    In this study, evidence for two novel metabolic processes catalyzed by a filamentous fungus, Graphium sp. strain ATCC 58400, is presented. First, our results indicate that this Graphium sp. can utilize the widely used solvent diethyl ether (DEE) as the sole source of carbon and energy for growth. The kinetics of biomass accumulation and DEE consumption closely followed each other, and the molar growth yield on DEE was indistinguishable from that with n-butane. n-Butane-grown mycelia also immediately oxidized DEE without the extracellular accumulation of organic oxidation products. This suggests a common pathway for the oxidation of both compounds. Acetylene, ethylene, and other unsaturated gaseous hydrocarbons completely inhibited the growth of this Graphium sp. on DEE and DEE oxidation by n-butane-grown mycelia. Second, our results indicate that gaseous n-alkane-grown Graphium mycelia can cometabolically degrade the gasoline oxygenate methyl tert-butyl ether (MTBE). The degradation of MTBE was also completely inhibited by acetylene, ethylene, and other unsaturated hydrocarbons and was strongly influenced by n-butane. Two products of MTBE degradation, tert-butyl formate (TBF) and tert-butyl alcohol (TBA), were detected. The kinetics of product formation suggest that TBF production temporally precedes TBA accumulation and that TBF is hydrolyzed both biotically and abiotically to yield TBA. Extracellular accumulation of TBA accounted for only a maximum of 25% of the total MTBE consumed. Our results suggest that both DEE oxidation and MTBE oxidation are initiated by cytochrome P-450-catalyzed reactions which lead to scission of the ether bonds in these compounds. Our findings also suggest a potential role for gaseous n-alkane-oxidizing fungi in the remediation of MTBE contamination. PMID:16535667

  16. 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.

  17. 40 CFR 98.408 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... GREENHOUSE GAS REPORTING Suppliers of Natural Gas and Natural Gas Liquids § 98.408 Definitions. All terms...) Natural Gas 1.027 MMBtu/Mscf 53.02 Propane 3.836 MMBtu/bbl 63.02 Normal butane 4.326 MMBtu/bbl 64.93... Unit Default CO2 emission value(MT CO2/Unit) Natural Gas Mscf 0.054452 Propane Barrel 0.241745...

  18. What are future petrochemical feedstocks?

    SciTech Connect

    Manning, T.J.

    1997-05-01

    Continuing growth in olefins and aromatics demand will require investment in production facilities worldwide. Feedstock selection for these new plants must take into account changing co-product demand patterns and production technology. Feedstock availability and logistics will be the most important considerations. Competition with fuel demand will encourage petrochemical producers to increase feedstock integration, to expand feedstock flexibility and to seek new feedstock sources. The paper discusses the following feedstocks: ethane, propane, butane, naphtha, gas oil, and condensate.

  19. Superacid catalysis of light hydrocarbon conversion. Sixth quarterly report, January 1, 1995--March 31, 1995

    SciTech Connect

    Gates, B.C.

    1995-08-01

    Iron- and Manganese-promoted sulfated zirconia is a catalyst for the conversion of propane, but the rate of conversion of propane is much less than the rate of conversion of butane. Whereas this catalyst appears to be a good candidate for practical, industrial conversion of butane, it appears to lack sufficient activity for practical conversion of propane. Perhaps more active catalysts will be useful for propane conversion. The propane conversion data reported here provide excellent insights into the chemistry of the catalytic conversions; they are consistent with the inference that the catalyst is a superacid and that the chemistry is analogous to. that determined in superacid solutions by G.A. Olah, who was awarded the most recent Nobel Prize in chemistry for his work. The catalyst was tested for conversion of propane at 1 bar, 200--300{degrees}C and propane partial pressures in the range of 0.01--0.05 bar. At 250{degrees}C, catalysis was demonstrated, as the number of propane molecules converted was at least 1 per sulfate group after 16 days of operation in a continues flow reactor. Propane was converted in high yield to butanes, but the conversions were low, for example being only a fraction of a percent at a space velocity of 9.1 {times} 10{sup {minus}7} mol(g of catalysis {center_dot} s) and 250{degrees}C. Coke formation was rapid. 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.

  20. Honey oil burns: a growing problem.

    PubMed

    Jensen, Guy; Bertelotti, Robert; Greenhalgh, David; Palmieri, Tina; Maguina, Pirko

    2015-01-01

    There is an emerging mechanism of burn injury as a result of the ignition of butane, during the manufacture of a tetrahydrocannabinol concentrate known as butane honey oil. The authors report of a series of patients who presented with this mechanism of injury and a description of the process that causes these burns. Patient data were gathered from the medical records of eight patients treated at the University of California Davis Medical Center and Shriners Hospital of Northern California. Information on the manufacturing process of butane honey oil was gathered from Internet searches and published literature on the topic. The burns witnessed at the abovementioned institutions ranged from 16 to 95% TBSA, with an average of 49.9%. The average length of stay for the patients was 118.3 hospital days and 114.4 intensive care unit days, with an average of 43.8 days spent on mechanical ventilation. The average age of patients was 22 years, with only one patient above the age of 30 years. Accidents during honey oil production have resulted in a surge of burn injuries in our community during the past year. The manufacture of this product, which involves the use of volatile butane gas, is gaining in popularity. Although considered to be safer than previous methods, multiple casualties with extensive burn injuries have resulted from this process. Associated injuries from blast trauma or chemical burns are not likely to occur in these types of explosions and have not been observed in the series reported in this article. In light of the increasing popularity of honey oil, it is important for burn care providers to gain awareness and understanding of this problem and its growing presence in the community.

  1. 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.

  2. 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.

  3. 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.

  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. Branch-Selective Alkene Hydroarylation by Cooperative Destabilization: Iridium-Catalyzed ortho-Alkylation of Acetanilides.

    PubMed

    Crisenza, Giacomo E M; Sokolova, Olga O; Bower, John F

    2015-12-01

    An iridium(I) catalyst system, modified with the wide-bite-angle and electron-deficient bisphosphine d(F) ppb (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

  6. 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.

  7. 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.

  8. The first route to highly stable crystalline microporous zirconium phosphonate metal-organic frameworks.

    PubMed

    Taddei, Marco; Costantino, Ferdinando; Marmottini, Fabio; Comotti, Angiolina; Sozzani, Piero; Vivani, Riccardo

    2014-12-01

    The first crystalline microporous zirconium phosphonate metal-organic framework (UPG-1) was synthesized using the novel tritopic ligand 2,4,6-tris(4-(phosphonomethyl)phenyl)-1,3,5-triazine. Its crystal structure was solved ab initio from laboratory powder X-ray diffraction data. UPG-1 displays remarkable thermal stability and hydrolysis resistance and has a good absorption affinity towards n-butane and CO2.

  9. Determination of volatile aroma compounds of Ganoderma lucidum by gas chromatography mass spectrometry (HS-GC/MS).

    PubMed

    Taşkın, Hatıra; Kafkas, Ebru; Çakıroğlu, Özgün; Büyükalaca, Saadet

    2013-01-01

    This study was conducted at Horticulture Department of Cukurova University, Adana, Turkey during 2010-2011. Fresh sample of Ganoderma lucidum collected from Mersin province of Turkey was used as material. Volatile aroma compounds were performed by Headspace Gas Chromatography (HS-GC/MS). Alcohols, aldehydes, acids, phenol, L-Alanine, d-Alanine, 3Methyl, 2-Butanamine, 2-Propanamine were determined. 1-Octen-3-ol (Alcohol) and 3-methyl butanal (Aldehyde) were identified as major aroma compounds.

  10. Amines in the marking fluid and anal sac secretion of the tiger, Panthera tigris.

    PubMed

    Banks, G R; Buglass, A J; Waterhouse, J S

    1992-01-01

    Analysis of the marking fluid of two tigers (one Bengal and one Sumatran) by GC using an amine-specific column and a nitrogen-specific detector has shown the presence of the following amines: ammonia, methylamine, dimethylamine, trimethylamine, triethylamine, propylamine, and butane-1,4-diamine (putrescine). In contrast to previously published reports, we were unable to detect 2-phenylethylamine. The anal sac secretion was found to have a similar amine content. PMID:1388518

  11. 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

  12. Honey oil burns: a growing problem.

    PubMed

    Jensen, Guy; Bertelotti, Robert; Greenhalgh, David; Palmieri, Tina; Maguina, Pirko

    2015-01-01

    There is an emerging mechanism of burn injury as a result of the ignition of butane, during the manufacture of a tetrahydrocannabinol concentrate known as butane honey oil. The authors report of a series of patients who presented with this mechanism of injury and a description of the process that causes these burns. Patient data were gathered from the medical records of eight patients treated at the University of California Davis Medical Center and Shriners Hospital of Northern California. Information on the manufacturing process of butane honey oil was gathered from Internet searches and published literature on the topic. The burns witnessed at the abovementioned institutions ranged from 16 to 95% TBSA, with an average of 49.9%. The average length of stay for the patients was 118.3 hospital days and 114.4 intensive care unit days, with an average of 43.8 days spent on mechanical ventilation. The average age of patients was 22 years, with only one patient above the age of 30 years. Accidents during honey oil production have resulted in a surge of burn injuries in our community during the past year. The manufacture of this product, which involves the use of volatile butane gas, is gaining in popularity. Although considered to be safer than previous methods, multiple casualties with extensive burn injuries have resulted from this process. Associated injuries from blast trauma or chemical burns are not likely to occur in these types of explosions and have not been observed in the series reported in this article. In light of the increasing popularity of honey oil, it is important for burn care providers to gain awareness and understanding of this problem and its growing presence in the community. PMID:24823328

  13. Self-organized Spiral and Circular Waves in Premixed Gas Flames

    NASA Technical Reports Server (NTRS)

    Pealman, Howard G.; Ronney, Paul D.

    1994-01-01

    A diffusive-thermal high Lewis number (Le) gas-phase oscillator has been observed in premixed flames using a lean mixture of butane and oxygen diluted with helium (Le approx. 3.0). This reactive-diffusive system exhibits both propagating radial pulsations and rotating spiral waves perhaps,analogous to those observed in other excitable media such as the Belousov-Zhabotinsky reaction.

  14. Self-organized spiral and circular waves in premixed gas flames

    NASA Technical Reports Server (NTRS)

    Pearlman, Howard G.; Ronney, Paul D.

    1994-01-01

    A diffusive-thermal high Lewis number (Le) gas-phase oscillator has been observed in premixed flames using a lean mixture of butane and oxygen diluted with helium (Le approximately equals 3.0). This reactive-diffusive system exhibits both propagating radial pulsations and rotating spiral waves perhaps analogous to those observed in other excitable media such as the Belousov-Zhabotinsky reaction.

  15. 40 CFR 60.707 - Chemicals affected by subpart RRR.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-7 Brometone 76-08-4 1,3-Butadiene 106-99-0 Butadiene and butene fractions n-Butane 106-97-8 1,4...-65-0 Butylbenzyl phthalate 85-68-7 tert-Butyl hydroperoxide 75-91-2 2-Butyne-1,4-diol 110-65-6... glycol 111-46-6 Di-isodecyl phthalate 26761-40-0 Dimethyl terephthalate 120-61-6 2,4-(and...

  16. A field-space conformal-solution method: Binary vapor-liquid phase behavior

    NASA Astrophysics Data System (ADS)

    Storvick, T. S.; Fox, J. R.

    1990-01-01

    The field-space conformal solution method provides an entirely new thermodynamic framework for the description of fluid mixtures in terms of the properties of a pure reference fluid. The utility and performance of the method are examined in the special case of vapor-liquid equilibrium correlation for simple mixtures. This is one of several cases in which field-space methods have numerical or theoretical advantages over methods presently used in mixture property correlation; only properties along the vapor pressure curve of the purefluid reference system are required for a complete description of the mixture phase behavior. Vapor-liquid equilibrium data for three binary hydrocarbon mixtures, n-butane + n-pentane, n-butane + n-hexane, and n-butane + n-octane, are correlated with a simple implementation of the method having two independent mixture parameters. Two pure-fluid equations of state, a Peng-Robinson equation and a 32-constant modified Benedict-Webb-Rubin equation, are tested as reference systems. The effects of differences in the quality of the reference system and of a range of mixture component size ratios are examined.

  17. 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

  18. LPG Dependence after a Suicide Attempt

    PubMed Central

    Aldemir, Ebru; Akyel, Betül; Altıntoprak, A. Ender; Aydın, Rezzan; Coşkunol, Hakan

    2015-01-01

    Inhalant abuse is a problem that is getting more common all around the world. The increase in prevalence of inhalant abuse escalates morbidity and mortality rates. About 22% of people using inhalant have died at their first attempt. Particularly propane, butane, or propane-butane mixture has highest mortality rates. Sudden sniffing death syndrome, cardiomyopathy, central nervous system toxicity, hematological abnormalities, kidney toxicity, and hepatocellular toxicities are the major complications of inhalant abuse. Herein we present a patient with inhalant use disorder. At the age of 19, after a stressful life event he had unsuccessfully tried to suicide by inhaling LPG (liquefied petroleum gas, a mixture of butane and propane gases). After he realized that he had hallucinations and felt better during the inhalation, he started to abuse it. He was addicted to LPG for 10 years at the time of admission. Besides being dangerous for the society security, this intense level of LPG inhalation (12 liters a day) not giving any physical harm makes this case interesting. PMID:25664196

  19. 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.

  20. Superacid catalysis of light hydrocarbon conversion. Eleventh quarterly report, April 1, 1996--June 30, 1996

    SciTech Connect

    Gates, B.C.

    1996-12-31

    The new catalyst Fe- and Mn-promoted sulfated zirconia is remarkably active for the low-temperature (even room temperature) isomerization of n-butane to give isobutane in the near absence of side products. Thus this catalyst offers excellent potential for practical application in this process. The catalyst is so active that it even converts smaller alkanes, including propane and ethane. The ethane conversion is orders of magnitude slower than the butane conversion, and the prospects for practical application with ethane are apparently negligible. However, the results for ethane conversion provide strong evidence that the alkane conversions proceed (at least under some conditions) by protonation of the alkane with the catalyst; thus the catalyst is comparable to superacids, and the chemistry is analogous to that occurring in superacid solutions. This insight will be useful in further improvement of the catalyst and the potential process for butane isomerization. The catalyst is active for alkane cracking at temperatures of typically 200-300{degrees}C, and evidence, summarized here, indicates that numerous reactions of alkanes begin as the catalyst protonates the alkane reactant. The kinetics data for this family of reactions fall on a linear compensation effect plot; such data for reactions that do not proceed via such a mechanism do not fall near the line representing the compensation effect. Thus the analysis of the kinetics data provides a good diagnostic tool for understanding the fundamental chemistry of the acid-catalyzed hydrocarbon conversions.

  1. 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.

  2. 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.

  3. Cut C/sub 4/ recovery costs

    SciTech Connect

    Strigle, R.F.; Fukuyo, K.

    1986-06-01

    A system to recover 1-butene, consisting of a four column distillation train, has been installed in Nippon Petrochemical Co., Ltd's. plant. The first two columns were operated in series and removed iso-butane overhead as distillate from the other C/sub 4/ hydrocarbons in the feed. The last two columns also were operated in series and recovered high purity 1-butene (99+ percent) as distillate using the bottoms from the first pair of columns as feed. The bottoms from this second pair of columns contained all the n-butane present in the feed to the system plus the 2-butene isomers. The distillate from the first pair of columns was combined with the bottoms from the second pair of columns, and this mixture was sold as butane fuel. Each of the first pair of columns contained 70 actual trays on 400-mm spacing. These single-pass trays developed an overall efficiency of only 59 percent. Table 1 shows the operation of the first pair of the trayed columns separating isobutane from 1-butene. The relative volatility between isobutane and 1-butene is very low-only 1.10. In fact, this separation has such a low relative volatility that the temperature rise is only 1/sup 0/C per theoretical stage.

  4. 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.

  5. 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

  6. 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

  7. Analysis of volatiles in meat from Iberian pigs and lean pigs after refrigeration and cooking by using SPME-GC-MS.

    PubMed

    Estévez, Mario; Morcuende, David; Ventanas, Sonia; Cava, Ramón

    2003-05-21

    The volatile compounds generated in meat from Iberian and lean pigs after four different treatments (raw, refrigerated, cooked, and refrigerated cooked meat) were analyzed. The different treatments showed different volatile profiles. Methyl alcohols and ketones (such as 2-ethyl-hexan-1-ol, 2-methyl-butan-1-ol, 3-methyl-butan-1-ol, and 3-hydroxy-butan-2-one) were the most representative in refrigerated meat because of the degradation of carbohydrates and proteins together with the Strecker degradation pathway. Lipid-derived volatiles were the most abundant in cooked meat and refrigerated cooked meat. Meat from different pig breeds presented different volatile profiles, probably due to different enzymatic and oxidative deterioration susceptibility. Otherwise, the fat content and its compositional characteristics also played an important role in the generation of volatiles. As compared to samples from lean pigs, muscles from Iberian pigs showed a higher content of heme iron that may have promoted the generation of higher content of total lipid-derived volatiles during the refrigeration of cooked meat. Despite that, the formation of volatiles with low thresholds and related to intense rancidity perception likely to be derived from polyunsaturated fatty acids was higher in lean pork than in meat from Iberian pigs. This might be expected to lead to a more intense development of a warmed over flavor during refrigeration of cooked samples from lean pigs.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  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. [Determination of butene-fipronil residue in dry samples by multiple adsorption synchronous purification-gas chromatography-mass spectrometry].

    PubMed

    Ding, Liping; Guo, Jing; Zheng, Ling; Chen, Chuntian; Chen, Zhitao

    2013-08-01

    A method was developed for the determination of butene-fipronil residue in dry samples by multiple adsorption synchronous purification (MASP) -gas chromatography (GC) -mass spectrometry (MS). After extracted with 1% acetic acid-acetonitrile, the samples were pretreated with MASP method including extraction, salting-out and purification procedures, and analyzed with GC-MS under the selected ion monitoring (SIM) mode, and then quantified by matrix-match standard solution with external standard method. The results showed good linearity in the range of 2 - 100 microg/L with the correlation coefficients (r(2)) not less than 0.999. The average fortified recovery of butene-fipronil in samples was found in the range of 92.2% - 97.5% at three fortified levels from 2 to 10 microg/kg, with the relative standard deviations of 2.69% - 5.21% (n = 6). The limit of detection (S/N = 3) for butane-fipronil was 2 microg/kg and the limit of quantification (S/N = 10) was 6 microg/kg. The method is simple, rapid and accurate, and could be used for the routine analysis of butane-fipronil in dry samples. Meanwhile, the pyrolysis mechanism of butane-fipronil, as a new substance, is discussed. PMID:24369607

  14. LPG Dependence after a Suicide Attempt.

    PubMed

    Aldemir, Ebru; Akyel, Betül; Altıntoprak, A Ender; Aydın, Rezzan; Coşkunol, Hakan

    2015-01-01

    Inhalant abuse is a problem that is getting more common all around the world. The increase in prevalence of inhalant abuse escalates morbidity and mortality rates. About 22% of people using inhalant have died at their first attempt. Particularly propane, butane, or propane-butane mixture has highest mortality rates. Sudden sniffing death syndrome, cardiomyopathy, central nervous system toxicity, hematological abnormalities, kidney toxicity, and hepatocellular toxicities are the major complications of inhalant abuse. Herein we present a patient with inhalant use disorder. At the age of 19, after a stressful life event he had unsuccessfully tried to suicide by inhaling LPG (liquefied petroleum gas, a mixture of butane and propane gases). After he realized that he had hallucinations and felt better during the inhalation, he started to abuse it. He was addicted to LPG for 10 years at the time of admission. Besides being dangerous for the society security, this intense level of LPG inhalation (12 liters a day) not giving any physical harm makes this case interesting. PMID:25664196

  15. Expansion fractionation capacity of the LPG-ULE plant

    SciTech Connect

    Morin, L.M.C.

    1999-07-01

    The Western Division of PDVSA has among other facilities a NGL Fractionation Complex located onshore in Ul'e. The complex consists of three plants, the first and second older plants, LPG-1 and LPG-2, which fractionate the NGL to produce propane, a butane mix and natural gasoline. The third plant, LPG-3, fractionates the butane mix from the LPG-1 and 2 plants to produce iso and normal butane. Several optimization projects already in progress will increase the NGL production to 12,200 b/d. For this reason it was decided to conduct a study of the existing fractionation facilities and utilities systems to determine their capacities. This evaluation revealed that some of the fractionation towers would have some limitations in the processing of the expected additional production. The study recommended an option to increase the capacity of the fractionation towers by lowering their operating pressure, in order to take advantage of relative volatility increase between the key components, which allows easier separation, as well as reducing the heat duty required. The completed study also determined that this option is more economically convenient than the replacement of the existing fractionation towers.

  16. Hybrid simulations: combining atomistic and coarse-grained force fields using virtual sites.

    PubMed

    Rzepiela, Andrzej J; Louhivuori, Martti; Peter, Christine; Marrink, Siewert J

    2011-06-14

    Hybrid simulations, in which part of the system is represented at atomic resolution and the remaining part at a reduced, coarse-grained, level offer a powerful way to combine the accuracy associated with the atomistic force fields to the sampling speed obtained with coarse-grained (CG) potentials. In this work we introduce a straightforward scheme to perform hybrid simulations, making use of virtual sites to couple the two levels of resolution. With the help of these virtual sites interactions between molecules at different levels of resolution, i.e. between CG and atomistic molecules, are treated the same way as the pure CG-CG interactions. To test our method, we combine the Gromos atomistic force field with a number of coarse-grained potentials, obtained through several approaches that are designed to obtain CG potentials based on an existing atomistic model, namely iterative Boltzmann inversion, force matching, and a potential of mean force subtraction procedure (SB). We also explore the use of the MARTINI force field for the CG potential. A simple system, consisting of atomistic butane molecules dissolved in CG butane, is used to study the performance of our hybrid scheme. Based on the potentials of mean force for atomistic butane in CG solvent, and the properties of 1:1 mixtures of atomistic and CG butane which should exhibit ideal mixing behavior, we conclude that the MARTINI and SB potentials are particularly suited to be combined with the atomistic force field. The MARTINI potential is subsequently used to perform hybrid simulations of atomistic dialanine peptides in both CG butane and water. Compared to a fully atomistic description of the system, the hybrid description gives similar results provided that the dielectric screening of water is accounted for. Within the field of biomolecules, our method appears ideally suited to study e.g. protein-ligand binding, where the active site and ligand are modeled in atomistic detail and the rest of the protein

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

    SciTech Connect

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

    2014-05-28

    In the present work, we have illustrated the physics of the multifunctional characteristics of nano-crystalline LaFeO{sub 3} powder prepared using auto-combustion synthesis. The synthesized powders were phase pure and crystallized into centro-symmetric Pnma space group. The temperature dependence of dielectric constant of pure LaFeO{sub 3} exhibits dielectric maxima similar to that observed in ferroelectric ceramics with non-centrosymmetric point group. The dielectric relaxation of LaFeO{sub 3} correlates well with small polaron conduction. The occurrence of polarization hysteresis in LaFeO{sub 3} (with centro-symmetric Pnma space group) is thought to be spin current induced type. The canting of the Fe{sup 3+} spins induce weak ferromagnetism in nano-crystalline LaFeO{sub 3}. Room temperature saturation magnetization of pure LaFeO{sub 3} is reported to be 3.0 emu/g. Due to the presence of both ferromagnetic as well as polarization ordering, LaFeO{sub 3} behaves like a single phase multiferroic ceramics. The magneto-electric coupling in this system has been demonstrated through the magneto-dielectric measurements which yield about 0.8% dielectric tuning (at 10 kHz) with the application of 2 T magnetic field. As a typical application of the synthesized nano-crystalline LaFeO{sub 3} powder, we have studied its butane sensing characteristics. The efficient butane sensing characteristics have been correlated to their catalytic activity towards oxidation of butane. Through X-ray photoelectron spectroscopy analyses, we detect the surface adsorbed oxygen species on LaFeO{sub 3} surface. Surface adsorbed oxygen species play major role in their low temperature butane sensing. Finally, we have hypothesized that the desorbed H{sub 2}O and O{sub 2} (originate from surface adsorbed hydroxyl and oxygen) initiate the catalytic oxidative dehydrogenation of n-butane resulting in weakening of the electrostatics of the gas molecules.

  18. 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

  19. Hydrophobic Dewatering of Fine Coal. Topical report, March 1, 1995-March 31, 1997

    SciTech Connect

    Yoon, R.; Sohn, S.; Luttrell, J.; Phillips, D.

    1997-12-31

    Many advanced fine coal cleaning technologies have been developed in recent years under the auspices of the U.S. Department of Energy. However, they are not as widely deployed in industry as originally anticipated. An important reason for this problem is that the cleaned coal product is difficult to dewater because of the large surface area associated with fine particles. Typically, mechanical dewatering, such as vacuum filtration and centrifugation, can reduce the moisture to 20-35% level, while thermal drying is costly. To address this important industrial problem, Virginia Tech has developed a novel dewatering process, in which water is displaced from the surface of fine particulate materials by liquid butane. Since the process is driven by the hydrophobic interaction between coal and liquid butane, it was referred to as hydrophobic dewatering (HD). A fine coal sample with 21.4 pm median size was subjected to a series of bench-scale HD tests. It was a mid-vol bituminous coal obtained from the Microcel flotation columns operating at the Middle Fork coal preparation plant, Virginia. All of the test results showed that the HD process can reduce the moisture to substantially less than 10%. The process is sensitive to the amount of liquid butane used in the process relative to the solids concentration in the feed stream. Neither the intensity nor the time of agitation is critical for the process. Also, the process does not require long time for phase separation. Under optimal operating conditions, the moisture of the fine coal can be reduced to 1% by weight of coal.

  20. Examination of DFT and TDDFT Methods II

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Gui

    2009-09-01

    We investigated the isomerization energies for C8 alkanes (n-octane and 2,2,3,3-tetra-methyl butane) and 1-X-propenes (X = CH3, F, Cl, Br) and the excited states for tropolone. The recently implemented TDDFT gradients enabled us to optimize the adiabatic excited-state structures and to obtain wave function files for excited-state electron density analyses with 25 functionals. The dispersion interactions had been found to be important for predicting the isomerization energies for n-octane and 2,2,3,3-tetra-methyl butane and for cis- and trans-1-X-propenes (X = CH3, F, Cl, Br). B3LYP failed to predict the isomerization energies for the first case but succeeded for the latter. We noticed that the integrated electron density and the merging contour values in the electron density difference plots were related to the isomerization energies; the DFT functionals (LSDA, BHandH, VSXC, and M052X) that could correctly account for the dispersion forces produced a greater electron density response for 2,2,3,3-tetramethyl butane than n-octane. Although the faster proton transfer reaction rate in the Ã1B2 excited state relative to the X˜1A1 ground state of tropolone could be reproduced only by M052X, the three newly designed functionals (BMK, CAM-B3LYP, and M052X) apparently performed better than other DFT functionals. The C-C' bond lengths of the Cs symmetry excited state were possibly underestimated by DFT methods; the underestimation of C-C' bond lengths contributed to the high proton transfer barriers in the Ã1B2 excited state of tropolone.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. Degradation of chlorinated butenes and butadienes in granular iron columns.

    PubMed

    Hughes, Rodney; Gui, Lai; Gillham, Robert W

    2009-10-01

    Manufacturing facilities for production of chlorobutyl rubber have the potential to release a mixture of at least 5 chlorinated butenes and butadienes including trans-1,4-dichlorobutene-2 (1,4-DCB-2), 3,4-dichlorobutene-1 (3,4-DCB-1), 2,3,4-trichlorobutene-1 (TCB), 2-chlorobutadiene-1,3 (chloroprene) and 2,3-dichlorobutadiene-1,3 (DCBD) into groundwater environment. To evaluate the potential of using granular iron in the remediation of the above contaminants, a series of column experiments were conducted. Degradation of all 5 compounds followed pseudo-first-order kinetics. The three chlorinated butenes degraded much faster (surface area normalized half-lives, t(1/2)', ranged from 1.6 to 5.2 min m2/mL) than the 2 chlorinated butadienes (t(1/2)' ranged from 102 to 197 min m2/mL). All contaminants fully dechlorinated by granular iron to 1,3-butadiene as a common reaction intermediate that then degraded to a mixture of relatively non-harmful end products consisting of 1-butene, cis-2-butene, trans-2-butene and n-butane. Based on the kinetic data, product distributions, and chlorine mass balances, reaction pathways for these compounds are proposed. For the chlorinated butenes, 3,4-DCB-1 and TCB, undergo reductive beta-elimination reactions resulting in 1,3-butadiene and chloroprene intermediates. Dechlorination of 1,4-DCB-2 to 1,3-butadiene occurs through a reductive elimination similar to reductive beta-elimination. For dechlorination of the two chlorinated butadienes, chloroprene and DCBD, dechlorination occurs through a hydrogenolysis pathway. The common non-chlorinated intermediate, 1,3-butadiene, undergoes catalytic hydrogenation resulting in a mixture of butane isomers and n-butane. The results suggest that granular iron is an effective material for treatment of groundwater contaminated with these compounds.

  6. Unravelling the impact of hydrocarbon structure on the fumarate addition mechanism--a gas-phase ab initio study.

    PubMed

    Bharadwaj, Vivek S; Vyas, Shubham; Villano, Stephanie M; Maupin, C Mark; Dean, Anthony M

    2015-02-14

    The fumarate addition reaction mechanism is central to the anaerobic biodegradation pathway of various hydrocarbons, both aromatic (e.g., toluene, ethyl benzene) and aliphatic (e.g., n-hexane, dodecane). Succinate synthase enzymes, which belong to the glycyl radical enzyme family, are the main facilitators of these biochemical reactions. The overall catalytic mechanism that converts hydrocarbons to a succinate molecule involves three steps: (1) initial H-abstraction from the hydrocarbon by the radical enzyme, (2) addition of the resulting hydrocarbon radical to fumarate, and (3) hydrogen abstraction by the addition product to regenerate the radical enzyme. Since the biodegradation of hydrocarbon fuels via the fumarate addition mechanism is linked to bio-corrosion, an improved understanding of this reaction is imperative to our efforts of predicting the susceptibility of proposed alternative fuels to biodegradation. An improved understanding of the fuel biodegradation process also has the potential to benefit bioremediation. In this study, we consider model aromatic (toluene) and aliphatic (butane) compounds to evaluate the impact of hydrocarbon structure on the energetics and kinetics of the fumarate addition mechanism by means of high level ab initio gas-phase calculations. We predict that the rate of toluene degradation is ∼100 times faster than butane at 298 K, and that the first abstraction step is kinetically significant for both hydrocarbons, which is consistent with deuterium isotope effect studies on toluene degradation. The detailed computations also show that the predicted stereo-chemical preference of the succinate products for both toluene and butane are due to the differences in the radical addition rate constants for the various isomers. The computational and kinetic modeling work presented here demonstrates the importance of considering pre-reaction and product complexes in order to accurately treat gas phase systems that involve intra and inter

  7. The anaerobic degradation of gaseous, nonmethane alkanes - From in situ processes to microorganisms.

    PubMed

    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 (13)C 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

  8. Synthesis and Antiviral Activity of Quercetin Brominated Derivatives.

    PubMed

    Karimova, Elza; Baltina, Lidia; Spirikhin, Leonid; Gabbasov, Tagir; Orshanskaya, Yana; Zarubaev, Vladimir

    2015-09-01

    Reaction of quercetin (QR) (1) with bromine under various conditions was studied. Interaction of QR with 2-3 equiv. of bromine in glacial acetic acid at 35-40°C for 2-4 h and 20-22°C for 24 h led to the formation of QR 6,8-dibromide (2) (52-54% yields, 96-98% purity by HPLC). Interaction of QR with 2-5 equiv. bromine in absolute ethanol at 0-5°C and 20-22°C for 24 h led to the formation of 3-O-ethyl-QR-2,3,6,8,5'-pentabromide (3) (95-97% purity by HPLC) the output of which depends on the quantity of bromine. It was shown in MDCK cell culture that compound 2 exhibits a moderate inhibitory activity against pandemic influenza virus A/H1N1/pdm09 (EC50 6.0 µg/mL, CTD50 97.7 µg/mL, SI 16). Compound 3 was inactive.

  9. Synthesis, structure and transmetalation of N-heterocyclic carbene complex of silver. Evidence of halogen exchange during the synthetic process.

    PubMed

    Xiao, Xu-Qiong; Jin, Guo-Xin

    2009-11-14

    Deprotonation of the bis(imidazolium) salt (1,1'-dimethyl-3,3'-ethylenediimidazolium dibromide, L x 2HBr) with silver oxide in a solution mixture of CH(2)Cl(2) and CH(3)OH affords a silver carbene complex [Ag(2)L(2)]Cl(2) (1, L = 1,1'-dimethyl-3,3'-ethylenediimidazol-2-ylidene). With CH(3)OH as the only solvent for the synthesis and after recrystallization in a chlorinated solvent in ambient condition, a polymeric silver complex [(L x 2H)(Ag(2)Br(4))](n) (2) was formed. The presence of chloride in complex 1 and bromide in complex 2 indicates that a halogen exchange reaction occurred unambiguously during the synthesis and not during recrystallization. The silver-carbene complex 1 undergoes a facile reaction with [(p-cymene)RuCl(2)](2) and (p-cymene)Ru[S(2)C(2)(B(10)H(10))] to yield the binuclear complexes [(p-cymene)RuCl(2)](2)L (3) and {(p-cymene)Ru[S(2)C(2)(B(10)H(10))]}(2)L (4). The latter compound contains a carbene ligand and a 1,2-dicarba-closo-dodecaborane ligand. Molecular structures of complexes 1-4 were confirmed by X-ray single-crystal analyses.

  10. A Nonconventional Approach to Patterned Nanoarrays of DNA Strands for Template-Assisted Assembly of Polyfluorene Nanowires.

    PubMed

    Bae, Dong Geun; Jeong, Ji-Eun; Kang, Seok Hee; Byun, Myunghwan; Han, Dong-Wook; Lin, Zhiqun; Woo, Han Young; Hong, Suck Won

    2016-08-01

    DNA molecules have been widely recognized as promising building blocks for constructing functional nanostructures with two main features, that is, self-assembly and rich chemical functionality. The intrinsic feature size of DNA makes it attractive for creating versatile nanostructures. Moreover, the ease of access to tune the surface of DNA by chemical functionalization offers numerous opportunities for many applications. Herein, a simple yet robust strategy is developed to yield the self-assembly of DNA by exploiting controlled evaporative assembly of DNA solution in a unique confined geometry. Intriguingly, depending on the concentration of DNA solution, highly aligned nanostructured fibrillar-like arrays and well-positioned concentric ring-like superstructures composed of DNAs are formed. Subsequently, the ring-like negatively charged DNA superstructures are employed as template to produce conductive organic nanowires on a silicon substrate by complexing with a positively charged conjugated polyelectrolyte poly[9,9-bis(6'-N,N,N-trimethylammoniumhexyl)fluorene dibromide] (PF2) through the strong electrostatic interaction. Finally, a monolithic integration of aligned arrays of DNA-templated PF2 nanowires to yield two DNA/PF2-based devices is demonstrated. It is envisioned that this strategy can be readily extended to pattern other biomolecules and may render a broad range of potential applications from the nucleotide sequence and hybridization as recognition events to transducing elements in chemical sensors. PMID:27351291

  11. Superfund Record of Decision (EPA Region 7): Hastings Ground Water Contamination FAR-MAR-CO subsite, Hastings Irrigation Pipe Company TCA Soils Operable Unit, Hastings, NE. (Second remedial action), September 1990

    SciTech Connect

    Not Available

    1990-09-28

    The Hastings Ground Water Contamination site (FAR-MAR-CO) is a contaminated aquifer in and near the city of Hastings, Adams County, Nebraska. The site consists of seven source areas, or subsites, contaminated with volatile industrial chemicals. The Record of Decision (ROD) addresses the Zone 2 portion of the FAR-MAR-CO subsite, which has been divided into two general areas of contamination referred to as Zone 1 and Zone 2. Zone 1, which includes grain elevators and areas to the north of the elevators, contains soil, soil-gas, and ground water contaminated with ethylene dibromide and carbon tetrachloride. Zone 1 contamination was addressed in a 1988 ROD. Zone 2, which is owned and operated by the Hastings Irrigation Pipe Company contains soil contamination primarily due to 1,1,1-trichloroethane (TCA) resulting from the disposal of cleaning solvents in Zone 2. Subsequent testing revealed that the concentration of TCA in Zone 2 had been reduced to a protective level. Response actions for ground water contamination near the FAR MAR CO subsite, however, will be addressed in subsequent remedial activities.

  12. Investigation of mortality from cancer and other causes of death among workers employed at an east Texas chemical plant

    SciTech Connect

    Sweeney, M.H.; Beaumont, J.J.; Waxweiler, R.J.; Halperin, W.E.

    1986-01-01

    The cause-specific mortality of 2,510 males employed at an east Texas chemical plant was examined in a historical prospective study to evaluate a suspected increase in deaths from multiple myeloma and brain cancer. Potential exposures from chemicals, either used in manufacturing processes or produced during the study period 1952-1977, included the fuel additive tetraethyl lead, ethylene dibromide and dichloride, inorganic lead, and vinyl chloride monomer. Overall mortality for all workers (156 observed vs. 211.14 expected) and for workers first employed between 1952 and 1959 (131 observed vs. 167.33 expected) when tetraethyl lead was the single major product was lower than expected when compared to the United States general population. There were no significant increases in mortality from malignancies or other causes of death. The deficits may be due to the small number of total deaths, and the low power for detecting excess risk of mortality from multiple myeloma (Z1-beta = 27, alpha = .05), brain cancer (Z1-beta = 31, alpha = .05), or other rare causes of death; lack of complete workplace exposure data for production workers; and the absence of historical measurements on the extent of environmental exposure to tetraethyl lead and other chemicals.

  13. Adaptor Protein Complex 2–Mediated Endocytosis Is Crucial for Male Reproductive Organ Development in Arabidopsis[W

    PubMed Central

    Kim, Soo Youn; Xu, Zheng-Yi; Song, Kyungyoung; Kim, Dae Heon; Kang, Hyangju; Reichardt, Ilka; Sohn, Eun Ju; Friml, Jiří; Juergens, Gerd; Hwang, Inhwan

    2013-01-01

    Fertilization in flowering plants requires the temporal and spatial coordination of many developmental processes, including pollen production, anther dehiscence, ovule production, and pollen tube elongation. However, it remains elusive as to how this coordination occurs during reproduction. Here, we present evidence that endocytosis, involving heterotetrameric adaptor protein complex 2 (AP-2), plays a crucial role in fertilization. An Arabidopsis thaliana mutant ap2m displays multiple defects in pollen production and viability, as well as elongation of staminal filaments and pollen tubes, all of which are pivotal processes needed for fertilization. Of these abnormalities, the defects in elongation of staminal filaments and pollen tubes were partially rescued by exogenous auxin. Moreover, DR5rev:GFP (for green fluorescent protein) expression was greatly reduced in filaments and anthers in ap2m mutant plants. At the cellular level, ap2m mutants displayed defects in both endocytosis of N-(3-triethylammonium-propyl)-4-(4-diethylaminophenylhexatrienyl) pyridinium dibromide, a lypophilic dye used as an endocytosis marker, and polar localization of auxin-efflux carrier PIN FORMED2 (PIN2) in the stamen filaments. Moreover, these defects were phenocopied by treatment with Tyrphostin A23, an inhibitor of endocytosis. Based on these results, we propose that AP-2–dependent endocytosis plays a crucial role in coordinating the multiple developmental aspects of male reproductive organs by modulating cellular auxin level through the regulation of the amount and polarity of PINs. PMID:23975898

  14. 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

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

    PubMed

    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.

  16. 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.

  17. The Hazard Evaluation System and Information Service: A Physician's Resource in Toxicology and Occupational Medicine

    PubMed Central

    Hooper, Kim

    1982-01-01

    Hazard evaluation is an emerging science. The Hazard Evaluation System and Information Service (HESIS), part of California's program in preventive occupational health, is a resource for clinicians who wish to stay abreast of the relationship between toxicology and occupational health. For example, advances in assays for cancer or reproductive effects in test animals enable us to identify with greater confidence significant cancer or reproductive hazards among the increasing variety of workplace exposures. Occupational experiences with dibromochloropropane (DBCP), Kepone, bis(chloromethyl) ether, benzidine and vinyl chloride demonstrate the shortcomings of relying on human data. The latency period of cancer, limited sensitivity of epidemiologic studies and severity of effects require us to use animal test data to evaluate the potential cancer and reproductive risks of workplace substances. HESIS gives appropriate weight to experimental data in hazard evaluations of chemicals such as ethylene oxide, ethylene dibromide, polychlorinated biphenyls and the glycol ethers. A similar approach is apparent in the California Department of Health Services' recently released Carcinogen Identification Policy. PMID:6819719

  18. 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.

  19. Health assessment for FMC Fresno National Priorities List (NPL) Site, Fresno, California, Region 9. CERCLIS No. CAD000629998. Preliminary report

    SciTech Connect

    Not Available

    1989-01-18

    The FMC Corporation Agricultural Chemical Group (FMC) Fresno plant has been proposed for the National Priorities List. FMC uses the plant to formulate pesticide products. Surface soil, subsurface soil, and ground water were sampled on- and off-site. No air sampling has been conducted. The soil samples identified several areas of contamination. Ground water samples show site related contaminants in the two upper water bearing zones of the Older Alluium Aquifer. The following contaminants are of public concern in the surface soil, subsurface soil, and groundwater: Toxaphene, DDD, DDT, DDE, BHC-beta, lindane, aldrin, endosulfan I, dieldrin, endosulfan II, methoxychlor, nitrate, 1,2-dichloropropane, pentachlorophenol, methyl ethyl ketone, methylene chloride, trichloroethylene, benefin, dibromochloropropane, casoron, and ethylene dibromide. The site is considered to be of public health concern because of the risk to human health caused by the likelihood of exposure to hazardous substances via inhalation of fugitive dust, ingestion of fugitive dust, soil, and ground water, and direct dermal contact with soil and ground water.

  20. Two different one-dimensional structural motifs in [catena-{Cu(tacn)}2Pd(CN)4]Br2.[catena-Cu(tacn)Pd(CN)4]2.H2O (tacn is 1,4,7-triazacyclononane).

    PubMed

    Kuchár, Juraj; Cernák, Juraj

    2009-07-01

    The title compound, catena-poly[[bis[(triazacyclononane-kappa(3)N,N',N'')copper(II)]-di-mu-cyanido-kappa(4)N:C-palladate(II)-di-mu-cyanido-kappa(4)C:N] dibromide bis[[(triazacyclononane-kappa(3)N,N',N'')copper(II)]-mu-cyanido-kappa(2)N:C-[dicyanidopalladate(II)]-mu-cyanido-kappa(2)C:N] monohydrate], {[Cu(2)Pd(CN)(4)(C(6)H(15)N(3))(2)]Br(2).[Cu(2)Pd(2)(CN)(8)(C(6)H(15)N(3))(2)].H(2)O}(n), (I), was isolated from an aqueous solution containing tacn.3HBr (tacn is 1,4,7-triazacyclononane), Cu(2+) and tetracyanidopalladate(2-) anions. The crystal structure of (I) is essentially ionic and built up of 2,2-electroneutral chains, viz. [Cu(tacn)(NC)-Pd(CN)(2)-(CN)-], positively charged 2,4-ribbons exhibiting the composition {[Cu(tacn)(NC)(2)-Pd(CN)(2)-Cu(tacn)](2n+)}(n), bromide anions and one disordered water molecule of crystallization. The O atom of the water molecule occupies two unique crystallographic positions, one on a centre of symmetry, which is half occupied, and the other in a general position with one-quarter occupancy. One of the tacn ligands also exhibits disorder. The formation of two different types of one-dimensional structural motif within the same structure is a unique feature of this compound. PMID:19578255