Comprehensive study of the evolution of gas-liquid partitioning of aroma compounds during wine alcoholic fermentation.

PubMed

Morakul, Sumallika; Athes, Violaine; Mouret, Jean-Roch; Sablayrolles, Jean-Marie

2010-09-22

Calculating the gas-liquid partitioning of aromatic molecules during winemaking fermentation is essential to minimize the loss of aroma and to optimize the fermentation conditions. In this study, the effect of the main fermentation parameters on the partition coefficients (ki) of higher alcohols (2-methylpropan-1-ol and 3-methyl butan-1-ol) and esters (ethyl acetate, 3-methyl-1-butyl acetate, and 2-ethyl hexanoate) was assessed. The values of ki were first determined in synthetic media simulating must and wine. They varied considerably with both the hydrophobicity of the compound and the composition of the medium. Then, the effect of temperature on ki was quantified. The absence of any effect of gas composition was also established by replacing air with CO2. Finally, the impact of CO2 stripping was assessed by running specific fermentations in which the rate of CO2 production was kept constant by perfusion with assimilable nitrogen. These fermentations showed that in contrast to temperature and must composition, CO2 stripping did not change the gas-liquid partitioning of higher alcohols and esters.

Solid-state molecular organometallic chemistry. Single-crystal to single-crystal reactivity and catalysis with light hydrocarbon substrates.

PubMed

Chadwick, F Mark; McKay, Alasdair I; Martinez-Martinez, Antonio J; Rees, Nicholas H; Krämer, Tobias; Macgregor, Stuart A; Weller, Andrew S

2017-08-01

Single-crystal to single-crystal solid/gas reactivity and catalysis starting from the precursor sigma-alkane complex [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(η 2 η 2 -NBA)][BAr F 4 ] (NBA = norbornane; Ar F = 3,5-(CF 3 ) 2 C 6 H 3 ) is reported. By adding ethene, propene and 1-butene to this precursor in solid/gas reactions the resulting alkene complexes [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(alkene) x ][BAr F 4 ] are formed. The ethene ( x = 2) complex, [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(ethene) 2 ][BAr F 4 ]-Oct , has been characterized in the solid-state (single-crystal X-ray diffraction) and by solution and solid-state NMR spectroscopy. Rapid, low temperature recrystallization using solution methods results in a different crystalline modification, [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(ethene) 2 ][BAr F 4 ]-Hex , that has a hexagonal microporous structure ( P 6 3 22). The propene complex ( x = 1) [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(propene)][BAr F 4 ] is characterized as having a π-bound alkene with a supporting γ-agostic Rh···H 3 C interaction at low temperature by single-crystal X-ray diffraction, variable temperature solution and solid-state NMR spectroscopy, as well as periodic density functional theory (DFT) calculations. A fluxional process occurs in both the solid-state and solution that is proposed to proceed via a tautomeric allyl-hydride. Gas/solid catalytic isomerization of d 3 -propene, H 2 C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 CHCD 3 , using [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(η 2 η 2 -NBA)][BAr F 4 ] scrambles the D-label into all possible positions of the propene, as shown by isotopic perturbation of equilibrium measurements for the agostic interaction. Periodic DFT calculations show a low barrier to H/D exchange (10.9 kcal mol -1 , PBE-D3 level), and GIPAW chemical shift calculations guide the assignment of the experimental data. When synthesized using solution routes a bis-propene complex, [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(propene) 2 ][BAr F 4 ] , is formed. [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(butene)][BAr F 4 ] ( x = 1) is characterized as having 2-butene bound as the cis -isomer and a single Rh···H 3 C agostic interaction. In the solid-state two low-energy fluxional processes are proposed. The first is a simple libration of the 2-butene that exchanges the agostic interaction, and the second is a butene isomerization process that proceeds via an allyl-hydride intermediate with a low computed barrier of 14.5 kcal mol -1 . [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(η 2 η 2 -NBA)][BAr F 4 ] and the polymorphs of [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(ethene) 2 ][BAr F 4 ] are shown to be effective in solid-state molecular organometallic catalysis (SMOM-Cat) for the isomerization of 1-butene to a mixture of cis - and trans -2-butene at 298 K and 1 atm, and studies suggest that catalysis is likely dominated by surface-active species. [Rh(Cy 2 PCH 2 CH 2 PCy 2 )(η 2 η 2 -NBA)][BAr F 4 ] is also shown to catalyze the transfer dehydrogenation of butane to 2-butene at 298 K using ethene as the sacrificial acceptor.

H Abstraction Channels in the Crossed-Beam Reaction of F + 1-Propanol, 1-Butene and 1-Hexene by DC Slice Imaging.

PubMed

Shi, Yuanyuan; Kamasah, Alexander; Suits, Arthur G

2016-11-17

We report a crossed molecular beam study of the reaction dynamics of fluorine atom with 1-propanol, 1-butene, and 1-hexene. The product alkoxy and alkenyl radicals were detected via dc slice imaging by 157 nm single photon ionization at collision energies around 10 kcal mol -1 . The analyzed data is interpreted with the aid of theoretical investigation of the relevant potential energy surfaces. The translational energy distribution and center-of-mass angular distribution of F + 1-propanol is quite similar to our previous results for F + n-butane, albeit with an increased fraction of the available energy in translation. In F atom reaction with alkenes, we also detected the HF formation channel. The low translational energy release and presence of significant backward scattering suggests the importance of an addition/elimination mechanism. Our selective single photon ionization probe allows us to examine the dynamics in minor channels in these systems. Although the probe is not sensitive to reaction at vinylic H sites, theoretical calculations consistently suggest a lower barrier from the addition complex to HF elimination involving vinylic H atoms.

40 CFR 1065.720 - Liquefied petroleum gas.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., C3H8 Minimum, 0.85 m3/m3 ASTM D2163-05. Vapor pressure at 38 °C Maximum, 1400 kPa ASTM D1267-02 or 2598-022. Volatility residue (evaporated temperature, 35 °C) Maximum, −38 °C ASTM D1837-02a. Butanes Maximum, 0.05 m3/m3 ASTM D2163-05. Butenes Maximum, 0.02 m3/m3 ASTM D2163-05. Pentenes and heavier Maximum...

Calculational and Experimental Investigations of the Pressure Effects on Radical - Radical Cross Combinations Reactions: C2H5 + C2H3

NASA Technical Reports Server (NTRS)

Fahr, Askar; Halpern, Joshua B.; Tardy, Dwight C.

2007-01-01

Pressure-dependent product yields have been experimentally determined for the cross-radical reaction C2H5 + C2H3. These results have been extended by calculations. It is shown that the chemically activated combination adduct, 1-C4H8*, is either stabilized by bimolecular collisions or subject to a variety of unimolecular reactions including cyclizations and decompositions. Therefore the "apparent" combination/disproportionation ratio exhibits a complex pressure dependence. The experimental studies were performed at 298 K and at selected pressures between about 4 Torr (0.5 kPa) and 760 Torr (101 kPa). Ethyl and vinyl radicals were simultaneously produced by 193 nm excimer laser photolysis of C2H5COC2H3 or photolysis of C2H3Br and C2H5COC2H5. Gas chromatograph/mass spectrometry/flame ionization detection (GC/MS/FID) were used to identify and quantify the final reaction products. The major combination reactions at pressures between 500 (66.5 kPa) and 760 Torr are (1c) C2H5 + C2H3 yields 1-butene, (2c) C2H5 + C2H5 yields n-butane, and (3c) C2H3 + C2H3 yields 1,3-butadiene. The major products of the disproportionation reactions are ethane, ethylene, and acetylene. At moderate and lower pressures, secondary products, including propene, propane, isobutene, 2-butene (cis and trans), 1-pentene, 1,4-pentadiene, and 1,5-hexadiene are also observed. Two isomers of C4H6, cyclobutene and/or 1,2-butadiene, were also among the likely products. The pressure-dependent yield of the cross-combination product, 1-butene, was compared to the yield of n-butane, the combination product of reaction (2c), which was found to be independent of pressure over the range of this study. The [ 1-C4H8]/[C4H10] ratio was reduced from approx.1.2 at 760 Torr (101 kPa) to approx.0.5 at 100 Torr (13.3 kPa) and approx.0.1 at pressures lower than about 5 Torr (approx.0.7 kPa). Electronic structure and RRKM calculations were used to simulate both unimolecular and bimolecular processes. The relative importance of C-C and C-H bond ruptures, cyclization, decyclization, and complex decompositions are discussed in terms of energetics and structural properties. The pressure dependence of the product yields were computed and dominant reaction paths in this chemically activated system were determined. Both modeling and experiment suggest that the observed pressure dependence of [1-C4H8]/[C4H10] is due to decomposition of the chemically activated combination adduct 1-C4H8* in which the weaker allylic C-C bond is broken: H2C=CHCH2CH3 yields C3H5 + CH3. This reaction occurs even at moderate pressures of approx.200 Torr (26 kPa) and becomes more significant at lower pressures. The additional products detected at lower pressures are formed from secondary radical-radical reactions involving allyl, methyl, ethyl, and vinyl radicals. The modeling studies have extended the predictions of product distributions to different temperatures (200-700 K) and a wider range of pressures (10(exp -3) - 10(exp 5) Torr). These calculations indicate that the high-pressure [1-C4H8]/[C4H10] yield ratio is 1.3 +/- 0.1.

Solid-state molecular organometallic chemistry. Single-crystal to single-crystal reactivity and catalysis with light hydrocarbon substrates† †Electronic supplementary information (ESI) available: Full details of experimental details, spectroscopic and other analytical data, X-ray crystallography, catalytic conditions, and computational studies. CCDC 1539832–1539836. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc01491k

PubMed Central

Chadwick, F. Mark; McKay, Alasdair I.; Martinez-Martinez, Antonio J.; Rees, Nicholas H.; Krämer, Tobias

2017-01-01

Single-crystal to single-crystal solid/gas reactivity and catalysis starting from the precursor sigma-alkane complex [Rh(Cy2PCH2CH2PCy2)(η2η2-NBA)][BArF4] (NBA = norbornane; ArF = 3,5-(CF3)2C6H3) is reported. By adding ethene, propene and 1-butene to this precursor in solid/gas reactions the resulting alkene complexes [Rh(Cy2PCH2CH2PCy2)(alkene)x][BArF4] are formed. The ethene (x = 2) complex, [Rh(Cy2PCH2CH2PCy2)(ethene)2][BArF4]-Oct, has been characterized in the solid-state (single-crystal X-ray diffraction) and by solution and solid-state NMR spectroscopy. Rapid, low temperature recrystallization using solution methods results in a different crystalline modification, [Rh(Cy2PCH2CH2PCy2)(ethene)2][BArF4]-Hex, that has a hexagonal microporous structure (P6322). The propene complex (x = 1) [Rh(Cy2PCH2CH2PCy2)(propene)][BArF4] is characterized as having a π-bound alkene with a supporting γ-agostic Rh···H3C interaction at low temperature by single-crystal X-ray diffraction, variable temperature solution and solid-state NMR spectroscopy, as well as periodic density functional theory (DFT) calculations. A fluxional process occurs in both the solid-state and solution that is proposed to proceed via a tautomeric allyl-hydride. Gas/solid catalytic isomerization of d3-propene, H2C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 CHCD3, using [Rh(Cy2PCH2CH2PCy2)(η2η2-NBA)][BArF4] scrambles the D-label into all possible positions of the propene, as shown by isotopic perturbation of equilibrium measurements for the agostic interaction. Periodic DFT calculations show a low barrier to H/D exchange (10.9 kcal mol–1, PBE-D3 level), and GIPAW chemical shift calculations guide the assignment of the experimental data. When synthesized using solution routes a bis-propene complex, [Rh(Cy2PCH2CH2PCy2)(propene)2][BArF4], is formed. [Rh(Cy2PCH2CH2PCy2)(butene)][BArF4] (x = 1) is characterized as having 2-butene bound as the cis-isomer and a single Rh···H3C agostic interaction. In the solid-state two low-energy fluxional processes are proposed. The first is a simple libration of the 2-butene that exchanges the agostic interaction, and the second is a butene isomerization process that proceeds via an allyl-hydride intermediate with a low computed barrier of 14.5 kcal mol–1. [Rh(Cy2PCH2CH2PCy2)(η2η2-NBA)][BArF4] and the polymorphs of [Rh(Cy2PCH2CH2PCy2)(ethene)2][BArF4] are shown to be effective in solid-state molecular organometallic catalysis (SMOM-Cat) for the isomerization of 1-butene to a mixture of cis- and trans-2-butene at 298 K and 1 atm, and studies suggest that catalysis is likely dominated by surface-active species. [Rh(Cy2PCH2CH2PCy2)(η2η2-NBA)][BArF4] is also shown to catalyze the transfer dehydrogenation of butane to 2-butene at 298 K using ethene as the sacrificial acceptor. PMID:28989631

SmoXYB1C1Z of Mycobacterium sp. Strain NBB4: a Soluble Methane Monooxygenase (sMMO)-Like Enzyme, Active on C2 to C4 Alkanes and Alkenes

PubMed Central

Martin, Kiri E.; Ozsvar, Jazmin

2014-01-01

Monooxygenase (MO) enzymes initiate the aerobic oxidation of alkanes and alkenes in bacteria. A cluster of MO genes (smoXYB1C1Z) of thus-far-unknown function was found previously in the genomes of two Mycobacterium strains (NBB3 and NBB4) which grow on hydrocarbons. The predicted Smo enzymes have only moderate amino acid identity (30 to 60%) to their closest homologs, the soluble methane and butane MOs (sMMO and sBMO), and the smo gene cluster has a different organization from those of sMMO and sBMO. The smoXYB1C1Z genes of NBB4 were cloned into pMycoFos to make pSmo, which was transformed into Mycobacterium smegmatis mc2-155. Cells of mc2-155(pSmo) metabolized C2 to C4 alkanes, alkenes, and chlorinated hydrocarbons. The activities of mc2-155(pSmo) cells were 0.94, 0.57, 0.12, and 0.04 nmol/min/mg of protein with ethene, ethane, propane, and butane as substrates, respectively. The mc2-155(pSmo) cells made epoxides from ethene, propene, and 1-butene, confirming that Smo was an oxygenase. Epoxides were not produced from larger alkenes (1-octene and styrene). Vinyl chloride and 1,2-dichloroethane were biodegraded by cells expressing Smo, with production of inorganic chloride. This study shows that Smo is a functional oxygenase which is active against small hydrocarbons. M. smegmatis mc2-155(pSmo) provides a new model for studying sMMO-like monooxygenases. PMID:25015887

Laboratory spectroscopic analyses of electron irradiated alkanes and alkenes in solar system ices

NASA Astrophysics Data System (ADS)

Hand, K. P.; Carlson, R. W.

2012-03-01

We report results from laboratory experiments of 10 keV electron irradiation of thin ice films of water and short-chain hydrocarbons at ˜10-8 Torr and temperatures ranging from 70-100 K. Hydrocarbon mixtures include water with C3H8, C3H6, C4H10 (butane and isobutane), and C4H8, (1-butene and cis/trans-2-butene). The double bonds of the alkenes in our initial mixtures were rapidly destroyed or converted to single carbon bonds, covalent bonds with hydrogen, bonds with -OH (hydroxyl), bonds with oxygen (C-O), or double bonds with oxygen (carbonyl). Spectra resulting from irradiation of alkane and alkene ices are largely indistinguishable; the initial differences in film composition are destroyed and the resulting mixture includes long-chain, branched aliphatics, aldehydes, ketones, esters, and alcohols. Methane was observed as a product during radiolysis but CO was largely absent. We find that while some of the carbon is oxidized and lost to CO2 formation, some carbon is sequestered into highly refractory, long-chain aliphatic compounds that remain as a thin residue even after the ice film has been raised to standard temperature and pressure. We conclude that the high availability of hydrogen in our experiments leads to the formation of the formyl radical which then serves as the precursor for formaldehyde and polymerization of longer hydrocarbon chains.

Final report on EURAMET.QM-S6/1195: Bilateral comparison of liquefied hydrocarbon mixtures in constant pressure (piston) cylinders

NASA Astrophysics Data System (ADS)

Brown, Andrew S.; Downey, Michael L.; Milton, Martin J. T.; van der Veen, Adriaan M. H.; Zalewska, Ewelina T.; Li, Jianrong

2013-01-01

Traceable liquid hydrocarbon mixtures are required in order to underpin measurements of the composition and other physical properties of LPG (liquefied petroleum gas) and LNG (liquefied natural gas), thus meeting the needs of an increasingly large European industrial market. The development of traceable liquid hydrocarbon standards by National Measurement Institutes (NMIs) was still at a relatively early stage at the time this comparison was proposed in 2011. NPL and VSL, who were the only NMIs active in this area, had developed methods for the preparation and analysis of such standards in constant pressure (piston) cylinders, but neither laboratory had Calibration and Measurement Capabilities (CMCs) for these mixtures. This report presents the results of EURAMET 1195, the first comparison of liquid hydrocarbon mixtures between NMIs, which assessed the preparation and analytical capabilities of NPL and VSL for these mixtures. The comparison operated between August 2011 and January 2012. Each laboratory prepared a liquid hydrocarbon standard with nominally the same composition and these standards were exchanged for analysis. The results of the comparison show a good agreement between the laboratories' results and the comparison reference values for the six components with amount fractions greater than 1.0 cmol/mol (propane, propene, iso-butene, n-butane, iso-butane and 1-butene). Measurement of the three components with lower amount fractions (1,3-butadiene, iso-pentane and n-pentane) proved more challenging. In all but one case, the differences from the comparison reference values for these three components were greater than the expanded measurement uncertainty. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Lanthanum-mediated dehydrogenation of butenes: Spectroscopy and formation of La(C4H6) isomers

NASA Astrophysics Data System (ADS)

Cao, Wenjin; Hewage, Dilrukshi; Yang, Dong-Sheng

2018-01-01

La atom reactions with 1-butene, 2-butene, and isobutene are carried out in a laser-vaporization molecular beam source. The three reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butenes. The dehydrogenated species La(C4H6) is the major product, which is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectrum of La(C4H6) produced from the La+1-butene reaction exhibits two band systems, whereas the MATI spectra produced from the La+2-butene and isobutene reactions display only a single band system. Each of these spectra shows a strong origin band and several vibrational progressions. The two band systems from the spectrum of the 1-butene reaction are assigned to the ionization of two isomers: La[C(CH2)3] (Iso A) and La(CH2CHCHCH2) (Iso B), and the single band system from the spectra of the 2-butene and isobutene reactions is attributed to Iso B and Iso A, respectively. The ground electronic states are 2A1 (C3v) for Iso A and 2A' (Cs) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and leads to the 1A1 ion of Iso A and the 1A' ion of Iso B. The formation of both isomers consists of La addition to the C=C double bond, La insertion into two C(sp3)—H bonds, and H2 elimination. In addition to these steps, the formation of Iso A from the La+1-butene reaction may involve the isomerization of 1-butene to isobutene prior to the C—H bond activation, whereas the formation of Iso B from the La+trans-2-butene reaction may include the trans- to cis-butene isomerization after the C—H bond activation.

Comparison of different real time VOC measurement techniques in a ponderosa pine forest

NASA Astrophysics Data System (ADS)

Kaser, L.; Karl, T.; Schnitzhofer, R.; Graus, M.; Herdlinger-Blatt, I. S.; DiGangi, J. P.; Sive, B.; Turnipseed, A.; Hornbrook, R. S.; Zheng, W.; Flocke, F. M.; Guenther, A.; Keutsch, F. N.; Apel, E.; Hansel, A.

2013-03-01

Volatile organic compound (VOC) mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa) during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS), a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS), a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA), a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS) and a Fiber Laser-Induced Fluorescence Instrument (FILIF). The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO) and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK) and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR) is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK + MAC) using PTR-(TOF)-MS at this site. A study-average relative contribution of 85% for MVK + MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20-25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study, and likely points to an offset in calibration, rather than a difference in the ability to measure the sum of terpenes. The contribution of isoprene relative to MBO inferred from PTR-MS and PTR-TOF-MS was smaller than 12% while GC-MS data suggested an average of 21% of isoprene relative to MBO. This comparison demonstrates that the current capability of VOC measurements to account for OH reactivity associated with the measured VOCs is within 20%.

Comparison of different real time VOC measurement techniques in a ponderosa pine forest

NASA Astrophysics Data System (ADS)

Kaser, L.; Karl, T.; Schnitzhofer, R.; Graus, M.; Herdlinger-Blatt, I. S.; DiGangi, J. P.; Sive, B.; Turnipseed, A.; Hornbrook, R. S.; Zheng, W.; Flocke, F. M.; Guenther, A.; Keutsch, F. N.; Apel, E.; Hansel, A.

2012-10-01

Volatile organic compound (VOC) mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa) during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS), a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS), a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA), a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS) and a Fiber Laser-Induced Fluorescence Instrument (FILIF). The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO) and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK) and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR) is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK+MAC) using PTR-(TOF)-MS at this site. A study-average relative contribution of 85% for MVK+MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20-25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study, and likely points to an offset in calibration, rather than a difference in the ability to measure the sum of terpenes. The contribution of isoprene relative to MBO inferred from PTR-MS and PTR-TOF-MS was smaller than 12% while GC-MS data suggested an average of 21% of isoprene relative to MBO. This comparison demonstrates that the current capability of VOC measurements to account for OH reactivity associated with the measured VOCs is within 20%.

Characterization of hydrocarbons, halocarbons and carbonyls in the atmosphere of Hong Kong.

PubMed

Guo, H; Lee, S C; Louie, P K K; Ho, K F

2004-12-01

Ambient air quality measurements of 156 species including 39 alkanes, 32 alkenes, 2 alkynes, 24 aromatic hydrocarbons, 43 halocarbons and 16 carbonyls, were carried out for 120 air samples collected at two sampling stations (CW and TW) in 2001 throughout Hong Kong. Spatial variations of volatile organic compounds (VOCs) in the atmosphere were investigated. Levels of most alkanes and alkenes at TW site were higher than that at the CW site, while the BTEX concentrations at the two sites were close. The BTEX ratios at CW and TW were 1.6:10.1:1.0:1.6 and 2.1:10.8:1.0:2.0, respectively. For major halogenated hydrocarbons, the mean concentrations of chloromethane, CFCs 12 and 22 did not show spatial variations at the two sites. However, site-specific differences were observed for trichloroethene and tetrachloroethene. Furthermore, there were no significant differences for carbonyls such as formaldehyde, acetaldehyde and acetone between the two sites. The levels of selected hydrocarbons in winter were 1-5 times that in summer. There were no common seasonal trends for carbonyls in Hong Kong. The ambient level of formaldehyde, the most abundant carbonyl, was higher in summer. However, levels of acetaldehyde, acetone and benzaldehyde in winter were 1.6-3.8 times that in summer. The levels of CFCs 11 and 12, and chloromethane in summer were higher than that in winter. Strong correlation of most hydrocarbons with propene and n-butane suggested that the primary contributors of hydrocarbons were vehicular emissions in Hong Kong. In addition, gasoline evaporation, use of solvents, leakage of liquefied petroleum gas (LPG), natural gas leakage and other industrial emissions, and even biogenic emissions affected the ambient levels of hydrocarbons. The sources of halocarbons were mainly materials used in industrial processes and as solvents. Correlation analysis suggested that photochemical reactions made significant contributions to the ambient levels of carbonyls in summer whereas in winter motor vehicle emissions would be the major sources of the carbonyls. The photochemical reactivity of selected VOCs was estimated in this study. The largest contributors to ozone formation were formaldehyde, toluene, propene, m,p-xylene, acetaldehyde, 1-butene/i-butene, isoprene and n-butane, suggesting that motor vehicles, gasoline evaporation, use of solvents, leakage of LPG, photochemical processes and biogenic emission are sources in the production of ozone. On the other hand, VOCs from vehicles and gasoline evaporation were predominant with respect to reactions with OH radical.

Kinetic and thermodynamic selectivity of intermolecular C-H activation at [Tp'Rh(PMe3)]. How does the ancillary ligand affect the metal-carbon bond strength?

PubMed

Jiao, Yunzhe; Morris, James; Brennessel, William W; Jones, William D

2013-10-30

Tp'Rh(PMe3)(CH3)H was synthesized as a precursor to produce the coordinatively unsaturated fragment [Tp'Rh(PMe3)], which reacts with benzene, mesitylene, 3,3-dimethyl-1-butene, 2-methoxy-2-methylpropane, 2-butyne, acetone, pentane, cyclopentane, trifluoroethane, fluoromethane, dimethyl ether, and difluoromethane at ambient temperature to give only one product in almost quantitative yield in each case. All of the complexes Tp'Rh(PMe3)(R)H were characterized by NMR spectroscopy, and their halogenated derivatives were fully characterized by NMR spectroscopy, elemental analysis, and X-ray crystallography. The active species [Tp'Rh(PMe3)] was also able to activate the alkynyl C-H bond of terminal alkynes to give activation products of the type Tp'Rh(PMe3)(C≡CR)H (R = t-Bu, SiMe3, hexyl, CF3, Ph, p-MeOC6H4, and p-CF3C6H4). The measured relative rhodium-carbon bond strengths display two linear correlations with the corresponding carbon-hydrogen bond strengths, giving a slope of 1.54 for α-unsubstituted hydrocarbons and a slope of 1.71 for substrates with α-substitution. Similar trends of energy correlations were established by DFT calculated metal-carbon bond strengths for the same groups of substrates.

1996 PAMS hydrocarbon QA studies in EPA Region II: Part II. Trends and insights

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teitz, A.; Kantz, M.

1997-12-31

Comparison of ambient air samples between EPA Region II and the PAMS monitoring organizations within the Region, and comparisons among EPA Regions I, II, and III, revealed the following analytical trends: (1) Agreement between laboratories was typically between 10-20% for many of the PAMS analytes found at higher concentrations, i.e., butane, isopentane, benzene, toluene, and m/p-xylene; (2) Nafion dryer systems tended to underestimate the amount of acetylene by 35-50%; (3) Isobutylene co-elution with 1-butene proved difficult to resolve unless a 100 meter DB-1 or a regular length PLOT GC column was used; (4) Organizations that monitor for polar compounds foundmore » that co-elution of ethanol/acetone can interfere with the analysis of 1-pentene; (5) Analytical systems capable of polar analyses can have co-elution and/or misidentification of these aldehydes, typically in the styrene/heptanal/o-xylene regions of the chromatogram; and (6) Tetrachloroethylene was found to interfere with octane quantitation in some analyses.« less

21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Viscosity. Poly-1-butene resins and the butene/ethylene copolymers have an intrinsic viscosity 1.0 to 3.2 as determined by ASTM method D1601-78, “Standard Test Method for Dilute Solution Viscosity of Ethylene Polymers...

The Bond Dissociation Energies of 1-Butene

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R. (Technical Monitor)

1994-01-01

The bond dissociation energies of 1-butene and several calibration systems are computed using the G2(MP2) approach. The agreement between the calibration systems and experiment is very good. The computed values for 1-butene are compared with calibration systems and the agreement between the computed results for 1-butene and the "rule of thumb" values from the smaller systems is remarkably good.

21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

Code of Federal Regulations, 2013 CFR

2013-04-01

... their characteristic infrared spectra. (ii) Viscosity. Poly-1-butene resins and the butene/ethylene copolymers have an intrinsic viscosity 1.0 to 3.2 as determined by ASTM method D1601-78, “Standard Test Method for Dilute Solution Viscosity of Ethylene Polymers,” which is incorporated by reference. Copies...

21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

Code of Federal Regulations, 2012 CFR

2012-04-01

... their characteristic infrared spectra. (ii) Viscosity. Poly-1-butene resins and the butene/ethylene copolymers have an intrinsic viscosity 1.0 to 3.2 as determined by ASTM method D1601-78, “Standard Test Method for Dilute Solution Viscosity of Ethylene Polymers,” which is incorporated by reference. Copies...

Assessment of the aroma impact of major odor-active thiols in pan-roasted white sesame seeds by calculation of odor activity values.

PubMed

Tamura, Hitoshi; Fujita, Akira; Steinhaus, Martin; Takahisa, Eisuke; Watanabe, Hiroyuki; Schieberle, Peter

2011-09-28

Eleven odor-active thiols, namely, 2-methyl-1-propene-1-thiol, (Z)-3-methyl-1-butene-1-thiol, (E)-3-methyl-1-butene-1-thiol, (Z)-2-methyl-1-butene-1-thiol, (E)-2-methyl-1-butene-1-thiol, 2-methyl-3-furanthiol, 3-mercapto-2-pentanone, 2-mercapto-3-pentanone, 4-mercapto-3-hexanone, 3-mercapto-3-methylbutyl formate, and 2-methyl-3-thiophenethiol, recently identified in an extract prepared from white sesame seeds, were quantitated in sesame using stable isotope dilution analyses. For that purpose, the following deuterium-labeled compounds were synthesized and used as internal standards in the quantitation assays: [2H6]-2-methyl-1-propene-1-thiol, [2H3]-(E)- and [2H3]-(Z)-2-methyl-1-butene-1-thiol, [2H3]-2-methyl-3-furanthiol, [2H2]-3-mercapto-2-pentanone, [2H3]-4-mercapto-3-hexanone, [2H6]-3-mercapto-3-methylbutyl formate, and [2H3]-2-methyl-3-thiophenethiol. On the basis of the results obtained, odor activity values (OAVs) were calculated as ratio of the concentration and odor threshold of the individual compounds in cooking oil. According to their high OAVs, particularly the 3-methyl-1-butene-1-thiols (OAV: 2400) and the 2-methyl-1-butene-1-thiols (OAV: 960) were identified as the most odor-active compounds in pan-roasted white sesame seeds. These compounds were therefore suggested to be mainly responsible for the characteristic but rather unstable sulfury aroma of freshly pan-roasted white sesame seeds.

21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly-1-butene resins and butene/ethylene copolymers... resins and butene/ethylene copolymers. The poly-1-butene resins and butene/ethylene copolymers identified... the catalytic polymerization of 1-butene liquid monomer. Butene/ethylene copolymers are produced by...

21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Poly-1-butene resins and butene/ethylene... Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1570 Poly-1-butene resins and butene/ethylene copolymers. The poly-1-butene resins and butene/ethylene copolymers...

Structure, vibrations and quantum chemical investigations of hydrogen bonded complex of bis(1-hydroxy-2-methylpropan-2-aminium)selenate

NASA Astrophysics Data System (ADS)

Thirunarayanan, S.; Arjunan, V.; Marchewka, M. K.; Mohan, S.

2017-04-01

The hydrogen bonded molecular complex bis(1-hydroxy-2-methylpropan-2-aminium)selenate (C8H24N2O6Se) has been prepared by the reaction of 2-amino-2-methyl propanol and selenic acid. The X-ray diffraction analysis revealed that the intermolecular proton transfer from selenic acid (SeO4H2) to 2-amino-2-methylpropanol results in the formation of bis(1-hydroxy-2-methylpropan-2-aminium)selenate (HMPAS) salt and the fragments are connected through H-bonding and ion pairing. The N-H⋯O and O-H⋯O interactions between 2-amino-2-methylpropanol and selenic acid determine the supramolecular arrangement in three-dimensional space. The salt crystallises in the space group P121/n1 of monoclinic system. The complete vibrational assignments of HMPAS have been performed by FTIR and FT-Raman spectroscopy. The experimental data are correlated with the structural properties namely the energy, thermodynamic parameters, atomic charges, hybridization concepts and vibrational frequencies determined by quantum chemical studies performed with B3LYP method using 6-311++G*, 6-31+G* and 6-31G** basis sets.

Laboratory Analysis Of Water, Hydrocarbon And Ammonia Ice Mixtures Exposed To High-energy Electron Irradiation

NASA Astrophysics Data System (ADS)

Hand, Kevin P.; Carlson, R. W.; Tsapin, A. I.

2006-09-01

Irradiation of low temperature ices in the laboratory provides insight into processes that may be occurring on icy bodies in the solar system. Here we report on results from high-energy (10keV) electron irradiation of thin ice films at 1e-8 torr and 70-120K. Mixtures include water with CO2, C3H8, C3H6, C4H10 (butane and isobutane), C4H8,(1-butene and cis/trans-2-butene), and NH3. During irradiation of H2O + alkane films at 80K, CO2 and CH4 production is observed and both species are retained in the ice, possibly trapped in clathrates. The -CH3 infrared bands initially present are seen to decrease with increasing dose. Bands associated with -CH2- persist, indicating polymerization of the initial short-chain hydrocarbons. In alkenes a similar evolution toward polymerization is observed, however the first step appears to be the destruction of the C=C bond. Upon warming of the film, mass spectra data compliment the mid-infrared data and indicate the production of H2CO, however glycolic acid is not explicitly seen in the mass spectra. When warmed to 300K, residues remained for all irradiated films except that of the H2O + CO2 mixtures. Residues were analyzed with Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI). Results show the production of large aliphatic, very refractory, hydrocarbons (with m/z up to 2500). Mid-infrared spectra of the residues indicate carbonyls and alcohols, likely due to polymerized aldehydes and carboxylic acids. Films of H2O + C3H8 + NH3 at 70K show the production of OCN- (cyanate ion), formamide, along with other possible amides and hydrocarbons. HPLC results indicate the production of racemic alanine. Finally, results of abiotic experiments are compared to results from the irradiation of bacterial spores in ice. The application to Europa and Enceladus is discussed.

Comparison of the Photodesorption Activities of cis-Butene, trans-Butene and Isobutene on the Rutile TiO 2(110) Surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson, Michael A.

2013-10-17

The chemical and photochemical properties of three butene molecules (cis-butene, trans-butene and isobutene) were explored on the clean rutile TiO 2(110) surface using temperature programmed desorption (TPD) and photon simulated desorption (PSD). At the low coverage limit, trans-butene was the most strongly bound butene on the TiO 2(110) surface, desorbing at ~ 210 K, however increased intermolecular repulsions between trans-butene molecules at higher coverage diminished its binding. Both cis-butene and isobutene saturated the first layer on TiO 2(110) at a coverage of ~0.50 ML in a single TPD feature at 184 and 192 K, respectively. In contrast, the maximum coveragemore » that trans-butene could achieve in its 210 K peak was ~1/3 ML, with higher coverages resulting a low temperature desorption at ~137 K. Coverages of these molecules above 0.50 ML resulted in population of second layer and multilayer states. The instability of trans-butene at a coverage of 0.5 ML on the surface was linked to the inversion center in its symmetry. In the absence of coadsorbed oxygen, the primary photochemical pathway of each butene molecule on TiO 2(110) was photodesorption. The photoactivities of these molecules on TiO 2(110) at an initial coverage of 0.50 ML followed the trend: isobutene > cis-butene > trans-butene. In contrast, the photoactivities of low coverages of cis-butene and trans-butene exceeded those measured at 0.50 ML. These data suggest that intermolecular interactions (repulsions) play a significant role in diminishing the photoactivities of weakly bound molecules on TiO 2 photocatalysts. Work reported here was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Chemical Sciences, Geosciences, and Biosciences, and performed in the Williams R. Wiley Environmental Molecular Science Laboratory (EMSL), a Department of Energy user facility funded by the Office of Biological and Environmental Research. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for the U.S. Department of Energy by the Battelle Memorial Institute under contract DEAC05-76RL01830.« less

Two polymeric nickel(II) complexes with aromatic benzene-1,2,4,5-tetracarboxylate and pyridine-2,5-dicarboxylate linkers.

PubMed

Atria, Ana María; Corsini, Gino; González, Lissette; Garland, Maria Teresa; Baggio, Ricardo

2009-07-01

(Mu-benzene-1,2,4,5-tetracarboxylato-kappa(2)O(1):O(4))bis[aquabis(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)] methanol disolvate tetrahydrate, [Ni(2)(C(10)H(2)O(8))(C(5)H(14)N(2))(4)(H(2)O)(2)].2CH(4)O.4H(2)O, (I), is dinuclear, with elemental units built up around an inversion centre halving the benzene-1,2,4,5-tetracarboxylate (btc) anion, which bridges two symmetry-related Ni(II) cations. The octahedral Ni polyhedron is completed by two chelating 2,2-methylpropane-1,3-diamine (dmpda) groups and a terminal aqua ligand. Two methanol and four water solvent molecules are involved in a number of N-H...O and O-H...O hydrogen bonds which define a strongly bound two-dimensional supramolecular structure. The structure of catena-poly[[[bis(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)]-mu-pyridine-2,5-dicarboxylato-kappa(3)O(5):N,O(2)-[(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)]-mu-pyridine-2,5-dicarboxylato-kappa(3)N,O(2):O(5)] octahydrate], {[Ni(2)(C(7)H(3)NO(4))(2)(C(5)H(14)N(2))(3)].8H(2)O}(n), (II), is polymeric, forming twisted chains around three independent Ni centres, two of which lie on inversion centres and the third in a general position. There are three chelating dmpda ligands (one disordered over two equally populated positions), which are each attached to a different cation, and two pyridine-2,5-dicarboxylate (pdc) anions, both chelating the Ni centre in general positions through an -O-C-C-N- loop, while acting as bridges to the remaining two centrosymmetric Ni atoms. There are, in addition, eight noncoordinated water molecules in the structure, some of which are disordered.

Advanced Testing of Safe-Solvent Replacements for CFC-113 for Use in Cleaning Oxygen Systems

DTIC Science & Technology

2005-06-01

2 -(trifluoromethyl)-3,3,3- trifluoropropene 2 Reactions/28 Impacts Failed 4-bromo- 3 - chloro -3,4,4-trifluoro-1-butene 2 ...bromo- 3 - chloro -3,4,4-trifluoro-1-butene, CH2=CH-CFCl-CF2Br § 1- chloro -2,2,2-trifluoroethyl difluoromethyl ether, CHF2-O-CHCl-CF3 § 2 - chloro -1,1,2...3,3,3- trifluoropropene 725°F Recommended 4-bromo- 3 - chloro -3,4,4-trifluoro-1-butene 378°F Caution 1- chloro -2,2,2-trifluoroethyl difluoromethyl ether

Metabolic engineering for the high-yield production of isoprenoid-based C 5 alcohols in E. coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

George, Kevin W.; Thompson, Mitchell G.; Kang, Aram

2015-06-08

Branched five carbon (C 5) alcohols are attractive targets for microbial production due to their desirable fuel properties and importance as platform chemicals. In this study, we engineered a heterologous isoprenoid pathway in E. coli for the high-yield production of 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, and 3-methyl-1-butanol, three C 5 alcohols that serve as potential biofuels. We first constructed a pathway for 3-methyl-3-buten-1-ol, where metabolite profiling identified NudB, a promiscuous phosphatase, as a likely pathway bottleneck. We achieved a 60% increase in the yield of 3-methyl-3-buten-1-ol by engineering the Shine-Dalgarno sequence of nudB, which increased protein levels by 9-fold and reduced isopentenyl diphosphatemore » (IPP) accumulation by 4-fold. To further optimize the pathway, we adjusted mevalonate kinase (MK) expression and investigated MK enzymes from alternative microbes such as Methanosarcina mazei. Next, we expressed a fusion protein of IPP isomerase and the phosphatase (Idi1~NudB) along with a reductase (NemA) to diversify production to 3-methyl-2-buten-1-ol and 3-methyl-1-butanol. Lastly, we used an oleyl alcohol overlay to improve alcohol recovery, achieving final titers of 2.23 g/L of 3-methyl-3-buten-1-ol (~70% of pathway-dependent theoretical yield), 150 mg/L of 3-methyl-2-buten-1-ol, and 300 mg/L of 3-methyl-1-butanol.« less

Metabolic engineering for the high-yield production of isoprenoid-based C5 alcohols in E. coli

PubMed Central

George, Kevin W.; Thompson, Mitchell G.; Kang, Aram; Baidoo, Edward; Wang, George; Chan, Leanne Jade G.; Adams, Paul D.; Petzold, Christopher J.; Keasling, Jay D.; Soon Lee, Taek

2015-01-01

Branched five carbon (C5) alcohols are attractive targets for microbial production due to their desirable fuel properties and importance as platform chemicals. In this study, we engineered a heterologous isoprenoid pathway in E. coli for the high-yield production of 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, and 3-methyl-1-butanol, three C5 alcohols that serve as potential biofuels. We first constructed a pathway for 3-methyl-3-buten-1-ol, where metabolite profiling identified NudB, a promiscuous phosphatase, as a likely pathway bottleneck. We achieved a 60% increase in the yield of 3-methyl-3-buten-1-ol by engineering the Shine-Dalgarno sequence of nudB, which increased protein levels by 9-fold and reduced isopentenyl diphosphate (IPP) accumulation by 4-fold. To further optimize the pathway, we adjusted mevalonate kinase (MK) expression and investigated MK enzymes from alternative microbes such as Methanosarcina mazei. Next, we expressed a fusion protein of IPP isomerase and the phosphatase (Idi1~NudB) along with a reductase (NemA) to diversify production to 3-methyl-2-buten-1-ol and 3-methyl-1-butanol. Finally, we used an oleyl alcohol overlay to improve alcohol recovery, achieving final titers of 2.23 g/L of 3-methyl-3-buten-1-ol (~70% of pathway-dependent theoretical yield), 150 mg/L of 3-methyl-2-buten-1-ol, and 300 mg/L of 3-methyl-1-butanol. PMID:26052683

Preparation of mesoporous alumina particles by spray pyrolysis and application to double bond migration of 2-butene.

PubMed

Song, Ki Chang; Kim, Joo Hyun; Kim, Jin Han; Jung, Kyeong Youl; Park, Young-Kwon; Jeon, Jong-Ki

2011-07-01

The objective of the present study is to investigate the catalytic performance of mesoporous alumina that were prepared via spray pyrolysis for double bond migration from 2-butene to 1-butene. The mesoporous alumina particles were prepared via spray pyrolysis by changing the types of organic surfactants and Al precursors. The texture and acidic properties of mesoporous alumina were analyzed through N2 adsorption, SEM, ammonia-temperature programmed desorption, and FT-IR of adsorbed pyridine. The morphologies and texture properties of the mesoporous alumina were found to have been strongly influenced by the combination of the Al precursor and the structure-directing agents. The mesoporous alumina samples had two kinds of acidic sites: a Lewis acid site and a H-bonded weak acid site. 1-Butene was produced selectively through double bond migration of 2-butene over all of the mesoporous alumina catalysts. The catalyst prepared by using a chloride compound as an aluminium precursor and CTAC as a structure-directing agent showed the highest activity in the double bond migration of 2-butene, which was attributed to its large surface area and an overall high amount of acid sites.

Temperature-dependent mid-IR absorption spectra of gaseous hydrocarbons

NASA Astrophysics Data System (ADS)

Klingbeil, Adam E.; Jeffries, Jay B.; Hanson, Ronald K.

2007-10-01

Quantitative mid-IR absorption spectra (2500 3400 cm-1) for 12 pure hydrocarbon compounds are measured at temperatures ranging from 25 to 500 °C using an FTIR spectrometer. The hydrocarbons studied are n-pentane, n-heptane, n-dodecane, 2,2,4-trimethyl-pentane (iso-octane), 2-methyl-butane, 2-methyl-pentane, 2,4,4-trimethyl-1-pentene, 2-methyl-2-butene, propene, toluene, m-xylene, and ethylbenzene. Room-temperature measurements of neat hydrocarbon vapor were made with an instrument resolution of both 0.1 and 1 cm-1 (FWHM) to confirm that the high-resolution setting was required only to resolve the propene absorption spectrum while the spectra of the other hydrocarbons could be resolved with 1 cm-1 resolution. High-resolution (0.1 cm-1), room-temperature measurements of neat hydrocarbons were made at low pressure (˜1 Torr, 133 Pa) and compared to measurements of hydrocarbon/N2 mixtures at atmospheric pressure to verify that no pressure broadening could be observed over this pressure range. The temperature was varied between 25 and 500 °C for atmospheric-pressure measurements of hydrocarbon/N2 mixtures (Xhydrocarbon˜0.06 1.5%) and it was found that the absorption cross section shows simple temperature-dependent behavior for a fixed wavelength over this temperature range. Comparisons with previous FTIR data over a limited temperature range and with high-resolution laser absorption data over a wide temperature range show good agreement.

Release of volatile organic compounds (VOCs) from the lung cancer cell line CALU-1 in vitro.

PubMed

Filipiak, Wojciech; Sponring, Andreas; Mikoviny, Tomas; Ager, Clemens; Schubert, Jochen; Miekisch, Wolfram; Amann, Anton; Troppmair, Jakob

2008-11-24

The aim of this work was to confirm the existence of volatile organic compounds (VOCs) specifically released or consumed by lung cancer cells. 50 million cells of the human non-small cell lung cancer (NSCLC) cell line CALU-1 were incubated in a sealed fermenter for 4 h or over night (18 hours). Then air samples from the headspace of the culture vessel were collected and preconcentrated by adsorption on solid sorbents with subsequent thermodesorption and analysis by means of gas chromatography mass spectrometry (GC-MS). Identification of altogether 60 compounds in GCMS measurement was done not only by spectral library match, but also by determination of retention times established with calibration mixtures of the respective pure compounds. The results showed a significant increase in the concentrations of 2,3,3-trimethylpentane, 2,3,5-trimethylhexane, 2,4-dimethylheptane and 4-methyloctane in the headspace of CALU-1 cell culture as compared to medium controls after 18 h. Decreased concentrations after 18 h of incubation were found for acetaldehyde, 3-methylbutanal, butyl acetate, acetonitrile, acrolein, methacrolein, 2-methylpropanal, 2-butanone, 2-methoxy-2-methylpropane, 2-ethoxy-2-methylpropane, and hexanal. Our findings demonstrate that certain volatile compounds can be cancer-cell derived and thus indicative of the presence of a tumor, whereas other compounds are not released but seem to be consumed by CALU-1 cells.

ALKYLATION OF ISOBUTANE WITH 2-BUTENE WITH IONIC LIQUID AS A "CLEAN" CATALYST

EPA Science Inventory

Alkylation of isobutane with 2-butene with Ionic liquid as a "clean" catalyst
Kyesang Yoo, 1 Vasudevan V. Namboodiri,2 Panagiotis G. Smirniotis,*1 and Rajender S. Varma*2
1 Department of Chemical Engineering, University of Cincinnati, Cincinnati, OH 45221-0171, USA.
E...

On the Radiolysis of Ethylene Ices by Energetic Electrons and Implications to the Extraterrestrial Hydrocarbon Chemistry

NASA Astrophysics Data System (ADS)

Zhou, Li; Maity, Surajit; Abplanalp, Matt; Turner, Andrew; Kaiser, Ralf I.

2014-07-01

The chemical processing of ethylene ices (C2H4) by energetic electrons was investigated at 11 K to simulate the energy transfer processes and synthesis of new molecules induced by secondary electrons generated in the track of galactic cosmic ray particles. A combination of Fourier transform infrared spectrometry (solid state) and quadrupole mass spectrometry (gas phase) resulted in the identification of six hydrocarbon molecules: methane (CH4), the C2 species acetylene (C2H2), ethane (C2H6), the ethyl radical (C2H5), and—for the very first time in ethylene irradiation experiments—the C4 hydrocarbons 1-butene (C4H8) and n-butane (C4H10). By tracing the temporal evolution of the newly formed molecules spectroscopically online and in situ, we were also able to fit the kinetic profiles with a system of coupled differential equations, eventually providing mechanistic information, reaction pathways, and rate constants on the radiolysis of ethylene ices and the inherent formation of smaller (C1) and more complex (C2, C4) hydrocarbons involving carbon-hydrogen bond ruptures, atomic hydrogen addition processes, and radical-radical recombination pathways. We also discuss the implications of these results on the hydrocarbon chemistry on Titan's surface and on ice-coated, methane-bearing interstellar grains as present in cold molecular clouds such as TMC-1.

Microwave-assisted direct synthesis of butene from high-selectivity methane

NASA Astrophysics Data System (ADS)

Lu, Yi-heng; Li, Kang; Lu, Yu-wei

2017-12-01

Methane was directly converted to butene liquid fuel by microwave-induced non-oxidative catalytic dehydrogenation under 0.1-0.2 MPa. The results show that, under microwave heating in a two-stage fixed-bed reactor, in which nickel powder and NiOx-MoOy/SiO2 are used as the catalyst, the methane-hydrogen mixture is used as the raw material, with no acetylene detected. The methane conversion is more than 73.2%, and the selectivity of methane to butene is 99.0%. Increasing the hydrogen/methane feed volume ratio increases methane conversion and selectivity. Gas chromatography/electron impact ionization/mass spectrometry chromatographic analysis showed that the liquid fuel produced by methane dehydrogenation oligomerization contained 89.44% of butene, and the rest was acetic acid, ethanol, butenol and butyric acid, and the content was 1.0-3.0 wt%.

Cobalt Oxide on N-Doped Carbon for 1-Butene Oligomerization to Produce Linear Octenes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Dongting; Xu, Zhuoran; Chada, Joseph P.

Cobalt oxide supported on N-doped carbon catalysts were investigated for 1-butene oligomerization. The materials were synthesized by treating activated carbon with nitric acid and subsequently with NH3 at 200, 400, 600, and 800 °C, followed by impregnation with cobalt. The 1-butene oligomerization selectivity increased with ammonia treatment temperature of the carbon support. The oligomerization selectivity of cobalt oxide on N-doped carbon synthesized at 800 °C (800A-CoOx/N-C) is 2.6 times higher than previously reported cobalt oxide on N-doped carbon synthesized with NH4OH (2A-CoOx/N-C). Over 70% of the butene dimers were linear C8 olefins for all catalysts. The oligomerization selectivity increased withmore » 1-butene conversion. The catalysts were characterized by elemental analysis, N2 adsorption, X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and X-ray photoelectron spectroscopy (XPS). The nitrogen content of the catalysts increases with ammonia treatment temperature as confirmed by elemental analysis. The surface content of pyridinic nitrogen with a binding energy of 398.4 ± 0.1 eV increased with ammonia treatment temperature as evidenced by deconvolution of N 1s XPS spectra.« less

Low-Temperature Synchrotron Photoionization Study of 2-Methyl-3-buten-2-ol (MBO) Oxidation Initiated by O(3P) Atoms in the 298-650 K Range.

PubMed

Fathi, Yasmin; Price, Chelsea; Meloni, Giovanni

2017-04-20

This work studies the oxidation of 2-methyl-3-buten-2-ol initiated by O( 3 P) atoms. The oxidation was investigated at room temperature, 550, and 650 K. Using the synchrotron radiation from the Advanced Light Source (ALS) of the Lawrence Berkley National Laboratory, reaction intermediates and products were studied by multiplexed photoionization mass spectrometry. Mass-to-charge ratios, kinetic time traces, photoionization spectra, and adiabatic ionization energies for each primary reaction species were obtained and used to characterize their identity. Using electronic structure calculations, potential energy surface scans of the different species produced throughout the oxidation were examined and presented in this paper to further validate the primary chemistry occurring. Branching fractions of primary products at all three temperatures were also provided. At room temperature only three primary products formed: ethenol (26.6%), acetaldehyde (4.2%), and acetone (53.4%). At 550 and 650 K the same primary products were observed in addition to propene (5.1%, 11.2%), ethenol (18.1%, 2.8%), acetaldehyde (8.9%, 5.7%), cyclobutene (1.6%, 10.8%), 1-butene (2.0%, 10.9%), trans-2-butene (3.2%, 23.1%), acetone (50.4%, 16.8%), 3-penten-2-one (1.0%, 11.5%), and 3-methyl-2-butenal (0.9%, 2.5%), where the first branching fraction value in parentheses corresponds to the 550 K data. At the highest temperature, a small amount of propyne (1.0%) was also observed.

Identification of novel aroma-active thiols in pan-roasted white sesame seeds.

PubMed

Tamura, Hitoshi; Fujita, Akira; Steinhaus, Martin; Takahisa, Eisuke; Watanabe, Hiroyuki; Schieberle, Peter

2010-06-23

Screening for aroma-active compounds in an aroma distillate obtained from freshly pan-roasted sesame seeds by aroma extract dilution analysis revealed 32 odorants in the FD factor range of 2-2048, 29 of which could be identified. The highest FD factors were found for the coffee-like smelling 2-furfurylthiol, the caramel-like smelling 4-hydroxy-2,5-dimethyl-3(2H)-furanone, the coffee-like smelling 2-thenylthiol (thiophen-2-yl-methylthiol), and the clove-like smelling 2-methoxy-4-vinylphenol. In addition, 9 odor-active thiols with sulfurous, meaty, and/or catty, black-currant-like odors were identified for the first time in roasted sesame seeds. Among them, 2-methyl-1-propene-1-thiol, (Z)-3-methyl-1-butene-1-thiol, (E)-3-methyl-1-butene-1-thiol, (Z)-2-methyl-1-butene-1-thiol, (E)-2-methyl-1-butene-1-thiol, and 4-mercapto-3-hexanone were previously unknown as food constituents. Their structures were confirmed by comparing their mass spectra and retention indices as well as their sensory properties with those of synthesized reference compounds. The relatively unstable 1-alkene-1-thiols represent a new class of food odorants and are suggested as the key contributors to the characteristic, but quickly vanishing, aroma of freshly ground roasted sesame seeds.

Structure determination and sensory analysis of bitter-tasting 4-vinylcatechol oligomers and their identification in roasted coffee by means of LC-MS/MS.

PubMed

Frank, Oliver; Blumberg, Simone; Kunert, Christof; Zehentbauer, Gerhard; Hofmann, Thomas

2007-03-07

Aimed at elucidating intense bitter-tasting molecules in coffee, various bean ingredients were thermally treated in model experiments and evaluated for their potential to produce bitter compounds. As caffeic acid was found to generate intense bitterness reminiscent of the bitter taste of a strongly roasted espresso-type coffee, the reaction products formed were screened for bitter compounds by means of taste dilution analysis, and the most bitter tastants were isolated and purified. LC-MS/MS as well as 1-D/2-D NMR experiments enabled the identification of 10 bitter compounds with rather low recognition threshold concentrations ranging between 23 and 178 micromol/L. These bitter compounds are the previously unreported 1,3-bis(3',4'-dihydroxyphenyl) butane, trans-1,3-bis(3',4'-dihydroxyphenyl)-1-butene, and eight multiply hydroxylated phenylindanes, among which five derivatives are reported for the first time. In addition, the occurrence of each of these bitter compounds in a coffee brew was verified by means of LC-MS/MS (ESI-) operating in the multiple reaction monitoring (MRM) mode. The structures of these bitter compounds show strong evidence that they are generated by oligomerization of 4-vinylcatechol released from caffeic acid moieties upon roasting.

Microwave-assisted direct synthesis of butene from high-selectivity methane

PubMed Central

Li, Kang; Lu, Yu-wei

2017-01-01

Methane was directly converted to butene liquid fuel by microwave-induced non-oxidative catalytic dehydrogenation under 0.1–0.2 MPa. The results show that, under microwave heating in a two-stage fixed-bed reactor, in which nickel powder and NiOx–MoOy/SiO2 are used as the catalyst, the methane–hydrogen mixture is used as the raw material, with no acetylene detected. The methane conversion is more than 73.2%, and the selectivity of methane to butene is 99.0%. Increasing the hydrogen/methane feed volume ratio increases methane conversion and selectivity. Gas chromatography/electron impact ionization/mass spectrometry chromatographic analysis showed that the liquid fuel produced by methane dehydrogenation oligomerization contained 89.44% of butene, and the rest was acetic acid, ethanol, butenol and butyric acid, and the content was 1.0–3.0 wt%. PMID:29308261

[Emission Characteristics of VOCs from Typical Restaurants in Beijing].

PubMed

Cui, Tong; Cheng, Jing-chen; He, Wan-qing; Ren, Pei-fang; Nie, Lei; Xu, Dong-yao; Pan, Tao

2015-05-01

Using the EPA method, emission of volatile organic compounds (VOCs) , sampled from barbecue, Chinese and Western fast-food, Sichuan cuisine and Zhejiang cuisine restaurants in Beijing was investigated. VOCs concentrations and components from different cuisines were studied. The results indicated that based on the calibrated baseline ventilation volume, the VOCs emission level from barbecue was the highest, reaching 12.22 mg · m(-3), while those from fast-food of either Chinese or Western, Sichuan cuisine and Zhejiang cuisine were about 4 mg · m(-3). The components of VOCs from barbecue were different from those in the other cuisines, which were mainly propylene, 1-butene, n-butane, etc. The non-barbecue cuisines consisted of high concentration of alcohols, and Western fast-food contained relatively high proportion of aldehydes and ketones organic compounds. According to emission concentration of baseline ventilation volume, barbecue released more pollutants than the non-barbecue cuisines at the same scale. So, barbecue should be supervised and controlled with the top priority.

Mechanistic Study of the Stereoselective Hydroxylation of [2-2 H1 ,3-2 H1 ]Butanes Catalyzed by Cytochrome P450 BM3 Variants.

PubMed

Yang, Chung-Ling; Lin, Cheng-Hung; Luo, Wen-I; Lee, Tsu-Lin; Ramu, Ravirala; Ng, Kok Yaoh; Tsai, Yi-Fang; Wei, Guor-Tzo; Yu, Steve S-F

2017-02-21

Engineered bacterial cytochrome P450s are noted for their ability in the oxidation of inert small alkanes. Cytochrome P450 BM3 L188P A328F (BM3 PF) and A74E L188P A328F (BM3 EPF) variants are able to efficiently oxidize n-butane to 2-butanol. Esterification of the 2-butanol derived from this reaction mediated by the aforementioned two mutants gives diastereomeric excesses (de) of -56±1 and -52±1 %, respectively, with the preference for the oxidation occurring at the C-H S bond. When tailored (2R,3R)- and (2S,3S)-[2- 2 H 1 ,3- 2 H 1 ]butane probes are employed as substrates for both variants, the obtained de values from (2R,3R)-[2- 2 H 1 ,3- 2 H 1 ]butane are -93 and -92 % for BM3 PF and EPF, respectively; whereas the obtained de values from (2S,3S)-[2- 2 H 1 ,3- 2 H 1 ]butane are 52 and 56 % in the BM3 PF and EPF systems, respectively. The kinetic isotope effects (KIEs) for the oxidation of (2R,3R)-[2- 2 H 1 ,3- 2 H 1 ]butane are 7.3 and 7.8 in BM3 PF and EPF, respectively; whereas KIEs for (2S,3S)-[2- 2 H 1 ,3- 2 H 1 ]butanes are 18 and 25 in BM3 PF and EPF, respectively. The discrepancy in KIEs obtained from the two substrates supports the two-state reactivity (TSR) that is proposed for alkane oxidation in cytochrome P450 systems. Moreover, for the first time, experimental evidence for tunneling in the oxidation mediated by P450 is given through the oxidation of the C-H R bond in (2S,3S)-[2- 2 H 1 ,3- 2 H 1 ]butane. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Amino-functionalized (meth)acryl polymers by use of a solvent-polarity sensitive protecting group (Br-t-BOC).

PubMed

Ritter, Helmut; Tabatabai, Monir; Herrmann, Markus

2016-01-01

We describe the synthesis of bromo-tert-butyloxycarbonyl (Br-t-BOC)-amino-protected monomers 2-((1-bromo-2-methylpropan-2-yl)oxycarbonylamino)ethyl (meth)acrylate 3a,b. For this purpose, 2-isocyanatoethyl (meth)acrylate 1a,b was reacted with 1-bromo-2-methylpropan-2-ol (2a). The free radical polymerization of (Br-t-BOC)-aminoethyl (meth)acrylates 3a,b yielded poly((Br-t-BOC)-aminoethyl (meth)acrylate) 6a,b bearing protected amino side groups. The subsequent solvolysis of the Br-t-BOC function led to the new polymers poly(2-aminoethyl (meth)acrylate) 8a,b with protonated free amino groups. The monomers and the resulting polymers were thoroughly characterized by (1)H NMR, IR, GPC and DSC methods. The kinetics of the deprotection step was followed by (1)H NMR spectroscopy. The solvent polarity and neighboring group effects on the kinetics of deprotection are discussed.

Canopy Level Emissions of 2-methyl-3-buten-2-ol, monoterpenes, and sesquiterpenes from a Pinus taeda Experimental Plantation

EPA Science Inventory

Emissions of biogenic volatile organic compounds (BVOC) observed during 2007 from a Pinus taeda experimental plantation in Central North Carolina are compared with model estimates from MEGAN 2.1. Relaxed Eddy Accumulation (REA) estimates of 2-methyl-3-buten-2-ol (MBO) fluxes are ...

On the radiolysis of ethylene ices by energetic electrons and implications to the extraterrestrial hydrocarbon chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Li; Maity, Surajit; Abplanalp, Matt

2014-07-20

The chemical processing of ethylene ices (C{sub 2}H{sub 4}) by energetic electrons was investigated at 11 K to simulate the energy transfer processes and synthesis of new molecules induced by secondary electrons generated in the track of galactic cosmic ray particles. A combination of Fourier transform infrared spectrometry (solid state) and quadrupole mass spectrometry (gas phase) resulted in the identification of six hydrocarbon molecules: methane (CH{sub 4}), the C2 species acetylene (C{sub 2}H{sub 2}), ethane (C{sub 2}H{sub 6}), the ethyl radical (C{sub 2}H{sub 5}), and—for the very first time in ethylene irradiation experiments—the C4 hydrocarbons 1-butene (C{sub 4}H{sub 8}) andmore » n-butane (C{sub 4}H{sub 10}). By tracing the temporal evolution of the newly formed molecules spectroscopically online and in situ, we were also able to fit the kinetic profiles with a system of coupled differential equations, eventually providing mechanistic information, reaction pathways, and rate constants on the radiolysis of ethylene ices and the inherent formation of smaller (C1) and more complex (C2, C4) hydrocarbons involving carbon-hydrogen bond ruptures, atomic hydrogen addition processes, and radical-radical recombination pathways. We also discuss the implications of these results on the hydrocarbon chemistry on Titan's surface and on ice-coated, methane-bearing interstellar grains as present in cold molecular clouds such as TMC-1.« less

IONIC LIQUID-CATALYZED ALKYLATION OF ISOBUTANE WITH 2-BUTENE

EPA Science Inventory

A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides?aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions,...

A sedge plant as the source of Kangaroo Island propolis rich in prenylated p-coumarate ester and stilbenes.

PubMed

Duke, Colin C; Tran, Van H; Duke, Rujee K; Abu-Mellal, Abdallah; Plunkett, George T; King, Douglas I; Hamid, Kaiser; Wilson, Karen L; Barrett, Russell L; Bruhl, Jeremy J

2017-02-01

Propolis samples from Kangaroo Island, South Australia, were investigated for chemical constituents using high-field nuclear magnetic resonance spectral profiling. A type of propolis was found containing a high proportion of prenylated hydroxystilbenes. Subsequently, the botanical origin of this type of propolis was identified using a beehive propolis depletion method and analysis of flora. Ligurian honey bees, Apis mellifera ligustica Spinola, were found to produce propolis from resin exuded by the Australian native sedge plant Lepidosperma sp. Montebello (Cyperaceae). The plants, commonly known as sword sedge, were found to have resin that matched with the propolis samples identified as the most abundant propolis type on the island containing C- and O-prenylated tetrahydroxystilbenes (pTHOS) in addition to a small amount of prenylated p-coumarate. The isolation of five pTHOS not previously characterized are reported: (E)-4-(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene, (E)-2,4-bis(3-methyl-2-buten-1-yl)-3,3',4',5-tetrahydroxystilbene, (E)-2-(3-methyl-2-buten-1-yl)-3-(3-methyl-2-butenyloxy)-3',4',5-trihydroxystilbene, (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,3',5,5'-tetrahydroxystilbene and (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene. A National Cancer Institute 60 human cell line anticancer screen of three of these compounds showed growth inhibitory activity. The large Australasian genus Lepidosperma is identified as a valuable resource for the isolation of substances with medicinal potential. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Isomerization of C[sub 4] alkenes

DOEpatents

Smith, L.A. Jr.

1984-11-13

A method is described for isomerizing isobutene or n-butene to produce a mixture of isobutene and normal butene, and polymerizing at least a portion thereof to produce isobutene/n-butene co-dimer, which comprises feeding at least 80 weight % of either the isobutene or n-butene to a catalytic distillation reactor containing a fixed bed acidic cation exchange resin catalyst packing which provides both the catalyst sites and distillation sites for the reaction products, isomerizing a portion of the isobutene or n-butene to produce a mixture of isobutene and n-butene and reacting at least a portion of the isobutene and n-butene to form co-dimer of isobutene and n-butene, whereby an overhead fraction containing any unreacted isobutene and n-butene and a bottoms fraction containing co-dimer is produced. The result of the reaction is substantially the same regardless whether the feed is isobutene or n-butene. Other aspects of the invention, include combinations of procedures to produce high purity isobutene and n-butene. Either isobutene or n-butene product (depending on the desired product) can be recycled as feed, thus substantially carrying out the isomerization to extinction and total conversion to the desired product. 1 fig.

[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.

Drugs for stroke: action of nitrone (Z)-N-(2-bromo-5-hydroxy-4-methoxybenzylidene)-2-methylpropan-2-amine oxide on rat cortical neurons in culture subjected to oxygen-glucose-deprivation.

PubMed

Arce, Carmen; Diaz-Castroverde, Sabela; Canales, María J; Marco-Contelles, José; Samadi, Abdelouahid; Oset-Gasque, María J; González, María P

2012-09-01

The action of (Z)-N-(2-bromo-5-hydroxy-4-methoxybenzylidene)-2-methylpropan-2-amine oxide (RP6) on rat cortical neurons in culture, under oxygen-glucose-deprivation conditions, is reported. Cortical neurons in culture were treated during 1 h with OGD. After, they were placed under normal conditions during 24 h (reperfusion) in absence and presence of RP6. Different parameters were measured under each condition (control, 1 h OGD and 1 h OGD + reperfusion in absence and presence of RP6). RP6 protects neurons against ROS generation, lipid peroxidation levels, LDH release and mitochondrial membrane potential alteration, when administered during reperfusion after the OGD damage. Consequently, these results show that nitrone RP6 protects cells against ischemia injury produced during the reoxygenation, and could be a potential drug for the ictus therapy. Copyright © 2012. Published by Elsevier Masson SAS.

EMISSION OF 2-METHYL-3-BUTEN-2-OL BY PINES: A POTENTIALLY LARGE NATURAL SOURCE OF REACTIVE CARBON TO THE ATMOSPHERE

EPA Science Inventory

High rates of emission of 2-methyl-3-buten-2-ol (MBO) were measured from needles of several pine species. Emissions of MBO in the light were 1 to 2 orders of magnitude higher than emissions of monoterpenes and, in contrast to monoterpene emissions from pines, were absent in the d...

21 CFR 177.1430 - Isobutylene-butene copolymers.

Code of Federal Regulations, 2014 CFR

2014-04-01

...: Isobutylene-butene copolymers Molecular weight (range) Viscosity (range) Maximum bromine value 1. Used as.../federal_register/code_of_federal_regulations/ibr_locations.html. (2) Viscosity. Viscosity shall be determined by ASTM method D445-74, “Test for Kinematic Viscosity of Transparent and Opaque Liquids,” which is...

Pyrolytic product characteristics of biosludge from the wastewater treatment plant of a petrochemical industry.

PubMed

Lin, Kuo-Hsiung; Hsu, Hui-Tsung; Ko, Ya-Wen; Shieh, Zhu-Xin; Chiang, Hung-Lung

2009-11-15

Biosludge was produced from the wastewater treatment plant of a petrochemical industry. The element compositions of pyrolytic residues, CO, CO(2), NOx, SOx, total hydrocarbons and detailed volatile organic compounds of pyrolytic gas, and C, H, N, S content and compositions in biofuel were determined in this study. Generally, 75-80% water content in sludge cakes and about 65-70% weight of water vapor and volatile compounds were volatilized during the drying process. Propene, propane, 1-butene, n-butane, isobutene, toluene and benzene were the major volatile organic compounds (VOCs) of the pyrolytic gas, and the concentrations for most of the top 20 VOC species were greater than 5 ppm. C(5)-C(9) compounds contributed 60% by weight of biofuel; 4-hydroxy-4-methyl-2-pentanone was the highest species, accounting for 28-53% of biofuel at various pyrolytic temperatures. Based on the dried residues, there was 8.5-13% weight in pyrolytic residues, 62-82% weight in liquid products (water and crude oil) and 5.8-30% weight in the gas phase after pyrolytic processing at 500-800 degrees C. Finally, 1.5-2.5 wt% liquid fuel was produced after the distillation process. The pyrolytic residues could be reused, the pyrolytic liquid product could be used as a fuel after distillation, and the pyrolytic gas could be recycled in the pyrolytic process to achieve non-toxic discharge and reduce the cost of sludge disposal.

Synthesis, structural, spectroscopic, anti-cancer and molecular docking studies on novel 2-[(Anthracene-9-ylmethylene)amino]-2-methylpropane-1,3-diol using XRD, FTIR, NMR, UV-Vis spectra and DFT

NASA Astrophysics Data System (ADS)

Pavitha, P.; Prashanth, J.; Ramu, G.; Ramesh, G.; Mamatha, K.; Venkatram Reddy, Byru

2017-11-01

The novel titled compound 2-[(Anthracene-9-ylmethylene)amino]-2-methylpropane-1,3-diol (AMD) has been synthesized by slow evaporation technique from mixed solvent system of methanol with anthracene-9-carbaldehyde and 2-amino-2-methylpropane-1,3-diol. The synthesized molecule AMD was characterized experimentally by single crystal XRD, FTIR, NMR and UV-Vis spectra and density functional theory (DFT) computations. The structure of the crystal has been determined as orthorhombic system with space group P 21 21 21 and the cell parameters are obtained using XRD data. The optimized ground state geometry of the molecule is determined by evaluating torsional potentials as a function of angle of free rotation around Csbnd C bonds of functional groups by DFT method employing B3LYP functional with 6-311++G(d,p) basis set. All the fundamental vibrations of the molecule are assigned unambiguously using potential energy distribution (PED) obtained in the DFT computations. The rms error between the observed and scaled frequencies is 6.20 cm-1. The values of dipole moment, polarizability and hyperpolarizability are evaluated to study the NLO behavior of the molecule. The HOMO-LUMO energies and thermodynamic parameters are also determined. The molecular electrostatic surface potential (MESP) is mapped to obtain the charge density distribution. The 1H and 13C NMR chemical shifts of the molecule are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. UV-visible spectrum of the compound is also recorded in the region 200-800 nm to know the type of electronic transitions involved. The anti-cancer activity of AMD is determined against human breast cancer cell line MCF-7 and human prostate cancer cell line PC-3 and correlated the results with study of molecular docking against pharmacological protein IDO-1 receptor.

On-road emission characteristics of VOCs from rural vehicles and their ozone formation potential in Beijing, China

NASA Astrophysics Data System (ADS)

Yao, Zhiliang; Wu, Bobo; Shen, Xianbao; Cao, Xinyue; Jiang, Xi; Ye, Yu; He, Kebin

2015-03-01

This paper is the second in a series of papers aimed at understanding volatile organic compound (VOC) emissions from motor vehicles in Beijing using on-board emission measurements, focusing specifically on rural vehicles (RVs). In this work, 13 RVs, including 6 different 3-wheel (3-W) RVs and 7 different 4-wheel (4-W) RVs, were examined using a portable emissions measurement system (PEMS) as the vehicles were driven on predesigned fixed test routes in rural areas of Beijing. Overall, 50 VOC species were quantified in this study, including 18 alkanes, 5 alkenes, 11 aromatics, 13 carbonyls and 3 other compounds. The average emission factor (EF) of the total VOCs for the 4-W RVs based on the distance traveled was 326.2 ± 129.3 mg/km, which is 2.5 times greater than that of the 3-W RVs. However, the VOC emissions for the 3-W RVs had higher EFs based on their CO2 emissions due to the different fuel economies of the two types of RVs. Formaldehyde, toluene, acetaldehyde, m-xylene, p-xylene, isopentane, benzene, ethylbenzene, n-pentane, 2-methoxy-2-methylpropane and butenal were the dominant VOC species from the RVs, accounting for an average of 68.6% of the total VOC emissions. Overall, the RVs had high proportions of aromatics and carbonyls. The ozone formation potentials (OFPs) were 670.6 ± 227.2 and 1454.1 ± 643.0 mg O3/km for the 3-W and 4-W RVs, respectively, and approximately 60%-70% of the OFP resulted from carbonyls. We estimated that the 3-W and 4-W RVs accounted for approximately 50% and 10%, respectively, of the total OFP caused by diesel vehicles (including diesel trucks and RVs) in Beijing in 2012. Thus, more attention should be given to VOC emissions and their impact on ozone formation.

Synthesis and evaluation of poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene)/magnetite nanoparticle composites as corrosion inhibitors for steel.

PubMed

El-Mahdy, Gamal A; Atta, Ayman M; Al-Lohedan, Hamad A

2014-01-30

Self-stabilized magnetic polymeric composite nanoparticles of coated poly-(sodium 2-acrylamido-2-methylpropane sulfonate-co-styrene)/magnetite (PAMPS-Na-co-St/Fe3O4) were prepared by emulsifier-free miniemulsion polymerization using styrene (St) as a monomer, 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na) as an ionic comonomer, N,N-methylenebisacrylamide (MBA) as crosslinker, hexadecane (HD) as a hydrophobic solvent, and 2,2-azodiisobutyronitrile (AIBN) as an initiator in the presence of hydrophobic oleic acid coated magnetite particles. Hydrophobic oleic acid coated magnetite particles with an average size of about 7-10 nm were prepared with the new modified water-based magnetite ferrofluid, synthesized by a chemical modified coprecipitation method. The morphology and the particle size distributions of the crosslinked PAMPS-Na-co-St/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM). The average Fe3O4 content of PAMPS-Na-co-St/Fe3O4 was determined by thermogravimetric analysis (TGA). The inhibitory action of PAMPS-Na-co-St/Fe3O4 towards steel corrosion in 1 M HCl solutions has been investigated by polarization and electrochemical impedance spectroscopy (EIS) methods. Polarization measurements indicate that PAMPS-Na-co-St/Fe3O4 acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

Quantitative determination of n-propane, iso-butane, and n-butane by headspace GC-MS in intoxications by inhalation of lighter fluid.

PubMed

Bouche, Marie-Paule L A; Lambert, Willy E; Van Bocxlaer, Jan F P; Piette, Michel H; De Leenheer, André P

2002-01-01

This report describes a fully elaborated and validated method for quantitation of the hydrocarbons n-propane, iso-butane, and n-butane in blood samples. The newly developed analytical procedure is suitable for both emergency cases and forensic medicine investigations. Its practical applicability is illustrated with a forensic blood sample after acute inhalative intoxication with lighter fluid; case history and toxicological findings are included. Identification and quantitation of the analytes were performed using static headspace extraction combined with gas chromatography-mass spectrometry. In order to reconcile the large gas volumes injected (0.5 mL) with the narrowbore capillary column and thus achieve preconcentration, cold trapping on a Tenax sorbent followed by flash desorption was applied. Adequate retention and separation were achieved isothermally at 35 degrees C on a thick-film capillary column. Sample preparation was kept to a strict minimum and involved simply adding 2.5 microL of a liquid solution of 1,1,2-trichlorotrifluoroethane in t-butyl-methylether as an internal standard to aliquots of blood in a capped vial. Standards were created by volumetric dilution departing from a gravimetrically prepared calibration gas mixture composed of 0.3% of n-propane, 0.7% of iso-butane, and 0.8% of n-butane in nitrogen. In the forensic blood sample, the following concentrations were measured: 90.0 microg/L for n-propane, 246 microg/L for iso-butane, and 846 microg/L for n-butane.

Thermophysical Properties of Matter - the TPRC Data Series. Volume 6S. Specific Heat - Nonmetallic Liquids and Gases

DTIC Science & Technology

1976-01-01

4018ELiquid: 184 CARBON DISULFIDE Gas: 5178 8282 10407 10530 10832 1 - CHLOROPROPANE 12105 13938 22026 22899 23007 Gas: 27788 35677 41431 23890 25591 25700...11 I-CHLORO-2-METHYLPROPANE ..... 22 a-DICHLOROETHANESee 1 , 1 -Dichloroethane ... ....... 27 S- CHLOROPROPANE ..............22...PHENYL CHLORIDE See 1 - Chloropropane . ........ 22 See Chlorobenzene .... ......... 21 PROPYLENE BROMIDE PHENY LETHANE See 1 , 2- Dibromopropane

Using ethane and butane as probes to the molecular structure of 1-alkyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] imide ionic liquids.

PubMed

Costa Gomes, Margarida F; Pison, Laure; Pensado, Alfonso S; Pádua, Agilio A H

2012-01-01

In this work, we have studied the solubility and the thermodynamic properties of solvation, between 298 and 343 K and at pressures close to atmospheric, of ethane and n-butane in several ionic liquids based on the bis[(trifluoromethyl) sulfonyl]imide anion and on 1-alkyl-3-methylimidazolium cations, [CnC1Im] [NTf2], with alkyl side-chains varying from two to ten carbon atoms. The solubility of butane is circa one order of magnitude larger than that of ethane with mole fractions as high as 0.15 in [C10C1Im][NTf2] at 300 K. The solubilities of both n-butane and ethane gases are higher for ionic liquids with longer alkyl chains. The behaviour encountered is explained by the preferential solvation of the gases in the non-polar domains of the solvents, the larger solubility of n-butane being attributed to the dispersive contributions to the interaction energy. The rise in solubility with increasing size of the alkyl-side chain is explained by a more favourable entropy of solvation in the ionic liquids with larger cations. These conclusions are corroborated by molecular dynamics simulation studies.

Chemical Kinetics of Hydrogen Atom Abstraction from Allylic Sites by 3O2; Implications for Combustion Modeling and Simulation.

PubMed

Zhou, Chong-Wen; Simmie, John M; Somers, Kieran P; Goldsmith, C Franklin; Curran, Henry J

2017-03-09

Hydrogen atom abstraction from allylic C-H bonds by molecular oxygen plays a very important role in determining the reactivity of fuel molecules having allylic hydrogen atoms. Rate constants for hydrogen atom abstraction by molecular oxygen from molecules with allylic sites have been calculated. A series of molecules with primary, secondary, tertiary, and super secondary allylic hydrogen atoms of alkene, furan, and alkylbenzene families are taken into consideration. Those molecules include propene, 2-butene, isobutene, 2-methylfuran, and toluene containing the primary allylic hydrogen atom; 1-butene, 1-pentene, 2-ethylfuran, ethylbenzene, and n-propylbenzene containing the secondary allylic hydrogen atom; 3-methyl-1-butene, 2-isopropylfuran, and isopropylbenzene containing tertiary allylic hydrogen atom; and 1-4-pentadiene containing super allylic secondary hydrogen atoms. The M06-2X/6-311++G(d,p) level of theory was used to optimize the geometries of all of the reactants, transition states, products and also the hinder rotation treatments for lower frequency modes. The G4 level of theory was used to calculate the electronic single point energies for those species to determine the 0 K barriers to reaction. Conventional transition state theory with Eckart tunnelling corrections was used to calculate the rate constants. The comparison between our calculated rate constants with the available experimental results from the literature shows good agreement for the reactions of propene and isobutene with molecular oxygen. The rate constant for toluene with O 2 is about an order magnitude slower than that experimentally derived from a comprehensive model proposed by Oehlschlaeger and coauthors. The results clearly indicate the need for a more detailed investigation of the combustion kinetics of toluene oxidation and its key pyrolysis and oxidation intermediates. Despite this, our computed barriers and rate constants retain an important internal consistency. Rate constants calculated in this work have also been used in predicting the reactivity of the target fuels of 1-butene, 2-butene, isobutene, 2-methylfuran, 2,5-dimethylfuran, and toluene, and the results show that the ignition delay times for those fuels have been increased by a factor of 1.5-3. This work provides a first systematic study of one of the key initiation reaction for compounds containing allylic hydrogen atoms.

Ethene, propene, butene and isoprene emissions from a ponderosa pine forest measured by relaxed eddy accumulation

NASA Astrophysics Data System (ADS)

Rhew, Robert C.; Deventer, Malte Julian; Turnipseed, Andrew A.; Warneke, Carsten; Ortega, John; Shen, Steve; Martinez, Luis; Koss, Abigail; Lerner, Brian M.; Gilman, Jessica B.; Smith, James N.; Guenther, Alex B.; de Gouw, Joost A.

2017-11-01

Alkenes are reactive hydrocarbons that influence local and regional atmospheric chemistry by playing important roles in the photochemical production of tropospheric ozone and in the formation of secondary organic aerosols. The simplest alkene, ethene (ethylene), is a major plant hormone and ripening agent for agricultural commodities. The group of light alkenes (C2-C4) originates from both biogenic and anthropogenic sources, but their biogenic sources are poorly characterized, with limited field-based flux observations. Here we report net ecosystem fluxes of light alkenes and isoprene from a semiarid ponderosa pine forest in the Rocky Mountains of Colorado, USA using the relaxed eddy accumulation (REA) technique during the summer of 2014. Ethene, propene, butene and isoprene emissions have strong diurnal cycles, with median daytime fluxes of 123, 95, 39 and 17 µg m-2 h-1, respectively. The fluxes were correlated with each other, followed general ecosystem trends of CO2 and water vapor, and showed similar sunlight and temperature response curves as other biogenic VOCs. The May through October flux, based on measurements and modeling, averaged 62, 52, 24 and 18 µg m-2 h-1 for ethene, propene, butene and isoprene, respectively. The light alkenes contribute significantly to the overall biogenic source of reactive hydrocarbons: roughly 18 % of the dominant biogenic VOC, 2-methyl-3-buten-2-ol. The measured ecosystem scale fluxes are 40-80 % larger than estimates used for global emissions models for this type of ecosystem.

Synthesis and spectral characterization of 2-((2-hydroxybenzylidene)amino)-2-methylpropane-1,3-diol derived complexes: Molecular docking and antimicrobial studies

NASA Astrophysics Data System (ADS)

Ansari, Istikhar A.; Sama, Farasha; Raizada, Mukul; Shahid, M.; Rajpoot, Ravi Kant; Siddiqi, Zafar A.

2017-01-01

A series of four homo-dinuclear transition metal complexes with stoichiometry [M2(HL)2(H2O)2] [M = Fe (1), Co (2), Ni (3) and Cu (4); H3L = 2-((2-hydroxybenzylidene)amino)-2-methylpropane-1,3-diol] has been prepared. Ligand (H3L) was obtained by the condensation of 2-amino-2-methyl-1,3-propanediol (H2ampd) with salicylaldehyde. The complexes (1-4) are characterized employing elemental analysis, FTIR, ESI mass, 1H &13C NMR, EPR, UV Visible, TGA, cyclic voltammetry, and magnetic studies. Spectral data ascertained the bonding features and the geometry of the complexes and revealed that all the complexes adopt distorted octahedral geometry with high spin state of metal ions. Thermal and ESI mass data confirmed the proposed stoichiometry of the complexes. Cyclic voltammetric (CV) studies ascertain the formation of MII/MIII quasi-reversible redox couples in solution. The antimicrobial activities of the present complexes have been examined against few bacteria (E. coli, B. subtilis, S. aureus and S. typhymurium) and fungi (C. albicans, A. fumigatus and P. marneffeiin) suggesting that the present compounds show moderate to high antimicrobial properties. Among all the compounds tested, complex (4) exhibited highest antibacterial as well as antifungal activity. Molecular docking studies of the free ligand and the complexes are performed with BDNA.

Sources of C₂-C₄ alkenes, the most important ozone nonmethane hydrocarbon precursors in the Pearl River Delta region.

PubMed

Zhang, Yanli; Wang, Xinming; Zhang, Zhou; Lü, Sujun; Huang, Zhonghui; Li, Longfeng

2015-01-01

Surface ozone is becoming an increasing concern in China's megacities such as the urban centers located in the highly industrialized and densely populated Pearl River Delta (PRD) region, where previous studies suggested that ozone production is sensitive to VOC emissions with alkenes being important precursors. However, little was known about sources of alkenes. Here we present our monitoring of ambient volatile organic compounds at four representative urban, suburban and rural sites in the PRD region during November-December 2009, which experienced frequent ozone episodes. C2-C4 alkenes, whose total mixing ratios were 11-20% of non-methane hydrocarbons (NMHCs) quantified, accounted for 38-64% of ozone formation potentials (OFPs) and 30-50% of the total hydroxyl radical (OH) reactivity by NMHCs. Ethylene was the most abundant alkene, accounting for 8-15% in total mixing ratios of NMHCs and contributed 25-46% of OFPs. Correlations between C2-C4 alkenes and typical source tracers suggested that ethylene might be largely related to vehicle exhausts and industry activities, while propene and butenes were much more LPG-related. Positive Matrix Factorization (PMF) confirmed that vehicle exhaust and liquefied petroleum gas (LPG) were two major sources that altogether accounted for 52-62%, 58-77%, 73-83%, 68-79% and 73-84% for ethylene, propene, 1-butene, trans-2-butene and cis-2-butene, respectively. Vehicle exhausts alone contributed 32-49% ethylene and 35-41% propene. Industry activities contributed 13-23% ethylene and 7-20% propene. LPG instead contributed the most to butenes (38-65%) and substantially to propene (23-36%). Extensive tests confirmed high fractions of propene and butenes in LPG then used in Guangzhou and in LPG combustion plumes; therefore, limiting alkene contents in LPG would benefit regional ozone control. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and Mass Spectra of Butenyltin Compounds

DTIC Science & Technology

1989-03-01

activities or operations. One instance of this concern has focused on the Navy’s use of tributyltin compounds as antifoulants on ships’ hulls. Such...butene, and 1-chloro- 2-butene were obtained from Pfaltz & Bauer (Waterbury, CT). Resublimed magne- sium chips, tetrabutyltin and tributyltin bromide...preferential elimination of R minus R to form RSn ’from R3Sn + The fragmentation patterns of tributyltin bromide and tributenyltin bromides are dominated

Mechanism studies of the conversion of 13C-labeled n-butane on zeolite H-ZSM-5 by using 13C magic angle spinning NMR spectroscopy and GC-MS analysis.

PubMed

Luzgin, Mikhail V; Stepanov, Alexander G; Arzumanov, Sergei S; Rogov, Vladimir A; Parmon, Valentin N; Wang, Wei; Hunger, Michael; Freude, Dieter

2005-12-23

By using 13C MAS NMR spectroscopy (MAS = magic angle spinning), the conversion of selectively 13C-labeled n-butane on zeolite H-ZSM-5 at 430-470 K has been demonstrated to proceed through two pathways: 1) scrambling of the selective 13C-label in the n-butane molecule, and 2) oligomerization-cracking and conjunct polymerization. The latter processes (2) produce isobutane and propane simultaneously with alkyl-substituted cyclopentenyl cations and condensed aromatic compounds. In situ 13C MAS NMR and complementary ex situ GC-MS data provided evidence for a monomolecular mechanism of the 13C-label scrambling, whereas both isobutane and propane are formed through intermolecular pathways. According to 13C MAS NMR kinetic measurements, both pathways proceed with nearly the same activation energies (E(a) = 75 kJ mol(-1) for the scrambling and 71 kJ mol(-1) for isobutane and propane formation). This can be rationalized by considering the intermolecular hydride transfer between a primarily initiated carbenium ion and n-butane as being the rate-determining stage of the n-butane conversion on zeolite H-ZSM-5.

Isomerization of C.sub.4 alkenes

DOEpatents

Smith, Jr., Lawrence A.

1984-01-01

A method for isomerizing isobutene or n-butene to produce a mixture of isobutene and normal butene, and polymerizing at least a portion thereof to produce isobutene/n-butene codimer, which comprieses feeding at least 80 weight % of either the isobutene or n-butene to a catalytic distillation reactor containing a fixed bed acidic cation exchange resin catalyst packing which provides both the catalyst sites and distillation sites for the reaction products, isomerizing a portion of the isobutene or n-butene to produce a mixture of isobutene and n-butene and reacting at least a portion of the isobutene and n-butene to form codimer of isobutene and n-butene, whereby an overhead fraction containing any unreacted isobutene and n-butene and a bottoms fraction containing codimer is produced. The result of the reaction is substantially the same regardless whether the feed is isobutene or n-butene. Other aspects of the invention, include combinations of procedures to produce high purity isobutene and n-butene. Either isobutene or n-butene product (depending on the desired product) can be recycled as feed, thus substantially carrying out the isomerization to extinction and total conversion to the desired product.

76 FR 69723 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-09

... manufacture of new chemicals. Under TSCA sections 5(d)(2) and 5(d)(3), EPA is required to publish in the... sections 5(d)(2) and 5(d)(3), EPA is required to publish in the Federal Register a notice of receipt of a...) Monomer to be (G)3-[(1-hydroxy- polymerized, 2-methylpropan-2- copolymerized yl)amino]-2- for use in...

Unimolecular dissociation of protonated trans-1,4-diphenyl-2-butene-1,4-dione in the gas phase: rearrangement versus simple cleavage.

PubMed

Wu, Lianming; Liu, David Q; Vogt, Frederick G

2006-01-01

Fragmentation mechanisms of trans-1,4-diphenyl-2-butene-1,4-dione were studied using a variety of mass spectrometric techniques. The major fragmentation pathways occur by various rearrangements by loss of H(2)O, CO, H(2)O and CO, and CO(2). The other fragmentation pathways via simple alpha cleavages were also observed but accounted for the minor dissociation channels in both a two-dimensional (2-D) linear ion trap and a quadrupole time-of-flight (Q-TOF) mass spectrometer. The elimination of CO(2) (rather than CH(3)CHO or C(3)H(8)), which was confirmed by an exact mass measurement using the Q-TOF instrument, represented a major fragmentation pathway in the 2-D linear ion trap mass spectrometer. However, the elimination of H(2)O and CO becomes more competitive in the beam-type Q-TOF instrument. The loss of CO is observed in both the MS(2) experiment of m/z 237 and the MS(3) experiment of m/z 219 but via the different transition states. The data suggest that the olefinic double bond in protonated trans-1,4-diphenyl-2-butene-1,4-dione plays a key role in stabilizing the rearrangement transition states and increasing the bond dissociation (cleavage) energy to give favorable rearrangement fragmentation pathways. Copyright (c) 2006 John Wiley & Sons, Ltd.

Isotope effects and the temperature dependences of the hyperfine coupling constants of muoniated sec-butyl radicals in condensed phases.

PubMed

Fleming, Donald G; Bridges, Michael D; Arseneau, Donald J; Chen, Ya Kun; Wang, Yan Alexander

2011-04-07

Reported here is the first μSR study of the muon (A(μ)) and proton (A(p)) β-hyperfine coupling constants (Hfcc) of muoniated sec-butyl radicals, formed by muonium (Mu) addition to 1-butene and to cis- and trans-2-butene. The data are compared with in vacuo spin-unrestricted MP2 and hybrid DFT/B3YLP calculations reported in the previous paper (I), which played an important part in the interpretation of the data. The T-dependences of both the (reduced) muon, A(μ)′(T), and proton, A(p)(T), Hfcc are surprisingly well explained by a simple model, in which the calculated Hfcc from paper I at energy minima of 0 and near ±120° are thermally averaged, assuming an energy dependence given by a basic 2-fold torsional potential. Fitted torsional barriers to A(μ)′(T) from this model are similar (~3 kJ/mol) for all muoniated butyl radicals, suggesting that these are dominated by ZPE effects arising from the C−Mu bond, but for A(p)(T) exhibit wide variations depending on environment. For the cis- and trans-2-butyl radicals formed from 2-butene, A(μ)′(T) exhibits clear discontinuities at bulk butene melting points, evidence for molecular interactions enhancing these muon Hfcc in the environment of the solid state, similar to that found in earlier reports for muoniated tert-butyl. In contrast, for Mu−sec-butyl formed from 1-butene, there is no such discontinuity. The muon hfcc for the trans-2-butyl radical are seemingly very well predicted by B3LYP calculations in the solid phase, but for sec-butyl from 1-butene, showing the absence of further interactions, much better agreement is found with the MP2 calculations across the whole temperature range. Examples of large proton Hfcc near 0 K are also reported, due to eclipsed C−H bonds, in like manner to C−Mu, which then also exhibit clear discontinuities in A(p)(T) at bulk melting points. The data suggest that the good agreement found between theory and experiment from the B3LYP calculations for eclipsed bonds in the solid phase may be fortuitous. For the staggered protons of the sec-butyl radicals formed, no discontinuities are seen at all in A(p)(T), also demonstrating no further effects of molecular interactions on these particular proton Hfcc.

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

Code of Federal Regulations, 2011 CFR

2011-07-01

...)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 substance...-hydroxy-4-benzoylphenoxy)butane (PMN P-93-483) is subject to reporting under this section for the...

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

Code of Federal Regulations, 2010 CFR

2010-07-01

...)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 substance...-hydroxy-4-benzoylphenoxy)butane (PMN P-93-483) is subject to reporting under this section for the...

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.

Biotreatment of ammonia- and butanal-containing waste gases.

PubMed

Weckhuysen, B; Vriens, L; Verachtert, H

1994-10-01

The biological removal of ammonia and butanal in contaminated air was investigated by using, respectively, a laboratory-scale filter and a scrubber-filter combination. It was shown that ammonia can be removed with an elimination efficiency of 83% at a volumetric load of 100 m3.m-2.h-1 with 4-16 ppm of ammonia. During the experiment percolates were analysed for nitrate, nitrite, ammonium and pH. It was found that the nitrification in the biofilter could deteriorate due to an inhibition of Nitrobacter species, when the free ammonia concentration was rising in the percolate. It should be easy to control such inhibition through periodic analysis of the liquid phase by using a filter-scrubber combination. Such a combination was studied for butanal removal. Butanal was removed with an elimination efficiency of 80% by a scrubber-filter combination at a volumetric load of 100 m3.m-2.h-1 and a high butanal input concentration. Mixing the filter material with CaCO3 and pH control of the liquid in the scrubber resulted in an increase of the elimination efficiency. These results, combined with previous results on the biofiltration of butanal and butyric acid, allow us to discuss the influence of odour compounds on the removal efficiency of such systems and methods for control. The results were used to construct a full-size system, which is described.

Electron collisions with methyl-substituted ethylenes: Cross section measurements and calculations for 2-methyl–2-butene and 2,3-dimethyl–2-butene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szmytkowski, Czesław, E-mail: czsz@mif.pg.gda.pl; Stefanowska, Sylwia; Zawadzki, Mateusz

We report electron-scattering cross sections determined for 2-methyl–2-butene [(H{sub 3}C)HC = C(CH{sub 3}){sub 2}] and 2,3-dimethyl–2-butene [(H{sub 3}C){sub 2}C = C(CH{sub 3}){sub 2}] molecules. Absolute grand-total cross sections (TCSs) were measured for incident electron energies in the 0.5–300 eV range, using a linear electron-transmission technique. The experimental TCS energy dependences for the both targets appear to be very similar with respect to the shape. In each TCS curve, three features are discernible: the resonant-like structure located around 2.6–2.7 eV, the broad distinct enhancement peaking near 8.5 eV, and a weak hump in the vicinity of 24 eV. Theoretical integral elasticmore » (ECS) and ionization (ICS) cross sections were computed up to 3 keV by means of the additivity rule (AR) approximation and the binary-encounter-Bethe method, respectively. Their sums, (ECS+ICS), are in a reasonable agreement with the respective measured TCSs. To examine the effect of methylation of hydrogen sides in the ethylene [H{sub 2}C = CH{sub 2}] molecule on the TCS, we compared the TCS energy curves for the sequence of methylated ethylenes: propene [H{sub 2}C = CH(CH{sub 3})], 2-methylpropene [H{sub 2}C = C(CH{sub 3}){sub 2}], 2-methyl–2-butene [(H{sub 3}C)HC = C(CH{sub 3}){sub 2}], and 2,3-dimethyl–2-butene [(H{sub 3}C){sub 2}C = C(CH{sub 3}){sub 2}], measured in the same laboratory. Moreover, the isomeric effect is also discussed for the C{sub 5}H{sub 10} and C{sub 6}H{sub 12} compounds.« less

Ultrafast non-adiabatic dynamics of methyl substituted ethylenes: the π3s Rydberg state.

PubMed

Wu, Guorong; Boguslavskiy, Andrey E; Schalk, Oliver; Schuurman, Michael S; Stolow, Albert

2011-10-28

Excited state unimolecular reactions of some polyenes exhibit localization of their dynamics at a single ethylenic double bond. Here we present studies of the fundamental photophysical processes in the ethylene unit itself. Combined femtosecond time-resolved photoelectron spectroscopy (TRPES) and ab initio quantum chemical calculations was applied to the study of excited state dynamics in cis-butene, trans-butene, trimethylethylene, and tetramethylethylene, following initial excitation to their respective π3s Rydberg states. The wavelength dependence of the π3s Rydberg state dynamics of tetramethylethylene was investigated in more detail. The π3s Rydberg to ππ(∗) valence state decay rate varies greatly with substituent: the 1,2-di- and tri-methyl substituted ethylenes (cis-butene, trans-butene, and trimethylethylene) show an ultrafast decay (∼20 fs), whereas the fully methylated tetramethylethylene shows a decay rate of 2 to 4 orders of magnitude slower. These observations are rationalized in terms of topographical trends in the relevant potential energy surfaces, as found from ab initio calculations: (1) the barrier between the π3s state and the ππ∗ state increases with increasing methylation, and (2) the π3s∕ππ∗ minimum energy conical intersection displaces monotonically away from the π3s Franck-Condon region with increasing methylation. The use of systematic methylation in combination with TRPES and ab initio computation is emerging as an important tool in discerning the excited state dynamics of unsaturated hydrocarbons.

Ultrafast non-adiabatic dynamics of methyl substituted ethylenes: The π3s Rydberg state

NASA Astrophysics Data System (ADS)

Wu, Guorong; Boguslavskiy, Andrey E.; Schalk, Oliver; Schuurman, Michael S.; Stolow, Albert

2011-10-01

Excited state unimolecular reactions of some polyenes exhibit localization of their dynamics at a single ethylenic double bond. Here we present studies of the fundamental photophysical processes in the ethylene unit itself. Combined femtosecond time-resolved photoelectron spectroscopy (TRPES) and ab initio quantum chemical calculations was applied to the study of excited state dynamics in cis-butene, trans-butene, trimethylethylene, and tetramethylethylene, following initial excitation to their respective π3s Rydberg states. The wavelength dependence of the π3s Rydberg state dynamics of tetramethylethylene was investigated in more detail. The π3s Rydberg to ππ* valence state decay rate varies greatly with substituent: the 1,2-di- and tri-methyl substituted ethylenes (cis-butene, trans-butene, and trimethylethylene) show an ultrafast decay (˜20 fs), whereas the fully methylated tetramethylethylene shows a decay rate of 2 to 4 orders of magnitude slower. These observations are rationalized in terms of topographical trends in the relevant potential energy surfaces, as found from ab initio calculations: (1) the barrier between the π3s state and the ππ* state increases with increasing methylation, and (2) the π3s/ππ* minimum energy conical intersection displaces monotonically away from the π3s Franck-Condon region with increasing methylation. The use of systematic methylation in combination with TRPES and ab initio computation is emerging as an important tool in discerning the excited state dynamics of unsaturated hydrocarbons.

Reactivity of propene, n-butene, and isobutene in the hydrogen transfer steps of n-hexane cracking over zeolites of different structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lukyanov, D.B.

The reaction of n-hexane cracking over HZSM-5, HY zeolite and mordenite (HM) was studied in accordance with the procedure of the [beta]-test recently proposed for quantitative characterization of zeolite hydrogen transfer activity. It is shown that this procedure allows one to obtain quantitative data on propene, n-butene, and isobutene reactivities in the hydrogen transfer steps of the reaction. The results demonstrate that in the absence of steric constraints (large pore HY and HM zeolites) isobutene is approximately 5 times more reactive in hydrogen transfer than n-butene. The latter, in turn, is about 1.3 times more reactive than propene. With mediummore » pore HZSM-5, steric inhibition of the hydrogen transfer between n-hexane and isobutene is observed. This results in a sharp decrease in the isobutene reactivity: over HZSM-5 zeolites isobutene is only 1.2 times more reactive in hydrogen transfer than n-butene. On the basis of these data it is concluded that the [beta]-test measures the [open quotes]real[close quotes] hydrogen transfer activity of zeolites, i.e., the activity that summarizes the effects of the acidic and structural properties of zeolites. An attempt is made to estimate the [open quotes]ideal[close quotes] zeolite hydrogen transfer activity, i.e., the activity determined by the zeolite acidic properties only. The estimations obtained show that this activity is approximately 1.8 and 1.6 times higher for HM zeolite in comparison with HZSM-5 and HY zeolites, respectively. 16 refs., 4 figs., 2 tabs.« less

Pulsed laser deposited ZnO film on side-polished fiber as a gas sensing element.

PubMed

Dikovska, Anna Og; Atanasov, Petar A; Stoyanchov, Toshko R; Andreev, Andrey T; Karakoleva, Elka I; Zafirova, Blagovesta S

2007-05-01

A simple sensor element consisting of a side-polished single-mode fiber and a planar metal oxide waveguide is described. The thin ZnO planar waveguide was produced on the polished fiber surface by pulsed laser deposition at optimized processing parameters. A measurement scheme for in situ control of the film thickness during the deposition process was developed and used. X-ray diffraction measurements and scanning electron microscopy were used to characterize the structure and the surface morphology of the planar waveguide, respectively. The numerical evaluation of the sensor sensitivity predicts the possibility to detect refractive index changes of less than 10(-4). Furthermore, preliminary gas sensor tests were performed by using a mixture of 1.5% butane diluted in N(2) and pure butane. A shift of the spectral position of the resonance points was observed from 3 to 5 s after gas exposure, which corresponds to refractive index changes of 3 x 10(-5) and 1.2 x 10(-3) for 1.5% butane and for pure butane, respectively.

Acetone in the atmosphere of Hong Kong: Abundance, sources and photochemical precursors

NASA Astrophysics Data System (ADS)

Guo, H.; Ling, Z. H.; Cheung, K.; Wang, D. W.; Simpson, I. J.; Blake, D. R.

2013-02-01

Intensive field measurements were carried out at a mountain site and an urban site at the foot of the mountain from September to November 2010 in Hong Kong. Acetone was monitored using both canister air samples and 2,4-dinitrophenylhydrazine cartridges. The spatiotemporal patterns of acetone showed no difference between the two sites (p > 0.05), and the mean acetone mixing ratios on O3 episode days were higher than those on non-O3 episode days at both sites (p < 0.05). The source contributions to ambient acetone at both sites were estimated using a receptor model i.e. Positive Matrix Factorization (PMF). The PMF results showed that vehicular emission and secondary formation made the most important contribution to ambient acetone, followed by the solvent use at both sites. However, the contribution of biogenic emission at the mountain site was significantly higher than that at the urban site, whereas biomass burning made more remarkable contribution at the urban site than that at the mountain site. The mechanism of oxidation formation of acetone was investigated using a photochemical box model. The results indicated that i-butene was the main precursor of secondary acetone at the mountain site, while the oxidation of i-butane was the major source of secondary acetone at the urban site.

Development of a Novel Leak-Free Constant-Pressure Cylinder for Certified Reference Materials of Liquid Hydrocarbon Mixtures.

PubMed

Kim, Yong Doo; Kang, Ji Hwan; Bae, Hyun Kil; Kang, Namgoo; Oh, Sang Hyub; Lee, Jin-Hong; Woo, Jin Chun; Lee, Sangil

2017-11-21

Liquid hydrocarbon mixtures such as liquefied petroleum gas and liquefied natural gas are becoming integral parts of the world's energy system. Certified reference materials (CRMs) of liquid hydrocarbon mixtures are necessary to allow assessment of the accuracy and traceability of the compositions of such materials. A piston-type constant-pressure cylinder (PCPC) comprising chambers for a pressurizing gas (helium) and liquid (hydrocarbons) separated by a piston can be used to develop accurate and traceable liquid hydrocarbon mixture CRMs. The development of accurate CRMs relies on the maintenance of their composition. However, a PCPC might allow hydrocarbons to leak owing to the imperfect seal of the piston. In this study, a novel leak-free bellows-type constant-pressure cylinder (BCPC) is designed and evaluated by comparison with PCPCs. Liquid hydrocarbon mixtures consisting of ethane, propane, propene, isobutane, n-butane, 1-butene, and isopentane were prepared in both types of constant pressure cylinders and then monitored to check leakages between the gas and liquid chambers. Overall, notable leakage occurred from and into both chambers in the PCPCs, whereas no leakage occurred in the BCPCs in the three months after their gravimetric preparation. The BCPCs maintained no leakage even 10 months after their preparation, whereas the PCPCs showed significantly increasing leakage during the same period.

Organosulfates as Tracers for Secondary Organic Aerosol (SOA) Formation from 2-Methyl-3-Buten-2 ol (MBO) in the Atmosphere

EPA Science Inventory

2-Methyl-3-buten-2-ol (MBO) is an important biogenic volatile organic compound (BVOC) emitted by pine trees and a potential precursor of atmospheric secondary organic aerosol (SOA) in forested regions. In the present study, hydroxyl radical (OH)-initiated oxidation of MBO was exa...

Reactions of butadiyne. 1: The reaction with hydrogen atoms

NASA Technical Reports Server (NTRS)

Schwanebeck, W.; Warnatz, J.

1984-01-01

The reaction of hydrogen (H) atoms with butadiene (C4H2) was studied at room temperature in a pressure range between w mbar and 10 mbar. The primary step was an addition of H to C4H2 which is in its high pressure range at p 1 mbar. Under these conditions the following addition of a second H atom lies in the transition region between low and high pressure range. Vibrationally excited C4H4 can be deactivated to form buten-(1)-yne-(3)(C4H4) or decomposes into two C2H2 molecules. The rate constant at room temperature for primary step is given. The second order rate constant for the consumption of buten-(1)-yne-(3) is an H atom excess at room temperature is given.

Biosynthesis of 2-methyl-3-buten-2-ol emitted from needles of Pinus ponderosa via the non-mevalonate DOXP/MEP pathway of isoprenoid formation.

PubMed

Zeidler, J; Lichtenthaler, H K

2001-06-01

The volatile hemiterpene 2-methyl-3-buten-2-ol (MBO) is emitted from the needles of several pine species from the Western United States and contributes to ozone formation in the atmosphere. It is synthesised enzymatically from dimethylallyl diphosphate (DMAPP). We show here that needles of Pinus ponderosa Laws. incorporated [1-2H1]-1-deoxy-D-xylulose (d-DOX) into the emitted MBO, but not D,L-[2-13C]mevalonic acid lactone. Furthermore, MBO emission was inhibited by fosmidomycin, a specific inhibitor of the second enzyme of the mevalonate-independent pathway of isopentenyl diphosphate and DMAPP formation, i.e. the 1-deoxy-D-xylulose 5-phosphate/2-C-methyl-D-erythritol 4-phosphate (DOXP/MEP) pathway. We thus prove that MBO emitted from needles of P. ponderosa is primarily formed via the DOXP/MEP pathway.

SOA Formation from the Atmospheric Oxidation of 2-Methyl-3-Buten-2-ol and Its Implications for PM2.5

EPA Science Inventory

The formation of secondary organic aerosol (SOA) generated by irradiating 2-methyl-3-buten-2-01 (MBO) in the presence and/or absence of NO_x H₂O2, and/or SO₂ was examined. Experiments were conducted. in smog chambers operated either in dyna....

Active-site-directed irreversible inhibitors of isopentenyl diphosphate isomerase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muhlbacher, M.

1987-01-01

Seven analogues of isopentenyl diphosphate, containing fluorine, epoxy, or ammonium functionalities were found to irreversibly inhibit isopentenyl diphosphate:dimethylallyl diphosphate isomerase isolated from the mold Claviceps purpurea. The mechanism of their inhibition of isomerase was studied. Syntheses of 3-(fluoromethyl)-3-buten-1-yl diphosphate, 2-dimethylamino-1-ethyl diphosphate, 3,4-epoxy-3-methyl-1-butyl diphosphate, 3,4,-epoxy-1-butyl diphosphate, and 2,3-epoxy-3-methyl-1-butyl diphosphate were developed and carried out in high overall yield affording 100 mg quantities of the triammonium diphosphate salts. Radiolabeled materials of these analogues with {sup 3}H, {sup 14}C, and {sup 32}P at appropriate positions were also prepared. Inactivation kinetics, substrate protection studies, and labeling experiments demonstrated that the analogues interact stoichiometrically withmore » the active-site of isomerase. Radioactive enzyme-inactivator complexes were isolated, that are stable to extended dialysis and chaotropic reagents. The complexes resulting from inactivation of the enzyme by 3-(fluoromethyl)-3-buten-1-yl diphosphate and 3,4-epoxy-3-methyl-1-butyl diphosphate are stable to ion exchange chromatography and gel electrophoresis. Stoichiometric fluoride ion release occurs during inactivation of isomerase with 3-(fluoromethyl)-3-buten-1-yl diphosphate. The complexes are not stable to high concentrations of mixtures of 2-mercaptoethanol-sodium dodecyl sulfate. The radiolabeled 2-dimethylamino-1-ethyl diphosphate isomerase complex loses radioactivity almost instantaneously when treated with base. Partial fragmentation of the inactivator molecule was observed.« less

IONIC LIQUIDS AS A CLEAN CATALYST FOR THE ALKYLATION OF ISOBUTANE WITH 2-BUTENE

EPA Science Inventory

Ionic liquids as a clean catalyst for the alkylation of isobutane with 2-butene
Kyesang Yoo, a Vasudevan V. Namboodiri,b Panagiotis G. Smirniotis,*a and Rajender S. Varma*b
a Department of Chemical Engineering, University of Cincinnati, Cincinnati, OH 45221-0171, USA.
...

Chlorine atom-initiated low-temperature oxidation of prenol and isoprenol: The effect of C=C double bonds on the peroxy radical chemistry in alcohol oxidation

DOE PAGES

Welz, Oliver; Savee, John D.; Osborn, David L.; ...

2014-07-04

The chlorine atom-initiated oxidation of two unsaturated primary C5 alcohols, prenol (3-methyl-2-buten-1-ol, (CH 3) 2CCHCH 2OH) and isoprenol (3-methyl-3-buten-1-ol, CH 2C(CH 3)CH 2CH 2OH), is studied at 550 K and low pressure (8 Torr). The time- and isomer-resolved formation of products is probed with multiplexed photoionization mass spectrometry (MPIMS) using tunable vacuum ultraviolet ionizing synchrotron radiation. The peroxy radical chemistry of the unsaturated alcohols appears much less rich than that of saturated C4 and C5 alcohols. The main products observed are the corresponding unsaturated aldehydes – prenal (3-methyl-2-butenal) from prenol oxidation and isoprenal (3-methyl-3-butenal) from isoprenol oxidation. No significant productsmore » arising from QOOH chemistry are observed. These results can be qualitatively explained by the formation of resonance stabilized allylic radicals via H-abstraction in the Cl + prenol and Cl + isoprenol initiation reactions. The loss of resonance stabilization upon O 2 addition causes the energies of the intermediate wells, saddle points, and products to increase relative to the energy of the initial radicals and O 2. These energetic shifts make most product channels observed in the peroxy radical chemistry of saturated alcohols inaccessible for these unsaturated alcohols. The experimental findings are underpinned by quantum-chemical calculations for stationary points on the potential energy surfaces for the reactions of the initial radicals with O 2. Under our conditions, the dominant channels in prenol and isoprenol oxidation are the chain-terminating HO 2-forming channels arising from radicals, in which the unpaired electron and the –OH group are on the same carbon atom, with stable prenal and isoprenal co-products, respectively. These results suggest that the presence of C=C double bonds in alcohols will reduce low-temperature reactivity during autoignition.« less

Neurochemical binding profiles of novel indole and benzofuran MDMA analogues.

PubMed

Shimshoni, Jakob A; Winkler, Ilan; Golan, Ezekiel; Nutt, David

2017-01-01

3,4-Methylenedioxy-N-methylamphetamine (MDMA) has been shown to be effective in the treatment of post-traumatic stress disorder (PTSD) in numerous clinical trials. In the present study, we have characterized the neurochemical binding profiles of three MDMA-benzofuran analogues (1-(benzofuran-5-yl)-propan-2-amine, 5-APB; 1-(benzofuran-6-yl)-N-methylpropan-2-amine, 6-MAPB; 1-(benzofuran-5-yl)-N-methylpropan-2-amine, 5-MAPB) and one MDMA-indole analogue (1-(1H-indol-5-yl)-2-methylamino-propan-1-ol, 5-IT). These compounds were screened as potential second-generation anti-PTSD drugs, against a battery of human and non-human receptors, transporters, and enzymes, and their potencies as 5-HT 2 receptor agonist and monoamine uptake inhibitors determined. All MDMA analogues displayed high binding affinities for 5-HT 2a,b,c and NE α2 receptors, as well as significant 5-HT, DA, and NE uptake inhibition. 5-APB revealed significant agonist activity at the 5-HT 2a,b,c receptors, while 6-MAPB, 5-MAPB, and 5-IT exhibited significant agonist activity at the 5-HT 2c receptor. There was a lack of correlation between the results of functional uptake and the monoamine transporter binding assay. MDMA analogues emerged as potent and selective monoamine oxidase A inhibitors. Based on 6-MAPB favorable pharmacological profile, it was further subjected to IC 50 determination for monoamine transporters. Overall, all MDMA analogues displayed higher monoamine receptor/transporter binding affinities and agonist activity at the 5-HT 2a,c receptors as compared to MDMA.

21 CFR 177.1430 - Isobutylene-butene copolymers.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) of this section. (b) Specifications: Isobutylene-butene copolymers Molecular weight (range) Viscosity...: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (2) Viscosity. Viscosity shall be determined by ASTM method D445-74, “Test for Kinematic Viscosity of Transparent and...

21 CFR 177.1430 - Isobutylene-butene copolymers.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) of this section. (b) Specifications: Isobutylene-butene copolymers Molecular weight (range) Viscosity...: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (2) Viscosity. Viscosity shall be determined by ASTM method D445-74, “Test for Kinematic Viscosity of Transparent and...

21 CFR 177.1430 - Isobutylene-butene copolymers.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) of this section. (b) Specifications: Isobutylene-butene copolymers Molecular weight (range) Viscosity...: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (2) Viscosity. Viscosity shall be determined by ASTM method D445-74, “Test for Kinematic Viscosity of Transparent and...

A dynamic dilution system-based evaluation of the procedure adopted for determining ozone precursor volatile compounds.

PubMed

Palluau, Fabienne; Mirabel, Philippe; Millet, Maurice

2005-02-01

A dynamic dilution system was created to evaluate the performance and the reliability of ozone precursor volatile organic compound (VOC) sampling ("TO-Can" canisters) and analysis (thermal desorption/gas chromatography/flame ionisation detection) techniques used by the "Laboratoire Interregional de Chimie du Grand Est (LIC)". Different atmospheres of VOCs were generated at concentrations between 0.8 and 25 ppb, with temperatures of 0, 10, 20 and 30 degrees C, and with relative humidities of 0, 30, 50, 70 and 90%. These conditions are generally representative of those commonly observed in ambient air in the eastern France. This dynamic dilution allows the simulation of a wide range of scenarios (concentrations, temperatures and relative humidities). After assessing the capacity and performance of the system, it was applied in order to evaluate the recoveries and stabilities of VOCs from canisters used for the collection and analysis of two mixtures of VOCs. The first mixture contained six alkanes (ethane, propane, butane, pentane, hexane and heptane), and the second contained five alkenes (ethene, propene, butene, 1-pentene and 1-hexene), five aromatics (benzene, toluene, ethylbenzene, m-xylene and o-xylene), acetylene, and 1,3-butadiene. No significant losses of alkanes from the canisters were observed after 21 days of storage, and good recoveries of alkanes from the canisters (>80%) were obtained regardless of the concentration, the temperature and the relative humidity. However, losses of certain aromatics were noted at low relative humidity.

Double addition of diethylamine to biacetylene (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trofimov, B.A.; Vavilova, A.N.

1986-03-01

Biacetylene reacts with an excess of diethylamine in dilute solutions of anhydrous acetonitrile, methanol, ethanol, and THF to form the diadduct 1,3-bis(diethyl-amino)-1,3-butadiene (lambda/sub max/ 325 nm). During concentration of the reaction mixture the latter undergoes hydration by the residual amounts of water in the 3-(diethylamino)-2-butenal. The spectral characteristics (UV, IR, PMR) of the intermediate reaction products are given. The kinetics of the stage of addition of the diethylamine and water to the monoadduct, 1-(diethylamino)-1-buten-3-yne, were studied. It was concluded that the addition of the nucleophile to the triple bond during its secondary amination and hydration is facilitated by the concertedmore » transfer of a proton.« less

Microwave-Assisted Synthesis of a Natural Insecticide on Basic Montmorillonite K10 Clay. Green Chemistry in the Undergraduate Organic Laboratory

ERIC Educational Resources Information Center

Dintzner, Matthew R.; Wucka, Paul R.; Lyons, Thomas W.

2006-01-01

A detailed investigation of the clay-catalyzed condensation of sesamol and other phenols with 3-methyl-2-butenal to give methylenedioxyprecocene (MDP) and other chromenes is presented. The clay-catalyzed microwave-assisted condensation of sesamol with 3-methyl-2-butenal is appropriate for incorporation into undergraduate organic laboratory…

Observation of H displacement and H2 elimination channels in the reaction of O(3P) with 1-butene from crossed beams and theoretical studies

NASA Astrophysics Data System (ADS)

Caracciolo, Adriana; Vanuzzo, Gianmarco; Balucani, Nadia; Stranges, Domenico; Cavallotti, Carlo; Casavecchia, Piergiorgio

2017-09-01

We report preliminary combined experimental/theoretical results on O(3P) + 1-butene reaction dynamics with focus on atomic hydrogen displacement and molecular hydrogen elimination channels. Dynamics and relative yield of the ethylvinoxy + H and ethylketene + H2 product channels are characterized in crossed beam experiments. Stationary points and energetics of triplet/singlet C4H8O potential energy surfaces (PESs) are calculated at CCSD(T)/CBS and CASPT2 level. O(3P) attack occurs on both unsaturated C-atoms with preference for the less substituted one leading, among other products, to C2H5CHCHO + H via an exit barrier on the triplet PES, and to C2H5CHCO + H2 via a very high exit barrier on the singlet PES following intersystem crossing.

Flowers of Clerodendrum volubile exacerbate immunomodulation by suppressing phagocytic oxidative burst and modulation of COX-2 activity.

PubMed

Erukainure, Ochuko L; Mesaik, Ahmed M; Muhammad, Aliyu; Chukwuma, Chika I; Manhas, Neha; Singh, Parvesh; Aremu, Oluwole S; Islam, Md Shahidul

2016-10-01

The immunomodulatory potentials of the crude methanolic extract and fractions [n-hexane (Hex), n-dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol (BuOH)] of Clerodendrum volubile flowers were investigated on whole blood phagocytic oxidative burst using luminol-amplified chemiluminescence technique. They were also investigated for their free radicals scavenging activities. The DCM fraction showed significant (p<0.05) anti-oxidative burst and free radical scavenging activities indicating high immunomodulatory and antioxidant potencies respectively. Cytotoxicity assay of the DCM fraction revealed a cytotoxic effect on CC-1 normal cell line. GCMS analysis revealed the presence of triacetin; 3,6-dimethyl-3-octanol; 2R - Acetoxymethyl-1,3,3-trimethtyl - 4t - (3-methyl-2-buten-1-yl) - 1c - cyclohexanol and Stigmastan - 3,5-diene in DCM fraction. These compounds were docked with the active sites of cyclooxygenase-2 (COX-2). Triacetin, 3,6-dimethyl-3-Octanol, and 2R-Acetoxymethyl-1,3,3-trimethtyl-4t-(3-methyl-2-buten-1-yl)-1c-cyclohexanol docked comfortably with COX-2 with good scoring function (-CDocker energy) indicating their inhibitory potency against COX-2. 3,6-dimethyl-3-Octanol, displayed the lowest predicted free energy of binding (-21.4kcalmol -1 ) suggesting its stronger interaction with COX-2, this was followed by 2R - Acetoxymethyl-1, 3, 3-trimethtyl-4t-(3-methyl-2-buten-1-yl)-1c-cyclhexanol (BE=-20.5kcalmol -1 ), and triacetin (BE=-10.9kcalmol -1 ). Stigmastan - 3,5-diene failed to dock with COX-2. The observed suppressive effect of the DCM fraction of C. volubile flower methanolic extract on phagocytic oxidative burst indicates an immunomodulatory potential. This is further reflected in its free scavenging activities and synergetic modulation of COX-2 activities by its identified compounds in silico. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Transport of hop aroma compounds across Caco-2 monolayers.

PubMed

Heinlein, A; Metzger, M; Walles, H; Buettner, A

2014-11-01

Although being reported and used as a sedative remedy for several years, the bioactive principle of hop preparations is still not decisively clarified. Understanding absorption and transformation processes of potential physiologically active constituents is essential to evaluate the likeliness of biological effects on humans. Therefore, single hop aroma compounds as well as digestive transformation products thereof have been investigated in view of their human intestinal absorption, applying Caco-2 transport experiments as well as investigations on potential biotransformation processes. Selective and sensitive identification and quantification were thereby achieved by application of two-dimensional high resolution gas chromatography-mass spectrometry in conjunction with stable isotope dilution analysis, leading to the determination of apparent permeability values by different mathematical approaches considering sink and non-sink conditions. Overall, calculated permeability values ranged from 2.6 × 10(-6) to 1.8 × 10(-4) cm s(-1) with all mathematical approaches, indicating high absorption potential and almost complete bioavailability for all tested compounds with hydroxyl-functionalities. Considering this high permeability together with the high lipophilicity of these substances, a passive transcellular uptake route can be speculated. Investigated sesquiterpenes and β-myrcene showed flat absorption profiles while the investigated esters showed decreasing profiles. In view of the lipophilic and volatile nature of the investigated substances, special attention was paid to recovery and mass balance determination. Furthermore, in the course of the transport experiments of 1-octen-3-ol and 3-methyl-2-buten-1-ol, additional biotransformation products were observed, namely 3-octanone and 3-methyl-2-butenal, respectively. The absence of these additional substances in control experiments strongly indicates an intestinal first-pass metabolism of the α,β-unsaturated alcohols 1-octen-3-ol and 3-methyl-2-buten-1-ol in Caco-2 cells.

Ice core records of monoterpene- and isoprene-SOA tracers from Aurora Peak in Alaska since 1660s: Implication for climate change variability in the North Pacific Rim

NASA Astrophysics Data System (ADS)

Pokhrel, Ambarish; Kawamura, Kimitaka; Ono, Kaori; Seki, Osamu; Fu, Pingqing; Matoba, Sumio; Shiraiwa, Takayuki

2016-04-01

Monoterpene and isoprene secondary organic aerosol (SOA) tracers are reported for the first time in an Alaskan ice core to better understand the biological source strength before and after the industrial revolution in the Northern Hemisphere. We found significantly high concentrations of monoterpene- and isoprene-SOA tracers (e.g., pinic, pinonic, and 2-methylglyceric acids, 2-methylthreitol and 2-methylerythritol) in the ice core, which show historical trends with good correlation to each other since 1660s. They show positive correlations with sugar compounds (e.g., mannitol, fructose, glucose, inositol and sucrose), and anti-correlations with α-dicarbonyls (glyoxal and methylglyoxal) and fatty acids (e.g., C18:1) in the same ice core. These results suggest similar sources and transport pathways for monoterpene- and isoprene-SOA tracers. In addition, we found that concentrations of C5-alkene triols (e.g., 3-methyl-2,3,4-trihydroxy-1-butene, cis-2-methyl 1,3,4-trihydroxy-1-butene and trans-2-methyl-1,3,4-trihydroxy-1-butene) in the ice core have increased after the Great Pacific Climate Shift (late 1970s). They show positive correlations with α-dicarbonyls and fatty acids (e.g., C18:1) in the ice core, suggesting that enhanced oceanic emissions of biogenic organic compounds through the marine boundary layer are recorded in the ice core from Alaska. Photochemical oxidation process for these monoterpene- and isoprene-/sesquiterpene-SOA tracers are suggested to be linked with the periodicity of multi-decadal climate oscillations and retreat of sea ice in the Northern Hemisphere.

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.

Cellular Lipids of a Nocardia Grown on Propane and n-Butane

PubMed Central

Davis, J. B.

1964-01-01

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

THE OZONE REACTION WITH BUTADIENE: FORMATION OF TOXIC PRODUCTS. (R826236)

EPA Science Inventory

Abstract

The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product ...

[Research on the modification of Kevlar fiber by polypropylene glycol and cis-2-butene-1,4-diol].

PubMed

Zheng, Yu-ying; Wang, Can-yao; Fu, Ming-lian; Cai, Wei-long; Wang, Liang-en

2005-03-01

The mechanism of the modification of Kevlar fiber by polypropylene glycol(PPG) and cis-2-butene-1, 4-diol was studied in the paper, the authors learned the esterification of toluene-2, 4-diisocyanate (TDI) onto Kevlar fiber by infrared spectrum. In the mean time, the infrared spectrograms of the productions which steadily disposed by PPG and butendiol were analysed respectively, the result showed that the intensity of the bands was reinforced at about 1700-1720 cm(-1) after the samples were steadily disposed, that is to say, the group of --NCO has been stabilized into --NHCO group, the effect of steady disposal was obvious; but the disposal effect of butendiol was apparently better than PPG's at the same condition. Finally, the authors compared the influence of different mol rates between TDI and butendiol on the productions. Based onthe consequence, excessive butendiol would prevent the Kevlar fiber from farther reaction, therefore, the mol rate between TDI and butendiol should approach 1:1.

Mechanical and Thermal Properties of Polypropylene Composites Reinforced with Lignocellulose Nanofibers Dried in Melted Ethylene-Butene Copolymer

PubMed Central

Iwamoto, Shinichiro; Yamamoto, Shigehiro; Lee, Seung-Hwan; Ito, Hirokazu; Endo, Takashi

2014-01-01

Lignocellulose nanofibers were prepared by the wet disk milling of wood flour. First, an ethylene-butene copolymer was pre-compounded with wood flour or lignocellulose nanofibers to prepare master batches. This process involved evaporating the water of the lignocellulose nanofiber suspension during compounding with ethylene-butene copolymer by heating at 105 °C. These master batches were compounded again with polypropylene to obtain the final composites. Since ethylene-butene copolymer is an elastomer, its addition increased the impact strength of polypropylene but decreased the stiffness. In contrast, the wood flour- and lignocellulose nanofiber-reinforced composites showed significantly higher flexural moduli and slightly higher flexural yield stresses than did the ethylene-butene/polypropylene blends. Further, the wood flour composites exhibited brittle fractures during tensile tests and had lower impact strengths than those of the ethylene-butene/polypropylene blends. On the other hand, the addition of the lignocellulose nanofibers did not decrease the impact strength of the ethylene-butene/polypropylene blends. Finally, the addition of wood flour and the lignocellulose nanofibers increased the crystallization temperature and crystallization rate of polypropylene. The increases were more remarkable in the case of the lignocellulose nanofibers than for wood flour. PMID:28788222

Optimisation and validation of a HS-SPME-GC-IT/MS method for analysis of carbonyl volatile compounds as biomarkers in human urine: Application in a pilot study to discriminate individuals with smoking habits.

PubMed

Calejo, Isabel; Moreira, Nathalie; Araújo, Ana Margarida; Carvalho, Márcia; Bastos, Maria de Lourdes; de Pinho, Paula Guedes

2016-02-01

A new and simple analytical approach consisting of an automated headspace solid-phase microextraction (HS-SPME) sampler coupled to gas chromatography-ion trap/mass spectrometry detection (GC-IT/MS) with a prior derivatization step with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was developed to detect volatile carbonyl metabolites with low molecular weights in human urine. A central composite design (CCD) was used to optimise the PFBHA concentration and extraction conditions that affect the efficiency of the SPME procedure. With a sample volume of 1 mL, optimal conditions were achieved by adding 300 mg/L of PFBHA and allowing the sample to equilibrate for 6 min at 62°C and then extracting the samples for 51 min at the same temperature, using a divinylbenzene/polydimethylsiloxane (DVB/PDMS) fibre. The method allowed the simultaneous identification and quantification of 44 carbonyl compounds consisting of aldehydes, dialdehydes, heterocyclic aldehydes and ketones. The method was validated with regards to the linearity, inter- and intra-day precision and accuracy. The detection limits ranged from 0.009 to 0.942 ng/mL, except for 4-hydroxy-2-nonenal (15 ng/mL), and the quantification limits varied from 0.029 to 1.66 ng/mL, except for butanal (2.78 ng/mL), 2-butanone (2.67 ng/mL), 4-heptanone (3.14 ng/mL) and 4-hydroxy-2-nonenal (50.0 ng/mL). The method accuracy was satisfactory, with recoveries ranging from 90 to 107%. The proof of applicability of the methodology was performed in a pilot target analysis of urine samples obtained from 18 healthy smokers and 18 healthy non-smokers (control group). Chemometric supervised analysis was performed using the volatile patterns acquired for these samples and clearly showed the potential of the volatile carbonyl profiles to discriminate urine from smoker and non-smoker subjects. 5-Methyl-2-furfural (p<0.0001), 2-methylpropanal, nonanal and 2-methylbutanal (p<0.05) were identified as potentially useful biomarkers to identify smoking habits. Copyright © 2015 Elsevier B.V. All rights reserved.

Using degrees of rate control to improve selective n-butane oxidation over model MOF-encapsulated catalysts: sterically-constrained Ag 3 Pd(111)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dix, Sean T.; Scott, Joseph K.; Getman, Rachel B.

2016-01-01

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 ofn-butane to 1-butanol with O 2over a model for MOF-encapsulated bimetallic nanoparticles. The model consists of a Ag 3Pd(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 atmore » 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 O 2pressure 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 O 2was 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 using a mixture of O 2and H 2O as the oxidant. This was further demonstrated by DRC analysis of a second microkinetic model based on a related but hypothetical catalyst, where the activation energies for two of the steps were modified.« less

Characteristics of volatile organic compounds (VOCs) emitted from a petroleum refinery in Beijing, China

NASA Astrophysics Data System (ADS)

Wei, Wei; Cheng, Shuiyuan; Li, Guohao; Wang, Gang; Wang, Haiyan

2014-06-01

This study made a field VOCs (volatile organic compounds) measurement for a petroleum refinery in Beijing by determining 56 PAMS VOCs, which are demanded for photochemical assessment in US, and obtained the characteristics of VOCs emitted from the whole refinery and from its inner main devices. During the monitoring period, this refinery brought about an average increase of 61 ppbv in the ambient TVOCs (sum of the PAMS VOCs) at the refinery surrounding area, while the background of TVOCs there was only 10-30 ppbv. In chemical profile, the VOCs emitted from the whole refinery was characteristic by isobutane (8.7%), n-butane (7.9%), isopentane (6.3%), n-pentane (4.9%%), n-hexane (7.6%), C6 branched alkanes (6.0%), propene (12.7%), 1-butene (4.1%), benzene (7.8%), and toluene (5.9%). On the other hand, the measurement for the inner 5 devices, catalytic cracking units (CCU2 and CCU3), catalytic reforming unit (CRU), tank farm (TF), and wastewater treatment(WT), revealed the higher level of VOCs pollutions (about several hundred ppbv of TVOCs), and the individual differences in VOCs chemical profiles. Based on the measured speciated VOCs data at the surrounding downwind area, PMF receptor model was applied to identify the VOCs sources in the refinery. Then, coupling with the VOCs chemical profiles measured at the device areas, we concluded that CCU1/3 contributes to 25.9% of the TVOCs at the surrounding downwind area by volume, followed by CCU2 (24.7%), CRU (18.9%), TF (18.3%) and WT (12.0%), which was accordant with the research of US EPA (2008). Finally, ozone formation potentials of the 5 devices were also calculated by MIR technique, which showed that catalytic cracking units, accounting for about 55.6% to photochemical ozone formation, should be given the consideration of VOCs control firstly.

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 iso...

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 iso...

40 CFR 60.707 - Chemicals affected by subpart RRR.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 123-42-2 1,4-Dichlorobutene 110-57-6 3,4-Dichloro-1-butene 64037-54-3 Dichlorodifluoromethane 75-71-8... Ethyl chloride 75-00-3 Ethylene 74-85-1 Ethylene dibromide 106-93-4 Ethylene dichloride 107-06-2...-7 (2-Ethylhexyl) amine 104-75-6 6-Ethyl-1,2,3,4-tetrahydro 9,10-anthracenedione 15547-17-8...

Poly[bis­[μ2-1,4-bis­(1H-imidazol-1-yl)butane]­dichloridonickel(II)

PubMed Central

Zhang, Jia; Song, Jiang-Feng

2011-01-01

The asymmetric unit of the title compound, [NiCl2(C10H14N4)2]n, consists of one Ni2+ ion which is located on an inversion center, one 1,4-bis­(imidazol-1-yl)butane (bimb) and one chloride ion. The Ni2+ ion exhibits a distorted octa­hedral coordination environment defined by four N atoms from four bimb ligands in the equatorial plane and two chloride ions in axial positions. The bridging coordination mode of the bimb ligands leads to the formation of inter­penetrating square Ni4(bimb)4 units that are arranged parallel to (001). The separation between the Ni atoms in these units is 13.740 (3) Å. PMID:22219855

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.

Determination of Tamoxifen and its Major Metabolites in Exposed Fish

EPA Science Inventory

Tamoxifen (TAM), (Z)-1-(p-dimethylaminoethoxyphenyl)-1, 2-diphenyl-1-butene, is a nonsteroidal agent that has been used in breast cancer treatment for decades. Its major metabolites are 4-hydroxytamoxifen (4-OHT), N-desmethyltamoxifen (DMT), and endoxifen. While TAM and metabolit...

Impact of the counterion on the solubility and physicochemical properties of salts of carboxylic acid drugs.

PubMed

David, S E; Timmins, P; Conway, B R

2012-01-01

Salt formation is a widely used approach to improve the physicochemical and solid state properties of an active pharmaceutical ingredient. In order to better understand the relationships between the active drug, the selected counterion and the resultant salt form, crystalline salts were formed using four different carboxylic acid drugs and a closely related series of amine counterions. Thirty-six related crystalline salts were prepared, characterized and the relationship between solubility and dissolution behaviour and other properties of the salt and the counterion studied. Salts of four model acid drugs, gemfibrozil, flurbiprofen, ibuprofen and etodolac were prepared using the counterions butylamine, hexylamine, octylamine, benzylamine, cyclohexylamine, tert-butylamine, 2-amino-2-methylpropan-1-ol, 2-amino-2-methylpropan-1,3-diol and tris(hydroxymethyl)aminomethane. Salt formation was confirmed, the salts were characterized and their corresponding solubilities determined and rationalized with respect to the counterions' properties. The properties of the salt highly dependent on the nature of the counterion and, although there is considerable variation, some general conclusion can be drawn. For the alkyl amines series, increasing chain length leads to a reduction in solubility across all the acidic drugs studied and a reduction in melting point, thus contradicting simplistic relationships between solubility and melting point. Small, compact counterions consistently produce crystalline salts with high melting point accompanied with a modest improvement in solubility and the nature of hydrogen bonding between the ions has a major impact on the solubility.

(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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, D.; Wang, L.; Beconi, M.

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.

Fluorescence emission induced by the femtosecond filament transmitting through the butane/air flame

NASA Astrophysics Data System (ADS)

Li, Suyu; Li, Yanhua; Shi, Zhe; Sui, Laizhi; Li, He; Li, Qingyi; Chen, Anmin; Jiang, Yuanfei; Jin, Mingxing

2018-01-01

We measure the backward fluorescence spectra generated by the femtosecond filament transmitting through the butane/air flame, and study the fluorescence emission from combustion intermediates (CN, CH and C2 radicals), air (mainly N2 and N2+). It is found that the fluorescence emission from combustion intermediates, N2 and N2+ shows difference when the femtosecond filament transmits through different parts of the butane/air flame, and we attempt to analyze it in this paper. This study demonstrates that the filament-induced fluorescence technique can be utilized to sense the combustion intermediates.

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.

Measuring urinary N-acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine (IPMA3) as a potential biomarker of isoprene exposure.

PubMed

Alwis, K Udeni; Bailey, T Liz; Patel, Dhrusti; Wang, Liqun; Blount, Benjamin C

2016-10-19

Isoprene, the 2-methyl analog of 1,3-butadiene, is identified as a possible human carcinogen by the International Agency for Research on Cancer (IARC). Isoprene is ubiquitous in the environment with numerous natural and anthropogenic sources. Tobacco smoke is the main exogenous source of isoprene exposure in indoor environments. Among smoke constituents, isoprene is thought to contribute significantly to cancer risk; however, no selective urinary biomarkers of isoprene exposure have been identified for humans. In this manuscript, we measured the minor isoprene metabolite IPMA1 (mixture of N-acetyl-S-(1-[hydroxymethyl]-2-methyl-2-propen-1-yl)-L-cysteine and N-acetyl-S-(2-hydroxy-3-methyl-3-buten-1-yl)-L-cysteine), and we identified IPMA3 (N-acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine) as a major isoprene metabolite and novel isoprene exposure biomarker for humans. Urinary isoprene metabolites were measured using ultra high performance liquid chromatography coupled with electrospray ionization triple quad tandem mass spectrometry (UPLC/ESI-MSMS). The detection rates of IPMA1 and IPMA3 are <20% and 82%, respectively. The selectivity and abundance of IPMA3 make it a useful urinary biomarker of isoprene exposure. The limit of detection of IPMA3 in urine was 0.5 ng mL -1 . IPMA3 was stable under different storage temperatures and following ten freeze-thaw cycles. The average recovery of urine spiked with IPMA3 at three different levels was 99%. IPMA3 was measured in urine samples received from 75 anonymous subjects; the median (25th percentile, 75th percentile) IPMA3 level in smokers was 36.2 (18.2, 56.8) ng mL -1 and non-smokers 2.31 (2.31, 4.38) ng mL -1 . Application of this method to large population studies will help to characterize isoprene exposure and assess potential health impact. Published by Elsevier B.V.

Reactions of Atomic Carbon with Butene Isomers: Implications for Molecular Growth in Carbon-Rich Environments

DOE PAGES

Bourgalais, J.; Spencer, Michael; Osborn, David L.; ...

2016-10-31

We carried out the product detection studies of C( 3P) atom reactions with butene (C 4H 8) isomers (but-1-ene, cis-but-2-ene, trans-but-2-ene) in a flow tube reactor at 353 K and 4 Torr under multiple collision conditions. Ground state carbon atoms are generated by 248 nm laser photolysis of tetrabromomethane, CBr 4, in a buffer of helium. Thermalized reaction products are detected using synchrotron tunable VUV photoionization and time-of-flight mass spectrometry. The temporal profiles of the detected ions are used to discriminate products from side or secondary reactions. Furthermore, for the C( 3P) + trans-but-2-ene and C( 3P) + cis-but-2-ene reactions,more » various isomers of C 4H 5 and C 5H 7 are identified as reaction products formed via CH 3 and H elimination. Assuming equal ionization cross sections for all C 4H 5 and C 5H 7 isomers, C 4H 5:C 5H 7 branching ratios of 0.63:1 and 0.60:1 are derived for the C( 3P) + trans-but-2-ene and the C( 3P) + cis-but-2-ene reactions, respectively. For the C( 3P) + but-1-ene reaction, two reaction channels are observed: the H-elimination channel, leading to the formation of the ethylpropargyl isomer, and the C 3H 3 + C 2H 5 channel. Assuming equal ionization cross sections for ethylpropargyl and C 3H 3 radicals, a branching ratio of 1:0.95 for the C 3H 3 + C 2H 5 and H + ethylpropargyl channels is derived. Finally, the experimental results are compared to previous H atom branching ratios and used to propose the most likely mechanisms for the reaction of ground state carbon atoms with butene isomers.« less

40 CFR 80.82 - Butane blending.

Code of Federal Regulations, 2011 CFR

2011-07-01

...% aromatics≤2.0 vol% benzene≤0.03 vol% sulfur≤140 ppm until December 31, 2003; ≤120 ppm in 2004; ≤30 ppm... results demonstrate the butane has the following properties: olefins≤10.0 vol% aromatics≤2.0 vol% benzene...

40 CFR 80.82 - Butane blending.

Code of Federal Regulations, 2010 CFR

2010-07-01

...% aromatics≤2.0 vol% benzene≤0.03 vol% sulfur≤140 ppm until December 31, 2003; ≤120 ppm in 2004; ≤30 ppm... results demonstrate the butane has the following properties: olefins≤10.0 vol% aromatics≤2.0 vol% benzene...

Kinetic analysis of volatile formation in milk subjected to pressure-assisted thermal treatments.

PubMed

Vazquez-Landaverde, P A; Qian, M C; Torres, J A

2007-09-01

Volatile formation in milk subjected to pressure-assisted thermal processing (PATP) was investigated from a reaction kinetic analysis point of view to illustrate the advantages of this technology. The concentration of 27 volatiles of different chemical class in milk subjected to pressure, temperature, and time treatments was fitted to zero-, 1st-, and 2nd-order chemical reaction models. Temperature and pressure effects on rate constants were analyzed to obtain activation energy (E(a)) and activation volume (deltaV*) values. Hexanal, heptanal, octanal, nonanal, and decanal followed 1st-order kinetics with rate constants characterized by E(a) values decreasing with pressure reflecting negative deltaV* values. Formation of 2-methylpropanal, 2,3-butanedione, and hydrogen sulfide followed zero-order kinetics with rate constants increasing with temperature but with unclear pressure effects. E(a) values for 2-methylpropanal and 2,3-butanedione increased with pressure, that is, deltaV* > 0, whereas values for hydrogen sulfide remained constant, that is, deltaV* = 0. The concentration of all other volatiles, including methanethiol, remained unchanged in pressure-treated samples, suggesting large negative deltaV* values. The concentration of methyl ketones, including 2-pentanone, 2-hexanone, 2-heptanone, 2-octanone, 2-nonanone, 2-decanone, and 2-undecanone, was independent of pressure and pressure-holding time. PATP promoted the formation of few compounds, had no effect on some, and inhibited the formation of volatiles reported to be factors of the consumer rejection of "cooked" milk flavor. The kinetic behavior observed suggested that new reaction formation mechanisms were not likely involved in volatile formation in PATP milk. The application of the Le Chatelier principle frequently used to explain the high quality of pressure-treated foods, often with no supporting experimental evidence, was not necessary.

Thermodynamic properties of {Delta}H{sub f 298}{degree}, S{sub 298}{degree}, and C{sub p}(T) for 2-fluoro-2-methylpropane, {Delta}H{sub f 298}{degree} of fluorinated ethanes, and group additivity for fluoroalkanes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamada, Takahiro; Bozzelli, J.W.

1999-09-09

G2(MP2) composite calculations are performed to obtain thermodynamic properties ({Delta}H{sub f 298}{degree}, S{sub 298}{degree} and C{sub p}(T)'s) of 2-fluoro-2-methylpropane. {Delta}H{sub f 298}{degree} is calculated from the G2(MP2) calculated enthalpy of reaction ({Delta}H{sub rxn 298}{degree}) and use of isodesmic reactions. Standard entropy (S{sub 298}{degree} in cal/(mol{center{underscore}dot}K)) and heat capacities (C{sub p}(T)'s in cal/(mol{center{underscore}dot}K)) are calculated using the rigid-rotor--harmonic-oscillator approximation with direct integration over energy levels of the intermolecular rotation potential energy curve. These thermodynamic properties are used to estimate data for the C/C3/F group. Enthalpies of formation ({Delta}H{sub f 298}{degree} in kcal/mol) for 1,2-difluoroethane ({minus}102.7), 1,1,2-trifluoroethane ({minus}156.9), 1,1,2,2- and 1,1,1,2-tetrafluoroethane (209.6more » and 213.3), and pentafluoroethane ({minus}264.1), are calculated using total energies obtained from G2(MP2) composite ab initio methods. Isodesmic reactions with existing literature values of {Delta}H{sub f 298}{degree} for ethane, 1-fluoroethane, 1,1-difjuoroethane and 1,1,1-trifluoroethane are used. Fluorine/fluorine interaction terms, F/F, 2F/F, 3F/F, 2F/2F, and 3F/2F, where ``/'' indicates interaction for alkane compounds, for {Delta}H{sub f 298}{degree} are reevaluated based on {Delta}H{sub f 298}{degree} of the above five fluoroethanes. Thermodynamic properties ({Delta}H{sub f 298}{degree}, S{sub 298}{degree} and C{sub p}(T)'s (300 {le} T/K {le} 1500)) for fluorinated carbon groups, C/C3F, C/C2/F/H, C/C2/F2, are calculated using data from ab initio methods and existing literature data. Fluorine-methyl (alkyl) group additivity corrections for gauche interactions are also evaluated.« less

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. © 2014 Wiley Periodicals, Inc.

Improved method for mutagenicity testing of gaseous compounds by using a gas sampling bag.

PubMed

Araki, A; Noguchi, T; Kato, F; Matsushima, T

1994-05-01

A simple and safety gas exposure method was developed using a gas sampling bag as an exposure vessel and a preparation vessel of diluted gas. The gas exposure conditions such as amount of S9 in the plate, volume of gas for the plate, amount of top agar, exposure period and exposure temperature were examined by mutagenicity testing of 1,3-butadiene using the gas sampling bag. Mutagenicity tests of 14 compounds and 1,3-butadiene on S. typhimurium TA98, TA100, TA1535 and TA1537, and E. coli WP2 uvrA were also examined by the developed gas exposure method. 1,3-Butadiene, propyne (methyl acetylene), monochlorodifluoromethane, ethylchloride, diborane and silane were mutagenic. 1-Butene, 2-butene, 2-methylpropene, methyl vinyl ether, trichlorofluoromethane, dichlorodifluoromethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, 1,1-difluoroethane and phosphine were not mutagenic on S. typhimurium TA98, TA100, TA1535 and TA1537, and E. coli WP2 uvrA with or without metabolic activation. These results were compatible with a previous report, and this developed method has the advantage that it can be tested easily and safely for combustible and self-combustible substances such as 1,3-butadiene and silane.

Difference in the volatile composition of pine-mushrooms (Tricholoma matsutake Sing.) according to their grades.

PubMed

Cho, In Hee; Choi, Hyung-Kyoon; Kim, Young-Suk

2006-06-28

The differences in volatile components of pine-mushrooms (Tricholoma matsutake Sing.) according to their grades were observed by applying multivariate statistical methods to GC-MS data sets. A total of 35 and 37 volatile components were identified in raw and cooked pine-mushrooms, respectively. The volatile components in pine-mushrooms were primarily composed of C8 species, such as 3-octanol, 1-octen-3-ol, 1-octanol, (E)-2-octen-1-ol, 3-octanone, 1-octen-3-one, (E)-2-octenal, and octanoic acid. The levels of ethyl octanoate, junipene, and 3-methyl-3-buten-2-one were much higher in raw pine-mushroom of higher grades, whereas the reverse was true for C8 components. On the other hand, furfuryl alcohol, benzyl alcohol, phenylethyl alcohol, dihydro-5-methyl-2(3H)-furanone, 2(5H)-furanone, (E)-2-methyl-2-butenal, furfural, phenylacetaldehyde, benzoic acid methyl ester, camphene, and beta-pinene were the major components of cooked mushrooms. These volatile components formed by various thermal reactions could be mainly responsible for the difference in volatile components of cooked pine-mushrooms according to their grades.

Temporal variation of VOC fluxes measured with PTR-TOF above a boreal forest

NASA Astrophysics Data System (ADS)

Schallhart, Simon; Rantala, Pekka; Kajos, Maija K.; Aalto, Juho; Mammarella, Ivan; Ruuskanen, Taina M.; Kulmala, Markku

2018-01-01

Between April and June 2013 fluxes of volatile organic compounds (VOCs) were measured in a Scots pine and Norway spruce forest using the eddy covariance (EC) method with a proton transfer reaction time-of-flight (PTR-TOF) mass spectrometer. The observations were performed above a boreal forest at the SMEAR II site in southern Finland.We found a total of 25 different compounds with exchange and investigated their seasonal variations from spring to summer. The majority of the net VOC flux was comprised of methanol, monoterpenes, acetone and butene + butanol. The butene + butanol emissions were concluded to not originate from the forest and, therefore, be anthropogenic. The VOC exchange followed a seasonal trend and the emissions increased from spring to summer. Only three compounds were emitted during the snowmelt while in summer emissions of some 19 VOCs were observed. During the measurement period in April, the emissions were dominated by butene + butanol, while during the start of the growing season and in summer, methanol was the most emitted compound. The main source of methanol was likely the growth of new biomass. During a 21-day period in June, the net VOC flux was 2.1 nmol m-2 s-1. This is on the lower end of PTR-TOF flux measurements from other ecosystems, which range from 2 to 10 nmol m-2 s-1. The EC flux results were compared with surface layer profile measurements, using a proton transfer reaction quadrupole mass spectrometer, which is permanently installed at the SMEAR II site. For the major compounds, the fluxes measured with the two different methods agreed well.

THERMODYNAMIC PROPERTIES HF 298, S 298, AND CP(T) FOR 2-FLUORO-2-METHYLPROPANE, HF 298 OF FLUORINATED ETHANES, AND GROUP ADDITIVITY FOR FLUOROALKANES. (R824970)

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...

Liquid-liquid equilibria for 2,3-butanediol + water + organic solvents at 303. 15 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, S.; Pandya, G.; Chakrabarti, T.

1994-10-01

2, 3-Butanediol, an important industrial chemical, is of interest because of its application as a solvent and liquid fuel additive. Liquid-liquid equilibria at 303.15 [+-] 0.5 K were measured for water + 2, 3-butanediol + butan-1-ol, + 3-methyl-1-butanol, + 4-methyl-2-pentanone, + tributyl phosphate, and + butyl acetate. Complete phase diagrams were obtained by evaluating the solubility and tie-line results for each ternary mixture. The consistency of the tie-line results was ascertained using an Othmer-Tobias plot. The distribution coefficient and separation factors were evaluated over the immiscibility region. Among the solvents studied, butan-1-ol is the most effective one though tributyl phosphatemore » and 3-methyl-1-butanol may be preferred because of their low solubility and high selectivity.« less

Replacing precious metals with carbide catalysts for hydrogenation reactions

DOE PAGES

Ruijun, Hou; Chen, Jingguang G.; Chang, Kuan; ...

2015-03-03

Molybdenum carbide (Mo₂C and Ni/Mo₂C) catalysts were compared with Pd/SiO₂ for the hydrogenation of several diene molecules, 1,3- butadiene, 1,3- and 1,4-cyclohexadiene (CHD). Compared to Pd/SiO₂, Mo₂C showed similar hydrogenation rate for 1,3-butadiene and 1,3-CHD and even higher rate for 1,4-CHD, but with significant deactivation rate for 1,3-CHD hydrogenation. However, the hydrogenation activity of Mo₂C could be completely regenerated by H₂ treatment at 723 K for the three molecules. The Ni modified Mo₂C catalysts retained similar activity for 1,3-butadiene hydrogenation with significantly enhanced selectivity for 1-butene production. The 1-butene selectivity increased with increasing Ni loading below 15%. Among the Nimore » modified Mo₂C catalysts, 8.6%Ni/Mo₂C showed the highest selectivity to 1-butene, which was even higher selectivity than that over Pd/SiO₂. Compared to Pd/SiO₂, both Mo₂C and Ni/Mo₂C showed combined advantages in hydrogenation activity and catalyst cost reduction, demonstrating the potential to use less expensive carbide catalysts to replace precious metals for hydrogenation reactions.« less

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 into...

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 into...

THE GAS PHASE REACTION OF OZONE WITH 1,3-BUTADIENE: FORMATION YIELDS OF SOME TOXIC PRODUCTS. (R826236)

EPA Science Inventory

The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product yields. In separa...

The Thermodynamic Conjugation Stabilization of 1,3-Butadiyne Is Zero

ERIC Educational Resources Information Center

Rogers, Donald W.; Zavitsas, Andreas A.; Matsunaga, Nikita

2010-01-01

Many textbooks point out that the thermodynamic stabilization enthalpy of 1 mol of 1,3-butadiene relative to 2 mol of 1-butene or to 1 mol of 1,4-pentadiene is slightly less than 4 kcal mol[superscript -1], owing to conjugation between the double bonds in the 1,3 configuration. It is reasonable to suppose that the analogous thermochemical…

Secondary metabolites of the grapevine pathogen Eutypa lata inhibit mitochondrial respiration, based on a model bioassay using the yeast Saccharomyces cerevisiae.

PubMed

Kim, Jong H; Mahoney, Noreen; Chan, Kathleen L; Molyneux, Russell J; Campbell, Bruce C

2004-10-01

Acetylenic phenols and a chromene isolated from the grapevine fungal pathogen Eutypa lata were examined for mode of toxicity. The compounds included eutypine (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzyl aldehyde), eutypinol (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzyl alcohol), eulatachromene, 2- isoprenyl-5-formyl-benzofuran, siccayne, and eulatinol. A bioassay using the yeast Saccharomyces cerevisiae showed that all compounds were either lethal or inhibited growth. A respiratory assay using 2,3,5-triphenyltetrazolium (TTC) indicated that eutypinol and eulatachromene inhibited mitochondrial respiration in wild-type yeast. Bioassays also showed that 2- isoprenyl-5-formyl-benzofuran and siccayne inhibited mitochondrial respiration in the S. cerevisiae deletion mutant vph2Delta, lacking a vacuolar type H (+) ATPase (V-ATPase) assembly protein. Cell growth of tsa1Delta, a deletion mutant of S. cerevisiae lacking a thioredoxin peroxidase (cTPx I), was greatly reduced when grown on media containing eutypinol or eulatachromene and exposed to hydrogen peroxide (H(2)O(2)) as an oxidative stress. This reduction in growth establishes the toxic mode of action of these compounds through inhibition of mitochondrial respiration.

Iron-catalyzed stereospecific activation of olefinic C-H bonds with Grignard reagent for synthesis of substituted olefins.

PubMed

Ilies, Laurean; Asako, Sobi; Nakamura, Eiichi

2011-05-25

The reaction of an aryl Grignard reagent with a cyclic or acyclic olefin possessing a directing group such as pyridine or imine results in the stereospecific substitution of the olefinic C-H bond syn to the directing group. The reaction takes place smoothly and without isomerization of the product olefin in the presence of a mild oxidant (1,2-dichloro-2-methylpropane) and an aromatic cosolvent. Several lines of evidence suggest that the reaction proceeds via iron-catalyzed olefinic C-H bond activation rather than an oxidative Mizoroki-Heck-type reaction.

Syntheses and structural characterization of Co(II) and Cd(II) coordination polymers with 1,4-bis(imidazolyl)butane ligand

NASA Astrophysics Data System (ADS)

Lalegani, Arash; Khalaj, Mehdi; Sedaghat, Sajjad; Łyczko, Krzysztof; Lipkowski, Janusz

2017-11-01

Two new coordination polymers, {[Co(bib)3](PF6)2}n (1) and [Cd (bib) Cl2]n (2), were prepared at room temperature by the reaction of appropriate salts of cobalt (II) and cadmium (II) with the flexible linker ligands 1,4-bis(imidazolyl) butane (bib). The compounds were characterized by elemental analyses, IR spectroscopy and single crystal X-ray diffraction. In the polymeric structure of 1, the Co(II) ion lies on an inversion centre and adopts the CoN6 octahedral geometry, while in the structure of 2, the Cd(II) ions adopt the CdN2Cl4 pseudo-octahedral geometry. In compound 1, six bib ligands are coordinated to one central cobalt (II) to form an open 3D 2-fold interpenetrating framework of the α-polonium (pcu) type topology, while in compound 2 two bib ligands are coordinated to one central cadmium (II) to form 2D network structure.

Ice core records of monoterpene- and isoprene-SOA tracers from Aurora Peak in Alaska since 1660s: Implication for climate variability in the North Pacific Rim

NASA Astrophysics Data System (ADS)

Pokhrel, A.; Kawamura, K.; Seki, O.; Ono, K.; Matoba, S.; Shiraiwa, T.

2015-12-01

180 m long ice core (ca. 343 years old) was drilled in the saddle of the Aurora Peak of Alaska, which is located southeast of Fairbanks (63.52°N; 146.54°W, elevation: 2,825 m). Samples were directly transported to the Institute of Low Temperature Science, Hokkaido University and have been analyzed for monoterpene- and isoprene-SOA tracers using gas chromatograph (GC; HP 6890) and mass spectrometry system (GC/MS; Agilent). Ice core collected from mountain glacier has not been explored for SOA yet. We found significantly high concentrations of these tracers (e.g., pinic, pinonic, and 2-methylglyceric acids, 2-methylthreitol and 2-methylrythritol), which show historical trends with good correlation with each other since 1665-2008. They show positive correlations with sugar compounds (e.g., mannitol, glucose, fructose, inositol, and sucrose), and anti-correlations with diacids (e.g., C9), w-oxocarboxylic (wC4-wC9), a-dicarbonyls and low molecular weight fatty acids (LFAs) (e.g., C18:1). LFAs show strong correlations with MSA- and nss-SO42- in the same ice core. These results suggest source regions of SOA tracers and ice core chemistry of Alaska. Concentrations of C5-alkene triols (e.g., 3-methyl-2,3,4-trihydroxy-1-butene, cis-2-methyl 1,3,4-trihydroxy-1-butene and trans-2-methyl-1,3,4-trihydroxy-1-butene) have increased in the ice core after the Great Pacific Climate Shift (late 1970's). They show positive correlations with a-dicarbonyls and LFAs (e.g., C18:1) in the ice core, suggesting that enhanced oceanic emissions of biogenic organic compounds through the surface microlayer are recorded in the ice core. Photochemical oxidation processes for these monoterpene- and isoprene-/sesquiterpene-SOA tracers are suggested to be linked with the periodicity of multi-decadal climate oscillations (e.g., North Pacific Index) and we can look at a whole range of environmental parameters in parallel with the robust reconstructed temperature changes in the Northern Hemisphere.

Major Groove Orientation of the (2S)-N6-(2-Hydroxy-3-buten-1-yl)-2′-deoxyadenosine DNA Adduct Induced by 1,2-Epoxy-3-butene

PubMed Central

2015-01-01

1,3-Butadiene (BD) is an environmental and occupational toxicant classified as a human carcinogen. It is oxidized by cytochrome P450 monooxygenases to 1,2-epoxy-3-butene (EB), which alkylates DNA. BD exposures lead to large numbers of mutations at A:T base pairs even though alkylation of guanines is more prevalent, suggesting that one or more adenine adducts of BD play a role in BD-mediated genotoxicity. However, the etiology of BD-mediated genotoxicity at adenine remains poorly understood. EB alkylates the N6 exocyclic nitrogen of adenine to form N6-(hydroxy-3-buten-1-yl)-2′-dA ((2S)-N6-HB-dA) adducts (TretyakovaN., LinY., SangaiahR., UptonP. B., and SwenbergJ. A. (1997) Carcinogenesis18, 137−1479054600). The structure of the (2S)-N6-HB-dA adduct has been determined in the 5′-d(C1G2G3A4C5Y6A7G8A9A10G11)-3′:5′-d(C12T13T14C15T16T17G18T19 C20C21G22)-3′ duplex [Y = (2S)-N6-HB-dA] containing codon 61 (underlined) of the human N-ras protooncogene, from NMR spectroscopy. The (2S)-N6-HB-dA adduct was positioned in the major groove, such that the butadiene moiety was oriented in the 3′ direction. At the Cα carbon, the methylene protons of the modified nucleobase Y6 faced the 5′ direction, which placed the Cβ carbon in the 3′ direction. The Cβ hydroxyl group faced toward the solvent, as did carbons Cγ and Cδ. The Cβ hydroxyl group did not form hydrogen bonds with either T16O4 or T17O4. The (2S)-N6-HB-dA nucleoside maintained the anti conformation about the glycosyl bond, and the modified base retained Watson–Crick base pairing with the complementary base (T17). The adduct perturbed stacking interactions at base pairs C5:G18, Y6:T17, and A7:T16 such that the Y6 base did not stack with its 5′ neighbor C5, but it did with its 3′ neighbor A7. The complementary thymine T17 stacked well with both 5′ and 3′ neighbors T16 and G18. The presence of the (2S)-N6-HB-dA resulted in a 5 °C reduction in the Tm of the duplex, which is attributed to less favorable stacking interactions and adduct accommodation in the major groove. PMID:25238403

21 CFR 573.310 - Crambe meal, heat toasted.

Code of Federal Regulations, 2012 CFR

2012-04-01

...; oil, not more than 4 percent; crude protein, not less than 24 percent; crude fiber, not more than 26 percent; glucosinolate calculated as epi-progoitrin, not more than 4 percent; goitrin, not more than 0.1 percent; nitrile calculated as 1-cyano-2-hydroxy-3-butene, not more than 1.4 percent. At least 50 percent...

21 CFR 573.310 - Crambe meal, heat toasted.

Code of Federal Regulations, 2010 CFR

2010-04-01

...; oil, not more than 4 percent; crude protein, not less than 24 percent; crude fiber, not more than 26 percent; glucosinolate calculated as epi-progoitrin, not more than 4 percent; goitrin, not more than 0.1 percent; nitrile calculated as 1-cyano-2-hydroxy-3-butene, not more than 1.4 percent. At least 50 percent...

21 CFR 573.310 - Crambe meal, heat toasted.

Code of Federal Regulations, 2013 CFR

2013-04-01

...; oil, not more than 4 percent; crude protein, not less than 24 percent; crude fiber, not more than 26 percent; glucosinolate calculated as epi-progoitrin, not more than 4 percent; goitrin, not more than 0.1 percent; nitrile calculated as 1-cyano-2-hydroxy-3-butene, not more than 1.4 percent. At least 50 percent...

21 CFR 573.310 - Crambe meal, heat toasted.

Code of Federal Regulations, 2014 CFR

2014-04-01

...; oil, not more than 4 percent; crude protein, not less than 24 percent; crude fiber, not more than 26 percent; glucosinolate calculated as epi-progoitrin, not more than 4 percent; goitrin, not more than 0.1 percent; nitrile calculated as 1-cyano-2-hydroxy-3-butene, not more than 1.4 percent. At least 50 percent...

21 CFR 573.310 - Crambe meal, heat toasted.

Code of Federal Regulations, 2011 CFR

2011-04-01

...; oil, not more than 4 percent; crude protein, not less than 24 percent; crude fiber, not more than 26 percent; glucosinolate calculated as epi-progoitrin, not more than 4 percent; goitrin, not more than 0.1 percent; nitrile calculated as 1-cyano-2-hydroxy-3-butene, not more than 1.4 percent. At least 50 percent...

Study of the Synchrotron Photoionization Oxidation of 2-Methylfuran Initiated by O(3P) under Low-Temperature Conditions at 550 and 650 K.

PubMed

Fathi, Yasmin; Meloni, Giovanni

2017-09-21

The O-( 3 P)-initiated oxidation of 2-methylfuran (2-MF) was investigated using vacuum-ultraviolet synchrotron radiation from the Advanced Light Source at Lawrence Berkeley National Laboratory. Reaction species were studied by multiplexed photoionization mass spectrometry at 550 and 650 K. The oxygen addition pathway is favored in this reaction, forming four triplet diradicals that undergo intersystem crossing into singlet epoxide species that lead to the formation of products at m/z 30 (formaldehyde), 42 (propene), 54 (1-butyne, 1,3-butadiene, and 2-butyne), and 70 (2-butenal, methyl vinyl ketone, and 3-butenal). Mass-to-charge ratios, photoionization spectra, and adiabatic ionization energies for each primary reaction species were obtained and used to characterize their identities. In addition, by means of electronic structure calculations, potential energy surface scans of the different species produced throughout the oxidation were examined to further validate the primary chemistry occurring. Branching fractions for the formation of the primary products were calculated at the two temperatures and contribute 81.0 ± 21.4% at 550 K and 92.1 ± 25.5% at 650 K.

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...

Metal catalyzed synthesis of hyperbranched ethylene and/or .alpha.-olefin polymers

DOEpatents

Sen, Ayusman; Kim, Jang Sub; Pawlow, James H.; Murtuza, Shahid; Kacker, Smita; Wojcinski, III, Louis M.

2001-01-01

Oily hyperbranched polymers derived from ethylene, propylene, butene and/or a C.sub.5 -C.sub.24 .alpha.-olefin, and a method for their synthesis, are disclosed. The polymers have non-regular microstructures and are characterized by a ratio ({character pullout})of methyl hydrogens centered around 0.85 ppm on the 1H-NMR spectra of the polymers relative to total aliphatic hydrogens of from about 0.40 to about 0.65 for polymers derived from ethylene or butene, and a ratio ({character pullout})of from greater than 0.50 to about 0.65 for polymers derived from propylene. A method for grafting hyperbranched polymers derived from ethylene, propylene, butene and/or a C.sub.5 -C.sub.24 .alpha.-olefin onto aromatic rings in organic molecules and polymers, and the resulting grafted materials, are also disclosed. The hyperbranched polymers and grafted materials are useful, for example, as lubricants and lubricant additives.

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...

Synthesis of water-soluble polyamine derivatives effective as N-methyl-D-aspartate receptor antagonists.

PubMed

Masuko, Takashi; Yoshida, Shuhei; Metori, Koichi; Kizawa, Yasuo; Kusama, Tadashi; Miyake, Muneharu

2010-06-01

The novel water-soluble N-methyl-D-aspartate (NMDA) receptor antagonists, N-{4-[4-(4-Guanidinobutylamino)butylamino]butyl}-p-toluenesulfonamide trihydrochloride (1a, TsHSPMG), N-{4-[4-(4-Guanidinobutylamino)butylamino]butyl}butane-1-sulfonamide trihydrochloride (1b, BsHSPMG), N-{3-[4-(3-Guanidinopropylamino)butylamino]propyl}-p-toluenesulfonamide trihydrochroride (2a, TsSPMG) and N-{3-[4-(3-Guanidinopropylamino)butylamino]propyl}butane-1-sulfonamide trihydrochroride (2b, BsSPMG), were synthesized, and the effects of these polyamine derivatives on NMDA receptors were studied using voltage-clamp recordings of recombinant NMDA receptors expressed in Xenopus oocytes. Although spermine potentiates 153% and 310% of NMDA (NR1A/NR2B) receptors in the presence of saturated and unsaturated glycine, respectively, all the novel polyamine derivatives, TsHSPMG (1a), BsHSPMG (1b), TsSPMG (2a) and BsSPMG (2b), significantly inhibited NR1A/NR2B receptors in both conditions. The degree of NMDA receptor inhibition by TsHSPMG (1a) and BsHSPMG (1b) was stronger than that by TsSPMG (2a) and BsSPMG (2b).

Study on Sources of Volatile Organic Compounds (CMB) in Pearl River Delta region, China

NASA Astrophysics Data System (ADS)

Liu, Y.; Shao, M.; Lu, S.; Chang, C.; Wang, C. J.; Wang, B.

2007-05-01

The profiles of major Volatile organic compounds (VOCs) sources including vehicle exhaust, gasoline vapor, painting, asphalt, liquefied petroleum gas (LPG), biomass burning and petrochemical industry in Pearl River Delta were experimentally determined. Source samples were taken by using dilution chamber for mobile and stationary sources, laboratory simulation for biomass burning. The concentrations of 108 VOC species of sources were quantified by using canister with pre-concentration-GC/MS system, from which 52 PAMS hydrocarbons and one kind of chlorinated hydrocarbon were deployed to build the source profiles for source apportionment of VOCs. Based the measurement of source profiles, the possible tracers for various emission sources were identified, e.g 2-methylbutane and 1,3-butadiene were the tracers for motor vehicle exhaust, the characteristic compounds of architectural and furnishing coatings are aromatics such as toluene and m/p-xylene; the light hydrocarbons, namely n-butane, trans-2-butene and n-pentane, dominated the composition of gasoline vapor; and the nonane, decane and undecane are found to represent the asphalt emissions etc.. The CMB receptor model was applied to source apportionment of 58 hydrocarbons measured at seven sites during the PRD campaign, 2004. The 12 kinds of VOC sources include gasoline/diesel-powered vehicle exhaust, gasoline/diesel headspace vapor, vehicle evaporative emissions, liquid petroleum gas (LPG) leakage, painting vapors, asphalt emission from paved road, biomass burning, coal burning, chemical industry and petroleum refinery. Vehicle exhaust was the largest sources contributing over half of the ambient VOCs at the three urban sites (GuangZhou, FoShan and ZhongShan). LPG leakage played an important role with the percentage of 8- 16% in most sites in PRD. Contributions from solvents usage were highest at DongGuan, an industrial site. At XinKen, the solvents and coatings had the largest percentage of 31% probably due to the influence of its upwind area of DongGuan. The local biomass burning was also found to be a noticeable source at XK.

Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis of Ethylene (C2H4) and D4-Ethylene (C2D4) Ices Exposed to Ionizing Radiation via Combined Infrared Spectroscopy and Reflectron Time-of-flight Mass Spectrometry

NASA Astrophysics Data System (ADS)

Abplanalp, Matthew J.; Kaiser, Ralf I.

2017-02-01

The processing of the hydrocarbon ice, ethylene (C2H4/C2D4), via energetic electrons, thus simulating the processes in the track of galactic cosmic-ray particles, was carried out in an ultrahigh vacuum apparatus. The chemical evolution of the ices was monitored online and in situ utilizing Fourier transform infrared spectroscopy (FTIR) and during temperature programmed desorption, via a quadrupole mass spectrometer utilizing electron impact ionization (EI-QMS) and a reflectron time-of-flight mass spectrometer utilizing a photoionization source (PI-ReTOF-MS). Several previous in situ studies of ethylene ice irradiation using FTIR were substantiated with the detection of six products: [CH4 (CD4)], acetylene [C2H2 (C2D2)], the ethyl radical [C2H5 (C2D5)], ethane [C2H6 (C2D6)], 1-butene [C4H8 (C4D8)], and n-butane [C4H10 (C4D10)]. Contrary to previous gas phase studies, the PI-ReTOF-MS detected several groups of hydrocarbon with varying degrees of saturation: C n H2n+2 (n = 4-10), C n H2n (n = 2-12, 14, 16), C n H2n-2 (n = 3-12, 14, 16), C n H2n-4 (n = 4-12, 14, 16), C n H2n-6 (n = 4-10, 12), C n H2n-8 (n = 6-10), and C n H2n-10 (n = 6-10). Multiple laboratory studies have shown the facile production of ethylene from methane, which is a known ice constituent in the interstellar medium. Various astrophysically interesting molecules can be associated with the groups detected here, such as allene/methylacetylene (C3H4) or 1, 3-butadiene (C4H6) and its isomers, which have been shown to lead to polycyclic aromatic hydrocarbons. Finally, several hydrocarbon groups detected here are unique to ethylene ice versus ethane ice and may provide understanding of how complex hydrocarbons form in astrophysical environments.

Volatile organic compound constituents from an integrated iron and steel facility.

PubMed

Tsai, Jiun-Horng; Lin, Kuo-Hsiung; Chen, Chih-Yu; Lai, Nina; Ma, Sen-Yi; Chiang, Hung-Lung

2008-09-15

This study measured the volatile organic compound (VOC) constituents of four processes in an integrated iron and steel industry; cokemaking, sintering, hot forming, and cold forming. Toluene, 1,2,4-trimethylbenzene, isopentane, m,p-xylene, 1-butene, ethylbenzene, and benzene were the predominant VOC species in these processes. However, some of the chlorinated compounds were high (hundreds ppbv), i.e., trichloroethylene in all four processes, carbon tetrachloride in the hot forming process, chlorobenzene in the cold forming process, and bromomethane in the sintering process. In the sintering process, the emission factors of toluene, benzene, xylene, isopentane, 1,2,4-trimethylbenzene, and ethylbenzene were over 9 g/tonne-product. In the vicinity of the manufacturing plant, toluene, isopentane, 1,2,4-trimethylbenzene, xylene and ethylbenzene were high. Toluene, 1,2,4-trimethylbenzene, xylene, 1-butene and isopentane were the major ozone formation species. Aromatic compounds were the predominant VOC groups, constituting 45-70% of the VOC concentration and contributing >70% to the high ozone formation potential in the stack exhaust and workplace air. The sequence of VOC concentration and ozone formation potential was as follows: cold forming>sintering>hot forming>cokemaking. For the workplace air, cokemaking was the highest producer, which was attributed to the fugitive emissions of the coke oven and working process release.

40 CFR 721.1925 - Substituted carboheterocyclic butane tetracarboxylate (generic).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted carboheterocyclic butane... Specific Chemical Substances § 721.1925 Substituted carboheterocyclic butane tetracarboxylate (generic). (a... generically as substituted carboheterocyclic butane tetracarboxylate (PMNs P-90-440 and P-95-4) is subject to...

40 CFR 721.1925 - Substituted carboheterocyclic butane tetracarboxylate (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted carboheterocyclic butane... Specific Chemical Substances § 721.1925 Substituted carboheterocyclic butane tetracarboxylate (generic). (a... generically as substituted carboheterocyclic butane tetracarboxylate (PMNs P-90-440 and P-95-4) is subject to...

Analysis of Non-Methane Hydrocarbon Data from 2004-2016 in a Subtropical Area close to the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Rappenglueck, B.

2017-12-01

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 along with NO, NO2, NOx, O3 have been collected continuously from January 2004-December 2016 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.

27 CFR 19.746 - Authorized materials.

Code of Federal Regulations, 2013 CFR

2013-04-01

... benzoate N.F. and 2 gallons of isopropyl alcohol. (c) Specifications. (1) Specifications for gasoline... mixture of butane, pentane, and hexane hydrocarbons extracted from natural gas; and (ii) Distillation...

27 CFR 19.746 - Authorized materials.

Code of Federal Regulations, 2011 CFR

2011-04-01

... benzoate N.F. and 2 gallons of isopropyl alcohol. (c) Specifications. (1) Specifications for gasoline... mixture of butane, pentane, and hexane hydrocarbons extracted from natural gas; and (ii) Distillation...

27 CFR 19.746 - Authorized materials.

Code of Federal Regulations, 2014 CFR

2014-04-01

... benzoate N.F. and 2 gallons of isopropyl alcohol. (c) Specifications. (1) Specifications for gasoline... mixture of butane, pentane, and hexane hydrocarbons extracted from natural gas; and (ii) Distillation...

27 CFR 19.746 - Authorized materials.

Code of Federal Regulations, 2012 CFR

2012-04-01

... benzoate N.F. and 2 gallons of isopropyl alcohol. (c) Specifications. (1) Specifications for gasoline... mixture of butane, pentane, and hexane hydrocarbons extracted from natural gas; and (ii) Distillation...

21 CFR 582.1165 - Butane.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Butane. 582.1165 Section 582.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS... Butane. (a) Product. Butane. (b) Conditions of use. This substance is generally recognized as safe when...

21 CFR 582.1165 - Butane.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Butane. 582.1165 Section 582.1165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS... Butane. (a) Product. Butane. (b) Conditions of use. This substance is generally recognized as safe when...

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 4.242...

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 4.242...

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 4.242...

Lipase-catalyzed kinetic resolution of novel antitubercular benzoxazole derivatives.

PubMed

Łukowska-Chojnacka, Edyta; Kowalkowska, Anna; Napiórkowska, Agnieszka

2018-04-01

Novel benzoxazole derivatives were synthesized, and their antitubercular activity against sensitive and drug-resistant Mycobacterium tuberculosis strains (M. tuberculosis H 37 Rv, M. tuberculosis sp. 210, M. tuberculosis sp. 192, Mycobacterium scrofulaceum, Mycobacterium intracellulare, Mycobacterium fortuitum, Mycobacterium avium, and Mycobacterium kansasii) was evaluated. The chemical step included preparation of ketones, alcohols, and esters bearing benzoxazole moiety. All racemic mixtures of alcohols and esters were separated in Novozyme SP 435-catalyzed transesterification and hydrolysis, respectively. The transesterification reactions were carried out in various organic solvents (tert-butyl methyl ether, toluene, diethyl ether, and diisopropyl ether), and depending on the solvent, the enantioselectivity of the reactions ranged from 4 to >100. The enzymatic hydrolysis of esters was performed in 2 phase tert-butyl methyl ether/phosphate buffer (pH = 7.2) system and provided also enantiomerically enriched products (ee 88-99%). The antitubercular activity assay has shown that synthesized compounds exhibit an interesting antitubercular activity. Racemic mixtures of alcohols, (±)-4-(1,3-benzoxazol-2-ylsulfanyl)butan-2-ol ((±)-3a), (±)-4-[(5-bromo-1,3-benzoxazol-2-yl)sulfanyl]butan-2-ol ((±)-3b), and (±)-4-[(5,7-dibromo-1,3-benzoxazol-2-yl)sulfanyl]butan-2-ol ((±)-3c), displayed as high activity against M. scrofulaceum, M. intracellulare, M. fortuitum, and M. kansasii as commercially available antituberculosis drug-Isoniazid. Moreover, these compounds exhibited twice higher activity toward M. avium (MIC 12.5) compared with Isoniazid (MIC 50). © 2017 Wiley Periodicals, Inc.

40 CFR 80.104 - Recordkeeping requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., and the Virgin Islands, as applicable. (xiv) In the case of butane blended into conventional gasoline under § 80.82, documentation of: (A) The volume of the butane added; (B) The volume of the gasoline prior to and subsequent to the butane blending; (C) The purity and properties of the butane under § 80...

40 CFR 80.104 - Recordkeeping requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., and the Virgin Islands, as applicable. (xiv) In the case of butane blended into conventional gasoline under § 80.82, documentation of: (A) The volume of the butane added; (B) The volume of the gasoline prior to and subsequent to the butane blending; (C) The purity and properties of the butane under § 80...

40 CFR 80.74 - Recordkeeping requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

...; (8) In the case of butane blended into reformulated gasoline or RBOB under § 80.82, documentation of: (i) The volume of butane added; (ii) The volume of reformulated gasoline or RBOB both prior to and subsequent to the butane blending; (iii) The purity and properties of the butane specified in § 80.82(c) and...

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

Code of Federal Regulations, 2013 CFR

2013-04-01

..., flammable gases at normal temperatures and pressures. They are easily liquefied under pressure at room... fractionation following absorption in oil, adsorption to surface-active agents, or refrigeration. (b) The... used as propellants, aerating agents, and gases as defined in § 170.3(o)(25) of this chapter. (2) The...

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

Code of Federal Regulations, 2012 CFR

2012-04-01

..., flammable gases at normal temperatures and pressures. They are easily liquefied under pressure at room... fractionation following absorption in oil, adsorption to surface-active agents, or refrigeration. (b) The... used as propellants, aerating agents, and gases as defined in § 170.3(o)(25) of this chapter. (2) The...

Canopy Level Emissions of 2-methyl-3-buten-2-ol ...

EPA Pesticide Factsheets

Emissions of biogenic volatile organic compounds (BVOC) observed during 2007 from a Pinus taeda experimental plantation in Central North Carolina are compared with model estimates from MEGAN 2.1. Relaxed Eddy Accumulation (REA) estimates of 2-methyl-3-buten-2-ol (MBO) fluxes are a factor of 3-4 higher than model estimates. MEGAN2.1 monoterpene emission estimates were approximately a factor of two higher than REA flux measurements. MEGAN2.1 β-caryophyllene emission estimates were within 60% of growing season REA flux estimates, but were several times higher than REA fluxes during cooler, dormant season periods. The sum of other sesquiterpene emissions estimated by MEGAN2.1 was several times higher than REA estimates throughout the year. Model components are examined to understand these discrepancies. Summertime LAI (and therefore foliar biomass) is a factor of two higher than assumed in MEGAN for the Pinus taeda default. Increasing the canopy mean MBO emission factor from 0.35 to 1.0 mg m-2 hr-1 also reduces MEGAN2.1 vs flux differences. This increase is within current emission factor uncertainties. The algorithm within MEGAN which adjusts isoprene emission estimates as a function of the previous 24 hour’s temperatures and light seems to also improve seasonal MEGAN MBO correlation with REA fluxes. Including the effects of the previous 240 hours, however, seems to degrade temporal model correlation with fluxes. This paper describes an emission inventory and mod

Anesthetic synergy between two n-alkanes.

PubMed

Brosnan, Robert J; Fukushima, Fabíola B; Pham, Trung L

2017-05-01

N-butane and n-pentane can both produce general anesthesia. Both compounds potentiate γ-aminobutyric acid type A (GABA A ) receptor function, but only butane inhibits N-methyl-d-aspartate (NMDA) receptors. It was hypothesized that butane and pentane would exhibit anesthetic synergy due to their different actions on ligand-gated ion channels. Prospective experimental study. A total of four Xenopus laevis frogs and 43 Sprague-Dawley rats. Alkane concentrations for all studies were determined via gas chromatography. Using a Xenopus oocyte expression model, standard two-electrode voltage clamp techniques were used to measure NMDA and GABA A receptor responses in vitro as a function of butane and pentane concentrations relevant to anesthesia. The minimum alveolar concentrations (MAC) of butane and pentane were measured separately in rats, and then pentane MAC was measured during coadministration of 0.25, 0.50 or 0.75 times MAC of butane. An isobole with 95% confidence intervals was constructed using regression analysis. A sum of butane and pentane that was statistically less than the lower-end confidence bound isobole indicated a synergistic interaction. Both butane and pentane dose-dependently potentiated GABA A receptor currents over the study concentration range. Butane dose-dependently inhibited NMDA receptor currents, but pentane did not modulate NMDA receptors. Butane and pentane MAC in rats was 39.4±0.7 and 13.7±0.4 %, respectively. A small but significant (p<0.03) synergistic anesthetic effect with pentane was observed during administration of either 0.50 or 0.75×MAC butane. Butane and pentane show synergistic anesthetic effects in vivo consistent with their different in vitro receptor effects. Findings support the relevance of NMDA receptors in mediating anesthetic actions for some, but not all, inhaled agents. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

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

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Nos. 106-97-8 and 75-28-5, respectively) are colorless, flammable gases at normal temperatures and..., adsorption to surface-active agents, or refrigeration. (b) The ingredients must be of a purity suitable for... manufacturing practice conditions of use: (1) The ingredients are used as propellants, aerating agents, and...

A Research-Based Undergraduate Organic Laboratory Project: Investigation of a One-Pot, Multicomponent, Environmentally Friendly Prins-Friedel-Crafts-Type Reaction

ERIC Educational Resources Information Center

Dintzner, Matthew R.; Maresh, Justin J.; Kinzie, Charles R.; Arena, Anthony F.; Speltz, Thomas

2012-01-01

Students in the undergraduate organic laboratory synthesize tetrahydro-2-(4-nitrophenyl)-4-phenyl-2"H"-pyran via the Montmorillonite K10 clay-catalyzed reaction of p-nitrobenzaldehye with methanol, 3-buten-1-ol, and benzene. The synthesis comprises an environmentally friendly tandem Prins-Friedel-Crafts-type multicomponent reaction (MCR) and sets…

40 CFR 60.489 - List of chemicals produced by affected facilities.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... 75-07-0 Acetaldehyde. 107-89-1 Acetaldol. 60-35-5 Acetamide. 103-84-4 Acetanilide. 64-19-7 Acetic.... 119-53-9 Benzoin. 100-47-0 Benzonitrile. 119-61-9 Benzophenone. 98-07-7 Benzotrichloride. 98-88-4...-4 Bromonaphthalene. 106-99-0 Butadiene. 106-98-9 1-butene. 123-86-4 n-butyl acetate. 141-32-2 n...

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

EPA Science Inventory

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

Synthesis, structural studies and antimicrobial activity of N'-((2Z, 3E)-3-(hydroxyimino)butan-2-ylidene)-2-phenylacetohydrazide and its Co(II), Ni(II) complexes

NASA Astrophysics Data System (ADS)

Karadeniz, Şeyma; Ataol, Cigdem Yuksektepe; Şahin, Onur; İdil, Önder; Bati, Hümeyra

2018-06-01

A new aroylhydrazoneoxime, N'-((2Z, 3E)-3-(hydroxyimino)butan-2-ylidene)-2-phenylacetohydrazide ligand (LH2) and its Ni(II) and Co(II) complexes, have been synthesized and characterized by elemental and thermal analyses, IR and UV-vis spectroscopy, magnetic moment and X-ray diffraction. The antimicrobial activities of these compounds were tested by using minimal inhibitory concentration method (MIC). The ligand-containing aroylhydrazone and oxime groups and its Ni complex crystallize in the triclinic system and P 1 - space group, while its Co complex crystallizes in the monoclinic system and the C 2/c space group. X-ray results show that the ligand in the keto form is transformed into enolic form when it forms coordination. From elemental analysis data, the stoichiometry of Co(II) complex was found to be 1:2 (metal/ligand), but 1:1 for Ni(II). IR spectra indicate that the ligand acts as monoanionic NNO- tridentate and coordination takes place form through the oxime nitrogen, imine nitrogen, and enolate oxygen atoms.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsz-Keung, Cheung; d`Itri, J.L.; Lange, F.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 frommore » 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.« less

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...

Adsorption of n-butane on graphene/Ru(0001)—A molecular beam scattering study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivapragasam, Nilushni; Nayakasinghe, Mindika T.; Burghaus, Uwe, E-mail: uwe.burghaus@ndsu.edu

2016-07-15

Adsorption kinetics/dynamics of n-butane on graphene, physical vapor deposited on Ru(0001) (hereafter G/Ru), and bare Ru(0001) (hereafter Ru) are discussed. The chemical activity of the supported-graphene as well as the support was probed by thermal desorption spectroscopy (adsorption kinetics). In addition and to the best of our knowledge, for the first time, molecular beam scattering data of larger molecules were collected for graphene (probing the adsorption dynamics). Furthermore, samples were inspected by x-ray photoelectron spectroscopy and Auger electron spectroscopy. At the measuring conditions used here, n-butane adsorption kinetics/dynamics are molecular and nonactivated. Binding energies of butane on Ru and G/Rumore » are indistinguishable within experimental uncertainty. Thus, G/Ru is “kinetically transparent.” Initial adsorption probabilities, S{sub 0}, of n-butane decrease with increasing impact energy (0.76–1.72 eV) and are adsorption temperature independent for both Ru and G/Ru, again consistent with molecular adsorption. Also, S{sub 0} of Ru and G/Ru are indistinguishable within experimental uncertainty. Thus, G/Ru is “dynamically transparent.” Coverage dependent adsorption probabilities indicate precursor effects for graphene/Ru.« less

Formation of Fused-Ring 2′-Deoxycytidine Adducts from 1-Chloro-3-buten-2-one, an in Vitro 1,3-Butadiene Metabolite, under in Vitro Physiological Conditions

PubMed Central

Sun, Liang; Pelah, Avishay; Zhang, Dong-Ping; Zhong, Yu-Fang; An, Jing; Yu, Ying-Xin; Zhang, Xin-Yu; Elfarra, Adnan A.

2013-01-01

1-Chloro-3-buten-2-one (CBO) is a potential metabolite of 1,3-butadiene (BD), a carcinogenic air pollutant. CBO is a bifunctional alkylating agent that readily reacts with glutathione (GSH) to form mono-GSH and di-GSH adducts. Recently, CBO and its precursor 1-chloro-2-hydroxy-3-butene (CHB) were found to be cytotoxic and genotoxic in human liver cells in culture with CBO being approximately 100-fold more potent than CHB. In the present study, CBO was shown to react readily with 2′-deoxycytidine (dC) under in vitro physiological conditions (pH 7.4, 37 °C) to form four dC adducts with the CBO moieties forming fused rings with the N3 and N4 atoms of dC. The four products were structurally characterized as 2-hydroxy-2-hydroxymethyl-7-(2-deoxy-β-D-erythro-pentofuranosyl)-1,2,3,4-tetrahy dro-6-oxo-6H,7H-pyrimido[1,6-a]pyrimidin-5-ium (dC-1 and dC-2, a pair of diastereomers), 4-chloromethyl-4-hydroxy-7-(2-deoxy-β-D-erythro-pentofuranosyl)-1,2,3,4-tetrahydr o-6-oxo-6H,7H-pyrimido[1,6-a]pyrimidin-5-ium (dC-3), and 2-chloromethyl-2-hydroxy-7-(2-deoxy-β-D-erythro-pentofuranosyl)-1,2,3,4-tetrahydr o-6-oxo-6H,7H-pyrimido[1,6-a]pyrimidin-5-ium (dC-4). Interestingly, dC-1 and dC-2 were stable under our experimental conditions (pH 7.4, 37 °C, 6 h) and existed in equilibrium as indicated by HPLC analysis, whereas dC-3 and dC-4 were labile with the half-lives being 3.0 ± 0.36 and 1.7 ± 0.06 h, respectively. Decomposition of dC-4 produced both dC-1 and dC-2, whereas acid hydrolysis of dC-1/dC-2 and dC-4 in 1 M HCl at 100 °C for 30 min yielded the deribosylated adducts dC-1H/dC-2H and dC-4H, respectively. Because fused-ring dC adducts of other chemicals are mutagenic, the characterized CBO-dC adducts could be mutagenic and play a role in the cytotoxicity and genotoxicity of CBO and its precursors, CHB and BD. The CBO-dC adducts may also be used as standards to characterize CBO-DNA adducts and to develop potential biomarkers for CBO formation in vivo. PMID:24020501

Synthesis and characterization of monomeric Mn (IV) and pseudo-tetrameric Mn (III) complexes: magnetic properties of Mn (III) complex.

PubMed

Yahsi, Yasemin; Kara, Hulya

2014-06-05

Two novel monomer Mn (IV) [Mn(3,5-ClL1)2]⋅(CH3OH), (1), [3,5-ClL1H2=N-(2-hydroxyethyl)-3,5-dichlorosalicylaldimine] (1) and hydrogen-bonded pseudo-tetramer Mn (III) [Mn(5-BrL2)(H2O)2]2⋅[Mn(5-BrL2)(H2O)]2⋅2⋅(ClO4), (2), [5-BrL2H2=N,N'-bis(5-bromosalicylidenato)-1,2-diamino-2-methylpropane)] (2) Schiff base complexes have been synthesized and their crystal structures have been determined by single crystal X-ray diffraction analysis. A variable temperature magnetic susceptibility measurement study has been performed for complex (2) and the result indicates there is a very weak antiferromagnetic interaction (J=-0.40±0.016cm(-1)) between the two manganese (III) centers. Copyright © 2014 Elsevier B.V. All rights reserved.

Material Evaluation of Optical Fibers and Payout Bobbins: An Overview

DTIC Science & Technology

1990-03-01

Viscosity at 25"C = 5 cps. Diacrylates 1. 1,4-butane-diol diacrylate 2. Neopentyl glycol diacrylate. Shrinkage = 14.2%; volatilization rate = 0.07 mg...min; b.p. = 1228C at 2 mm; viscosity = 32 cps at 25°C. 3. Diethylene glycol diacrylate 4. 1,6-Hexanediol diacrylate. Volatilization rate - 0.02 mg/min

Microbiology: Deep-sea secrets of butane metabolism

NASA Astrophysics Data System (ADS)

Ragsdale, Stephen W.

2016-11-01

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

Zn/Cd/Cu- frameworks constructed by 3,3‧-diphenyldicarboxylate and 1,4-bis(1,2,4-triazol-1-yl)butane: Syntheses, structure, luminescence and luminescence sensing for metal ion in aqueous medium

NASA Astrophysics Data System (ADS)

Zhang, Mei-Na; Fan, Ting-Ting; Wang, Qiu-Shuang; Han, Hong-Liang; Li, Xia

2018-02-01

Three metal-organic frameworks (MOFs), [M(dpdc)(btb)0.5]n (M = Zn 1, Cd 2; dpdc = 3,3‧-diphenyldicarboxylate and btb = 1,4-bis(1,2,4-triazol-1-yl)butane) and [Cu3(dpdc)3(btb)2]n (3) were prepared and structurally determined. 1 is a 2D structure with the topology of {33·47·54·6}, while 2 possesses a 3D framework with the {312·429·514} topology. Complex 3 displays a 3D framework with the topology of {315.435.55}2{36.48.512.6.7}. 1-2 exhibit intense blue luminescence and high stability in water, which make them highly promising candidates as sensors using in aqueous medium. Complex 1 is a potential bi-functional chemosensor for Fe3+ and Al3+ ions while 2 displays a selective sensing ability to Fe3+ ion. Quenching mechanism of Fe3+ on the luminescence of 1-2 is attributed to the charge transfer process LMCT. 1 and 2 have same compositions but have different structures, thermally stabilities and different luminescence sensing functions. The relationship between MOF structures and luminescence sensing toward metal ions are further discussed.

Sequential and direct ionic excitation in the strong-field ionization of 1-butene molecules.

PubMed

Schell, Felix; Boguslavskiy, Andrey E; Schulz, Claus Peter; Patchkovskii, Serguei; Vrakking, Marc J J; Stolow, Albert; Mikosch, Jochen

2018-05-18

We study the Strong-Field Ionization (SFI) of the hydrocarbon 1-butene as a function of wavelength using photoion-photoelectron covariance and coincidence spectroscopy. We observe a striking transition in the fragment-associated photoelectron spectra: from a single Above Threshold Ionization (ATI) progression for photon energies less than the cation D0-D1 gap to two ATI progressions for a photon energy greater than this gap. For the first case, electronically excited cations are created by SFI populating the ground cationic state D0, followed by sequential post-ionization excitation. For the second case, direct sub-cycle SFI to the D1 excited cation state contributes significantly. Our experiments access ionization dynamics in a regime where strong-field and resonance-enhanced processes can interplay.

Determination of thermodynamic properties of isotactic poly(1-butene) at infinite dilution using density and inverse gas chromatography.

PubMed

Kozłowska, Marta Karolina; Domańska, Urszula; Lempert, Małgorzata; Rogalski, Marek

2005-03-18

The partial molar volumes, V1(M), and the molar volume of isotactic crystalline low-molecular-weight poly(1-butene), iPBu-1, V1, have been calculated from the measured density of {iPBu-1 + solvent (n-hexane, n-heptane, n-nonane, n-decane, p-xylene, cyclohexane and chloroform)} systems. Some of the thermodynamic quantities were also obtained for the iPBu-1 with eight hydrocarbons (n-octane, n-decane, n-undecane, n-dodecane, n-tridecane, o-xylene, m-xylene, p-xylene) by the method of inverse gas chromatography at various temperatures. The weight fraction activity coefficients of the solvent at infinite dilution, omega2(infinity) and the Flory-Huggins thermodynamic interaction parameters, chi21(infinity), between polymer and solvents were determined. The partial molar free energy, deltaG2(infinity), the partial molar heat of mixing, deltaH2(infinity), at infinite dilution and the polymer solubility parameter, delta1, were calculated. Additionally, the (solid + liquid) binary mixtures equilibria, SLE, of iPBu-1 with three hydrocarbons (n-octane, n-decane and m-xylene) were studied by a dynamic method. By performing these experiments over a large concentration range, the T-x phase diagrams of the polymer-solvent systems were constructed. The excess Gibbs energy models were used to describe the nonideal behaviour of the liquid phase. The omega2(infinity) were determined from the solubility measurements and were predicted by using the UNIFAC FV model.

Isotope Dilution nanoLC/ESI+-HRMS3 Quantitation of Urinary N7-(1-Hydroxy-3-buten-2-yl) Guanine Adducts in Humans and Their Use as Biomarkers of Exposure to 1,3-Butadiene.

PubMed

Sangaraju, Dewakar; Boldry, Emily J; Patel, Yesha M; Walker, Vernon; Stepanov, Irina; Stram, Daniel; Hatsukami, Dorothy; Tretyakova, Natalia

2017-02-20

1,3-Butadiene (BD) is an important industrial and environmental chemical classified as a known human carcinogen. Occupational exposure to BD in the polymer and monomer industries is associated with an increased incidence of lymphoma. BD is present in automobile exhaust, cigarette smoke, and forest fires, raising concern about potential exposure of the general population to this carcinogen. Following inhalation exposure, BD is bioactivated to 3,4-epoxy-1-butene (EB). If not detoxified, EB is capable of modifying guanine and adenine bases of DNA to form nucleobase adducts, which interfere with accurate DNA replication and cause cancer-initiating mutations. We have developed a nanoLC/ESI + -HRMS 3 methodology for N7-(1-hydroxy-3-buten-2-yl) guanine (EB-GII) adducts in human urine (limit of detection: 0.25 fmol/mL urine; limit of quantitation: 1.0 fmol/mL urine). This new method was successfully used to quantify EB-GII in urine of F344 rats treated with 0-200 ppm of BD, occupationally exposed workers, and smokers belonging to two different ethnic groups. EB-GII amounts increased in a dose-dependent manner in urine of laboratory rats exposed to 0, 62.5, or 200 ppm of BD. Urinary EB-GII levels were significantly increased in workers occupationally exposed to 0.1-2.2 ppm of BD (1.25 ± 0.51 pg/mg of creatinine) as compared to administrative controls exposed to <0.01 ppm of BD (0.22 ± 0.08 and pg/mg of creatinine) (p = 0.0024), validating the use of EB-GII as a biomarker of human exposure to BD. EB-GII was also detected in smokers' urine with European American smokers excreting significantly higher amounts of EB-GII than African American smokers (0.48 ± 0.09 vs 0.12 ± 0.02 pg/mg of creatinine, p = 3.1 × 10 -7 ). Interestingly, small amounts of EB-GII were observed in animals and humans with no known exposure to BD, providing preliminary evidence for its endogenous formation. Urinary EB-GII adduct levels and urinary mercapturic acids of BD (MHBMA, DHBMA) were compared in a genotyped multiethnic smoker cohort.

Open Burn/Open Detonation Dispersion Model (OBODM) User’s Guide. Volume I. User’s Instructions

DTIC Science & Technology

1998-02-01

Fuel/Expl6sives Data Base File OBODFUEL.OBD ...... 51 4.9 SIGMAPLOT File Format and Contents ...... .............. .. 106 4.10 Grid Coordinates and...135.2 0.9391 0 2.95E-07 trans-2-Butene 125.0 1.1830 0 1.97E-07 Propellant, PBXN -110 1000 0 44 1,2,4-Trimethylbenzene 120.2 0.8758 0 4.25E-07 1,2,4...Calculation height, if applicable 106 The solution data follow and depend on the output options selected. The following record group is written only if N

[Pollution characteristics and health risk assessment of atmospheric VOCs in the downtown area of Guangzhou, China].

PubMed

Li, Lei; Li, Hong; Wang, Xue-Zhong; Zhang, Xin-Min; Wen, Chong

2013-12-01

The measurements of 31 kinds of VOCs in the ambient air of a site were carried out in the downtown of Guangzhou by online method from November 5, 2009 to November 9, 2009. The ambient level and composition characteristics, temporal variation characteristics, sources identification, and chemical reactivity of VOCs were studied, and the health risk of VOCs in the ambient air in the study area was assessed by using the international recognized health risk assessment method. Results showed that the mean and the range of the mass concentrations of 31 VOCs were 114.51 microg x m(-3) and 29.42-546.06 microg x m(-3), respectively. The mass concentrations of 31 VOCs, and those of alkanes, alkenes, and aromatics all showed a changing trend of higher in the morning and in the evening, and lower at noontime. Vehicular exhaust, gasoline and liquefied petroleum gas evaporates were the main sources of VOCs with the volatilization of paints and solvents being important emission sources. Toluene, trans-2-butene, m/p-xylene, i-butane, and 1,3,5-trimethylbenzene were the key reactive species among the 31 VOCs. Vehicular exhaust and gasoline evaporation were the main sources of VOCs leading to the formation of ozone. Health risk assessment showed that n-hexane, 1,3-butadiene, benzene, toluene, ethylbenzene, m/p-xylene and o-xylene had no appreciable risk of adverse non-cancer health effect on the exposed population, but 1, 3-butadiene and benzene had potential cancer risk. By comparing the corresponding data about health risk assessment of benzene compounds in some cities in China, it is concluded that benzene can impose relatively high cancer risk to the exposed populations in the ambient air of some cities in China. Therefore, strict countermeasures should be taken to further control the pollution of benzene in the ambient air of cities, and it is imperative to start the related studies and develop the atmospheric environmental health criteria and national ambient air quality standard for benzene in China.

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

Grubbs's Cross Metathesis of Eugenol with cis-2-butene-1, 4-diol to Make a Natural Product: An Organometallic Experiment for the Undergraduate Lab

ERIC Educational Resources Information Center

Taber, Douglass F.; Frankowski, Kevin J.

2006-01-01

A modified experimental procedure for the one-step synthesis that is suitable for the undergraduate organic lab is presented. In the course of work towards the more routine use of air-sensitive organometallic complexes such as the Grubb's catalyst, the natural product (E)-4-(4-hydroxy-3-methoxyphenyl) but-2-en-ol, 4, was synthesized.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

A novel MVA-mediated pathway for isoprene production in engineered E. coli.

PubMed

Yang, Jianming; Nie, Qingjuan; Liu, Hui; Xian, Mo; Liu, Huizhou

2016-01-20

To deal with the increasingly severe energy crisis and environmental consequences, biofuels and biochemicals generated from renewable resources could serve as a promising alternative for replacing petroleum as a source of fuel and chemicals, among which isoprene (2-methyl-1,3-butadiene) in particular is of great significance in that it is an important platform chemical, which has been used in industrial production of synthetic rubber for tires and coatings or aviation fuel. We firstly introduced fatty acid decarboxylase (OleTJE) from Jeotgalicoccus species into E. coli to directly convert MVA(mevalonate) into 3-methy-3-buten-1-ol. And then to transform 3-methy-3-buten-1-ol to isoprene, oleate hydratase (OhyAEM) from Elizabethkingia meningoseptica was overexpressed in E. coli. A novel biosynthetic pathway of isoprene in E. coli was established by co-expressing the heterologous mvaE gene encoding acetyl-CoA acetyltransferase/HMG-CoA reductase and mvaS gene encoding HMG-CoA synthase from Enterococcus faecalis, fatty acid decarboxylase (OleTJE) and oleate hydratase (OhyAEM). Furthermore, to enhance isoprene production, a further optimization of expression level of OleTJE, OhyAEM was carried out by using different promoters and copy numbers of plasmids. Thereafter, the fermentation process was also optimized to improve the production of isoprene. The final engineered strain, YJM33, bearing the innovative biosynthetic pathway of isoprene, was found to produce isoprene up to 2.2 mg/L and 620 mg/L under flask and fed-batch fermentation conditions, respectively. In this study, by using metabolic engineering techniques, the novel MVA-mediated biosynthetic pathway of isoprene was successfully assembled in E. coli BL21(DE3) with the heterologous MVA upper pathway, OleTJE from Jeotgalicoccus species and OhyAEM from Elizabethkingia meningoseptica. Compared with traditional MVA pathway, the novel pathway is shortened by 3 steps. In addition, this is the first report on the reaction of converting MVA into 3-methy-3-buten-1-ol by fatty acid decarboxylase (OleTJE) from Jeotgalicoccus species. In brief, this study provided an alternative method for isoprene biosynthesis, which is largely different from the well-developed MEP pathway or MVA pathway.

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.

Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis of Ethylene (C{sub 2}H{sub 4}) and D4-Ethylene (C{sub 2}D{sub 4}) Ices Exposed to Ionizing Radiation via Combined Infrared Spectroscopy and Reflectron Time-of-flight Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abplanalp, Matthew J.; Kaiser, Ralf I., E-mail: ra

The processing of the hydrocarbon ice, ethylene (C{sub 2}H{sub 4}/C{sub 2}D{sub 4}), via energetic electrons, thus simulating the processes in the track of galactic cosmic-ray particles, was carried out in an ultrahigh vacuum apparatus. The chemical evolution of the ices was monitored online and in situ utilizing Fourier transform infrared spectroscopy (FTIR) and during temperature programmed desorption, via a quadrupole mass spectrometer utilizing electron impact ionization (EI-QMS) and a reflectron time-of-flight mass spectrometer utilizing a photoionization source (PI-ReTOF-MS). Several previous in situ studies of ethylene ice irradiation using FTIR were substantiated with the detection of six products: [CH{sub 4} (CD{submore » 4})], acetylene [C{sub 2}H{sub 2} (C{sub 2}D{sub 2})], the ethyl radical [C{sub 2}H{sub 5} (C{sub 2}D{sub 5})], ethane [C{sub 2}H{sub 6} (C{sub 2}D{sub 6})], 1-butene [C{sub 4}H{sub 8} (C{sub 4}D{sub 8})], and n -butane [C{sub 4}H{sub 10} (C{sub 4}D{sub 10})]. Contrary to previous gas phase studies, the PI-ReTOF-MS detected several groups of hydrocarbon with varying degrees of saturation: C{sub n}H{sub 2n+2} (n = 4–10), C{sub n}H{sub 2n} ( n = 2–12, 14, 16), C{sub n}H{sub 2n−2} ( n = 3–12, 14, 16), C{sub n}H{sub 2n−4} (n = 4–12, 14, 16), C{sub n}H{sub 2n−6} (n = 4–10, 12), C{sub n}H{sub 2n−8} ( n = 6–10), and C{sub n}H{sub 2n−10} ( n = 6–10). Multiple laboratory studies have shown the facile production of ethylene from methane, which is a known ice constituent in the interstellar medium. Various astrophysically interesting molecules can be associated with the groups detected here, such as allene/methylacetylene (C{sub 3}H{sub 4}) or 1, 3-butadiene (C{sub 4}H{sub 6}) and its isomers, which have been shown to lead to polycyclic aromatic hydrocarbons. Finally, several hydrocarbon groups detected here are unique to ethylene ice versus ethane ice and may provide understanding of how complex hydrocarbons form in astrophysical environments.« less

Effect of cysteine and cystine addition on sensory profile and potent odorants of extruded potato snacks.

PubMed

Majcher, Małgorzata A; Jeleń, Henryk H

2007-07-11

Aromas generated in extruded potato snacks without and with addition of 0.25, 0.5, and 1% (w/w) of flavor precursors, cysteine and cystine, were compared and evaluated by descriptive sensory profiling. The results showed that high addition of cysteine (0.5 and 1%) resulted in the formation of undesirable odor and taste described as mercaptanic/sulfur, onion-like, and bitter; on the contrary, addition of cystine even at high concentration gave product with pleasant odor and taste, slightly changed into breadlike notes. GC/O analysis showed cysteine to be a much more reactive flavor precursor than cystine, stimulating formation of 12 compounds with garlic, sulfury, burnt, pungent/beer, cabbage/mold, meatlike, roasted, and popcorn odor notes. Further analysis performed by the AEDA technique identified 2-methyl-3-furanthiol (FD 2048) as a most potent odorant of extruded potato snacks with 1% addition of cysteine. Other identified compounds with high FD were butanal, 3-methyl-2-butenethiol, 2-methylthiazole, methional, 2-acetyl-1-pyrroline, and 3-hydroxy-4,5-dimethyl-2(5H)-furanone. In the case of cystine addition (1%) the highest FD factors were calculated for butanal, 2-acetyl-1-pyrroline, benzenemethanethiol, methional, phenylacetaldehyde, dimethyltrisulfide, 1-octen-3-ol, 1,5-octadien-3-one, and 2-acetylpyrazine.

Studies on volatile organic compounds of some truffles and false truffles.

PubMed

D'Auria, Maurizio; Racioppi, Rocco; Rana, Gian Luigi; Laurita, Alessandro

2014-01-01

Results of solid phase micro-extraction coupled to gas chromatography and mass spectrometry analyses, accomplished on sporophores of 11 species of truffles and false truffles, are reported. Volatile organic compounds (VOCs) found in Gautieria morchelliformis were dimethyl sulphide, 1,3-octadiene, 3,7-dimethyl-1,6-octadien-3-ol, amorphadiene, isoledene and cis-muurola-3,5-diene. In Hymenogaster luteus var. luteus, presence of 1,3-octadiene, 1-octen-3-ol, 3-octanone, 3-octanol and 4-acetylanisole was revealed. Two VOCs, 4-acetylanisole and β-farnesene, constituted aroma of Hymenogaster olivaceus.Melanogaster broomeanus exhibited as components of its aroma 2-methyl-1,3-butadiene, 2-methylpropanal, 2-methylpropanol, isobutyl acetate, 3,7-dimethyl-1,6-octadien-3-ol, 3-octanone and β-curcumene. VOC profile of Octavianina asterosperma was characterised by the presence of dimethyl sulphide, ethyl 2-methylpropanoate, methyl 2-methylbutanoate and 3-octanone. Tuber rufum var. rufum and Pachyphloeus conglomeratus showed the presence of dimethyl sulphide only.

1,2,4-Butanetriol: Analysis and Synthesis

DTIC Science & Technology

1982-12-08

also sought to lower the cost of 3-butene-l-ol by modification of the catalytic dehydration method commonly used to produce it from 1,3-butanediol. CH...monoepoxide of 1-methoxybutadiene, which on hydrolysis gives 3,4-dihydroxybutanal. This material can then be converted to BT by hydrogenation over Raney nickel...induce decomposition of reactive organics at elevated temperatures. The columns were usually heated in an oven from ’OQ0 to 300’% at 15%C per minute

Verification of diffusive and pumped samplers for volatile organic compounds using a controlled atmosphere test facility

NASA Astrophysics Data System (ADS)

Martin, Nicholas A.; Leming, Edward J.; Henderson, Malcolm H.; Lipscombe, Robert P.; Black, John K.; Jarvis, Scott D.

2010-09-01

There is a requirement to verify the performance of sorbent-based passive or active samplers and to extend their use, where possible, to monitor volatile organic compounds (VOCs) that are known to be photochemical ozone pre-cursors or are relevant to the activities of the petrochemical industry. We report measurements of the 14-day diffusive uptake rates for the VOCs: i-butane (2-methyl propane), n-butane, i-pentane (2-methyl butane), n-pentane, n-hexane, benzene, toluene, and m-xylene (at environmental level concentrations) for industry standard axial samplers (Perkin-Elmer-type samplers) containing the sorbents Carbopack-X, -Z, -B or Tenax-TA. We also present data on back-diffusion, blank levels, and storage for the above sorbents, and describe the simultaneous use of the sorbent Carbopack-X for pumped sampling of certain VOCs. The results were obtained by dosing samplers in a controlled atmosphere test facility (CATFAC) operating under well-defined conditions of concentration, nominal temperature of 20 °C, wind speed of 0.5 m s -1, and relative humidities of 0% and 80%. Field measurements were also obtained to provide supplementary data to support the laboratory study. Results are compared to existing published data, where these are available.

Catalytic production of biofuels (butene oligomers) and biochemicals (tetrahydrofurfuryl alcohol) from corn stover.

PubMed

Byun, Jaewon; Han, Jeehoon

2016-07-01

A strategy is presented that produces liquid hydrocarbon fuels (butene oligomers (BO)) from cellulose (C6) fraction and commodity chemicals (tetrahydrofurfuryl alcohol (THFA)) from hemicellulose (C5) of corn stover based on catalytic conversion technologies using 2-sec-butylphenol (SBP) solvents. This strategy integrates the conversion subsystems based on experimental studies and separation subsystems for recovery of biomass derivatives and SBP solvents. Moreover, a heat exchanger network is designed to reduce total heating requirements to the lowest level, which is satisfied from combustion of biomass residues (lignin and humins). Based on the strategy, this work offers two possible process designs (design A: generating electricity internally vs. design B: purchasing electricity externally), and performs an economic feasibility study for both the designs based on a comparison of the minimum selling price (MSP) of THFA. This strategy with the design B leads to a better MSP of $1.93 per kg THFA. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristics of butanol metabolism in alcohol dehydrogenase-deficient deermice.

PubMed Central

Alderman, J A; Kato, S; Lieber, C S

1989-01-01

Deermice lacking the low-Km alcohol dehydrogenase eliminated butan-1-ol, a substrate for microsomal oxidation but not for catalase, at 117 mumol/min per kg body wt. Microsomal fractions and hepatocytes metabolized butan-1-ol also (Vmax. = 6.7 nmol/min per nmol of cytochrome P-450, Km = 0.85 mM; Vmax. = 5.3 nmol/min per 10(6) cells, Km = 0.71 mM respectively). These results are consistent with alcohol oxidation by the microsomal system in these deermice. PMID:2930472

Encyclopedia of Explosives and Related Items. Volume 7. H2 to Lysol

DTIC Science & Technology

1975-01-01

68. (21) 2.75 0 15 C3H7CI I1- Chloropropane -31.10 699 55.0 (21) 2.98 0 16 C3H Propane -24.82 626 63.3 (21) 2.48 0 17 C4H8 1 .Butene -0.03 825 59.1 ( 1 ...Information Service (formerly Clearinghouse) US Department of Commerce Springfield, Virginia 22151 1 -800-553-6847 USA only 703-605-6000 www.ntis.gov/FCPC...in Volume 1 in order to understand the authors’ way of presenting the subject matter In preparation for and during the writing of this Encyclopedia

International comparison CCQM-K119 liquefied petroleum gas

NASA Astrophysics Data System (ADS)

Brewer, P. J.; Downey, M. L.; Atkins, E.; Brown, R. J. C.; Brown, A. S.; Zalewska, E. T.; van der Veen, A. M. H.; Smeulders, D. E.; McCallum, J. B.; Satumba, R. T.; Kim, Y. D.; Kang, N.; Bae, H. K.; Woo, J. C.; Konopelko, L. A.; Popova, T. A.; Meshkov, A. V.; Efremova, O. V.; Kustikov, Y.

2018-01-01

Liquefied hydrocarbon mixtures with traceable composition are required in order to underpin measurements of the composition and other physical properties of LPG (liquefied petroleum gas), thus meeting the needs of an increasingly large industrial market. This comparison aims to assess the analytical capabilities of laboratories for measuring the composition of a Liquid Petroleum Gas (LPG) mixture when sampled in the liquid phase from a Constant Pressure Cylinder. Mixtures contained ethane, propane, propene, i-butane, n-butane, but-1-ene and i-pentane with nominal amount fractions of 2, 71, 9, 4, 10, 3 and 1 cmol mol-1 respectively. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Spectroscopic and DFT studies of bis-3-hydroxypyridinium and bis-3-hydroxymethylpyridinium dibromides with tetramethylene linker

NASA Astrophysics Data System (ADS)

Komasa, Anna

2018-01-01

Experimental and theoretical IR, Raman, UV-Vis, 1H and 13C NMR spectra of 1,4-di(3-hydroxypyridinium)butane dibromide and 1,4-di(3-hydroxymethylpyridinium)butane dibromide were obtained and analyzed. Optimized geometrical structures of the studied compounds were calculated by B3LYP method using 6-311++G(d,p) basis set and employed to determine the theoretical wavenumbers and intensities of IR and Raman spectra. The frequency assignments were supported by the potential energy distribution (PED) analysis. The significant role of the intermolecular interactions and the hydrogen bond was revealed on the basis of IR spectra. The calculated GIAO/B3LYP/6-311++G(d,p) isotropic magnetic shielding constants were used to predict the 1H and 13C chemical shifts for the optimized structures. Accuracy of the prediction of 1H and 13C chemical shifts was significantly improved by a simulation of the solvent in calculations. On the basis of UV-Vis spectra the acid-base equilibrium in the water solution of 1,4-di(3-hydroxypyridinium)butane dibromide was found.

Butane dihedral angle dynamics in water is dominated by internal friction.

PubMed

Daldrop, Jan O; Kappler, Julian; Brünig, Florian N; Netz, Roland R

2018-05-15

The dihedral dynamics of butane in water is known to be rather insensitive to the water viscosity; possible explanations for this involve inertial effects or Kramers' turnover, the finite memory time of friction, and the presence of so-called internal friction. To disentangle these factors, we introduce a method to directly extract the friction memory function from unconstrained simulations in the presence of an arbitrary free-energy landscape. By analysis of the dihedral friction in butane for varying water viscosity, we demonstrate the existence of an internal friction contribution that does not scale linearly with water viscosity. At normal water viscosity, the internal friction turns out to be eight times larger than the solvent friction and thus completely dominates the effective friction. By comparison with simulations of a constrained butane molecule that has the dihedral as the only degree of freedom, we show that internal friction comes from the six additional degrees of freedom in unconstrained butane that are orthogonal to the dihedral angle reaction coordinate. While the insensitivity of butane's dihedral dynamics to water viscosity is solely due to the presence of internal friction, inertial effects nevertheless crucially influence the resultant transition rates. In contrast, non-Markovian effects due to the finite memory time are present but do not significantly influence the dihedral barrier-crossing rate of butane. These results not only settle the character of dihedral dynamics in small solvated molecular systems such as butane, they also have important implications for the folding of polymers and proteins. Copyright © 2018 the Author(s). Published by PNAS.

Isentropic expansion and related thermodynamic properties of non-ionic amphiphile-water mixtures.

PubMed

Reis, João Carlos R; Douhéret, Gérard; Davis, Michael I; Fjellanger, Inger Johanne; Høiland, Harald

2008-01-28

A concise thermodynamic formalism is developed for the molar isentropic thermal expansion, ES,m = ( partial differential Vm/ partial differential T)(Sm,x), and the ideal and excess quantities for the molar, apparent molar and partial molar isentropic expansions of binary liquid mixtures. Ultrasound speeds were determined by means of the pulse-echo-overlap method in aqueous mixtures of 2-methylpropan-2-ol at 298.15 K over the entire composition range. These data complement selected extensive literature data on density, isobaric heat capacity and ultrasound speed for 9 amphiphile (methanol, ethanol, propan-1-ol, propan-2-ol, 2-methylpropan-2-ol, ethane-1,2-diol, 2-methoxyethanol, 2-ethoxyethanol or 2-butoxyethanol)-water binary systems, which form the basis of tables listing molar and excess molar isobaric expansions and heat capacities, and molar and excess molar isentropic compressions and expansions at 298.15 K and at 65 fixed mole fractions spanning the entire composition range and fine-grained in the water-rich region. The dependence on composition of these 9 systems is graphically depicted for the excess molar isobaric and isentropic expansions and for the excess partial molar isobaric and isentropic expansions of the amphiphile. The analysis shows that isentropic thermal expansion properties give a much stronger response to amphiphile-water molecular interactions than do their isobaric counterparts. Depending on the pair property-system, the maximum excess molar isentropic value is generally twenty- to a hundred-fold greater than the corresponding maximum isobaric value, and occurs at a lower mole fraction of the amphiphile. Values at infinite dilution of the 9 amphiphiles in water are given for the excess partial molar isobaric heat capacity, isentropic compression, isobaric expansion and isentropic expansion. These values are interpreted in terms of the changes occurring when amphiphile molecules cluster into an oligomeric form. Present results are discussed from theoretical and experimental thermodynamic viewpoints. It is concluded that isentropic thermal expansion properties constitute a new distinct resource for revealing particular features and trends in complex mixing processes, and that analyses using these new properties compare favourably with conventional approaches.

Emission of 2-methyl-3-buten-2-ol by pines: A potentially large natural source of reactive carbon to the atmosphere

NASA Astrophysics Data System (ADS)

Harley, Peter; Fridd-Stroud, Verity; Greenberg, James; Guenther, Alex; Vasconcellos, PéRola

1998-10-01

High rates of emission of 2-methyl-3-buten-2-ol (MBO) were measured from needles of several pine species. Emissions of MBO in the light were 1 to 2 orders of magnitude higher than emissions of monoterpenes and, in contrast to monoterpene emissions from pines, were absent in the dark. MBO emissions were strongly dependent on incident light, behaving similarly to net photosynthesis. Emission rates of MBO increased exponentially with temperature up to approximately 35°C. Above approximately 42°C, emission rates declined rapidly. Emissions could be modeled using existing algorithms for isoprene emission. We propose that emissions of MBO from lodgepole and ponderosa pine are the primary source of high concentrations of this compound, averaging 1-3 ppbv, found in ambient air samples collected in Colorado at an isolated mountain site approximately 3050 m above sea level. Subsequent field studies in a ponderosa pine plantation in California confirmed high MBO emissions, which averaged 25 μg C g-1 h-1 for 1-year-old needles, corrected to 30°C and photon flux of 1000 μmol m-2 s-1. A total of 34 pine species growing at Eddy Arboretum in Placerville, California, were investigated, of which 11 exhibited high emissions of MBO (>5 μg C g-1 h-1), and 6 emitted small but detectable amounts. All the emitting species are of North American origin, and most are restricted to western North America. These results indicate that MBO emissions from pines may constitute a significant source of reactive carbon and a significant source of acetone, to the atmosphere, particularly in the western United States.

Theoretical investigation of the oxidation pathways of the Cl-initiated reaction of 2-methyl-3-buten-2-ol

NASA Astrophysics Data System (ADS)

Zhang, Weichao; Zhang, Dongju

2012-12-01

The mechanism and products of the reaction of 2-methyl-3-buten-2-ol (MBO232) with Cl atoms in the presence of O2 have been elucidated by performing high-level quantum chemistry calculations. The geometries of the reactants, intermediates, transition states, and products are optimized at the MP2(full)/6-311G(d, p) level, and their single-point energies are refined at the CCSD(T)/6-311 + G(d, p) level. The potential energy surface profiles have been constructed at the CCSD(T)/6-311 + G(d, p)//MP2(full)/6-311G(d, p) + 0.95 × ZPE level of theory, and the possible channels involved in the reaction are also discussed. The calculations indicate that the reaction predominantly proceeds via the addition of Cl atoms to the double bond rather than the direct abstraction of the H atoms in MBO232. The nascent adducts (CH3)2C(OH)CHCH2Cl (IM1) and (CH3)2C(OH)CHClCH2 (IM2) do not undergo subsequent isomerization and dissociation reactions, but rather react with O2. The theoretical results show that the major products are CH2ClCHO and CH3C(O)CH3 for the reaction of MBO232 + Cl in the presence of O2, which is in good agreement with the experimental finding.

Highly Selective and Considerable Subcritical Butane Extraction to Separate Abamectin in Green Tea.

PubMed

Zhang, Yating; Gu, Lingbiao; Wang, Fei; Kong, Lingjun; Pang, Huili; Qin, Guangyong

2017-06-01

We specially carried out the subcritical butane extraction to separate abamectin from tea leaves. Four parameters, such as extraction temperature, extraction time, number of extraction cycles, and solid-liquid ratio were studied and optimized through the response surface methodology with design matrix developed by Box-Behnken. Seventeen experiments with three various factors and three variable levels were employed to investigate the effect of these parameters on the extraction of abamectin. Besides, catechins, theanine, caffeine, and aroma components were determined by both high-performance liquid chromatography and gas chromatography-mass spectrometry to evaluate the tea quality before and after the extraction. The results showed that the extraction temperature was the uppermost parameter compared with others. The optimal extraction conditions selected as follows: extraction temperature, 42°C; number of extraction cycles and extraction time, 1 and 30 min, respectively; and solid-liquid ratio, 1:10. Based on the above study, the separation efficiency of abamectin was up to 93.95%. It is notable that there has a quite low loss rate, including the negligible damage of aroma components, the bits reduce of catechins within the range of 0.7%-13.1%, and a handful lessen of caffeine and theanine of 1.81% and 2.6%, respectively. The proposed method suggested subcritical butane possesses solubility for lipid-soluble pesticides, and since most of the pesticides are attached to the surfaces of tea, thus the as-applied method was successfully effective to separate abamectin because of the so practical and promising method.

40 CFR 80.46 - Measurement of reformulated gasoline fuel parameters.

Code of Federal Regulations, 2010 CFR

2010-07-01

...)−0.347 RVP kPa = (0.956 * X)−2.39 (d) Distillation. Distillation parameters must be determined using...)(3) of this section. (2) Beginning January 1, 2004, the sulfur content of butane must be determined... paragraph (a)(2) of this section: (i) ASTM standard method D 4468-85 (Reapproved 2000), “Standard Test...

Regular square planer bis-(4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione)/copper(II) complex: Trans/cis-DFT isomerization, crystal structure, thermal, solvatochromism, hirshfeld surface and DNA-binding analysis

NASA Astrophysics Data System (ADS)

Hema, M. K.; Karthik, C. S.; Warad, Ismail; Lokanath, N. K.; Zarrouk, Abdelkader; Kumara, Karthik; Pampa, K. J.; Mallu, P.

2018-04-01

Trans-[Cu(O∩O)2] complex, O∩O = 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione was reported with high potential toward CT-DNA binder. The solved XRD-structure of complex indicated a perfect regular square-planer geometry around the Cu(II) center. The trans/cis-DFT-isomerization calculation supported the XRD seen in reflecting the trans-isomer as the kinetic-favor isomer. The desired complex structure was also characterized by conductivity measurement, CHN-elemental analyses, MS, EDX, SEM, UV-Vis., FT-IR, HAS and TG/DTG. The Solvatochromism behavior of the complex was evaluated using four different polar solvents. MPE and Hirshfeld surface analysis (HSA) come to an agreement that fluoride and thiophene protons atoms are with suitable electro-potential environment to form non-classical H-bonds of type CThsbnd H⋯F. The DNA-binding properties were investigated by viscosity tests and spectrometric titrations, the results revealed the complex as strong calf-thymus DNA binder. High intrinsic-binding constants value ∼1.8 × 105 was collected.

Interaction of alkanes with an amorphous methanol film at 15-180 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Souda, Ryutaro

2005-09-15

The hydrogen-bond imperfections and glass-liquid transition of the amorphous methanol film have been investigated on the basis of the film dewetting and the incorporation/desorption of alkane molecules adsorbed on the surface. The butane is incorporated completely in the bulk of the porous methanol film up to 70 K. At least two distinct states exist for the incorporated butane; one is assignable to solvated molecules in the bulk and the other is weakly bound species at the surface or in the subsurface site. For the nonporous methanol film, the uptake of butane in the bulk is quenched but butane forms amore » surface complex with methanol above 80 K. The butane incorporated in the bulk of the glassy methanol film is released at 120 K, where dewetting of the methanol film occurs simultaneously due to evolution of the supercooled liquid phase.« less

Direct observation of OH production from the ozonolysis of olefins

NASA Astrophysics Data System (ADS)

Donahue, Neil M.; Kroll, Jesse H.; Anderson, James G.; Demerjian, Kenneth L.

Ozone olefin reactions may be a significant source of OH in the urban atmosphere, but current evidence for OH production is indirect and contested. We report the first direct observation of OH radicals from the reaction of ozone with a series of olefins (ethene, isoprene, trans-2-butene and 2,3 dimethyl-2-butene) in 4-6 torr of nitrogen. Using LIF to directly observe the steady-state of OH produced by the initial ozone-olefin reaction and subsequently destroyed by the OH-olefin reaction, we are able to establish OH yields broadly consistent with indirect values. The identification of the OH is unequivocal, and there is no indication that it is produced by a secondary process. To support these observations, we present a complete ab-initio potential energy surface for the O3-ethene reaction, extending from the reactants to available products.

Composite Materials with Improved Properties in Compression: Synthesis of 3-Methylene-1,1-Dichlorosilacyclobutane and 1,1-Dichlorosilacyclopent-3-ene

DTIC Science & Technology

1990-05-09

reagents may in fact be involved. Of synthetic interest, V undergoes intramolecular Grignard ring closure to yield III (10%). While the yield of III is low...VII) as the major product along with 1,4-bis(trichlorosilyl)- cis-2-butene (VIII). VII undergoes cyclization by an intramolec- ular Grignard ring...addition of methyl Grignard to III. The 1H 8 am NMR chemical shifts of I in diethyl ether are consistently about 0.4 ppm downfield from those previously

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.

Trapping of cis-2-butene-1,4-dial to measure furan metabolism in human liver microsomes by cytochrome P450 enzymes.

PubMed

Gates, Leah A; Lu, Ding; Peterson, Lisa A

2012-03-01

Furan is a liver toxicant and carcinogen in rodents. It is classified as a possible human carcinogen, but the human health effects of furan exposure remain unknown. The oxidation of furan by cytochrome P450 (P450) enzymes is necessary for furan toxicity. The product of this reaction is the reactive α,β-unsaturated dialdehyde, cis-2-butene-1,4-dial (BDA). To determine whether human liver microsomes metabolize furan to BDA, a liquid chromatography/tandem mass spectrometry method was developed to detect and quantify BDA by trapping this reactive metabolite with N-acetyl-l-cysteine (NAC) and N-acetyl-l-lysine (NAL). Reaction of NAC and NAL with BDA generates N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-l-cysteine (NAC-BDA-NAL). Formation of NAC-BDA-NAL was quantified in 21 different human liver microsomal preparations. The levels of metabolism were comparable to that observed in F-344 rat and B6C3F1 mouse liver microsomes, two species known to be sensitive to furan-induced toxicity. Studies with recombinant human liver P450s indicated that CYP2E1 is the most active human liver furan oxidase. The activity of CYP2E1 as measured by p-nitrophenol hydroxylase activity was correlated to the extent of NAC-BDA-NAL formation in human liver microsomes. The formation of NAC-BDA-NAL was blocked by CYP2E1 inhibitors but not other P450 inhibitors. These results suggest that humans are capable of oxidizing furan to its toxic metabolite, BDA, at rates comparable to those of species sensitive to furan exposure. Therefore, humans may be susceptible to furan's toxic effects.

Trapping of cis-2-Butene-1,4-dial to Measure Furan Metabolism in Human Liver Microsomes by Cytochrome P450 Enzymes

PubMed Central

Gates, Leah A.; Lu, Ding

2012-01-01

Furan is a liver toxicant and carcinogen in rodents. It is classified as a possible human carcinogen, but the human health effects of furan exposure remain unknown. The oxidation of furan by cytochrome P450 (P450) enzymes is necessary for furan toxicity. The product of this reaction is the reactive α,β-unsaturated dialdehyde, cis-2-butene-1,4-dial (BDA). To determine whether human liver microsomes metabolize furan to BDA, a liquid chromatography/tandem mass spectrometry method was developed to detect and quantify BDA by trapping this reactive metabolite with N-acetyl-l-cysteine (NAC) and N-acetyl-l-lysine (NAL). Reaction of NAC and NAL with BDA generates N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-l-cysteine (NAC-BDA-NAL). Formation of NAC-BDA-NAL was quantified in 21 different human liver microsomal preparations. The levels of metabolism were comparable to that observed in F-344 rat and B6C3F1 mouse liver microsomes, two species known to be sensitive to furan-induced toxicity. Studies with recombinant human liver P450s indicated that CYP2E1 is the most active human liver furan oxidase. The activity of CYP2E1 as measured by p-nitrophenol hydroxylase activity was correlated to the extent of NAC-BDA-NAL formation in human liver microsomes. The formation of NAC-BDA-NAL was blocked by CYP2E1 inhibitors but not other P450 inhibitors. These results suggest that humans are capable of oxidizing furan to its toxic metabolite, BDA, at rates comparable to those of species sensitive to furan exposure. Therefore, humans may be susceptible to furan's toxic effects. PMID:22187484

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.

Overnight storage of whole blood: a comparison of two designs of butane-1,4-diol cooling plates.

PubMed

van der Meer, Pieter F; Pietersz, Ruby N I

2007-11-01

Whole blood (WB) can be stored overnight before processing, provided that it is quickly cooled to room temperature (20-25 degrees C), for example, with butane-1,4-diol plates. A new design of cooling plates became available (CompoCool-WB, Fresenius HemoCare), where WB must be placed vertically against the plates, versus placing of WB under plates in the current version (Compocool). This study compared cooling efficiency and in vitro quality of plasma and of stored white cell (WBC)-reduced red cells (RBCs) from overnight-stored WB, cooled with either of the systems. Temperature curves following cooling with Compocool or CompoCool-WB were studied with a 25 percent glycerol solution as simulated WB. WB from voluntary donors was cooled with Compocool or CompoCool-WB, stored overnight at room temperature, centrifuged, and separated into components. WBC-reduced RBCs in SAGM were stored until Day 42 with measurement of in vitro parameters (n=23/group). Simulated WB reached a temperature of less than 25 degrees C after 2:15+/-1:04 hours for Compocool versus 1:39+/-0:38 hours for CompoCool-WB (p=0.02). On Day 35, RBCs had a hemolysis of 0.3+/-0.2 percent in both groups, and ATP levels were 3.3+/-0.5 and 3.6+/-0.5 micromol per g hemoglobin for Compocool and CompoCool-WB, respectively (not significant). Factor VIII content in plasma was 1.05+/-0.25 and 0.97+/-0.18 IU per mL for Compocool and CompoCool-WB, respectively. WB can be cooled to room temperature within 2 hours with both Compocool and CompoCool-WB butane-1,4-diol plates, improving temperature uniformity in WB donations. Application of either design for overnight storage of WB at room temperature had no adverse effects on the composition of subsequently prepared blood components.

Butane dihedral angle dynamics in water is dominated by internal friction

PubMed Central

Daldrop, Jan O.; Kappler, Julian; Brünig, Florian N.; Netz, Roland R.

2018-01-01

The dihedral dynamics of butane in water is known to be rather insensitive to the water viscosity; possible explanations for this involve inertial effects or Kramers’ turnover, the finite memory time of friction, and the presence of so-called internal friction. To disentangle these factors, we introduce a method to directly extract the friction memory function from unconstrained simulations in the presence of an arbitrary free-energy landscape. By analysis of the dihedral friction in butane for varying water viscosity, we demonstrate the existence of an internal friction contribution that does not scale linearly with water viscosity. At normal water viscosity, the internal friction turns out to be eight times larger than the solvent friction and thus completely dominates the effective friction. By comparison with simulations of a constrained butane molecule that has the dihedral as the only degree of freedom, we show that internal friction comes from the six additional degrees of freedom in unconstrained butane that are orthogonal to the dihedral angle reaction coordinate. While the insensitivity of butane’s dihedral dynamics to water viscosity is solely due to the presence of internal friction, inertial effects nevertheless crucially influence the resultant transition rates. In contrast, non-Markovian effects due to the finite memory time are present but do not significantly influence the dihedral barrier-crossing rate of butane. These results not only settle the character of dihedral dynamics in small solvated molecular systems such as butane, they also have important implications for the folding of polymers and proteins. PMID:29712838

Changes in Atmospheric Butanes and Pentanes and Their Isomeric Ratios in the Continental United States

NASA Astrophysics Data System (ADS)

Rossabi, Sam; Helmig, Detlev

2018-04-01

Nonmethane hydrocarbons have been used as tracers in research on emissions and atmospheric oxidation chemistry. This research investigates source region mixing ratio trends of the nonmethane hydrocarbons i-butane, n-butane, i-pentane, and n-pentane, and the (i/n) isomeric ratios of these compounds between 2001 and 2015. Data collected at Photochemical Assessment Monitoring Stations, mandated by the U.S. Environmental Protection Agency in ozone nonattainment areas, and data collected at Global Greenhouse Gas Reference Network sites within the National Oceanic and Atmospheric Administration network, and analyzed at the Institute of Arctic and Alpine Research at the University of Colorado-Boulder, were examined. Among all considered species, linear regression analyses on concentration time series had negative slopes at 81% of sites, indicating predominantly declining butane and pentane atmospheric concentrations. Mostly negative slopes (78% of sites) were found for the (i/n) butane and pentane isomeric ratios, including all six and seven statistically significant (i/n) butane and pentane trends, respectively. Over the 15 year investigation period and averaged over all sites, total relative changes were 30 and 45% for the (i/n) ratios of butanes and pentanes, respectively, with a relative increase in the prominence of the n-isomers. Most likely causes include changing isomeric ratios in gasoline sector emissions, and increasing influence of oil and natural gas industry emissions. Changes in concentrations and isomeric ratios depend on proximity of contributing emission sources to measurement sites.

Computer Series, 60: Bits and Pieces, 23.

ERIC Educational Resources Information Center

Moore, John W., Ed.

1985-01-01

Describes: (1) an interactive computer simulation for a science fair display of chromatography inks; (2) analytical chemistry programs; (3) microcomputer-assisted drills in organic synthesis; (4) programs for conformation analysis of ethane and butane; (5) MOLPIX--a program for generating and displaying molecular structures; and (6) chemical…

Assessing Subsurface Bioaugmentation of a Mixed Culture Capable of Chlorinated Solvent Cometabolism via Molecular Methods

NASA Astrophysics Data System (ADS)

Dolan, M. E.; Lim, H. K.; Semprini, L.; Giovanonni, S.; Vergin, K.; McCarty, P. L.; Hopkins, G. D.

2001-12-01

The goal of this project is the successful bioaugmentation of a mixed culture capable of aerobic cometabolism of chlorinated solvent mixtures into an aquifer test zone at Moffett Federal Airfield, CA (Moffett). The test zone consists of two parallel well legs both fed butane and oxygen. One leg will be bioaugmented and the other will serve as an indigenous control. Injection and extraction wells and six (3 per leg) intermediately placed groundwater monitoring points will be frequently monitored for chlorinated solvents, butane, dissolved oxygen, and pH. Groundwater will also be periodically analyzed for microbial content using terminal restriction fragment length polymorphism (T-RFLP) and fluorescence in-situ hybridization (FISH) analyses. In each well leg, two fully-penetrating wells containing solid media will be periodically analyzed for microbial colonization (T-RFLP). The mixed bioaugmentation culture originated from environmental samples taken from Hanford, WA. The culture was enriched on butane and tested for viability in Moffett groundwater and aquifer solids. A clone library was created from the 16S rDNA in the mixed culture and 86 clones were sorted based on RFLP patterns. Complete sequencing of the 16S rDNA gene from the three most prevalent clones revealed 45 clones similar to Acidovorax or Hydrogenophaga, gram negative proteobacterium, and 12 clones similar to Rhodococcus, a gram positive filamentous organism. Fluorescently-labeled rRNA probes were designed for FISH analyses and appropriate restriction enzymes were chosen for T-RFLP analyses based upon the sequence information. Microcosm tests were conducted prior to the initiation of the field study to evaluate butane, 1,1-dichloroethylene (1,1-DCE), and 1,1,1-trichloroethane (TCA) degradation kinetics and microbial community composition. Bioaugmented microcosms began butane utilization sooner than non-bioaugmented ones in the presence and absence of 1,1-DCE, and were able to degrade more 1,1-DCE (up to 500 Yg/L) faster than non-bioaugmented microcosms. T-RFLP analyses of triplicate bottles produced very consistent results. An organism(s) with a T-RFLP signature of 183 bp was found to dominate in bioaugmented microcosms and was consistently absent from non-bioaugmented microcosms. T-RFLP and FISH analyses of groundwater and solid media during the bioaugmentation field demonstration are expected to reveal the extent of transport and subsurface colonization of the bioaugmentation culture.

Influence of organic load rate (OLR) on the hydrolytic acidification of 2-butenal manufacture wastewater and analysis of bacterial community structure.

PubMed

Song, Guangqing; Xi, Hongbo; Zhou, Yuexi; Fu, Liya; Xing, Xin; Wu, Changyong

2017-11-01

The influence of organic loading rate (OLR) on the performance of hydrolytic acidification process for treating 2-butenal manufacture wastewater was comprehensively studied, while its impact on microbial community was thoroughly investigated. The results demonstrated that over 21.0% of the average COD removal rate was observed in the range of OLR from 0.52 to 3.98g COD/L·d, whereas it reduced to 15.3% with increasing OLR to 6.09g COD/L·d. The acidification degree dramatically decreased from 17.1% to 4.7% when OLR increased from 3.98 to 6.09g COD/L·d. In addition, the removal rates of three kinds of typical matters were less than 65% at the OLR 6.09g COD/L·d. Illumina MiSeq sequencing revealed that Proteobacteria, Chloroflexi, Firmicutes, and Bacteroidetes were dominant phyla at different OLRs. Finally, multivariate analysis suggested that the genera Longilinea and T78 had a positive correlation with the degradation of three kinds of typical matters and COD removal rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protective Effect of 4-(3,4-Dihydroxyphenyl)-3-Buten-2-One from Phellinus linteus on Naproxen-Induced Gastric Antral Ulcers in Rats.

PubMed

Kim, Jeong-Hwan; Kwon, Hyun Ju; Kim, Byung Woo

2016-05-28

The present study investigated the protective effect of naturally purified 4-(3,4- dihydroxyphenyl)-3-buten-2-one (DHP) from Phellinus linteus against naproxen-induced gastric antral ulcers in rats. To verify the protective effect of DHP on naproxen-induced gastric antral ulcers, various doses (1, 5, and 10 μg/kg) of DHP were pretreated for 3 days, and then gastric damage was caused by 80 mg/kg naproxen applied for 3 days. DHP prevented naproxen-induced gastric antral ulcers in a dose-dependent manner. In particular, 10 μg/kg DHP showed the best protective effect against naproxen-induced gastric antral ulcers. Moreover, DHP significantly attenuated the naproxen-induced lipid peroxide level in gastric mucosa and increased the activities of radical scavenging enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, in a dose-dependent manner. A histological examination clearly demonstrated that the gastric antral ulcer induced by naproxen nearly disappeared after the pretreatment of DHP. These results suggest that DHP can inhibit naproxen-induced gastric antral ulcers through prevention of lipid peroxidation and activation of radical scavenging enzymes.

Survival of aerosolized bacteriophage phi X174 in air containing ozone--olefin mixtures.

PubMed Central

Mik, G.; de Groot, I.; Gerbrandy, J. L.

1977-01-01

The effects of ozone and ozonized olefins on aerosol survival of bacteriophage phiX174 were studied. The ozone concentrations used were between 0 and 110 parts/10(9), giving decay rates up to 0-03 min-1. The olefins used were trans-2-butene and cyclohexene in concentrations of 500 parts/10(9) and 2-4 parts/10(6), respectively. Olefins alone have no effect, whereas in combination with ozone, decay rates of 0-1 min-1 and higher were obtained. The results are discussed in relation to the viricidal effect of open air. PMID:265341

Biodegradation of buprofezin by Rhodococcus sp. strain YL-1 isolated from rice field soil.

PubMed

Li, Chao; Zhang, Ji; Wu, Zhi-Guo; Cao, Li; Yan, Xin; Li, Shun-Peng

2012-03-14

A buprofezin-degrading bacterium, YL-1, was isolated from rice field soil. YL-1 was identified as Rhodococcus sp. on the basis of the comparative analysis of 16S rDNA sequences. The strain could use buprofezin as the sole source of carbon and nitrogen for growth and was able to degrade 92.4% of 50 mg L(-1) buprofezin within 48 h in liquid culture. During the degradation of buprofezin, four possible metabolites, 2-tert-butylimino-3-isopropyl-1,3,5-thiadiazinan-4-one, N-tert-butyl-thioformimidic acid formylaminomethyl ester, 2-isothiocyanato-2-methyl-propane, and 2-isothiocyanato-propane, were identified using gas chromatography-mass spectrometry (GC-MS) analysis. The catechol 2,3-dioxygenase activity was strongly induced during the degradation of buprofezin. A novel microbial biodegradation pathway for buprofezin was proposed on the basis of these metabolites. The inoculation of soils treated with buprofezin with strain YL-1 resulted in a higher degradation rate than that observed in noninoculated soils, indicating that strain YL-1 has the potential to be used in the bioremediation of buprofezin-contaminated environments.

Ionization Study of Isomeric Molecules in Strong-field Laser Pulses

DOE PAGES

Zigo, Stefan; Le, Anh-Thu; Timilsina, Pratap; ...

2017-02-10

Through the use of the technique of time-of-flight mass spectroscopy, we obtain strong-field ionization yields for randomly oriented 1,2-dichloroethylene (1,2-DCE) (C 2H 2Cl 2) and 2-butene (C 4H 8). Here, we are interested in studying the effect of conformal structure in strong-field ionization and, in particular, the role of molecular polarity. That is, we can perform strong-field ionization studies in polar vs non-polar molecules that have the same chemical composition. Here, we report our findings through the ionization yields and the ratio (trans/cis) of each stereoisomer pair as a function of intensity.

21 CFR 177.1430 - Isobutylene-butene copolymers.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Maximum bromine value 1. Used as release agents in petroleum wax complying with § 178.3710 of this chapter... release coatings on backings or linings for pressure-sensitive adhesive labels complying with § 175.125 of...

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 Normal...

Detection of butane gas inhalation at 16days after hypoxic encephalopathy: A case report.

PubMed

Sato, Takako; Nishioka, Hiroshi; Tsuboi, Kento; Katagi, Munehiro; Miki, Akihiro; Saito, Takashi; Abe, Shuntaro; Nomura, Masakatsu; Kitagawa, Misa; Tsuchihashi, Hitoshi; Suzuki, Koichi

2017-11-01

In Japan, there are increasing reports of death by poisoning following butane abuse. To determine the specific cause of death in such cases, it is important to confirm the presence of fuel gas components in the body, although careful analysis is required because of their volatile properties. In most reported cases, the subject died suddenly during or immediately after butane aspiration. Thus, the butane concentration in the samples from the deceased should be relatively high. Herein, we present a case of an 18-year-old man found with cardiopulmonary arrest, who then exhibited hypoxic encephalopathy for 16days in a hospital. At autopsy, we detected hypoxic encephalopathy, pneumonia, and ischemia-reperfusion injury of the myocardium, while the cause of cardiac arrest remained unclear. Toxicological analysis was then performed for fuel gas components in several specimens collected at autopsy. Results showed that n-butane and isobutane were detected in the adipose tissue at 16days after inhalation, indicating a role of butane gas inhalation as the cause of death. These data suggest that adipose tissue may be the most appropriate analysis sample to be collected at postmortem in cases where involvement of volatile and fat-soluble gas inhalation is suspected. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Natural Gas and Natural Gas Liquids Pt. 98, Subpt. NN, Table NN-2 Table NN-2 to Subpart NN of Part 98.../Unit) 1 Natural Gas Mscf 0.0544 Propane Barrel 0.241 Normal butane Barrel 0.281 Ethane Barrel 0.170...

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.

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.

Phase-separation induced extraordinary toughening of magnetic hydrogels

NASA Astrophysics Data System (ADS)

Tang, Jingda; Li, Chenghai; Li, Haomin; Lv, Zengyao; Sheng, Hao; Lu, Tongqing; Wang, T. J.

2018-05-01

Phase separation markedly influences the physical properties of hydrogels. Here, we find that poly (N, N-dimethylacrylamide) (PDMA) hydrogels suffer from phase separation in aqueous sodium hydroxide solutions when the concentration is higher than 2 M. The polymer volume fraction and mechanical properties show an abrupt change around the transition point. We utilize this phase separation mechanism to synthesize tough magnetic PDMA hydrogels with the in-situ precipitation method. For comparison, we also prepared magnetic poly (2-acrylamido-2-methyl-propane sulfonic acid sodium) (PNaAMPS) magnetic hydrogels, where no phase separation occurs. The phase-separated magnetic PDMA hydrogels exhibit an extraordinarily high toughness of ˜1000 J m-2; while non-phase-separated magnetic PNaAMPS hydrogels only show a toughness of ˜1 J m-2, three orders of magnitude lower than that of PDMA hydrogels. This phase separation mechanism may become a new approach to prepare tough magnetic hydrogels and inspire more applications.

Influence of Water on the H2SO4 Yield from the Ozonolysis of 2,3-dimethyl-butene (TME) in Presence of SO2

NASA Astrophysics Data System (ADS)

Véronique, D.; Kukui, A.; Chen, H.; Mellouki, A.

2016-12-01

The influence of the water vapor content on the yield of H2SO4 from the ozonolysis of 2,3-dimethyl-butene (TME) in presence of SO2 was studied using laminar flow reactor coupled with Chemical Ionisation Mass Spectrometer (CIMS) for the H2SO4 monitoring within the range of H2O from 10 ppmv to 3×104 ppmv at different concentrations of TME, O3, SO2. The observed dependences of the H2SO4 yield on H2O concentration can be interpreted by assuming two different paths of the H2SO4 formation: 1) via the formation of SO3 in the reaction of Stabilized Criegee Intermediate (SCI) with SO2 (2a) followed by the reaction of SO3 with H2O (3) and 2) via the formation of stabilized secondary ozonide (SOZ) (2b) producing H2SO4 in the reaction with H2O (4a) in competition with the SOZ decomposition to other products (5): O3+TME => (CH3)2COO (1) (CH3)2COO + SO2 => SO3 (2a) => SOZ (2b) SO3 + H2O => H2SO4 (3) SOZ + H2O => H2SO4 (or SO3) (4a) SOZ + M => products (5) The yield of the SCI, SOZ and the rates of the SCI and SOZ decomposition relative to their reactions with SO2 and H2O, respectively, were estimated from the dependencies of the H2SO4 yield on the concentrations of the reactants.

Hydrogenation of 1-butene on nanosized Pd/ZnO catalysts.

PubMed

Agelakopoulou, T; Roubani-Kalantzopoulou, F

2008-07-25

The reaction concerning the hydrogenation of 1-butene has occupied the researchers conducting research based on the method of reversed-flow inverse gas chromatography (RF-IGC), for extended time periods. This work aims to define and record, with the utmost accuracy, the phenomena and their possible parallel reactions. It was a challenge for the RF-IGC, which was met. The venture consisted of many parts. Answers had to be provided to the following questions: (a) Can RF-IGC deal with issues of catalysis? (b) Can RF-IGC be applied to thin films? (c) Can RF-IGC identify peaks? (d) Can RF-IGC define the gnostic regions of adsorption, desorption, surface diffusion, surface reaction, the existence of more than one reaction? (e) Can it kinetically follow the above? The answer is certainly yes. The effort made is presented in this work and aims to answer all the above questions.

Splitting a C-O bond in dialkylethers with bis(1,2,4-tri-t-butylcyclopentadienyl) cerium-hydride does not occur by a sigma-bond metathesis pathway: a combined experimental and DFT computational study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werkema, Evan; Yahia, Ahmed; Maron, Laurent

2010-04-06

Addition of diethylether to [1,2,4(Me3C)3C5H2]2CeH, abbreviated Cp'2CeH, gives Cp'2CeOEt and ethane. Similarly, di-n-propyl- or di-n-butylether gives Cp'2Ce(O-n-Pr) and propane or Cp'2Ce(O-n-Bu) and butane, respectively. Using Cp'2CeD, the propane and butane contain deuterium predominantly in their methyl groups. Mechanisms, formulated on the basis of DFT computational studies, show that the reactions begin by an alpha or beta-CH activation with comparable activation barriers but only the beta-CH activation intermediate evolves into the alkoxide product and an olefin. The olefin then inserts into the Ce-H bond forming the alkyl derivative, Cp'2CeR, that eliminates alkane. The alpha-CH activation intermediate is in equilibrium with themore » starting reagents, Cp'2CeH and the ether, which accounts for the deuterium label in the methyl groups of the alkane. The one-step sigma-bond metathesis mechanism has a much higher activation barrier than either of the two-step mechanisms.« less

Catalytic conversion of cellulose to liquid hydrocarbon fuels by progressive removal of oxygen to facilitate separation processes and achieve high selectivities

DOEpatents

Dumesic, James A.; Ruiz, Juan Carlos Serrano; West, Ryan M.

2015-06-30

Described is a method to make liquid chemicals. The method includes deconstructing cellulose to yield a product mixture comprising levulinic acid and formic acid, converting the levulinic acid to .gamma.-valerolactone, and converting the .gamma.-valerolactone to pentanoic acid. Alternatively, the .gamma.-valerolactone can be converted to a mixture of n-butenes. The pentanoic acid can be decarboxylated yield 1-butene or ketonized to yield 5-nonanone. The 5-nonanone can be hydrodeoxygenated to yield nonane, or 5-nonanone can be reduced to yield 5-nonanol. The 5-nonanol can be dehydrated to yield nonene, which can be dimerized to yield a mixture of C.sub.9 and C.sub.18 olefins, which can be hydrogenated to yield a mixture of alkanes.

Catalytic conversion of cellulose to liquid hydrocarbon fuels by progressive removal of oxygen to facilitate separation processes and achieve high selectivities

DOEpatents

Dumesic, James A [Verona, WI; Ruiz, Juan Carlos Serrano [Madison, WI; West, Ryan M [Madison, WI

2014-01-07

Described is a method to make liquid chemicals. The method includes deconstructing cellulose to yield a product mixture comprising levulinic acid and formic acid, converting the levulinic acid to .gamma.-valerolactone, and converting the .gamma.-valerolactone to pentanoic acid. Alternatively, the .gamma.-valerolactone can be conveted to a mixture of n-butenes. The pentanoic acid can be decarboxylated yield 1-butene or ketonized to yield 5-nonanone. The 5-nonanone can be hydrodeoxygenated to yield nonane, or 5-nonanone can be reduced to yield 5-nonanol. The 5-nonanol can be dehydrated to yield nonene, which can be dimerized to yield a mixture of C.sub.9 and C.sub.18 olefins, which can be hydrogenated to yield a mixture of alkanes.

Preferential solvation of Brooker's merocyanine in binary solvent mixtures composed of formamides and hydroxylic solvents.

PubMed

Bevilaqua, Tharly; da Silva, Domingas C; Machado, Vanderlei G

2004-03-01

The ET polarity values of 4-[(1-methyl-4(1H)-pyridinylidene)-ethylidene]-2,5-cyclohexadien-1-one (Brooker's merocyanine) were collected in mixed-solvent systems comprising a formamide [N,N-dimethylformamide (DMF), N-methylformamide (NMF) or formamide (FA)] and a hydroxylic (water, methanol, ethanol, propan-2-ol or butan-1-ol) solvent. Binary mixtures involving DMF and the other formamides (NMF and FA) as well as NMF and FA were also studied. These data were employed in the investigation of the preferential solvation (PS) of the probe. Each solvent system was analyzed in terms of both solute-solvent and solvent-solvent interactions. These latter interactions were responsible for the synergism observed in many binary mixtures. This synergistic behaviour was observed for DMF-propan-2-ol, DMF-butan-1-ol, FA-methanol, FA-ethanol and for the mixtures of the alcohols with NMF. All data were successfully fitted to a model based on solvent-exchange equilibria, which allowed the separation of the different contributions of the solvent species in the solvation shell of the dye. The results suggest that both hydrogen bonding and solvophobic interactions contribute to the formation of the solvent complexes responsible for the observed synergistic effects in the PS of the dye.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

SnO2 quantum dots with rapid butane detection at lower ppm-level

NASA Astrophysics Data System (ADS)

Cai, Pan; Dong, Chengjun; Jiang, Ming; Shen, Yuanyuan; Tao, You; Wang, Yude

2018-04-01

SnO2 quantum dots (QDs) were successfully synthesized by a facile approach employing benzyl alcohol and ammonium hydroxide at lower temperature of 130 °C. It is revealed that the SnO2 QDs is about 3 nm in size to form clusters. The gas sensor based on SnO2 QDs shows a high potential for detecting low-ppm-level butane at 400 °C, exhibiting a high sensitivity, short response and rapid recovery time, and effective selectivity. The sensing mechanism is understood in terms of adsorbed oxygen species. Significantly, the excellent sensing performance is attributed to the smaller size of SnO2 and larger surface area (204.85 m2/g).

Forensic medical evaluation of deaths resulting from inhalation of cigarette lighter refill fuel in Turkey.

PubMed

Özdemir, Erdinç; Eş, Hüseyin; Demir, Muhammet; Üzün, İbrahim

2017-01-01

Voluntary inhalation/abuse of volatile substances is an important public health problem which especially affects adolescent and young populations worldwide and may be encountered in all socioeconomic and cultural levels. Lighter gas abuse-related death is still an important health problem in Turkey. In this study, 25,265 case files and final reports submitted to the Institute of Forensic Medicine of the First Specialization Board between January 2011 and December 2015 were evaluated retrospectively. In 56 of these cases, lighter gas inhalation (n-butane, propane, isobutane) was recorded as the cause of death. All subjects were male with a mean age of 16.8years. According to eyewitness and crime scene investigation reports, in 48 (85.7%) of the cases, a lighter refill container was found at the scene. It was determined that 21.4% of the cases used a plastic bag to increase the effects of lighter gas and 76.8% inhaled the lighter gas via their mouth and nose. The toxicological analysis of the samples taken while hospitalized showed no lighter refill components (n-butane, propane, isobutane) in 66% of the cases, n-butane in 32.1% of the cases, and n-butane+propane+isobutane in 1.9% of the cases. The importance of lighter gas inhalation-related deaths in Turkey has been increasing. Strict measures against the abuse of these very dangerous substances should be undertaken by the mutual efforts of medical specialists and legislators. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Synthesis of Lipid Based Polyols from 1-butene Metathesized Palm Oil for Use in Polyurethane Foam Applications

NASA Astrophysics Data System (ADS)

Sasidharan Pillai, Prasanth Kumar

This thesis explores the use of 1-butene cross metathesized palm oil (PMTAG) as a feedstock for preparation of polyols which can be used to prepare rigid and flexible polyurethane foams. PMTAG is advantageous over its precursor feedstock, palm oil, for synthesizing polyols, especially for the preparation of rigid foams, because of the reduction of dangling chain effects associated with the omega unsaturated fatty acids. 1-butene cross metathesis results in shortening of the unsaturated fatty acid moieties, with approximately half of the unsaturated fatty acids assuming terminal double bonds. It was shown that the associated terminal OH groups introduced through epoxidation and hydroxylation result in rigid foams with a compressive strength approximately 2.5 times higher than that of rigid foams from palm and soybean oil polyols. Up to 1.5 times improvement in the compressive strength value of the rigid foams from the PMTAG polyol was further obtained following dry and/or solvent assisted fractionation of PMTAG in order to reduce the dangling chain effects associated with the saturated components of the PMTAG. Flexible foams with excellent recovery was achieved from the polyols of PMTAG and the high olein fraction of PMTAG indicating that these bio-derived polyurethane foams may be suitable for flexible foam applications. PMTAG polyols with controlled OH values prepared via an optimized green solvent free synthetic strategy provided flexible foams with lower compressive strength and higher recovery; i.e., better flexible foam potential compared to the PMTAG derived foams with non-controlled OH values. Overall, this study has revealed that the dangling chain issues of vegetable oils can be addressed in part using appropriate chemical and physical modification techniques such as cross metathesis and fractionation, respectively. In fact, the rigidity and the compressive strength of the polyurethane foams were in very close agreement with the percentage of terminal hydroxyl and OH value of the polyol. The results obtained from the study can be used to convert PMTAG like materials into industrially valuable materials.

ESTIMATES OF REGIONAL NATURAL VOLATILE ORGANIC COMPOUND FLUXES FROM ENCLOSURE AND AMBIENT MEASUREMENTS

EPA Science Inventory

The paper discusses results of an investigation at two forested sites in the Southeastern United States. A variety of VOC compounds including methanol, 2-methyl-3-buten-2-ol, 6-methyl-5-hepten-
2-one, isoprene, and 15 monoterpenes were emitted from vegetation at these sites. D...

Prediction and assessment of flammability hazards associated with metered-dose inhalers containing flammable propellants.

PubMed

Dalby, R N

1992-05-01

Several potential replacements for chlorofluorocarbons (CFCs) in metered-dose inhalers (MDIs) are flammable. The flammability hazard associated with their use was assessed using a range of MDIs containing 0-100% (w/w) n-butane (flammable) in HFC-134a (non-flammable) fitted with either 25-, 63-, or 100-microliters metering valves or continuous valves. In flame projection tests each MDI was fired horizontally into a flame, and the ignited flume length emitted from the MDI was measured. Flame projections of greater than or equal to 60 cm were produced by all formulations fitted with continuous valves which contained greater than or equal to 40% (w/w) n-butane in HFC-134a. Using metering valves the maximum flame projection obtained was 30 cm. This was observed with a formulation containing 90% (w/w) n-butane in HFC-134a and a 100-microliters valve. For a particular formulation, smaller metering valves produced shorter flame projections. Because many MDIs are used in conjunction with extension devices, the likelihood of accidental propellant vapor ignition was determined in Nebuhaler and Inspirease reservoirs and a Breathancer spacer. Ignition was predictable based on propellant composition, metered volume, number of actuations, and spacer capacity. Calculated n-butane concentrations in excess of the lower flammability limit [LFL; 1.9% (v/v)] but below the upper flammability limit [UFL; 8.5% (v/v)] were usually predictive of flammability following ignition by a glowing nichrome wire mounted inside the extension device. No ignition was predicted or observed following one or two 25-microliters actuations of 100% n-butane into large volume Nebuhaler (750 ml) or Inspirease (660 ml) devices.(ABSTRACT TRUNCATED AT 250 WORDS)

Secondary Organic Aerosol Formation from 2-Methyl-3-Buten-2-ol Photooxidation: Evidence of Acid-Catalyzed Reactive Uptake of Epoxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Haofei; Zhang, Zhenfa; Cui, Tianqu

2014-04-08

Secondary organic aerosol (SOA) formation from 2-methyl-3-buten-2-ol (MBO) photooxidation has recently been observed in both field and laboratory studies. Similar to isoprene, MBO-derived SOA increases with elevated aerosol acidity in the absence of nitric oxide; therefore, an epoxide intermediate, (3,3-dimethyloxiran-2-yl)methanol (MBO epoxide) was synthesized and tentatively proposed here to explain this enhancement. In the present study, the potential of the synthetic MBO epoxide to form SOA via reactive uptake was systematically examined. SOA was observed only in the presence of acidic aerosols. Major SOA constituents, 2,3-dihydroxyisopentanol (DHIP) and MBO-derived organosulfate isomers, were chemically characterized in both laboratory-generated SOA and inmore » ambient fine aerosols collected from the BEACHON-RoMBAS field campaign during summer 2011, where MBO emissions are substantial. Our results support epoxides as potential products of MBO photooxidation leading to formation of atmospheric SOA and suggest that reactive uptake of epoxides may generally explain acid enhancement of SOA observed from other biogenic hydrocarbons.« less

Two new coumarins from Micromelum falcatum with cytotoxicity and brine shrimp larvae toxicity.

PubMed

Luo, Xiongming; He, Weihong; Yin, Hao; Li, Qingxin; Liu, Qiao; Huang, Yongzhong; Zhang, Si

2012-06-06

Two new coumarins, 7-methoxy-8-(2-hydroxmethyl-1-O-isovaleryl-4-butenyl)-coumarin (1) and 7-methoxy-8-(1-hydroxy-2-O-β-glucopyranosyl-3-methyl-4-butene-1-yl)coumarin (2), and twelve known coumarins 3-14 were isolated from the stem bark of Micromelum falcatum. The structures of compounds 1-14 were elucidated by extensive spectroscopic data analyses. The toxicity of compounds 1-14 was tested using a brine shrimp assay and in vitro antiproliferative assay against mammary cancer (F10) and lung cancer (HvEvc) cell lines by the MTT method. Some compounds had moderate activities. All compounds were also tested against the microorganisms Bacillus subtilis, Bacillus thuringiensis and Escherichia coli, but no activity was observed.

Substantially isotactic, linear, alternating copolymers of carbon monoxide and an olefin

DOEpatents

Sen, Ayusman; Jiang, Zhaozhong

1996-01-01

The compound, [Pd(Me-DUPHOS)(MeCN).sub.2 ](BF.sub.4).sub.2, [Me-DUPHOS: 1,2-bis(2,5-dimethylphospholano)benzene] is an effective catalyst for the highly enantioselective, alternating copolymerization of olefins, such as aliphatic .alpha.-olefins, with carbon monoxide to form optically active, isotactic polymers which can serve as excellent starting materials for the synthesis of other classes of chiral polymers. For example, the complete reduction of a propylene-carbon monoxide copolymer resulted in the formation of a novel, optically active poly(1,4-alcohol). Also, the previously described catalyst is a catalyst for the novel alternating isomerization cooligomerization of 2-butene with carbon monoxide to form optically active, isotactic poly(1,5-ketone)

Substantially isotactic, linear, alternating copolymers of carbon monoxide and an olefin

DOEpatents

Sen, A.; Jiang, Z.

1996-05-28

The compound, [Pd(Me-DUPHOS)(MeCN){sub 2}](BF{sub 4}){sub 2}, [Me-DUPHOS: 1,2-bis(2,5-dimethylphospholano)benzene] is an effective catalyst for the highly enantioselective, alternating copolymerization of olefins, such as aliphatic {alpha}-olefins, with carbon monoxide to form optically active, isotactic polymers which can serve as excellent starting materials for the synthesis of other classes of chiral polymers. For example, the complete reduction of a propylene-carbon monoxide copolymer resulted in the formation of a novel, optically active poly(1,4-alcohol). Also, the previously described catalyst is a catalyst for the novel alternating isomerization cooligomerization of 2-butene with carbon monoxide to form optically active, isotactic poly(1,5-ketone).

Pathway and Surface Mechanism Studies of 1,3-butadiene Selective Oxidation Over Vanadium-Molybdenum-Oxygen Catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schroeder, William David

2001-01-01

The partial oxidation of 1,3-butadiene has been investigated over VMoO catalysts synthesized by sol-gel techniques. Surface areas were 9-14 m 2/g, and compositions were within the solid solution regime, i.e. below 15.0 mol % MoO 3/(MoO 3 + V 2O 5). Laser Raman Spectroscopy and XRD data indicated that solid solutions were formed, and pre- and post-reaction XPS data indicated that catalyst surfaces contained some V +4 and were further reduced in 1,3-butadiene oxidation. A reaction pathway for 1,3-butadiene partial oxidation to maleic anhydride was shown to involve intermediates such as 3,4-epoxy-1-butene, crotonaldehyde, furan, and 2-butene-1,4-dial. The addition of watermore » to the reaction stream substantially increased catalyst activity and improved selectivity to crotonaldehyde and furan at specific reaction temperatures. At higher water addition concentrations, furan selectivity increased from 12% to over 25%. The catalytic effects of water addition were related to competitive adsorption with various V 2O 5-based surface sites, including the vanadyl V=O, corner sharing V-O-V and edge sharing V-O oxygen. Higher levels of water addition were proposed to impose acidic character by dissociative adsorption. In addition, a novel combinatorial synthesis technique for VMoO was used to investigate the phase transitions of V 2O 5, solid solutions of Mo in V 2O 5, V 9Mo 6O 40, and other reduced VMoO compounds, characterized by laser Raman spectroscopy. The natural composition gradient imposed by the sputter deposition apparatus was used to create VMoO arrays containing 225 samples ranging from 7.0-42 mol% MoO 3/(V 2O 5 + MoO 3), determined by EDS analysis.« less

Unusual open chain quinolinyl peroxol and its alcohol counterpart obtained through a modified Skraup-Doebner-Von Miller quinoline synthesis: theoretical studies and complete (1) H- and (13) C-NMR assignments.

PubMed

Fotie, Jean; Kemami Wangun, Hilaire V; Dreux, Katelyn; Sommerfeld, Thomas; Pittman, Jacob

2012-01-01

Because of their extreme instability, it is generally difficult to synthesize and fully characterize open chain peroxides, also known as peroxols. In our attempt to investigate the mechanism of the Skraup-Doebner-Von Miller quinoline synthesis, we were able to obtain an unusual open chain peroxy-quinoline, namely, 4-(8-ethoxy-2,3-dihydro-1H-cyclopenta[c]quinolin-4-yl)butane-1-peroxol (1), and its alcohol counterpart, namely 4-(8-ethoxy-2,3-dihydro-1H-cyclopenta[c]quinolin-4-yl)butan-1-ol (2) obtained as a side product during the same reaction. Although structurally similar, these two compounds appeared to display some very distinct physical and spectroscopic characteristics. This work reports detailed NMR studies and full (1) H and (13)  C NMR assignments for these two compounds. These assignments are based upon the analysis of the NMR spectra of these compounds including (1) H, (13)  C, COSY, gHSQC and gHMBC. The effect of the peroxide functional group on the chemical shift of neighboring carbons and protons was also investigated by comparing the NMR data of these two compounds. Furthermore, the effects of potential hydrogen bondings in 1, 2, and possible 1-1 dimer, 2-2 dimer and in prototypical model systems, as well as the stability of these compounds, were investigated computationally. The computed dissociation energies and NMR data support the interpretation of the experimental data. Copyright © 2012 John Wiley & Sons, Ltd.

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. Copyright 2010 Elsevier B.V. All rights reserved.

Organosulfates as tracers for secondary organic aerosol (SOA) formation from 2-methyl-3-buten-2-ol (MBO) in the atmosphere.

PubMed

Zhang, Haofei; Worton, David R; Lewandowski, Michael; Ortega, John; Rubitschun, Caitlin L; Park, Jeong-Hoo; Kristensen, Kasper; Campuzano-Jost, Pedro; Day, Douglas A; Jimenez, Jose L; Jaoui, Mohammed; Offenberg, John H; Kleindienst, Tadeusz E; Gilman, Jessica; Kuster, William C; de Gouw, Joost; Park, Changhyoun; Schade, Gunnar W; Frossard, Amanda A; Russell, Lynn; Kaser, Lisa; Jud, Werner; Hansel, Armin; Cappellin, Luca; Karl, Thomas; Glasius, Marianne; Guenther, Alex; Goldstein, Allen H; Seinfeld, John H; Gold, Avram; Kamens, Richard M; Surratt, Jason D

2012-09-04

2-Methyl-3-buten-2-ol (MBO) is an important biogenic volatile organic compound (BVOC) emitted by pine trees and a potential precursor of atmospheric secondary organic aerosol (SOA) in forested regions. In the present study, hydroxyl radical (OH)-initiated oxidation of MBO was examined in smog chambers under varied initial nitric oxide (NO) and aerosol acidity levels. Results indicate measurable SOA from MBO under low-NO conditions. Moreover, increasing aerosol acidity was found to enhance MBO SOA. Chemical characterization of laboratory-generated MBO SOA reveals that an organosulfate species (C(5)H(12)O(6)S, MW 200) formed and was substantially enhanced with elevated aerosol acidity. Ambient fine aerosol (PM(2.5)) samples collected from the BEARPEX campaign during 2007 and 2009, as well as from the BEACHON-RoMBAS campaign during 2011, were also analyzed. The MBO-derived organosulfate characterized from laboratory-generated aerosol was observed in PM(2.5) collected from these campaigns, demonstrating that it is a molecular tracer for MBO-initiated SOA in the atmosphere. Furthermore, mass concentrations of the MBO-derived organosulfate are well correlated with MBO mixing ratio, temperature, and acidity in the field campaigns. Importantly, this compound accounted for an average of 0.25% and as high as 1% of the total organic aerosol mass during BEARPEX 2009. An epoxide intermediate generated under low-NO conditions is tentatively proposed to produce MBO SOA.

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.

10 CFR 205.13 - Where to file.

Code of Federal Regulations, 2010 CFR

2010-01-01

...; (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...

10 CFR 205.13 - Where to file.

Code of Federal Regulations, 2011 CFR

2011-01-01

...; (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...

Quantification and sensory studies of character impact odorants of different soybean lecithins.

PubMed

Stephan, A; Steinhart, H

1999-10-01

Fifty-four potent odorants in standardized, hydrolyzed, and deoiled and hydrolyzed soybean lecithins were quantified by high-resolution gas chromatography/mass spectrometry (HRGC/MS). The characterization of their aroma impact was performed by calculation of nasal (n) and retronasal (r) odor activity values (OAVs). For this, the nasal and retronasal recognition thresholds of 18 odor-active compounds were determined in vegetable oil. The following compounds showed the highest nOAVs: 2,3-diethyl-5-methylpyrazine, methylpropanal, acetic acid, pentanoic acid, 2-ethyl-3,5-dimethylpyrazine, pentylpyridine, (Z)-1,5-octadien-3-one, 2-methylbutanal, and beta-damascenone. In addition to the compounds above, 1-octen-3-one, 1-nonen-3-one, and 3-methyl-2,4-nonandione showed potent rOAVs. The results of quantification and OAV calculation were confirmed by a model mixture of 25 impact odorants, which yielded a highly similar sensory profile to that of the original soybean lecithin. The sensory importance of pyrazines and free acids increased through enzymatic hydrolysis and decreased by the process of deoiling. The impact of unsaturated ketones on the lecithin aroma was not changed by either process.

Additional conformer observed in the microwave spectrum of methyl vinyl ketone

NASA Astrophysics Data System (ADS)

Wilcox, David S.; Shirar, Amanda J.; Williams, Owen L.; Dian, Brian C.

2011-05-01

A chirped-pulse Fourier transform microwave spectrometer was used to record the rotational spectrum of methyl vinyl ketone (MVK, 3-butene-2-one). Two stable conformations were identified: the previously documented antiperiplanar (ap) conformer and synperiplanar (sp), which is reported for the first time in this microwave study. Methyl torsional analysis resulted in V3 barrier heights of 433.8(1) and 376.6(2) cm-1 for ap- and sp-MVK, respectively. Heavy atom isotopic species of both conformers were detected in natural abundance allowing bond lengths and angles of the molecular frames to be calculated through Kraitchman analysis. A comparison with ab initio calculations is included.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Disselkamp, Robert S.; Denslow, Kayte M.; Hart, Todd R.

We have studied the effect of cavitating ultrasound on the heterogeneous aqueous hydrogenation of cis-2-buten-1-ol (C4 olefin) and cis-2-penten-1-ol (C5 olefin) on Pd-black to form the trans-olefins (trans-2-buten-1-ol and trans-2-penten-1-ol) and saturated alcohols (1-butanol and 1-pentanol, respectively). Silent (and magnetically stirred) experiments served as control experiments. As described in an earlier publication by our group, we have added an inert dopant, 1-propanol, in the reaction mixture to ensure the rapid onset of cavitation in the ultrasound-assisted reactions that can lead to altered selectivity compared to silent reaction systems [R.S. Disselkamp, Ya-Huei Chin, C.H.F. Peden, J. Catal. 227 (2004) 552]. Themore » motivation for this study is to examine whether cavitating ultrasound can reduce the [trans-olefin/saturated alcohol] molar ratio during the course of the reaction. This could have practical application in that it may offer an alternative processing methodology of synthesizing healthier edible seed oils by reducing trans-fat content.We have observed that cavitating ultrasound results in a [(trans-olefin/saturated alcohol)ultrasound/(trans-olefin/saturated alcohol)silent] ratio quantity less than 0.5 at the reaction mid-point for both the C4 and C5 olefin systems. This indicates that ultrasound reduces trans-olefin production compared to the silent control experiment. Furthermore, there is an added 30% reduction for the C5 versus C4 olefin compounds again at reaction mid-point. We attribute differences in the ratio quantity as a moment of inertia effect. In principle, the C4 versus C5 olefins has a {approx}52% increase in moment of inertia about C2 C3 double bond slowing isomerization. Since seed oils are C18 multiple cis-olefins and have a moment of inertia even greater than our C5 olefin here, our study suggests that even a greater reduction in trans-olefin content may occur for partial hydrogenation of C18 seed oils.« less

Activity of cationically substituted bis-benzimidazoles against experimental Pneumocystis carinii pneumonia.

PubMed Central

Tidwell, R R; Jones, S K; Naiman, N A; Berger, L C; Brake, W B; Dykstra, C C; Hall, J E

1993-01-01

On the basis of a previously observed correlation between the antimicrobial activity and DNA binding strength of dicationic molecules, a series of 10 dicationically substituted bis-benzimidazoles were tested for activity in the rat model of Pneumocystis carinii pneumonia. One of the compounds, 1,4-bis[5-(2-imidazolinyl)-2-benzimidazolyl]butane, was found to be more potent and less toxic than pentamidine. PMID:8215291

Antiproliferative constituents in plants 14. Coumarins and acridone alkaloids from Boenninghausenia japonica NAKAI.

PubMed

Chaya, Norihito; Terauchi, Kazuko; Yamagata, Yuriko; Kinjo, Junei; Okabe, Hikaru

2004-08-01

The MeOH extracts of the ground part and the root of Boenninghausenia japonica NAKAI showed inhibitory activity against tumor cell growth. Fractionation of the extracts has resulted in isolation of 1,3-dihydroxy-4-(2'-hydroxy-3'-hydroxymethyl-3',4'-epoxy-butyl)-N-methylacridone, 1,3-dihydroxy-4-[(Z)-3'-hydroxy-3'-methyl-buten-1'-yl]-N-methylacridone, 3-(1',1'-dimethylallyl)-7-hydroxy-8-methoxy-2H-1-benzopyran-2-one, casegravol, cis-casegravol, and edgeworin in addition to 9 compounds reported from B. japonica and B. albiflora. The isolates from this plant and some related compounds were tested for antiproliferative activity against human gastric adenocarcinoma (MK-1), human uterus carcinoma (HeLa), and murine melanoma (B16F10) cells.

Novel adducts from the reaction of 1-chloro-3-buten-2-one with 2'-deoxyguanosine. Structural characterization and potential as tools to investigate 1,3-butadiene carcinogenicity.

PubMed

Zheng, Jin; Li, Yan; Yu, Ying-Xin; An, Jing; Zhang, Xin-Yu; Elfarra, Adnan A

2015-01-25

1-Chloro-3-buten-2-one (CBO) is a potential reactive metabolite of 1,3-butadiene (BD), a carcinogenic air pollutant. To develop tools that may help investigate the role of CBO in BD carcinogenicity and to develop biomarkers that can be used to assess BD exposure, the reaction of CBO with 2'-deoxyguanosine (dG) under in vitro physiological conditions (pH 7.4, 37°C) was investigated and the products (designated as CG-1, CG-2, CG-3, CG-4, CG-5, and CG-6 based on their retention times on HPLC) were characterized by MS and NMR spectroscopy. The structures of CG-1, CG-2, CG-3, and CG-4 were 1,N2-(3-hydroxy-3-hydroxymethylpropan-1,3-diyl)-2'-deoxyguanosine, N7-(4-chloro-3-oxobutyl)-2'-deoxyguanosine, N7,8-(3-hydroxy-3-chloromethylpropan-1,3-diyl)guanine and N2-(4-chloro-3-oxobutyl)-2'-deoxyguanosine, respectively. CG-5 and CG-6, a pair of diastereomers, were characterized as 1,N2-(3-hydroxy-3-chloromethylpropan-1,3-diyl)-2'-deoxyguanosine. CG-1 was stable under in vitro physiological conditions, whereas CG-2, CG-3, CG-4, and CG-5/6 were unstable and exhibited the half-lives at <1.0, 4.8±0.1, 6.7±0.3, and 2.7±0.1 h, respectively. CG-2 decomposed primarily via a retro-Michael reaction to produce dG and CBO, with only a small fraction of CG-2 degrading to CG-3. Decomposition of CG-4 proceeded via a cyclization reaction and/or replacement of the chlorine atom by a hydroxyl group to form 1,N2-(1-hydroxy-1-hydroxymethylpropan-1,3-diyl)-2'-deoxyguanosine (CG-4D1) and N(2)-(4-hydroxy-3-oxobutyl)-2'-deoxyguanosine (CG-4D2), whereas decomposition of CG-5/6 yielded CG-1. Collectively, the newly characterized CBO adducts could be used to investigate the role of CBO in the mechanism of BD carcinogenicity and could also be used to develop biomarkers for BD exposure. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Well treating fluids and additives therefor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, B.

1991-07-16

This patent describes a solid, dry additive for reducing the water loss and improving other properties of well treating fluids in high temperature environments. It comprises a mixture of a water soluble copolymer of N-vinyl pyrrolidone and the sodium salt of 2- acrylamido-2-methylpropane sulfonic acid and an organic compound selected from the group consisting of lignites, tannins, asphaltic materials, derivatives thereof and mixtures of such compounds, the mixture of the water soluble copolymer and organic compound being prepared by mixing a water and oil emulsion containing the copolymer with the organic compound followed by removing the oil and water frommore » the resultant mixture.« less

METABOLISM OF N-ALKYLATED SPERMINE ANALOGUES BY POLYAMINE AND SPERMINE OXIDASES

PubMed Central

Häkkinen, Merja R.; Hyvönen, Mervi T.; Auriola, Seppo; Casero, Robert A.; Vepsäläinen, Jouko; Khomutov, Alex R.; Alhonen, Leena; Keinänen, Tuomo A.

2010-01-01

SUMMARY N-alkylated polyamine analogues have potential as anticancer and antiparasitic drugs. However, their metabolism in the host has remained incompletely defined thus potentially limiting their utility. Here, we have studied the degradation of three different spermine analogues N,N′-bis-(3-ethylaminopropyl)butane-1,4-diamine (DESPM), N-(3-benzyl-aminopropyl)-N'-(3-ethylaminopropyl)butane-1,4-diamine (BnEtSPM) and N,N′-bis-(3-benzylaminopropyl)butane-1,4-diamine (DBSPM) and related mono-alkylated derivatives as substrates of recombinant human polyamine oxidase (APAO) and spermine oxidase (SMO). APAO and SMO metabolized DESPM to EtSPD (Km(APAO)=10μM, kcat(APAO)=1.1s−1 and Km(SMO)=28μM, kcat(SMO)=0.8s−1, respectively), metabolized BnEtSPM to EtSPD (Km(APAO)=0.9 μM, kcat(APAO)=1.1s−1 and Km(SMO)=51μM, kcat(SMO)=0.4s−1, respectively), and metabolized DBSPM to BnSPD (Km(APAO)=5.4μM, kcat(APAO)= 2.0s−1 and Km(SMO)=33μM, kcat(SMO)=0.3s−1, respectively). Interestingly, mono-alkylated spermine derivatives were metabolized by APAO and SMO to SPD (EtSPM Km(APAO)=16μM, kcat(APAO)=1.5s−1; Km(SMO)=25μM, kcat(SMO) =8.2s−1; BnSPM Km(APAO)=6.0μM, kcat(APAO)=2.8s−1; Km(SMO)=19μM, kcat(SMO)=0.8s−1, respectively). Surprisingly, E t S P D ( Km(APAO)=37μM, kcat(APAO)=0.1s−1; Km(SMO)=48μM, kcat(SMO)=0.05s−1) and BnSPD (Km(APAO)=2.5μM, kcat(APAO)=3.5s−1; Km(SMO)=60μM, kcat(SMO)=0.54s−1) were metabolized to SPD by both the oxidases. Furthermore, we studied the degradation of DESPM, BnEtSPM or DBSPM in the DU145 prostate carcinoma cell line. The same major metabolites EtSPD and/or BnSPD were detected both in the culture medium and intracellularly after 48 hours of culture. Moreover, EtSPM and BnSPM were detected from cell samples. Present data shows that inducible SMO parallel with APAO could play an important role in polyamine based drug action, i.e. degradation of parent drug and its metabolites, having significant impact on efficiency of these drugs, and hence for the development of novel N-alkylated polyamine analogues. PMID:20012116

Characterization of the Major Purine and Pyrimidine Adducts Formed after Incubations of 1-Chloro-3-buten-2-one with Single-/Double-Stranded DNA and Human Cells.

PubMed

Liu, Ling-Yan; Zheng, Jin; Kong, Cong; An, Jing; Yu, Ying-Xin; Zhang, Xin-Yu; Elfarra, Adnan A

2017-02-20

We have previously shown that 1-chloro-3-buten-2-one (CBO), a potential reactive metabolite of 1,3-butadiene (BD), exhibits potent cytotoxicity and genotoxicity that have been attributed in part to its reactivity toward DNA. In an effort to identify the DNA adducts of CBO, we characterized the CBO reactions with 2'-deoxyguanosine (dG), 2'-deoxycytidine (dC), and 2'-deoxyadenosine (dA) under in vitro physiological conditions (pH 7.4, 37 °C). In the present study, we investigated the CBO reaction with 2'-deoxythymidine (dT) and compared the rate constants of the reactions of CBO with dA, dC, dG, and dT at both individual- and mixed-nucleosides levels. We also investigated the reactions of CBO with single- and double-stranded DNA using HPLC with UV detection after adducts were released by either acid or enzymatic hydrolysis of DNA. Consistent with the results from the nucleoside reactions and the rate constant experiments, 1,N 6 -(1-hydroxy-1-chloromethylpropan-1,3-diyl)adenine (A-2D) was identified as the major DNA adduct detected after acid hydrolysis, followed by N7-(4-chloro-3-oxobutyl)guanine (CG-2H) and a small amount of 1,N 6 -(1-hydroxy-1-hydroxymethylpropan-1,3-diyl)adenine (A-1D). After enzymatic hydrolysis, 1,N 6 -(1-hydroxy-1-hydroxymethylpropan-1,3-diyl)-2'-dexoyadenosine (dA-1), 3,N 4 -(1-hydroxy-1-hydroxymethylpropan-1,3-diyl)-2'-deoxycytidine (dC-1/2), and 1,N 2 -(3-hydroxy-3-hydroxymethylpropan-1,3-diyl)-2'-dexoyguanosine (CG-1) were detected, with dA-1 being the major product, followed by dC-1/2. When a nontoxic concentration of CBO (1 μM) was incubated with HepG2 cells, no adducts could be detected by LC-MS. However, pretreatment of cells with l-buthionine sulfoximine to deplete GSH levels allowed A-2D to be consistently detected in cellular DNA. These results may contribute to a better understanding of the role of the DNA adducts in CBO genotoxicity and mutagenicity. It also suggests that A-2D could be developed as a biomarker of CBO formation after BD exposure in vivo.

Studying the internal ballistics of a combustion-driven potato cannon using high-speed video

NASA Astrophysics Data System (ADS)

Courtney, E. D. S.; Courtney, M. W.

2013-07-01

A potato cannon was designed to accommodate several different experimental propellants and have a transparent barrel so the movement of the projectile could be recorded on high-speed video (at 2000 frames per second). Five experimental propellants were tested: propane (C3H8), acetylene (C2H2), ethanol (C2H6O), methanol (CH4O) and butane (C4H10). The quantity of each experimental propellant was calculated to approximate a stoichometric mixture and considering the upper and lower flammability limits, which in turn were affected by the volume of the combustion chamber. Cylindrical projectiles were cut from raw potatoes so that there was an airtight fit, and each weighed 50 (± 0.5) g. For each trial, position as a function of time was determined via frame-by-frame analysis. Five trials were made for each experimental propellant and the results analyzed to compute velocity and acceleration as functions of time. Additional quantities, including force on the potato and the pressure applied to the potato, were also computed. For each experimental propellant average velocity versus barrel position curves were plotted. The most effective experimental propellant was defined as that which accelerated the potato to the highest muzzle velocity. The experimental propellant acetylene performed the best on average (138.1 m s-1), followed by methanol (48.2 m s-1), butane (34.6 m s-1), ethanol (33.3 m s-1) and propane (27.9 m s-1), respectively.

3,3-Dimethyl-1-[5-(1H-1,2,4-triazol-1-yl­meth­yl)-1,3,4-thia­diazol-2-ylsulfan­yl]butan-2-one

PubMed Central

Wei, Qing-Li; He, Fu-Jin; Li, Fang; Bi, Sai

2008-01-01

In the mol­ecule of the title compound, C11H15N5OS2, the thia­diazole and triazole rings are not coplanar, the dihedral angle formed by their mean planes being 59.9 (2)°. The exocyclic S atom, and the methyl­ene, carbonyl, tert-butyl and one methyl carbon form an approximately planar zigzag chain, which makes a dihedral angle of 74.6 (1)° with the thia­diazole ring. PMID:21201440

Protection of rats against 3-butene-1,2-diol-induced hepatotoxicity and hypoglycemia by N-acetyl-L-cysteine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprague, Christopher L.; Elfarra, Adnan A.

2005-09-15

3-Butene-1,2-diol (BDD), an allylic alcohol and major metabolite of 1,3-butadiene, has previously been shown to cause hepatotoxicity and hypoglycemia in male Sprague-Dawley rats, but the mechanisms of toxicity were unclear. In this study, rats were administered BDD (250 mg/kg) or saline, ip, and serum insulin levels, hepatic lactate levels, and hepatic cellular and mitochondrial GSH, GSSG, ATP, and ADP levels were measured 1 or 4 h after treatment. The results show that serum insulin levels were not causing the hypoglycemia and that the hypoglycemia was not caused by an enhancement of the metabolism of pyruvate to lactate because hepatic lactatemore » levels were either similar (1 h) or lower (4 h) than controls. However, both hepatic cellular and mitochondrial GSH and GSSG levels were severely depleted 1 and 4 h after treatment and the mitochondrial ATP/ADP ratio was also lowered 4 h after treatment relative to controls. Because these results suggested a role for hepatic cellular and mitochondrial GSH in BDD toxicity, additional rats were administered N-acetyl-L-cysteine (NAC; 200 mg/kg) 15 min after BDD administration. NAC treatment partially prevented depletion of hepatic cellular and mitochondrial GSH and preserved the mitochondrial ATP/ADP ratio. NAC also prevented the severe depletion of serum glucose concentration and the elevation of serum alanine aminotransferase activity after BDD treatment without affecting the plasma concentration of BDD. Thus, depletion of hepatic cellular and mitochondrial GSH followed by the decrease in the mitochondrial ATP/ADP ratio was likely contributing to the mechanisms of hepatotoxicity and hypoglycemia in the rat.« less

Impact of Hong Kong's Voluntary Catalytic Converter Replacement Programme on Roadside Air Quality

NASA Astrophysics Data System (ADS)

Simpson, I. J.; Guo, H.; Louie, P. K. K.; Luk, C.; Lyu, X.; Meinardi, S.; Yam, Y. S.; Blake, D. R.

2015-12-01

As part of its ongoing policies to improve roadside air quality, in 2013 the Hong Kong government launched an incentive programme to replace catalytic converters and oxygen sensors in taxis and light buses mainly fueled by liquefied petroleum gas (LPG). The majority of replacements occurred from October 2013 to April 2014, with 75% of eligible vehicles participating in the programme, or 16,472 vehicles. Based on taxi exhaust measurements at a Hong Kong vehicle testing facility, the concentrations of n-butane, propane and i-butane (the primary components of LPG) decreased by 97% following the replacements. To determine the impact of the programme on roadside air quality, long-term measurements of volatile organic compounds (VOCs) were analyzed before, during and after the replacement programme, mainly at a busy roadside location in Mong Kok, Hong Kong. A clear decrease in the levels of major pollutants associated with LPG vehicle exhaust was observed at the roadside. For example, average (± 1 standard deviation) n-butane levels from October to April decreased from 13.0 ± 3.6 and 13.9 ± 2.6 ppbv in the two years preceding the programme, to 9.2 ± 2.9 ppbv during the programme, to 6.2 ± 1.7 ppbv the year after the programme. By contrast, compounds such as i-pentane that are not strongly associated with LPG or with LPG exhaust remained steady, averaging 0.90 ± 0.34, 1.01 ± 0.31, 0.93 ± 0.37, and 0.91 ± 0.42 ppbv from October to April of 2011/12, 2012/13, 2013/14 and 2014/15, respectively. Impacts of the programme on roadside levels of nitrogen oxides (NOx) and ozone (O3) will also be discussed. Because many taxis are high mileage vehicles that travel several hundred kilometers daily, their catalytic converters need to be replaced approximately every 18 months. Therefore ongoing vehicle maintenance will be required in order to preserve the gains made from this initial subsidy programme.

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...

Identification of A Butyrophenone Analog as a Potential Atypical Antipsychotic Agent: 4-[4-(4-Chlorophenyl)-1,4-diazepan-1-yl]-1-(4-fluorophenyl)butan-1-one

PubMed Central

Ablordeppey, Seth Y.; Altundas, Ramazan; Bricker, Barbara; Zhu, Xue Y.; Eyunni, Suresh E. V. K.; Jackson, Tanise; Khan, Abdul; Roth, Bryan L.

2009-01-01

The synthesis and exploration of novel butyrophenones have led to the identification of a diazepane analog of haloperidol, 4-[4-(4-Chlorophenyl)-1,4-diazepan-1-yl]-1-(4-fluorophenyl)butan-1-one (Compound 13) with an interesting multireceptor binding profile. Compound 13 was evaluated for its binding affinities at DA subtype receptors, 5HT subtype receptors, H-1, M-1 receptors and at NET, DAT and SERT transporters. At each of these receptors, compound 13 was equipotent or better than several of the standards currently in use. In in vivo mouse and rat models to evaluate its efficacy and propensity to elicit catalepsy and hence EPS in humans, compound 13 showed similar efficacy as clozapine and did not produce catalepsy at five times its ED50 value. PMID:18595716

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

PubMed

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

2013-05-01

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 (13)C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in (13)C, 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.

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.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hypolipidemic and antioxidant activity of mountain celery (Cryptotaenia japonica Hassk) seed essential oils.

PubMed

Cheng, Ming-Ching; Lin, Li-Yun; Yu, Tung-Hsi; Peng, Robert Y

2008-06-11

Mountain celery seed essential oils (MC-E) contained 109 compounds, including mainly nine kinds of monoterpenoids, 31 kinds of of sesquiterpenoids, and 22 kinds of alcohols. A successive gel column adsorption with solvent fractionation yielded four fractionates. The pentane fractionate revealed potent hypolipidemic but poor antioxidant activities. The ether fractionate exhibited strong hypolipidemic activity in addition to excellent 1,1-diphenyl-2-picrylhydrazyl free radical- and superoxide anion-scavenging capabilities. The third acetone fractionate only showed moderate superoxide anion-scavenging activity. Finally, the fourth methanol fractionate having a rather high content of gamma-selinene, 2-methylpropanal, and Z-9-octadecenamide uniquely revealed very strong superoxide anion-scavenging capability. All MC diets except the MC-E-added diet simultaneously exhibited both significant hypolipidemic and high-density lipoprotein-cholesterol (HDL-C)-elevating capabilities. However, all diets totally failed to affect the hepatic phospholipid levels. Conclusively, the MC-E can be fractionated by such a separation technology to produce products uniquely possessing hypolipidemic and HDL-C-elevating activities.

Catalytic conversion of cellulose to liquid hydrocarbon fuels by progressive removal of oxygen to facilitate separation processes and achieve high selectivities

DOEpatents

Dumesic, James A [Verona, WI; Ruiz, Juan Carlos Serrano [Madison, WI; West, Ryan M [Madison, WI

2012-04-03

Described is a method to make liquid chemicals, such as functional intermediates, solvents, and liquid fuels from biomass-derived cellulose. The method is cascading; the product stream from an upstream reaction can be used as the feedstock in the next downstream reaction. The method includes the steps of deconstructing cellulose to yield a product mixture comprising levulinic acid and formic acid, converting the levulinic acid to .gamma.-valerolactone, and converting the .gamma.-valerolactone to pentanoic acid. Alternatively, the .gamma.-valerolactone can be converted to a mixture of n-butenes. The pentanoic acid so formed can be further reacted to yield a host of valuable products. For example, the pentanoic acid can be decarboxylated yield 1-butene or ketonized to yield 5-nonanone. The 5-nonanone can be hydrodeoxygenated to yield nonane, or 5-nonanone can be reduced to yield 5-nonanol. The 5-nonanol can be dehydrated to yield nonene, which can be dimerized to yield a mixture of C.sub.9 and C.sub.18 olefins, which can be hydrogenated to yield a mixture of alkanes. Alternatively, the nonene may be isomerized to yield a mixture of branched olefins, which can be hydrogenated to yield a mixture of branched alkanes. The mixture of n-butenes formed from .gamma.-valerolactone can also be subjected to isomerization and oligomerization to yield olefins in the gasoline, jet and Diesel fuel ranges.

The Production and Recovery of C2-C4 Olefins from Syngas.

ERIC Educational Resources Information Center

Murchison, C. B.; And Others

1986-01-01

Discusses reacting coal-derived hydrogen and carbon monoxide (syngas) at relatively high selectivity to ethylene, propylene, and butenes over novel catalysts. In addition, data are given which illustrate a unique ethylene removal step which is compatible with operating the olefin synthesis at low conversion. (JN)

Crystal structures of eight 3D molecular adducts derived from bis-imidazole, bis(benzimidazole), and organic acids

NASA Astrophysics Data System (ADS)

Ding, Aihua; Jin, Shouwen; Jin, Shide; Hu, KaiKai; Lin, Zhihao; Liu, Hui; Wang, Daqi

2018-01-01

Cocrystallization of the bis(imidazole)/bis(benzimidazole) with a series of organic acids gave a total of eight molecular adducts with the compositions: (3,6-bis(imidazole-1-yl)pyridazine): (trichloroacetic acid)2(1) [(H2L1)2+ · (tca-)2, L1 = 3,6-bis(imidazole-1-yl)pyridazine, tca- = trichloroacetate], (bis(N-imidazolyl)methane): (suberic acid) (2) [(L2) · (H2suba), L2 = bis(N-imidazolyl)methane, H2suba = suberic acid], bis(N-imidazolyl)methane: (3-nitrophthalic acid): 3H2O (3) [(H2L2)2+ · (3-Hnpa-)2 · 3H2O, 3-Hnpa- = 3-nitro hydrogenphthalate], (bis(N-imidazolyl)butane)0.5: (4-nitrophthalic acid): H2O (4) [(H2L3)0.5+ · (4-Hnpa-)- · H2O, L3 = bis(N-imidazolyl)butane, 4-Hnpa- = 4-nitro hydrogenphthalate], (1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole): (3,5-dinitrosalicylic acid) (5) [(HL4) · (3,5-dns-), L4 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole, 3,5-dns- = 3,5-dinitrosalicylate], (1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole): (3-nitrophthalic acid) (6) [(H2L4) · (3-npa2-), L4 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole, 3-npa2-=3-nitrogenphthalate], (bis(N-imidazolyl)butane): (pamoic acid) (7) [(H2L3) · (pam), pam = pamoate], and (3,6-bis(imidazole-1-yl)pyridazine): (1,5-naphthalenedisulfonic acid) [(H2L1)2+ · (npda)2- = 1,5-naphthalenedisulfonate] (8). The eight adducts have been characterized by X-ray diffraction technique, infrared spectrum, and elemental analysis, and the melting points of all adducts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the eight investigated crystals both the end ring N in the bis(imidazole) moieties are protonated when the organic acids are deprotonated except 2, and 5, and the crystal packing is interpreted in terms of the strong ionic Nsbnd H⋯O H-bond between the imidazolium and the deprotonated acidic groups. Except the Nsbnd H⋯O H-bond, the Osbnd H⋯O H-bonds were also found at the salts 3, 4, 5, and 7, salt 5 has the additional Nsbnd H⋯N H-bond, the Nsbnd H⋯S H-bond was established at 8. Further analysis of the crystal packing of the adducts indicated that a different set of additional CHsbnd O/CH2sbnd O, CHsbnd Cl, CH-π/CH2-π, Clsbnd C, Clsbnd N, Osbnd O, O-π, OH-π, and π-π associations contribute to the stabilization and expansion of the total 3D frameworks. For the coexistence of the various weak interactions these structures had homo or hetero supramolecular synthons or both. Some supramolecular synthons, such as R12(4), R22(7), and R22(8) usually found in crystals of organic acids with imidazole unit, were again shown to be appeared in constructing most of these H-bond networks.

Structural confirmation of regioisomers of Lopinavir impurities using MS and gradient COSY (1H and 13C NMR assignment of Lopinavir impurities).

PubMed

Siva Lakshmi Devi, A; Srinivasa Rao, Y; Suresh, Y; Yogeswar Reddy, M; Jyothi, G; Rajababu, B; Prasad, V S R; Umamaheswar Rao, V

2007-05-01

We report the complete (1)H and (13)C NMR assignment of impurities of six Lopinavir (2S)-N-[(2S, 4S, 5S)-5-{[2-(2,6-dimethylphenoxy)acetyl]amino}-4-hydroxy-1,6-diphenyl hexan-2-yl]-3-methyl-2-(2-oxo-1,3-diazinan-1-yl)butan- amide. Two of the impurities are regioisomers and GCOSY used to differentiate the two structures. The spectral assignments for all six impurities were achieved by concerted application of one and two-dimensional NMR techniques ((1)H NMR, (13)C NMR, DEPT, GCOSY, GHSQC and GHMBC). Copyright (c) 2007 John Wiley & Sons, Ltd.

Mammalian pheromones VIII Chemical characterization of preorbital gland secretion of grey duiker,Sylvicapra grimmia (Artiodactyla: Bovidae).

PubMed

Burger, B V; Pretorius, P J; Spies, H S; Bigalke, R C; Grierson, G R

1990-02-01

Using gas chromatography-mass spectrometry 33 constituents of the preorbital gland of the grey duiker,Sylvicapra grimmia, were identified as unbranched alkanes, 2-alkanones, alkanals, alkanoic acids, alkan-4-olides, as well as 3-methyl-3-buten-1-ol, (Z)-9-octadecenoic acid, benzyl cyanide, diethyl sulfoxide, 2-isobutyl-1,3-thiazole, 2-isobutyl-4,5-dihydro-1,3-thiazole, and 3,4-epoxy-2-dodecanone. Determination of the relative concentrations of these components in a limited number of secretion samples taken from males and females revealed that in these samples the two thiazole derivatives and the epoxy ketone were present in consistently and significantly higher concentrations in male than in female secretions. This suggests that they could act as sex recognition cues.

16 CFR 1210.5 - Findings.

Code of Federal Regulations, 2010 CFR

2010-01-01

... percent of all lighters sold are pocket-sized disposable butane models; of the remaining 5 percent, most are pocket refillable butane models. A small proportion of refillables is comprised of pocket liquid-fuel models; still smaller proportions are represented by table lighters and by “novelty” lighters...

The Microwave Spectrum of Methyl Vinyl Ketone Revisited

NASA Astrophysics Data System (ADS)

Wilcox, David S.; Shirar, Amanda J.; Williams, Owen L.; Dian, Brian C.

2011-06-01

A chirped-pulse Fourier transform microwave spectrometer was used to record the rotational spectrum of methyl vinyl ketone (MVK, 3-butene-2-one) from 6 to 18.9 GHz. Two stable conformations were identified: the previously documented antiperiplanar (ap) conformer and synperiplanar (sp), which is reported for the first time in this microwave study. Methyl torsional analysis with XIAM resulted in V3 barrier heights of 433.8(1) and 376.6(2) Cm-1 for ap- and sp-MVK, respectively. Heavy atom isotopic species were detected in natural abundance allowing bond lengths and angles of the molecular frames to be calculated through Kraitchman analysis. A comparison with ab initio calculations is included.

RUTHENIUM-CATALYZED TANDEM OLEFIN MIGRATION-ALDOL AND MANNICH-TYPE REACTIONS IN IONIC LIQUID.

EPA Science Inventory

In the presence of a catalytic amount of RuCl2(PPh3)3, a cross-coupling of 3-buten-2-ol with aldehydes and imines was developed via a tandem olefin migration--aldol--Mannich reaction in bmim[PF6]. With In(OAc)3 as a co-catalyst, a-vinylbenzyl alcohol and aldehydes underwent sim...

A sputtering derived atomic oxygen source for studying fast atom reactions

NASA Technical Reports Server (NTRS)

Ferrieri, Richard A.; Yung, Y. Chu; Wolf, Alfred P.

1987-01-01

A technique for the generation of fast atomic oxygen was developed. These atoms are created by ion beam sputtering from metal oxide surfaces. Mass resolved ion beams at energies up to 60 KeV are produced for this purpose using a 150 cm isotope separator. Studies have shown that particles sputtered with 40 KeV Ar(+) on Ta2O5 were dominantly neutral and exclusively atomic. The atomic oxygen also resided exclusively in its 3P ground state. The translational energy distribution for these atoms peaked at ca 7 eV (the metal-oxygen bond energy). Additional measurements on V2O5 yielded a bimodal distribution with the lower energy peak at ca 5 eV coinciding reasonably well with the metal-oxygen bond energy. The 7 eV source was used to investigate fast oxygen atom reactions with the 2-butene stereoisomers. Relative excitation functions for H-abstraction and pi-bond reaction were measured with trans-2-butene. The abstraction channel, although of minor relative importance at thermal energy, becomes comparable to the addition channel at 0.9 eV and dominates the high-energy regime. Structural effects on the specific channels were also found to be important at high energy.

Cost effective propulsion systems for small satellites using butane propellant

NASA Astrophysics Data System (ADS)

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

2002-07-01

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

40 CFR 80.75 - Reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... section: (i) The batch number; (ii) The date of production; (iii) The volume of the batch; (iv) The grade... the refinery: (A) Identification of the previously certified gasoline as such; (B) The batch number... batch as commercial or non-commercial grade butane; (C) The batch number of the butane; (D) The date of...

Histrionicotoxins: roentgen-ray analysis of the novel allenic and acetylenie spiroalkaloids isolated from a Colombian frog, Dendrobates histrionicus.

PubMed

Daly, J W; Karle, I; Myers, C W; Tokuyama, T; Waters, J A; Witkop, B

1971-08-01

The structures and absolute configuration of two unique alkaloids isolated from the Colombian frog, Dendrobates histrionicus, have been elucidated by Roentgen-ray (x-ray) crystallography. Histrionicotoxin is (2pR, 6S, 7pS, 8aS)-7-(cis-1-buten-3-ynyl)-8-hydroxy-2-(cis-2-penten-4- ynyl)-1-azaspiro[5.5] undecane, while in dihydro-isohistrionicotoxin the acetylenic 2-pentenynyl side chain is replaced by an allenic 2-(3,4 pentadienyl) substituent. Dendrobates histrionicus exhibits remarkable interpopulational variations in amounts and composition of skin toxins, in behavior, and in phenotypic characters, aspects of which are illustrated in a color plate. The histrionico-toxins are the third class of alkaloids isolated from the defensive skin secretions of Neotropical (Dendrobatidae) frogs.

Process optimization and characterization of fragrant oil from red pepper (Capsicum annuum L.) seed extracted by subcritical butane extraction.

PubMed

Gu, Ling-Biao; Pang, Hui-Li; Lu, Ke-Ke; Liu, Hua-Min; Wang, Xue-De; Qin, Guang-Yong

2017-04-01

Red pepper seeds account for 450-500 g kg -1 of the total pepper weight and are often discarded as waste. In this study, process optimization and characterization of fragrant oil from roasted red pepper seed extracted by subcritical butane extraction were carried out. The optimal conditions of extraction were a temperature of 74.61 °C, a time of 68.65 min and a liquid/solid ratio of 30.24:1. The oil had a refractive index (25 °C) of 1.471, a relative density of 0.900, an acid value of 1.421 mg g -1 oil, an iodine value of 127.035 g per 100 g, a saponification value of 184.060 mg KOH g -1 , an unsaponifiable matter content of 12.400 g kg -1 , a peroxide value of 2.465 meq. O 2 kg -1 and a viscosity of 52.094 cP. The main fatty acids in the oil were linoleic acid (72.95%) followed by palmitic acid (11.43%) and oleic acid (10.00%). The oil showed desirable thermal and oxidative stability. A total of 19 volatile compounds, mostly aldehydes and alkenes, were identified from the oil. The results indicated that the method is appropriate for the preparation of fragrant red pepper seed oil, and the oil is suitable for used as edible oil. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

EXTENDED ALKYLATE PRODUCTION ACTIVITY DURING FIXED-BED SUPERCRITICAL 1-BUTENE/ISOBUTANE ALKYLATION ON SOLID ACID CATALYSTS USING CARBON DIOXIDE AS DILUENT. (R824729)

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...

Sensory and chemical changes in tomato sauces during storage.

PubMed

Landy, Pascale; Boucon, Claire; Kooyman, Gonnie M; Musters, Pieter A D; Rosing, Ed A E; De Joode, Teun; Laan, Jan; Haring, Peter G M

2002-05-22

The present work aimed to identify the key odorants of tomato sauces responsible for the flavor change during storage. Products made from paste or canned tomatoes were stored at 25 and 40 degrees C. Sensory properties and quantification of the key odorants were measured and correlated. Significant sensory changes appeared after 1 and 3 months at 25 degrees C in the respective dice and paste sauces (p < 0.01). The dice sauce was characterized by a steep loss of the sensory quality during the early storage and then by identical changes within the same time span at 25 and 40 degrees C. In the paste sauce the sensory deterioration was slower than for the dice sauce and occurred more extensively at 40 degrees C than at 25 degrees C. Correlation between sensory and instrumental data revealed that the source of sensory changes should be (E,E)-deca-2,4-dienal in the dice sauce. The sensory change in the paste sauce could be due to acetaldehyde, methylpropanal, 3-methylbutanal, oct-1-en-3-one, 3-methylbutanoic acid, deca-2,4-dienal, 2-methoxyphenol, and beta-damascenone.

Microgravity

NASA Image and Video Library

2001-01-24

The Laminar Soot Processes (LSP) experiment under way during the Microgravity Sciences Lab-1 mission in 1997. LSP-2 will fly in the STS-107 Research 1 mission in 2001. The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner, similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a temperature sensor, and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

Microgravity

NASA Image and Video Library

2001-01-24

Image of soot (smoke) plume made for the Laminar Soot Processes (LSP) experiment during the Microgravity Sciences Lab-1 mission in 1997. LSP-2 will fly in the STS-107 Research 1 mission in 2002. The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner, similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a temperature sensor, and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

Laminar Soot Processes

NASA Technical Reports Server (NTRS)

2001-01-01

The Laminar Soot Processes (LSP) experiment under way during the Microgravity Sciences Lab-1 mission in 1997. LSP-2 will fly in the STS-107 Research 1 mission in 2001. The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner, similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a temperature sensor, and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

A widely-tunable and sensitive optical sensor for multi-species detection in the mid-IR

NASA Astrophysics Data System (ADS)

Alquaity, Awad B. S.; Al-Saif, Bidoor; Farooq, Aamir

2018-01-01

Pulsed cavity ringdown spectroscopy (CRDS) technique was used to develop a novel widely-tunable laser-based sensor for sensitive measurements of ethylene, propene, 1-butene and allene in the mid-IR. The use of an external-cavity quantum cascade laser (EC-QCL) enabled the sensor to cover a wide wavelength range from 10 to 11.1 µm (900-1000 cm-1) to detect multiple gases relevant to combustion and environment. The sensor operation was validated in a room-temperature static cell using well-characterized absorption lines of carbon dioxide near 938.69 cm-1 and 974.62 cm-1. Detection limits for ethylene, propene, 1-butene, and allene were measured to be 17, 134, 754 and 378 ppb, respectively, at 296 K and 760 Torr for a single-pass path-length of 70 cm with averaging time of 4 ms. The excellent sensitivity of the optical sensor enabled it to measure the aforementioned gases at levels smaller than 1% of their recommended exposure limits. To the best of our knowledge, this is one of the first successful applications of the pulsed CRDS technique to measure trace levels of multiple gases in the 10-11 µm wavelength region.

Geologic Emissions of Methane and C2 - C5 Alkanes at the La Brea Tar Pits, Los Angeles, CA

NASA Astrophysics Data System (ADS)

Doezema, L. A.; Etiope, G.; Pacheco, C.

2017-12-01

Natural hydrocarbon (oil and gas) seeps are widespread in Los Angeles due to gas migration, along faults, from numerous subsurface petroleum fields. These seeps may represent important natural contributors of methane (CH4) and heavier alkanes (C2-C4) for the atmosphere. Methane flux measurements were made from various locations at the La Brea Tar Pits in Los Angeles, CA. Measurements were made using a closed-chamber method and spectroscopic sensors for CH4 and CO2, at 26 oil-asphalt seeps and 188 other sites, without gas manifestations, homogeneously distributed throughout the park. The molecular C1 - C5 composition of gas released from seeps and soil was also analyzed using either FTIR spectroscopy or gas chromatography (GC-FID). Methane emissions from seeps varied from approximately 7 to 54,000 g m-2 day-1, while emissions from soil degassing were between 0 and 9,000 g m-2 day-1. Total emissions were estimated to be in the order of 103 kg day-1 for methane, and at least 10 and 5 kg day-1 for ethane and propane, respectively. The seeping gas exhibited high C1/(C2 + C3) ratios, likely due to molecular fractionation during gas migration from a subsurface petroleum reservoir. Evidence for biodegredation in certain samples was indicated by large i-butane to n-butane ratios. These molecular alterations can be important tracers of natural seepage and should be considered in the atmospheric modelling of the relative contribution of fossil fuel (anthropogenic fugitive emission and natural geologic sources) vs biogenic sources, on local and global scales.

A series of divalent metal coordination polymers based on isomeric tetracarboxylic acids: synthesis, structures and magnetic properties.

PubMed

Han, Min-Le; Duan, Ya-Ping; Li, Dong-Sheng; Xu, Guo-Wang; Wu, Ya-Pan; Zhao, Jun

2014-12-14

Five new coordination polymers, namely, [Mn(2,2′-bipy)(H2O)2(H2L1)]n (1), {[Co(btb)(H2O)2(H2L1)]·0.5H2O}n (2), [Co(bib)(H2O)2(H2L1)]n (3), [Ni2(bpm)(H2O)3(L2)]n (4), and {[Co2(H2O)3(OH)(HL2)]·H2O}n (5), (H4L1 = 1,1′:2′,1′′-terphenyl-4,4′,4′′,5′-tetracarboxylic acid, H4L2 = 1,1′:2′,1′′-terphenyl-3,3′′,4′,5′-tetracarboxylic acid, 2,2′-bipy = 2,2′-bipyridine, btb = 1,4-bis(1,2,4-triazol-1-yl)butane, bib = 1,4-bis(imidazol-1-yl)butane, bpm = bis(4-pyridyl)amine), have been obtained under hydrothermal conditions. Complex 1 exhibits a 3D supramolecular framework based on 1D chains. Both complexes 2 and 3 are 3D supramolecular frameworks constructed from 1D zig-zag chains. Complex 4 features a 3D tetra-nodal (3,4,4,5)-connected architecture containing 1D μ-COO bridged chains with (5(2)·6(2)·7.9)(5(2)·6(4)·7(3)·8)2(5(2)·6)2(6(3)·7(2)·9) topology. Complex 5 shows a 3D penta-nodal (3,4,4,6,6)-connected net containing 1D μ-OH/μ-COO bridged chains and mononuclear Co(II) nodes with a (4(2)·6(3)·8)(4(3))2(4(4)·6(2))2(4(4)·6(6)·8(5))2(4(4)·6(7)·8(4)) topology. Variable-temperature magnetic susceptibility measurements reveal that complexes 2 and 3 show antiferromagnetic interactions between the adjacent Co(II) ions, whereas 4 is a ferromagnetic system.

A novel triterpenoid carbon skeleton in immature sulphur-rich sediments

NASA Astrophysics Data System (ADS)

Schouten, Stefan; Sinninghe Damsté, Jaap S.; de Leeuw, Jan W.

1995-03-01

A novel S compound, 1,4-bis(2',5',5',8a'-tetramethylhexahydrothiochroman)-butane has been detected in several immature S-rich sediments, of which the desulphurized counterpart was unambiguously identified by synthesis of an authentic standard and coinjection experiments. This C skeleton of the S compound, 1,10-bis(2',2',6'-trimethylcyclohexyl)-3,8-dimethyldodecane(I), has not been reported yet in any sediment or organism. We suggest that it may be biosynthesized through an enzymatic cyclization reaction of squalene (II), which shows similarities with the biosynthesis of β,β-carotene (III) from lycopene (IV).

Laminar Soot Processes

NASA Technical Reports Server (NTRS)

2001-01-01

Interior of the Equipment Module for the Laminar Soot Processes (LSP-2) experiment that fly in the STS-107 Research 1 mission in 2002 (LSP-1 flew on Microgravity Sciences Lab-1 mission in 1997). The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner (yellow ellipse), similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a radiometer or heat sensor (blue circle), and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

Microgravity

NASA Image and Video Library

2001-01-24

Interior of the Equipment Module for the Laminar Soot Processes (LSP-2) experiment that fly in the STS-107 Research 1 mission in 2002 (LSP-1 flew on Microgravity Sciences Lab-1 mission in 1997). The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner (yellow ellipse), similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a radiometer or heat sensor (blue circle), and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

Addressing the selectivity issue of cobalt doped zinc oxide thin film iso-butane sensors: Conductance transients and principal component analyses

NASA Astrophysics Data System (ADS)

Ghosh, A.; Majumder, S. B.

2017-07-01

Iso-butane (i-C4H10) is one of the major components of liquefied petroleum gas which is used as fuel in domestic and industrial applications. Developing chemi-resistive selective i-C4H10 thin film sensors remains a major challenge. Two strategies were undertaken to differentiate carbon monoxide, hydrogen, and iso-butane gases from the measured conductance transients of cobalt doped zinc oxide thin films. Following the first strategy, the response and recovery transients of conductances in these gas environments are fitted using the Langmuir adsorption kinetic model to estimate the heat of adsorption, response time constant, and activation energies for adsorption (response) and desorption (recovery). Although these test gases have seemingly different vapor densities, molecular diameters, and reactivities, analyzing the estimated heat of adsorption and activation energies (for both adsorption and desorption), we could not differentiate these gases unequivocally. However, we have found that the lower the vapor density, the faster the response time irrespective of the test gas concentration. As a second strategy, we demonstrated that feature extraction of conductance transients (using fast Fourier transformation) in conjunction with the pattern recognition algorithm (principal component analysis) is more fruitful to address the cross-sensitivity of Co doped ZnO thin film sensors. We have found that although the dispersion among different concentrations of hydrogen and carbon monoxide could not be avoided, each of these three gases forms distinct clusters in the plot of principal component 2 versus 1 and therefore could easily be differentiated.

Synthesis of carbon nanoparticles from commercially available liquified petroleum gas

NASA Astrophysics Data System (ADS)

Nandiyanto, A. B. D.; Fadhlulloh, M. A.; Rahman, T.; Mudzakir, A.

2016-04-01

The aim of this study was to synthesize carbon nanoparticles (CNPs) from commercially available liquefied petroleum gas (LPG). In the research procedure, LPG was reacted with air to construct CNPs. To confirm the successful synthesis of CNPs, we conducted several sample analyses: Gas Chromatography-Mass Spectrometry (GC-MS), Transmission Electron Microscope (TEM), X-ray Diffraction (XRD), and Infrared Spectra (FTIR). We also varied LPG and oxygen mole ratios at 0.8; 2.4; 4.8; and 7.2. The GC-MS results indicated the composition of LPG was propane (58.90%), isobutane (18.35%), butane (22.26%), and butane, 2-methyl (0.48%). The TEM results showed that the particles were spheres with sizes of between 25 and 35 nm. The sizes of particles were controllable, depending on the mole ratio. The XRD results showed mole ratios of LPG and oxygen of 0.80 and 2.40 were natural graphite, whereas the mole ratios of 4.80 and 7.20 were hexagonal graphite. FT-IR results showed CNPs have absorption peaks at wave number (i) 752 (C-H bend sp2); (ii) 835 (C=C); (iii) 1274 (C-O-C vibration); (iv) 1400 and 1600 (C-C stretch aromatic); (v) 2800 (C-H sp2); (vi) 2900 (CH sp3); (vii) 3100 (C-H aromatic); and (viii) 3400 cm-1 (O-H). From the FTIR analysis results, the sample contained allotrope graphite due to detection of peaks at 1400 and 1600 cm-1 (C-C stretch aromatic) and 3100 cm-1 (C-H aromatic).

2-Methyl-3-buten-2-ol (MBO) synthase expression in Nostoc punctiforme leads to over production of phytols.

PubMed

Gupta, Dinesh; Ip, Tina; Summers, Michael L; Basu, Chhandak

2015-01-01

Phytol is a diterpene alcohol of medicinal importance and it also has potential to be used as biofuel. We found over production of phytol in Nostoc punctiforme by expressing a 2-Methyl-3-buten-2-ol (MBO) synthase gene. MBO synthase catalyzes the conversion of dimethylallyl pyrophosphate (DMAPP) into MBO, a volatile hemiterpene alcohol, in Pinus sabiniana. The result of enhanced phytol production in N. punctiforme, instead of MBO, could be explained by one of the 2 models: either the presence of a native prenyltransferase enzyme with a broad substrate specificity, or appropriation of a MBO synthase metabolic intermediate by a native geranyl diphosphate (GDP) synthase. In this work, an expression vector with an indigenous petE promoter for gene expression in the cyanobacterium N. punctiforme was constructed and MBO synthase gene expression was successfully shown using reverse transcriptase (RT)-PCR and SDS-PAGE. Gas chromatography--mass spectrophotometry (GC-MS) was performed to confirm phytol production from the transgenic N. punctiforme strains. We conclude that the expression of MBO synthase in N. punctiforme leads to overproduction of an economically important compound, phytol. This study provides insights about metabolic channeling of isoprenoids in cyanobacteria and also illustrates the challenges of bioengineering non-native hosts to produce economically important compounds.

Color reduction of sulfonated eucalyptus kraft lignin.

PubMed

Zhang, Hui; Bai, Youcan; Zhou, Wanpeng; Chen, Fangeng

2017-04-01

Several eucalyptus lignins named as HSL, SML and BSL were prepared by high temperature sulfonation, sulfomethylation, butane sultone sulfonation respectively. The color properties of samples were investigated. Under optimized conditions the sulfonic group (SO 3 H) content of HSL, SML and BSL reached 1.52, 1.60 and 1.58mmol/g, respectively. Samples were characterized by UV-vis spectroscopy, FTIR spectroscopy, 1 H NMR spectroscopy, GPC and brightness test, respectively. The results revealed that BSL performed a higher molecular weight and lighter color due to the phenolic hydroxyl blocking by 1,4-butane sultone (1,4-BS). The color reduction of sodium borohydride treated BSL (labeled as SBSL) was further enhanced and the brightness value was improved by 76.1% compared with the darkest HSL. SBSL process was much better than HSL and SML process. Hydroxyl blocking effect of 1,4-BS and reducibility of sodium borohydride played important roles in the color reduction of sulfonated eucalyptus kraft lignin. Copyright © 2017 Elsevier B.V. All rights reserved.

Preliminary Work for Identifying and Tracking Combustion Reaction Pathways by Coherent Microwave Mapping of Photoelectrons

DTIC Science & Technology

2016-06-24

wall Radar technique has been built and preliminary results of pyrolysis of iso-butane have been obtained. Qualitative measurements of ethylene in...The (2+1) REMPI ionizations of ethylene (C2H4, 11B3u(π,3p) Rydberg manifold) was selectively induced at 310─325nm. The ethylene was detectable at...quantitative measurements of ethylene as one of the pyrolysis products by using coherent microwave Rayleigh scattering (Radar) from Resonant Enhanced Multi

Quantitation of DNA Adducts Induced by 1,3-Butadiene

NASA Astrophysics Data System (ADS)

Sangaraju, Dewakar; Villalta, Peter W.; Wickramaratne, Susith; Swenberg, James; Tretyakova, Natalia

2014-07-01

Human exposure to 1,3-butadiene (BD) present in automobile exhaust, cigarette smoke, and forest fires is of great concern because of its potent carcinogenicity. The adverse health effects of BD are mediated by its epoxide metabolites such as 3,4-epoxy-1-butene (EB), which covalently modify genomic DNA to form promutagenic nucleobase adducts. Because of their direct role in cancer, BD-DNA adducts can be used as mechanism-based biomarkers of BD exposure. In the present work, a mass spectrometry-based methodology was developed for accurate, sensitive, and precise quantification of EB-induced N-7-(1-hydroxy-3-buten-2-yl) guanine (EB-GII) DNA adducts in vivo. In our approach, EB-GII adducts are selectively released from DNA backbone by neutral thermal hydrolysis, followed by ultrafiltration, offline HPLC purification, and isotope dilution nanoLC/ESI+-HRMS3 analysis on an Orbitrap Velos mass spectrometer. Following method validation, EB-GII lesions were quantified in human fibrosarcoma (HT1080) cells treated with micromolar concentrations of EB and in liver tissues of rats exposed to sub-ppm concentrations of BD (0.5-1.5 ppm). EB-GII concentrations increased linearly from 1.15 ± 0.23 to 10.11 ± 0.45 adducts per 106 nucleotides in HT1080 cells treated with 0.5-10 μM DEB. EB-GII concentrations in DNA of laboratory rats exposed to 0.5, 1.0, and 1.5 ppm BD were 0.17 ± 0.05, 0.33 ± 0.08, and 0.50 ± 0.04 adducts per 106 nucleotides, respectively. We also used the new method to determine the in vivo half-life of EB-GII adducts in rat liver DNA (2.20 ± 0.12 d) and to detect EB-GII in human blood DNA. To our knowledge, this is the first application of nanoLC/ESI+-HRMS3 Orbitrap methodology to quantitative analysis of DNA adducts in vivo.

Structural and physicochemical studies of two key intermediates and the impurity in the new synthesis route of vitamin MK-7

NASA Astrophysics Data System (ADS)

Łaszcz, Marta; Trzcińska, Kinga; Kubiszewski, Marek; Krajewski, Krzysztof

2018-05-01

The MK-7 homologues of vitamin K2 are characterized by the best bioavailability among other K vitamins and act effectively in the treatment of osteoporosis and cardiovascular diseases. In this article comprehensive structural studies of two intermediates 1,4-diethoxy-2-methylnaphtalene (M2) and 1,4-diethoxy-2-methyl-3-[(2E)-3-methyl-4-(phenylsulfonyl)-2-buten-1-yl]naphtalene (M3) from the multi-step synthesis of MK-7 vitamin were described. The compounds crystallize in a monoclinic system in P21/n and P21/c for M2 and M3, respectively. Also, the isomer (2E)-4-chloro-3-methyl-1-(phenylsulfonyl)but-2-ene (M1-E verso) was isolated and the single crystal studies were performed. These three compounds were fully characterized by the 1D and 2D NMR technique as well as by Fourier-transformed infrared and Raman spectroscopies.

Isolation and characterisation of an unexpected byproduct in the regioselective butane diacetal protection of α-methyl galactopyranoside.

PubMed

Fontenelle, Clément Q; Kuppala, Ramakrishna; Light, Mark; Linclau, Bruno

2018-01-02

The regioselective protection of both methyl galactopyranoside anomers at the 2 and 3-positions as the butane diacetal (BDA) is well known. Here we describe the formation of an unexpected byproduct, which mainly occurs when α-methyl galactopyranoside is reacted with 2,3-butanedione under BF 3 •OEt 2 catalysis. The structure of the byproduct, which did not arise from anomerisation to the β-anomer or from BDA formation at the galactopyranoside 3,4-positions, was elucidated by NMR and X-ray crystallographic analysis, and proved to be the expected BDA protected galactopyranoside, but in which the stereochemistry of both its BDA acetal centres are inverted. Interestingly, the conformation of the resulting six-membered BDA ring was distorted to a skew boat conformation in order to maintain anomeric stabilisation. Copyright © 2017. Published by Elsevier Ltd.

KINETIC ANALYSIS OF THE ALKYLATION REACTION OF ISOBUTANE WITH 1-BUTENE ON A SOLID ACID CATALYST IN GAS, LIQUID, AND SUPERCRITICAL REACTION MEDIA. (R826694C669)

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...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Dong; Xu, Pinghong; Browning, Nigel D.

The initial steps of rhodium cluster formation from zeolite-supported mononuclear Rh(C2H4)2 complexes in H2 at 373 K and 1 bar were investigated by infrared and extended X-ray absorption fine structure spectroscopies and scanning transmission electron microscopy (STEM). The data show that ethylene ligands on the rhodium react with H2 to give supported rhodium hydrides and trigger the formation of rhodium clusters. STEM provided the first images of the smallest rhodium clusters (Rh2) and their further conversion into larger clusters. The samples were investigated in a plug-flow reactor as catalysts for the conversion of ethylene + H2 in a molar ratiomore » of 4:1 at 1 bar and 298 K, with the results showing how the changes in catalyst structure affect the activity and selectivity; the rhodium clusters are more active for hydrogenation of ethylene than the single-site complexes, which are more selective for dimerization of ethylene to give butenes« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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)more » 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.« less

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.

Sulforaphane and its methylcarbonyl analogs inhibit the LPS-stimulated inflammatory response in human monocytes through modulating cytokine production, suppressing chemotactic migration and phagocytosis in a NF-κB- and MAPK-dependent manner.

PubMed

Reddy, Shridhivya A; Shelar, Sandeep B; Dang, Truong-Minh; Lee, Baxter Neng-Cun; Yang, Hong; Ong, Siew-Min; Ng, Hui-Li; Chui, Wai-Keung; Wong, Siew-Cheng; Chew, Eng-Hui

2015-02-01

Sulforaphane [SF; 1-isothiocyanato-4-(methylsulfinyl)-butane], an aliphatic isothiocyanate (ITC) naturally derived from cruciferous vegetables and largely known for its chemopreventive potential also appears to possess anti-inflammatory potential. In this study, structural analogs of SF {compound 1 [1-isothiocyanato-4-(methylcarbonyl)-butane] and 2 [1-isothiocyanato-3-(methylcarbonyl)-propane]} containing a carbonyl group in place of the sulfinyl group in SF, were evaluated for their anti-inflammatory activities. In RAW 264.7 cells, the ITCs at non-toxic concentrations caused an inhibition of NO and prostaglandin E2 (PGE2) release through suppressing expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), as well as a reduction in matrix metalloproteinase-9 (MMP-9) expression, secretion and gelatinolytic activity. Further work performed on human monocytes isolated from blood of healthy donors revealed that the ITCs not only suppressed the expression and release of pro-inflammatory mediators IL-1β, IL-6, TNF-α and MMP-9, but also suppressed their antibody-independent phagocytic and chemotactic migratory abilities. These anti-inflammatory activities were mediated through suppression of the NF-κB and MAPK signaling pathways. In addition, the ITCs were revealed to interact with the cysteines in inhibitor of nuclear factor-κB kinase β subunit (IKKβ), which could contribute at least partly to the suppression of NF-κB signaling. In conclusion, results obtained in this study provide deeper insights into the anti-inflammatory properties of SF and its methylcarbonyl analogs and the underlying mechanisms. These compounds thus serve as promising candidates for clinical applications in controlling inflammatory conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Microbial oxidation of gaseous hydrocarbons: production of methylketones from corresponding n-alkanes by methane-utilizing bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, R.N.; Hou, C.T.; Laskin, A.I.

Cell suspensions of methane-utilizing bacteria grown on methane oxidized n-alkanes (propane, butane, pentane, hexane) to their corresponding methylketones (acetone, 2-butanone, 2-pentanone, 2-hexanone). The product methylketones accumulated extracellularly. The rate of production of methylketones varied with the organism used for oxidation; however, the average rate of acetone, 2-butanone, 2-pentanone, and 2-hexanone production was 1.2, 1.0, 0.15, and 0.025 ..mu..mol/h per 5.0 mg of protein in cell suspensions. Primary alcohols and aldehydes were also detected in low amounts as products of n-alkane (propane and butane) oxidation, but were rapidly metabolized further by cell suspensions. The optimal conditions for in vivo methylketone formationmore » from n-alkanes were compared in Methylococcus capsulatus (Texas strain), Methylosinus sp. (CRL-15), and Methylobacterium sp. (CRL-26). The rate of acetone and 2-butanone production was linear for the first 60 min of incubation and directly increased with cell concentration up to 10 mg of protein per ml for all three cultures tested. The optimal temperatures for the production of acetone and 2-butanone were 35/sup 0/C for Methylosinus trichosporium sp. (CRL-15) and Methylobacterium sp. (CRL-26) and 40/sup 0/C for Methylococcus capsulatus (Texas). Metal-chelating agents inhibited the production of methylketones, suggesting the involvement of a metal-containing enzymatic system in the oxidation of n-alkanes to the corresponding methylketones. The soluble crude extracts derived from methane-utilizing bacteria contained an oxidized nicotinamide adenine dinucleotide-dependent dehydrogenase which catalyzed the oxidation of secondary alcohols.« less

Histrionicotoxins: Roentgen-Ray Analysis of the Novel Allenic and Acetylenic Spiroalkaloids Isolated from a Colombian Frog, Dendrobates histrionicus

PubMed Central

Daly, John W.; Karle, Isabella; Myers, Charles W.; Tokuyama, Takashi; Waters, James A.; Witkop, Bernhard

1971-01-01

The structures and absolute configuration of two unique alkaloids isolated from the Colombian frog, Dendrobates histrionicus, have been elucidated by Roentgen-ray (x-ray) crystallography. Histrionicotoxin is (2pR, 6S, 7pS, 8aS)-7-(cis-1-buten-3-ynyl)-8-hydroxy-2-(cis-2-penten-4- ynyl)-1-azaspiro[5.5] undecane, while in dihydro-isohistrionicotoxin the acetylenic 2-pentenynyl side chain is replaced by an allenic 2-(3,4 pentadienyl) substituent. Dendrobates histrionicus exhibits remarkable interpopulational variations in amounts and composition of skin toxins, in behavior, and in phenotypic characters, aspects of which are illustrated in a color plate. The histrionico-toxins are the third class of alkaloids isolated from the defensive skin secretions of Neotropical (Dendrobatidae) frogs. Images PMID:5288773

A selected ion flow tube study of the reactions of H3O+, NO+ and O2+ with some oxygenated biogenic volatile organic compounds

NASA Astrophysics Data System (ADS)

Amelynck, C.; Schoon, N.; Kuppens, T.; Bultinck, P.; Arijs, E.

2005-12-01

The rate constants and product ion distributions of the reactions of H3O+, NO+ and O2+ with 2-methyl-3-buten-2-ol, cis-3-hexen-1-ol, cis-3-hexenyl acetate, 1,8-cineole, 6-methyl-5-hepten-2-one, camphor and linalool have been determined at 150 Pa and 297 K using a selected ion flow tube (SIFT). All reactions were found to proceed at a rate close to the collision rate, calculated with the Su and Chesnavich model, using the polarizability and electric dipole moment of the compounds derived from B3LYP/aug-cc-pVDZ quantum chemical calculations. Additionally the product ion distributions of the reactions of these three ions with the terpenoid alcohols nerol and geraniol have been obtained.

Molybdenum chloride catalysts for Z-selective olefin metathesis reactions

NASA Astrophysics Data System (ADS)

Koh, Ming Joo; Nguyen, Thach T.; Lam, Jonathan K.; Torker, Sebastian; Hyvl, Jakub; Schrock, Richard R.; Hoveyda, Amir H.

2017-01-01

The development of catalyst-controlled stereoselective olefin metathesis processes has been a pivotal recent advance in chemistry. The incorporation of appropriate ligands within complexes based on molybdenum, tungsten and ruthenium has led to reactivity and selectivity levels that were previously inaccessible. Here we show that molybdenum monoaryloxide chloride complexes furnish higher-energy (Z) isomers of trifluoromethyl-substituted alkenes through cross-metathesis reactions with the commercially available, inexpensive and typically inert Z-1,1,1,4,4,4-hexafluoro-2-butene. Furthermore, otherwise inefficient and non-stereoselective transformations with Z-1,2-dichloroethene and 1,2-dibromoethene can be effected with substantially improved efficiency and Z selectivity. The use of such molybdenum monoaryloxide chloride complexes enables the synthesis of representative biologically active molecules and trifluoromethyl analogues of medicinally relevant compounds. The origins of the activity and selectivity levels observed, which contradict previously proposed principles, are elucidated with the aid of density functional theory calculations.

Solar Heating of Buildings and Domestic Hot Water. Revision.

DTIC Science & Technology

1980-05-01

trrladb kfl a’herk Problems Slar. ,rVT urf rfain ol r e luv I Seifae GXJ.roundr pit io of0f’ Coi llecto ma wE cjT’inad akilovrTe F~igure 2-2 3...propane, butane = 95,500 Btu/gal Bituminous coal = 2.46 x 107 Btu/short ton Purchased steam = 1,390 Btu/lb 114 i Oil , No. 2 = 140,000 Btii/gal: 5.84 x 106...may e improved hY t1%111g different Ti anti T. for each month. jl 143 r- --V. -- --... WORKSIII< 1)- I MONTIl I.Y SOLAR ( OIL (TION P.\\RA\\lI- I ’[ , JoIA

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)

Laminar Soot Processes

NASA Technical Reports Server (NTRS)

2001-01-01

Image of soot (smoke) plume made for the Laminar Soot Processes (LSP) experiment during the Microgravity Sciences Lab-1 mission in 1997. LSP-2 will fly in the STS-107 Research 1 mission in 2002. The principal investigator is Dr. Gerard Faeth of the University of Michigan. LSP uses a small jet burner, similar to a classroom butane lighter, that produces flames up to 60 mm (2.3 in) long. Measurements include color TV cameras and a temperature sensor, and laser images whose darkness indicates the quantity of soot produced in the flame. Glenn Research in Cleveland, OH, manages the project.

Identification of Furan Metabolites Derived from Cysteine-cis-2-Butene-1,4-Dial-Lysine Crosslinks

PubMed Central

Lu, Ding; Peterson, Lisa A.

2010-01-01

Furan is a rodent hepatotoxicant and carcinogen. Since this compound is an important industrial intermediate and has been detected in heat-processed foods and smoke, humans are likely exposed to this toxic compound. Characterization of urinary metabolites of furan will lead to the development of biomarkers to assess human health risks associated with furan exposure. Previous studies indicate that furan is oxidized to a reactive α, β-unsaturated dialdehyde, cis-2-butene-1,4-dial (BDA), in a reaction catalyzed by cytochrome P450. Five previously characterized metabolites are derived from the reaction of BDA with cellular nucleophiles such as glutathione and protein. They include the mono-glutathione reaction product, N-[4-carboxy-4-(3-mercapto-1H-pyrrol-1-yl)-1-oxobutyl]-L-cysteinylglycine cyclic sulfide and its downstream metabolite, S-[1-(1,3-dicarboxypropyl)-1H-pyrrol-3-yl]methylthiol as well as R-2-acetylamino-6-(2,5-dihydro-2-oxo-1H-pyrrol-1-yl)-1-hexanoic acid and N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-L-cysteine and its sulfoxide. The last two compounds are downstream metabolites of a BDA-derived cysteine-lysine crosslink, S-[1-(5-amino-5-carboxypentyl)-1H-pyrrol-3-yl]-L-cysteine. In this report, we present the characterization of seven additional urinary furan metabolites, all of which are derived from this crosslink. The cysteinyl residue is subject to several biotransformation reactions, including N-acetylation and S-oxidation. Alternatively, it can undergo β-elimination followed by S-methylation to a methylthiol intermediate that is further oxidized to a sulfoxide. The lysine portion of the crosslink is either N-acetylated or undergoes an oxidative transamination reaction to generate an α-ketoacid metabolite that undergoes oxidative decarboxylation. Some of these metabolites are among the most abundant furan metabolites present in urine as judged by LC-MS/MS analysis, indicating that the oxidation of furan to BDA and BDA’s subsequent reaction with cellular cysteine and lysine residues may represent a significant in vivo pathway of furan biotransformation. Since they are derived from cellular BDA reaction products, these metabolites are markers of furan exposure and bioactivation and could be explored as potential biomarkers in human studies. PMID:20043645

Demonstration of isoleucine 199 as a structural determinant for the selective inhibition of human monoamine oxidase B by specific reversible inhibitors.

PubMed

Hubálek, Frantisek; Binda, Claudia; Khalil, Ashraf; Li, Min; Mattevi, Andrea; Castagnoli, Neal; Edmondson, Dale E

2005-04-22

Several reversible inhibitors selective for human monoamine oxidase B (MAO B) that do not inhibit MAO A have been described in the literature. The following compounds: 8-(3-chlorostyryl)caffeine, 1,4-diphenyl-2-butene, and trans,trans-farnesol are shown to inhibit competitively human, horse, rat, and mouse MAO B with K(i) values in the low micromolar range but are without effect on either bovine or sheep MAO B or human MAO A. In contrast, the reversible competitive inhibitor isatin binds to all known MAO B and MAO A with similar affinities. Sequence alignments and the crystal structures of human MAO B in complex with 1,4-diphenyl-2-butene or with trans,trans-farnesol provide molecular insights into these specificities. These inhibitors span the substrate and entrance cavities with the side chain of Ile-199 rotated out of its normal conformation suggesting that Ile-199 is gating the substrate cavity. Ile-199 is conserved in all known MAO B sequences except bovine MAO B, which has Phe in this position (the sequence of sheep MAO B is unknown). Phe is conserved in the analogous position in MAO A sequences. The human MAO B I199F mutant protein of MAO B binds to isatin (K(i) = 3 microM) but not to the three inhibitors listed above. The crystal structure of this mutant demonstrates that the side chain of Phe-199 interferes with the binding of those compounds. This suggests that the Ile-199 "gate" is a determinant for the specificity of these MAO B inhibitors and provides a molecular basis for the development of MAO B-specific reversible inhibitors without interference with MAO A function in neurotransmitter metabolism.

Future perspectives of using hollow fibers as structured packings in light hydrocarbon distillation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Dali; Orler, Bruce; Tornga, Stephanie

2011-01-26

Olefin and paraffin are the largest chemical commodities. Furthermore, they are major building blocks for the petrochemical industry. Each year, petroleum refining, consumes 4,500 TBtu/yr in separation energy, making it one of the most energy-intensive industries in the United States). Just considering liquefied petroleum gas (ethane/propane/butane) and olefins (ethylene and propylene) alone, the distillation energy consumption is about 400 TBtu/yr in the US. Since petroleum distillation is a mature technology, incremental improvements in column/tray design will only provide a few percent improvements in the performance. However, each percent saving in net energy use amounts to savings of 10 TBtu/yr andmore » reduces CO{sub 2} emissions by 0.2 MTon/yr. In practice, distillation columns require 100 to 200 trays to achieve the desired separation. The height of a transfer unit (HTU) of conventional packings is typical in the range of 36-60 inch. Since 2006, we had explored using several non-selective membranes as the structured packings to replace the conventional packing materials used in propane and propylene distillation. We obtained the lowest HTU of < 8 inch for the hollow fiber column, which was >5 times shorter than that of the conventional packing materials. In 2008, we also investigated this type of packing materials in iso-/n-butane distillation. Because of a slightly larger relative volatility of iso-/n-butane than that of propane/propylene, a wider and a more stable operational range was obtained for the iso-/n-butane pair. However, all of the experiments were conducted on a small scale with flowrate of < 25 gram/min. Recently, we demonstrated this technology on a larger scale (<250 gram/min). Within the loading range of F-factor < 2.2 Pa{sup 0.5}, a pressure drop on the vapor side is below 50 mbar/m, which suggests that the pressure drop of hollow fibers packings is not an engineering barrier for the applications in distillations. The thermal stability study suggests that polypropylene hollow fibers are stable after a long time exposure to C{sub 2} - C{sub 4} mixtures. The effects of packing density on the separation efficiency will be discussed.« less

Quantum chemical modeling of zeolite-catalyzed methylation reactions: toward chemical accuracy for barriers.

PubMed

Svelle, Stian; Tuma, Christian; Rozanska, Xavier; Kerber, Torsten; Sauer, Joachim

2009-01-21

The methylation of ethene, propene, and t-2-butene by methanol over the acidic microporous H-ZSM-5 catalyst has been investigated by a range of computational methods. Density functional theory (DFT) with periodic boundary conditions (PBE functional) fails to describe the experimentally determined decrease of apparent energy barriers with the alkene size due to inadequate description of dispersion forces. Adding a damped dispersion term expressed as a parametrized sum over atom pair C(6) contributions leads to uniformly underestimated barriers due to self-interaction errors. A hybrid MP2:DFT scheme is presented that combines MP2 energy calculations on a series of cluster models of increasing size with periodic DFT calculations, which allows extrapolation to the periodic MP2 limit. Additionally, errors caused by the use of finite basis sets, contributions of higher order correlation effects, zero-point vibrational energy, and thermal contributions to the enthalpy were evaluated and added to the "periodic" MP2 estimate. This multistep approach leads to enthalpy barriers at 623 K of 104, 77, and 48 kJ/mol for ethene, propene, and t-2-butene, respectively, which deviate from the experimentally measured values by 0, +13, and +8 kJ/mol. Hence, enthalpy barriers can be calculated with near chemical accuracy, which constitutes significant progress in the quantum chemical modeling of reactions in heterogeneous catalysis in general and microporous zeolites in particular.

Gas-phase binding energies for non-covalent Aβ-40 peptide/small molecule complexes from CID mass spectrometry and RRKM theory.

PubMed

Mayer, Paul M; Martineau, Eric

2011-03-21

The gas-phase binding of small molecules to the Amyloid β-40 peptide generated by electrospray ionization has been explored with collision-induced dissociation mass spectrometry and kinetic rate theory. This study discusses a simple procedure used to theoretically model the experimental breakdown diagrams for the Aβ-40 peptide complexed with a series of aminosulfonate small molecules, namely homotaurine, 3-cyclohexylamino-2-hydroxy-1-propanesulfonic acid (CAPSO), 3-(1,3,4,9-tetrahydro-2H-β-carbolin-2-yl)propane-1-sulfonic acid, 3-(1,3,4,9-tetrahydro-2H-β-carbolin-2-yl)butane-1-sulfonic acid, and 3-(cyclohexylamino)propane-1-sulfonic acid. An alternative procedure employing an extrapolation procedure for k(E) is also discussed.

Vibrations At Surfaces During Heterogeneous Catalytic Reactions

NASA Astrophysics Data System (ADS)

Aragno, A.; Basini, Luca; Marchionna, M.; Raffaelli, A.

1989-12-01

FTIR spectroscopies can be used in a wide range of temperature and pressure conditions to investigate on the chemistry and the physics of heterogeneous catalytic reactions. In this paper we have shortly discussed the spectroscopic results obtained during the study of two different reactions; the skeletal isomerization of 1-butene to obtain 2-methylpropene and the surface aggregation and fragmentation of rhodium carbonyl complexes during thermal treatments in N2, H2, CO, CH4 atmospheres. In the first case high temperature proton tran-sfer reactions are proposed to be responsible for the skeletal isomerization reaction. In the second case our experiments have shown a partial reversibility of the nucleation processes at the surfaces and revealed a low temperature reactivity of methane on rhodium car-bonyl surface complexes.

[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.

VOCs emission characteristics and priority control analysis based on VOCs emission inventories and ozone formation potentials in Zhoushan

NASA Astrophysics Data System (ADS)

Wang, Qiaoli; Li, Sujing; Dong, Minli; Li, Wei; Gao, Xiang; Ye, Rongmin; Zhang, Dongxiao

2018-06-01

Zhoushan is an island city with booming tourism and service industry, but also has many developed VOCs and/or NOX emission industries. It is necessary to carry out regional VOCs and O3 pollution control in Zhoushan as the only new area owns the provincial economic and social administration rights. Anthropogenic VOCs emission inventories were built based on emission factor method and main emission sources were identified according to the emission inventories. Then, localized VOCs source profiles were built based on in-site sampling and referring to other studies. Furthermore, ozone formation potentials (OFPs) profiles were built through VOCs source profiles and maximum incremental reactivity (MIR) theory. At last, the priority control analysis results showed that industrial processes, especially surface coating, are the key of VOCs and O3 control. Alkanes were the most emitted group, accounting for 58.67%, while aromatics contributed the most to ozone production accounting for 69.97% in total OFPs. n-butane, m/p-xylene, i-pentane, n-decane, toluene, propane, n-undecane, o-xylene, methyl cyclohexane and ethyl benzene were the top 10 VOC species that should be preferentially controlled for VOCs emission control. However, m/p-xylene, o-xylene, ethylene, n-butane, toluene, propene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene, ethyl benzene and 1,2,3-trimethyl benzene were the top 10 VOC species that required preferential control for O3 pollution control.

2,2'-[2,4-Bis(naphthalen-1-yl)cyclo-butane-1,3-di-yl]bis-(1-methyl-pyridinium) diiodide: thermal-induced [2 + 2] cyclo-addition reaction of a heterostilbene.

PubMed

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

2012-01-01

The asymmetric unit of the title compound, C(36)H(32)N(2) (2+)·2I(-), consists of one half-mol-ecule of the cation and one I(-) anion. The cation is located on an inversion centre. The dihedral angle between the pyridinium ring and the naphthalene ring system in the asymmetric unit is 19.01 (14)°. In the crystal, the cations and the anions are linked by C-H⋯I inter-actions into a layer parallel to the bc plane. Intra- and inter-molecular π-π inter-actions with centroid-centroid distances of 3.533 (2)-3.807 (2) Å are also observed.

Analysis of aldehydes in beer by gas-diffusion microextraction: characterization by high-performance liquid chromatography-diode-array detection-atmospheric pressure chemical ionization-mass spectrometry.

PubMed

Gonçalves, Luís Moreira; Magalhães, Paulo Jorge; Valente, Inês Maria; Pacheco, João Grosso; Dostálek, Pavel; Sýkora, David; Rodrigues, José António; Barros, Aquiles Araújo

2010-06-11

In this work, a recently developed extraction technique for sample preparation aiming the analysis of volatile and semi-volatile compounds named gas-diffusion microextraction (GDME) is applied in the chromatographic analysis of aldehydes in beer. Aldehydes-namely acetaldehyde (AA), methylpropanal (MA) and furfural (FA)-were simultaneously extracted and derivatized with 2,4-dinitrophenylhydrazine (DNPH), then the derivatives were separated and analyzed by high-performance liquid chromatography with spectrophotometric detection (HPLC-UV). The identity of the eluted compounds was confirmed by high-performance liquid chromatography-atmospheric pressure chemical ionization-mass-spectrometry detection in the negative ion mode (HPLC-APCI-MS). The developed methodology showed good repeatability (ca. 5%) and linearity as well as good limits of detection (AA-12.3, FA-1.5 and MA 5.4microgL(-1)) and quantification (AA-41, FA-4.9 and MA 18microgL(-1)); it also appears to be competitive in terms of speed and cost of analysis. Copyright 2010 Elsevier B.V. All rights reserved.

Near-infrared incoherent broadband cavity enhanced absorption spectroscopy (NIR-IBBCEAS) for detection and quantification of natural gas components.

PubMed

Prakash, Neeraj; Ramachandran, Arun; Varma, Ravi; Chen, Jun; Mazzoleni, Claudio; Du, Ke

2018-06-28

The principle of near-infrared incoherent broadband cavity enhanced absorption spectroscopy was employed to develop a novel instrument for detecting natural gas leaks as well as for testing the quality of natural gas mixtures. The instrument utilizes the absorption features of methane, butane, ethane, and propane in the wavelength region of 1100 nm to 1250 nm. The absorption cross-section spectrum in this region for methane was adopted from the HITRAN database, and those for the other three gases were measured in the laboratory. A singular-value decomposition (SVD) based analysis scheme was employed for quantifying methane, butane, ethane, and propane by performing a linear least-square fit. The developed instrument achieved a detection limit of 460 ppm, 141 ppm, 175 ppm and 173 ppm for methane, butane, ethane, and propane, respectively, with a measurement time of 1 second and a cavity length of 0.59 m. These detection limits are less than 1% of the Lower Explosive Limit (LEL) for each gas. The sensitivity can be further enhanced by changing the experimental parameters (such as cavity length, lamp power etc.) and using longer averaging intervals. The detection system is a low-cost and portable instrument suitable for performing field monitorings. The results obtained on the gas mixture emphasize the instrument's potential for deployment at industrial facilities dealing with natural gas, where potential leaks pose a threat to public safety.

Emission of Methane and Heavier Alkanes From the La Brea Tar Pits Seepage Area, Los Angeles

NASA Astrophysics Data System (ADS)

Etiope, G.; Doezema, L. A.; Pacheco, C.

2017-11-01

Natural hydrocarbon (oil and gas) seeps are widespread in Los Angeles, California, due to gas migration, along faults, from numerous subsurface petroleum fields. These seeps may represent important natural contributors of methane (CH4) and heavier alkanes (C2-C4) to the atmosphere, in addition to anthropogenic fossil fuel and biogenic sources. We measured the CH4 flux by closed-chamber method from the La Brea Tar Pits park (0.1 km2), one of the largest seepage sites in Los Angeles. The gas seepage occurs throughout the park, not only from visible oil-asphalt seeps but also diffusely from the soil, affecting grass physiology. About 500 kg CH4 d-1 is emitted from the park, especially along a belt of enhanced degassing that corresponds to the 6th Street Fault. Additional emissions are from bubble plumes in the lake within the park (order of 102-103 kg d-1) and at the intersection of Wilshire Boulevard and Curson Avenue (>130 kg d-1), along the same fault. The investigated area has the highest natural gas flux measured thus far for any onshore seepage zone in the USA. Gas migration, oil biodegradation, and secondary methanogenesis altered the molecular composition of the original gas accumulated in the Salt Lake Oil Field (>300 m deep), leading to high C1/C2+ and i-butane/n-butane ratios. These molecular alterations can be important tracers of natural seepage and should be considered in the atmospheric modeling of the relative contribution of fossil fuel (anthropogenic fugitive emission and natural geologic sources) versus biogenic sources of methane, on local and global scales.

Theoretical Kinetics Analysis for Ḣ Atom Addition to 1,3-Butadiene and Related Reactions on the Ċ4H7 Potential Energy Surface.

PubMed

Li, Yang; Klippenstein, Stephen J; Zhou, Chong-Wen; Curran, Henry J

2017-10-12

The oxidation chemistry of the simplest conjugated hydrocarbon, 1,3-butadiene, can provide a first step in understanding the role of polyunsaturated hydrocarbons in combustion and, in particular, an understanding of their contribution toward soot formation. On the basis of our previous work on propene and the butene isomers (1-, 2-, and isobutene), it was found that the reaction kinetics of Ḣ-atom addition to the C═C double bond plays a significant role in fuel consumption kinetics and influences the predictions of high-temperature ignition delay times, product species concentrations, and flame speed measurements. In this study, the rate constants and thermodynamic properties for Ḣ-atom addition to 1,3-butadiene and related reactions on the Ċ 4 H 7 potential energy surface have been calculated using two different series of quantum chemical methods and two different kinetic codes. Excellent agreement is obtained between the two different kinetics codes. The calculated results including zero-point energies, single-point energies, rate constants, barrier heights, and thermochemistry are systematically compared among the two quantum chemical methods. 1-Methylallyl (Ċ 4 H 7 1-3) and 3-buten-1-yl (Ċ 4 H 7 1-4) radicals and C 2 H 4 + Ċ 2 H 3 are found to be the most important channels and reactivity-promoting products, respectively. We calculated that terminal addition is dominant (>80%) compared to internal Ḣ-atom addition at all temperatures in the range 298-2000 K. However, this dominance decreases with increasing temperature. The calculated rate constants for the bimolecular reaction C 4 H 6 + Ḣ → products and C 2 H 4 + Ċ 2 H 3 → products are in excellent agreement with both experimental and theoretical results from the literature. For selected C 4 species, the calculated thermochemical values are also in good agreement with literature data. In addition, the rate constants for H atom abstraction by Ḣ atoms have also been calculated, and it is found that abstraction from the central carbon atoms is the dominant channel (>70%) at temperatures in the range of 298-2000 K. Finally, by incorporating our calculated rate constants for both Ḣ atom addition and abstraction into our recently developed 1,3-butadiene model, we show that laminar flame speed predictions are significantly improved, emphasizing the value of this study.

One-step production of long-chain hydrocarbons from waste-biomass-derived chemicals using bi-functional heterogeneous catalysts.

PubMed

Wen, Cun; Barrow, Elizabeth; Hattrick-Simpers, Jason; Lauterbach, Jochen

2014-02-21

In this study, we demonstrate the production of long-chain hydrocarbons (C8+) from 2-methylfuran (2MF) and butanal in a single step reactive process by utilizing a bi-functional catalyst with both acid and metallic sites. Our approach utilizes a solid acid for the hydroalkylation function and as a support as well as a transition metal as hydrodeoxygenation catalyst. A series of solid acids was screened, among which MCM-41 demonstrated the best combination of activity and stability. Platinum nanoparticles were then incorporated into the MCM-41. The Pt/MCM-41 catalyst showed 96% yield for C8+ hydrocarbons and the catalytic performance was stable over four reaction cycles of 20 hour each. The reaction pathways for the production of long-chain hydrocarbons is probed with a combination of infrared spectroscopy and steady-state reaction experiments. It is proposed that 2MF and butanal go through hydroalkylation first on the acid site followed by hydrodeoxygenation to produce the hydrocarbon fuels.

Identification and physicochemical characterization of 4-fluorobutyrfentanyl (1-((4-fluorophenyl)(1-phenethylpiperidin-4-yl)amino)butan-1-one, 4-FBF) in seized materials and post-mortem biological samples.

PubMed

Rojkiewicz, Marcin; Majchrzak, Milena; Celiński, Rafał; Kuś, Piotr; Sajewicz, Mieczysław

2017-03-01

During the last decade, a substantial growth in new psychoactive substances (NPS) has been recorded. Within this group, a considerably fast-growing sub-group is represented by the opioids, which are based on modifications of the fentanyl structure. In this study, identification and analytical characterization of a new fentanyl derivative, 4-fluorobutyrfentanyl (1-((4-fluorophenyl)(1-phenethylpiperidin-4-yl)amino)butan-1-one, 4-FBF), is described. Apart from the seized powder, 4-FBF was also identified in the e-cigarette liquid secured in Case 1. The concentration of the compound in the liquid was 35 mg/mL. The main component of the liquid was glycerol, and nicotine was also present. This substance was detected in seized material that originated from the illegal drug market in Poland. To the best of the authors' knowledge, this report presents the first two analytically confirmed cases of fatal intoxication associated with 4-FBF. Case 1 was a 26-year-old male drug user who was found dead at home. Case 2 was a 25-year-old female, occasional user of NPS and drugs, who was also found dead at home. The concentrations of 4-FBF in blood were 91 and 112 ng/mL and in urine 200 and 414 ng/mL. The concentrations of 4-FBF in liver and kidney were 902 and 411 ng/g, and 136 and 197 ng/g, for Case 1 and Case 2, respectively. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

(E)-2-[(E)-3-(Hy-droxy-imino)-butan-2-yl-idene]-N-methyl-hydrazinecarbothio-amide.

PubMed

Abduelftah, Halema Shaban; Ali, Amna Qasem; Eltayeb, Naser Eltaher; Teoh, Siang Guan; Fun, Hoong-Kun

2012-01-01

In the title compound, C(6)H(12)N(4)OS, an intra-molecular N-H⋯N hydrogen-bond is present giving rise to an S(5) ring motif. In the crystal, double-stranded chains propagating along [10[Formula: see text

Structure of Titan's evaporites

NASA Astrophysics Data System (ADS)

Cordier, D.; Cornet, T.; Barnes, J. W.; MacKenzie, S. M.; Le Bahers, T.; Nna-Mvondo, D.; Rannou, P.; Ferreira, A. G.

2016-05-01

Numerous geological features that could be evaporitic in origin have been identified on the surface of Titan. Although they seem to be water-ice poor, their main properties - chemical composition, thickness, stratification - are essentially unknown. In this paper, which follows on a previous one focusing on the surface composition (Cordier, D., Barnes, J.W., Ferreira, A.G. [2013b]. Icarus 226(2),1431-1437), we provide some answers to these questions derived from a new model. This model, based on the up-to-date thermodynamic theory known as ;PC-SAFT;, has been validated with available laboratory measurements and specifically developed for our purpose. 1-D models confirm the possibility of an acetylene and/or butane enriched central layer of evaporitic deposit. The estimated thickness of this acetylene-butane layer could explain the strong RADAR brightness of the evaporites. The 2-D computations indicate an accumulation of poorly soluble species at the deposit's margin. Among these species, HCN or aerosols similar to tholins could play a dominant role. Our model predicts the existence of chemically trimodal ;bathtub rings; which is consistent with what it is observed at the south polar lake Ontario Lacus. This work also provides plausible explanations to the lack of evaporites in the south polar region and to the high radar reflectivity of dry lakebeds.

Synthesis, spectral, thermal, X-ray single crystal of new RuCl₂(dppb)diamine complexes and their application in hydrogenation of Cinnamic aldehyde.

PubMed

Warad, Ismail; Al-Hussain, Hanan; Al-Far, Rawhi; Mahfouz, Refaat; Hammouti, Belkheir; Hadda, Taibi Ben

2012-09-01

The preparation of new three trans-[RuCl(2)(dppb)(N-N)] with mixed diamine (N-N) and 1,4-bis-(diphenylphosphino)butane (dppb) ligands, starting from RuCl(2)(PPh(3))(3) as precursor is presented. The complexes are characterized on the basis of elemental analysis, IR, (1)H, (13)C and (31)P{(1)H}NMR, FAB-MS, TG/DTA and single crystal X-ray diffraction studies. Complex (2L(1)) crystallizes in the monoclinic unit cells with the space group P2(1). The catalysts are evaluated for their Cinnamic aldehyde hydrogenation. The catalysts show excellent activity and selectivity for the unsaturated carbonyl compound under mild conditions. Copyright © 2012 Elsevier B.V. All rights reserved.

A simulation for predicting potential cooling effect on LPG-fuelled vehicles

NASA Astrophysics Data System (ADS)

Setiyo, M.; Soeparman, S.; Wahyudi, S.; Hamidi, N.

2016-03-01

Liquefied Petroleum Gas vehicles (LPG Vehicles) provide a potential cooling effect about 430 kJ/kg LPG consumption. This cooling effect is obtained from the LPG phase change from liquid to vapor in the vaporizer. In the existing system, energy to evaporate LPG is obtained from the coolant which is circulated around the vaporizer. One advantage is that the LPG (70/30 propane / butane) when expanded from 8 bar to at 1.2 bar, the temperature is less than -25 °C. These conditions provide opportunities to evaporate LPG with ambient air flow, then produce a cooling effect for cooling car's cabin. In this study, some LPG mix was investigated to determine the optimum condition. A simulation was carried out to estimate potential cooling effects of 2000 cc engine from 1000 rpm to 6000 rpm. In this case, the mass flow rate of LPG is a function of fuel consumption. The simulation result shows that the LPG (70/30 propane/butane) provide the greatest cooling effect compared with other mixtures. In conclusion, the 2000 cc engine fueled LPG at 3000 rpm provides potential cooling effect more than 1.3 kW, despite in the low engine speed (1000 rpm) only provides about 0.5 kW.

In-Situ Bioremediation of Solvent Saturated Soils Using Methane, Propane, and Butane-Oxidizers

DTIC Science & Technology

2000-02-02

used as a degreasing agent, dry cleaning agent and solvent in various industries. It also can be found in household products such as spot cleaner...solvent widely used in various industries and can be found in many household products . 1,1,1-TCA is considered relatively highly soluble, therefore

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

DTIC Science & Technology

1980-10-29

adsorbed oxygen on powders. 23. Jaeger, C.D.; Bard, A.J. J. Ph s. Chem. 1979, 83, 3746. 24. Izumi, I; Dunn, W. W.; Wilbourn , K. 0.; Fan, F-R. F.; Bard, A... Joseph Singer, Code 302-1 Electrochimica Corporation NASA-Lewis Attention: Technical Library 21000 BrookDark Road 2485 Charleston Poad Cleveland, Ohio

Purification and biological evaluation of the metabolites produced by Streptomyces sp. TK-VL_333.

PubMed

Kavitha, Alapati; Prabhakar, Peddikotla; Vijayalakshmi, Muvva; Venkateswarlu, Yenamandra

2010-06-01

An Actinobacterium strain isolated from laterite soils of the Guntur region was identified as Streptomyces sp. TK-VL_333 by 16S rRNA analysis. Cultural, morphological and physiological characteristics of the strain were recorded. The secondary metabolites produced by the strain cultured on galactose-tyrosine broth were extracted and concentrated followed by defatting of the crude extract with cyclohexane to afford polar and non-polar residues. Purification of the two residues by column chromatography led to isolation of five polar and one non-polar fraction. Bioactivity- guided fractions were rechromatographed on a silica gel column to obtain four compounds, namely 1H-indole-3-carboxylic acid, 2,3-dihydroxy-5-(hydroxymethyl) benzaldehyde, 4-(4-hydroxyphenoxy) butan-2-one and acetic acid-2-hydroxy-6-(3-oxo-butyl)-phenyl ester from three active polar fractions and 8-methyl decanoic acid from one non-polar fraction. The structure of the compounds was elucidated on the basis of FT-IR, mass and NMR spectroscopy. The antimicrobial activity of the bioactive compounds produced by the strain was tested against the bacteria and fungi and expressed in terms of minimum inhibitory concentration. Antifungal activity of indole-3-carboxylic acid was further evaluated under in vitro and in vivo conditions. This is the first report of 2,3-dihydroxy-5-(hydroxymethyl) benzaldehyde, 4-(4-hydroxyphenoxy) butan-2-one, acetic acid-2-hydroxy-6-(3-oxo-butyl)-phenyl ester and 8-methyl decanoic acid from the genus Streptomyces. 2010 Elsevier Masson SAS. All rights reserved.

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.

Two cases of acute propane/butane poisoning in prison.

PubMed

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

2012-05-01

Hydrocarbon inhalation is seldom chosen as a means to commit suicide. This practice is exclusively a prerogative of the prison population; it is, however, only exceptionally found in this environment. The two cases of lethal inhalation of propane/butane gas observed by us over a very short time occurred in this context. Toxicologic analyses were performed by means of gas chromatography (head space) and revealed a propane/butane mixture in all specimens (heart blood, bile, and urine) except vitreous humor. Although fatal arrhythmia posthydrocarbon gas abuse is well known, the concentrations of the two hydrocarbons were sufficient to induce death by asphyxiation and were distributed (fairly) homogeneously in all biological fluids and organs examined, a parameter permitting one to assume that death occurred within a relatively short period of time. The absence of finding in vitreous humor and the trace amount in urine suggests that both men died very quickly. © 2011 American Academy of Forensic Sciences.

On-fiber furan formation from volatile precursors: a critical example of artefact formation during Solid-Phase Microextraction.

PubMed

Adams, An; Van Lancker, Fien; De Meulenaer, Bruno; Owczarek-Fendor, Agnieszka; De Kimpe, Norbert

2012-05-15

For the analysis of furan, a possible carcinogen formed during thermal treatment of food, Solid-Phase Microextraction (SPME) is a preferred and validated sampling method. However, when volatile furan precursors are adsorbed on the carboxen/PDMS fiber, additional amounts of furan can be formed on the fiber during thermal desorption, as shown here for 2-butenal and furfural. No significant increase in furan amounts was found upon heating the furan precursor 2-butenal, indicating that the furan amounts formed during precursor heating experiments are negligible as compared to the additional amounts of furan formed during fiber desorption. This artefactual furan formation increased with increasing desorption time, but especially with increasing desorption temperature. Although this effect was most pronounced on the Carboxen/PDMS SPME-fiber, it was also noted on two other SPME-fibers tested (PDMS and DVB/Carboxen/PDMS). The general impact on furan data from food and model systems in literature will depend on the amounts of volatile precursors present, but will probably remain limited. However, considering the importance of this worldwide food contaminant, special care has to be taken during SPME-analysis of furan. Especially when performing precursor studies, static headspace sampling should preferably be applied for furan analysis. Copyright © 2012 Elsevier B.V. All rights reserved.

Structure of five molecular salts assembled from noncovalent associations between organic acids, imidazole, benzimidazole, and 1-(2-(1H-benzimidazol-1-yl)ethyl)-1H-benzimidazole

NASA Astrophysics Data System (ADS)

Chen, Xuchong; Jin, Shouwen; Zhang, Huan; Xiao, Xiao; Liu, Bin; Wang, Daqi

2017-09-01

Cocrystallization of the imidazole derivatives, L1-L3, with a series of organic acids gave a total of five molecular salts with the compositions: (imidazole): (DL-10-camphorsulfonic acid) [(HL1+)·(cpsa-), cpsa- = DL-10-camphorsulfonate] (1), (imidazole): (3,5-dihydroxybenzoic acid) [(HL1+) · (3,5-dba-), 3,5-dba- = 3,5-dihydroxybenzoate] (2), (imidazole): (isophthalic acid): H2O [(HL1)+·(Hmpa)-·H2O, Hmpa- = hydrogenisophthalate] (3), (benzimidazole): (butane-1,2,3,4-tetracarboxylic acid) [(HL2+)·(H3bta -), H3bta- = trihydrogen butane-1,2,3,4-tetracarboxylate] (4), and (benzimidazole)2: 1-(2-(1H-benzimidazol-1-yl)ethyl)-1H-benzimidazole: (5-nitrosalicylic acid)2 [(L2)2·(H2L3)2+·(5-nsa-)2, 5-nsa- = 5-nitrosalicylate], (5). The five salts have been characterized by XRD technique, IR, and EA, and the melting points of all the salts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the five investigated crystals the ring N in the imidazole moieties are protonated when the organic acids are ionized, and the crystal packing is interpreted in terms of the strong Nsbnd H⋯O H-bond from the imidazole and the ionized acids. In addition to the Nsbnd H⋯O H-bond, the Osbnd H⋯O H-bonds were also established at the salts 2-5, compound 1 has the additional Nsbnd H⋯S H-bonds. Further analysis of the crystal packing of the salts displayed that a different family of additional CHsbnd O/CH2sbnd O/CH3sbnd O, CHsbnd S, CHsbnd π, NHsbnd π, and πsbnd π associations contribute to the stabilization and expansion of the total 3D framework structures. For the coexistence of the various weak interactions these structures had homo or hetero supramolecular synthons or both. Some classical supramolecular synthons, such as R12(4), R22(7), and R22(8) usually observed in crystals of organic acids with imidazole, were again shown to be involved in constructing most of these hydrogen bonding networks.

Nontoxic, Hydrophilic Cationic Polymers-Identified as Class of Antimicrobial Polymers.

PubMed

Strassburg, Arne; Kracke, Frauke; Wenners, Julia; Jemeljanova, Anna; Kuepper, Jannis; Petersen, Hanne; Tiller, Joerg C

2015-12-01

Amphiphilic polycations are an alternative to biocides but also toxic to mammalian cells. Antimicrobially active hydrophilic polycations based on 1,4-dibromo-2-butene and tetramethyl-1,3-propanediamine named PBI are not hemotoxic for porcine red blood cells with a hemocytotoxicity (HC50) of more than 40,000 μg · mL(-1). They are quickly killing bacterial cells at their MIC (minimal inhibitory concentration). The highest found selectivity HC50 /MIC is more than 20,000 for S. epidermidis. Investigations on sequentially prepared PBIs with defined molecular weight Mn and tailored end groups revealed that there is a dependence of antimicrobial activity and selectivity on Mn and nature of the end groups. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Grignard-like Organic Reaction in Water

NASA Astrophysics Data System (ADS)

Breton, Gary W.; Hughey, Christine A.

1998-01-01

The addition of a Grignard reagent to a carbonyl-containing compound to form an alcohol is an important reaction to demonstrate in organic chemistry laboratory courses. However, the reaction presents several practical problems for the lab instructor including the need for anhydrous solvents (e.g., ether), dry glassware, and the occasional problem of slow reaction initiation. We have scaled, and tested, a known Grignard-like reaction between allyl bromide and benzaldehyde mediated by zinc metal in aqueous media. The procedure retains the desirable features of the traditional Grignard reaction, while eliminating some of the commonly encountered difficulties. Thus, addition of allyl bromide (1.2 eq) to benzaldehyde and zinc in a two-phase mixture of THF and saturated aqueous NH4Cl afforded addition product 1-phenyl-3-buten-1-ol in 70-85% yields.

New series of aromatic/ five-membered heteroaromatic butanesulfonyl hydrazones as potent biological agents: Synthesis, physicochemical and electronic properties

NASA Astrophysics Data System (ADS)

Hamurcu, Fatma; Mamaş, Serhat; Ozdemir, Ummuhan Ozmen; Gündüzalp, Ayla Balaban; Senturk, Ozan Sanlı

2016-08-01

The aromatic/five-membered heteroaromatic butanesulfonylhydrazone derivatives; 5-bromosalicylaldehydebutanesulfonylhydrazone(1), 2-hydroxy-1-naphthaldehydebutane sulfonylhydrazone(2), indole-3-carboxaldehydebutanesulfonylhydrazone (3), 2-acetylfuran- carboxyaldehydebutanesulfonylhydrazone(4), 2-acetylthiophenecarboxyaldehydebutane- sulfonylhydrazone(5) and 2-acetyl-5-chlorothiophenecarboxyaldehydebutanesulfonyl hydrazone (6) were synthesized by the reaction of butane sulfonic acid hydrazide with aldehydes/ketones and characterized by using elemental analysis, 1H NMR, 13C NMR and FT-IR technique. Their geometric parameters and electronic properties consist of global reactivity descriptors were also determined by theoretical methods. The electrochemical behavior of the butanesulfonylhydrazones were investigated by using cyclic voltammetry (CV), controlled potential electrolysis and chronoamperometry (CA) techniques. The number of electrons transferred (n), diffusion coefficient (D) and standard heterogeneous rate constants (ks) were determined by electrochemical methods.

Associations between butane hash oil use and cannabis-related problems.

PubMed

Meier, Madeline H

2017-10-01

High-potency cannabis concentrates are increasingly popular in the United States, and there is concern that use of high-potency cannabis might increase risk for cannabis-related problems. However, little is known about the potential negative consequences of concentrate use. This study reports on associations between past-year use of a high-potency cannabis concentrate, known as butane hash oil (BHO), and cannabis-related problems. A sample of 821 college students were recruited to complete a survey about their health and behavior. Participants who had used cannabis in the past year (33%, n=273) completed questions about their cannabis use, including their use of BHO and cannabis-related problems in eight domains: physical dependence, impaired control, academic-occupational problems, social-interpersonal problems, self-care problems, self-perception, risk behavior, and blackouts. Approximately 44% (n=121) of past-year cannabis users had used BHO in the past year. More frequent BHO use was associated with higher levels of physical dependence (RR=1.8, p<0.001), impaired control (RR=1.3, p<0.001), cannabis-related academic/occupational problems (RR=1.5, p=0.004), poor self-care (RR=1.3, p=0.002), and cannabis-related risk behavior (RR=1.2, p=0.001). After accounting for sociodemographic factors, age of onset of cannabis use, sensation seeking, overall frequency of cannabis use, and frequency of other substance use, BHO use was still associated with higher levels of physical dependence (RR=1.2, p=0.014). BHO use is associated with greater physiological dependence on cannabis, even after accounting for potential confounders. Longitudinal research is needed to determine if cannabis users with higher levels of physiological dependence seek out BHO and/or if BHO use increases risk for physiological dependence. Copyright © 2017 Elsevier B.V. All rights reserved.

Transportation Security Administration's suspension of the butane lighter ban onboard commercial aircraft.

DOT National Transportation Integrated Search

2008-12-05

1) The August 2006 attempt by individuals to carry liquid explosives onboard multiple commercial aircraft bound for the United States from the United Kingdom has highlighted both the continued importance of securing the civil aviation system and the ...

Sustainable Pathways to Pyrroles through Iron-Catalyzed N-Heterocyclization from Unsaturated Diols and Primary Amines.

PubMed

Yan, Tao; Barta, Katalin

2016-09-08

Pyrroles are prominent scaffolds in pharmaceutically active compounds and play an important role in medicinal chemistry. Therefore, the development of new, atom-economic, and sustainable catalytic strategies to obtain these moieties is highly desired. Direct catalytic pathways that utilize readily available alcohol substrates have been recently established; however, these approaches rely on the use of noble metals such as ruthenium or iridium. Here, we report on the direct synthesis of pyrroles using a catalyst based on the earth-abundant and inexpensive iron. The method uses 2-butyne-1,4-diol or 2-butene-1,4-diol that can be directly coupled with anilines, benzyl amines, and aliphatic amines to obtain a variety of N-substituted pyrroles in moderate-to-excellent isolated yields. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Excited singlet molecular O2 (1Δg) is generated enzymatically from excited carbonyls in the dark

PubMed Central

Mano, Camila M.; Prado, Fernanda M.; Massari, Júlio; Ronsein, Graziella E.; Martinez, Glaucia R.; Miyamoto, Sayuri; Cadet, Jean; Sies, Helmut; Medeiros, Marisa H. G.; Bechara, Etelvino J. H.; Di Mascio, Paolo

2014-01-01

In mammalian tissues, ultraweak chemiluminescence arising from biomolecule oxidation has been attributed to the radiative deactivation of singlet molecular oxygen [O2 (1Δg)] and electronically excited triplet carbonyl products involving dioxetane intermediates. Herein, we describe evidence of the generation of O2 (1Δg) in aqueous solution via energy transfer from excited triplet acetone. This involves thermolysis of 3,3,4,4-tetramethyl-1,2-dioxetane, a chemical source, and horseradish peroxidase-catalyzed oxidation of 2-methylpropanal, as an enzymatic source. Both sources of excited carbonyls showed characteristic light emission at 1,270 nm, directly indicative of the monomolecular decay of O2 (1Δg). Indirect analysis of O2 (1Δg) by electron paramagnetic resonance using the chemical trap 2,2,6,6-tetramethylpiperidine showed the formation of 2,2,6,6-tetramethylpiperidine-1-oxyl. Using [18O]-labeled triplet, ground state molecular oxygen [18O2 (3Σg-)], chemical trapping of 18O2 (1Δg) with disodium salt of anthracene-9,10-diyldiethane-2,1-diyl disulfate yielding the corresponding double-[18O]-labeled 9,10-endoperoxide, was detected through mass spectrometry. This corroborates formation of O2 (1Δg). Altogether, photoemission and chemical trapping studies clearly demonstrate that chemically and enzymatically nascent excited carbonyl generates 18O2 (1Δg) by triplet-triplet energy transfer to ground state oxygen O2 (3Σg−), and supports the long formulated hypothesis of O2 (1Δg) involvement in physiological and pathophysiological events that might take place in tissues in the absence of light. PMID:25087485

Use of Tetragenococcus halophilus as a starter culture for flavor improvement in fish sauce fermentation.

PubMed

Udomsil, Natteewan; Rodtong, Sureelak; Choi, Yeung Joon; Hua, Yanglin; Yongsawatdigul, Jirawat

2011-08-10

The potential of Tetragenococcus halophilus as a starter culture for flavor improvement in fish sauce fermentation was elucidated. Four strains of T. halophilus isolated from fish sauce mashes were inoculated to anchovy mixed with 25% NaCl with an approximate cell count of 10(6) CFU/mL. The α-amino content of 6-month-old fish sauce samples inoculated with T. halophilus was 780-784 mM. The addition of T. halophilus MRC10-1-3 and T. halophilus MCD10-5-10 resulted in a reduction of histamine (P < 0.05). Fish sauce inoculated with T. halophilus showed high contents of total amino acids with predominantly high glutamic acid. Major volatile compounds in fish sauce were 2-methylpropanal, 2-methylbutanal, 3-methylbutanal, and benzaldehyde. T. halophilus-inoculated fish sauce samples demonstrated the ability to reduce dimethyl disulfide, a compound contributing to a fecal note. The use of T. halophilus for fish sauce fermentation improves amino acid profiles and volatile compounds as well as reduces biogenic amine content of a fish sauce product.

Effectiveness of replacing catalytic converters in LPG-fueled vehicles in Hong Kong

NASA Astrophysics Data System (ADS)

Lyu, Xiaopu; Guo, Hai; Simpson, Isobel J.; Meinardi, Simone; Louie, Peter K. K.; Ling, Zhenhao; Wang, Yu; Liu, Ming; Luk, Connie W. Y.; Wang, Nan; Blake, Donald R.

2016-05-01

Many taxis and public buses are powered by liquefied petroleum gas (LPG) in Hong Kong. With more vehicles using LPG, they have become the major contributor to ambient volatile organic compounds (VOCs) in Hong Kong. An intervention program which aimed to reduce the emissions of VOCs and nitrogen oxides (NOx) from LPG-fueled vehicles was implemented by the Hong Kong government in September 2013. Long-term real-time measurements indicated that the program was remarkably effective in reducing LPG-related VOCs, NOx and nitric oxide (NO) in the atmosphere. Receptor modeling results further revealed that propane, propene, i-butane, n-butane and NO in LPG-fueled vehicle exhaust emissions decreased by 40.8 ± 0.1, 45.7 ± 0.2, 35.7 ± 0.1, 47.8 ± 0.1 and 88.6 ± 0.7 %, respectively, during the implementation of the program. In contrast, despite the reduction of VOCs and NOx, O3 following the program increased by 0.40 ± 0.03 ppbv (˜ 5.6 %). The LPG-fueled vehicle exhaust was generally destructive to OH and HO2. However, the destruction effect weakened for OH and it even turned to positive contribution to HO2 during the program. These changes led to the increases of OH, HO2 and HO2 / OH ratio, which might explain the positive O3 increment. Analysis of O3-VOCs-NOx sensitivity in ambient air indicated VOC-limited regimes in the O3 formation before and during the program. Moreover, a maximum reduction percentage of NOx (i.e., 69 %) and the lowest reduction ratio of VOCs / NOx (i.e., 1.1) in LPG-fueled vehicle exhaust were determined to give a zero O3 increment. The findings are of great help to future formulation and implementation of control strategies on vehicle emissions in Hong Kong, and could be extended to other regions in China and around the world.

Two double and triple interpenetrated Cd(II) and Zn(II) coordination polymers based on mixed O- and N-donor ligands: Syntheses, crystal structures and luminescent properties

NASA Astrophysics Data System (ADS)

Zhang, Li; Li, Xiaohui; Zhang, Yan

2016-01-01

Two interpenetrated 3D coordination polymers, namely [Cd2(tdc)2(bpp) (DMA)]n (1) and [Zn2(tdc)2(bib)2]n·2n(DMA) (2) (H2tdc = 2,5-thiophenedicarboxylic acid, bpp = 1,3-di(4-pyridyl)propane, bib = 1, 4-bis(imidazolyl)butane, DMA = N,N-dimethylacetamide), have been solvothermally synthesized by the self-assembly of flexible N-donor and dicarboxylate ligands. Single crystal X-ray diffraction analyses revealed that compound 1 features a 2-fold interpenetrated 3D framework based on dinuclear [Cd2(COO)3] subunits and can be simplified into a 6-connected pcu topology, and compound 2 features a 3-fold interpenetrated 3D framework with 4-connected dia topology. Moreover, the thermal stabilities and luminescent properties of these two compounds were also investigated.

2,2′-[2,4-Bis(naphthalen-1-yl)cyclo­butane-1,3-di­yl]bis­(1-methyl­pyridinium) diiodide: thermal-induced [2 + 2] cyclo­addition reaction of a heterostilbene1

PubMed Central

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

2012-01-01

The asymmetric unit of the title compound, C36H32N2 2+·2I−, consists of one half-mol­ecule of the cation and one I− anion. The cation is located on an inversion centre. The dihedral angle between the pyridinium ring and the naphthalene ring system in the asymmetric unit is 19.01 (14)°. In the crystal, the cations and the anions are linked by C—H⋯I inter­actions into a layer parallel to the bc plane. Intra- and inter­molecular π–π inter­actions with centroid–centroid distances of 3.533 (2)–3.807 (2) Å are also observed. PMID:22259568

Growth of Rhodococcus sp. strain BCP1 on gaseous n-alkanes: new metabolic insights and transcriptional analysis of two soluble di-iron monooxygenase genes

PubMed Central

Cappelletti, Martina; Presentato, Alessandro; Milazzo, Giorgio; Turner, Raymond J.; Fedi, Stefano; Frascari, Dario; Zannoni, Davide

2015-01-01

Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane) were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from n-butane metabolism. Two gene clusters, prmABCD and smoABCD—coding for Soluble Di-Iron Monooxgenases (SDIMOs) involved in gaseous n-alkanes oxidation—were detected in the BCP1 genome. By means of Reverse Transcriptase-quantitative PCR (RT-qPCR) analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids, or during the cell growth on rich medium (Luria–Bertani broth). The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane) and/or liquid (n-hexane) short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step. PMID:26029173

An exploratory study on the peroxyl-radical-scavenging activity of 2,6-dimethyl-5-hepten-2-ol and its heterocyclic analogues

NASA Astrophysics Data System (ADS)

Stobiecka, Agnieszka; Sikora, Magdalena; Bonikowski, Radosław; Kula, Józef

2016-03-01

The structural properties and radical scavenging activity of 2,6-dimethyl-5-hepten-2-ol (1) and its new heterocyclic analogues, i.e. 2-methyl-4-(5-methylfuran-2-yl)-butan-2-ol (2) and 2-methyl-4-(5-methylthiophen-2-yl)-butan-2-ol (3) and have been studied by using the experimental and theoretical methods for the first time. Activity of title compounds against the peroxyl radical was determined by using standard fluorimetric test, i.e. the Oxygen Radical Absorbance Capacity assay (ORACFL). Furthermore, the electron-donating ability of odorants has been evaluated by using colorimetric ABTS assay. According to the experimental results obtained from the ORACFL test 2,6-dimethyl-5-hepten-2-ol was characterized by the highest activity in comparison with the novel counterparts. Nevertheless, all investigated compounds exhibited pronounced anti-peroxyl radical activity comparable to that exerted by the one of the most prominent antioxidant among the monoterpene alcohols, i.e. by linalool. On the other hand, the title compounds exerted relatively low capacity to quench the radical cation of ABTS. Theoretical calculations based on the Density Functional Theory (DFT) method with the hybrid functional B3LYP were carried out in order to investigate selected structural and electronic properties including the geometrical parameters as well as the energy of frontier molecular orbitals of parent molecules and the resulting radicals. Furthermore, the possible mechanism of peroxyl-radical-scavenging has been determined by using the thermodynamic descriptors such as the bond dissociation enthalpies (BDEs) and ionization potentials (IPs). These theoretical data pointed out the relevance of HAT mechanism in the peroxyl-radical-scavenging exhibited by 2,6-dimethyl-5-hepten-2-ol and its new heterocyclic analogues in polar and non-polar medium.

Alkyl sulfonic acide hydrazides: Synthesis, characterization, computational studies and anticancer, antibacterial, anticarbonic anhydrase II (hCA II) activities

NASA Astrophysics Data System (ADS)

O. Ozdemir, Ummuhan; İlbiz, Firdevs; Balaban Gunduzalp, Ayla; Ozbek, Neslihan; Karagoz Genç, Zuhal; Hamurcu, Fatma; Tekin, Suat

2015-11-01

Methane sulfonic acide hydrazide, CH3SO2NHNH2 (1), ethane sulfonic acide hydrazide, CH3CH2SO2NHNH2 (2), propane sulfonic acide hydrazide, CH3CH2CH2SO2NHNH2 (3) and butane sulfonic acide hydrazide, CH3CH2CH2CH2SO2NHNH2 (4) have been synthesized as homologous series and characterized by using elemental analysis, spectrophotometric methods (1H-13C NMR, FT-IR, LC-MS). In order to gain insight into the structure of the compounds, we have performed computational studies by using 6-311G(d, p) functional in which B3LYP functional were implemented. The geometry of the sulfonic acide hydrazides were optimized at the DFT method with Gaussian 09 program package. A conformational analysis of compounds were performed by using NMR theoretical calculations with DFT/B3LYP/6-311++G(2d, 2p) level of theory by applying the (GIAO) approach. The anticancer activities of these compounds on MCF-7 human breast cancer cell line investigated by comparing IC50 values. The antibacterial activities of synthesized compounds were studied against Gram positive bacteria; Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Gram negative bacteria; Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442, Klebsiella pneumonia ATCC 70063 by using the disc diffusion method. The inhibition activities of these compounds on carbonic anhydrase II enzyme (hCA II) have been investigated by comparing IC50 and Ki values. The biological activity screening shows that butane sulfonic acide hydrazide (4) has more activity than the others against tested breast cancer cell lines MCF-7, Gram negative/Gram positive bacteria and carbonic anhydrase II (hCA II) isoenzyme.

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…

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

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-26

... Customs Value for Cigarette Lighters AGENCY: Consumer Product Safety Commission. ACTION: Final rule... refillable lighters that use butane or similar fuels and have a Customs Value or ex-factory price below a threshold value (initially set at $2.00 in 1993). The standard provides that the initial $2.00 value adjusts...

Occurrence of high gravity oil in an Oligocene Vicksburg age sandstone in Jim Hogg County, Texas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, L.W.; Hilton, N.

1980-01-01

On October 1, 1979 the Guardian Oil Co. E-1 Mestena oil and gas well was completed in an Oligocene, Vicksburg sandstone. The initial potential was 245 BOPD of 75 API gravity oil. A hydrocarbon analysis of a sample obtained from the E-1 well revealed an oil composed primarily of propane and butane with a significant portion of pentane to heptane range material which accounts for the exceptionally high gravity of the liquid hydrocarbons. This analysis further showed that the E-1 well is producing almost no methane, ethane, or other hydrocarbons of greater molecular weight than nonane. Several faults, adjacent tomore » the well, could have provided a path of migration for the hydrocarbons. A detailed analysis of the butane to heptane fluid produced by the E-1 well indicated the fluid contained a large amount of compounds characteristic of an immature crude. Coal fragments present in the cutting from a nearby well and the regional geology of the Vicksburg Formation suggest that one possible source for the hydrocarbons of the E-1 well could have been lipid rich Cannel-type coal.« less

Synthesis and application of imidazolium-based ionic liquids as extraction solvent for pretreatment of triazole fungicides in water samples.

PubMed

Yang, Jiale; Fan, Chen; Kong, Dandan; Tang, Gang; Zhang, Wenbing; Dong, Hongqiang; Liang, You; Wang, Deng; Cao, Yongsong

2018-02-01

Five novel ionic liquids (ILs), 1,3-dibutylimidazolium bromide [BBMIm][Br], 1-pentyl-3-butylimidazolium bromide [BPMIm][Br], 1-hexyl-3-butylimidazolium bromide [BHMIm][Br], 1,1'-(butane-1,4-diyl)bis(3-butylimidazolium) bromide [C 4 (BMIm) 2 ][Br 2 ], and 1,1'-(butane-1,4-diyl)bis(3-methylimidazolium) bromide [C 4 (MIm) 2 ][Br 2 ], were prepared and used in situ to react with bis(trifluoromethane)sulfonamide lithium salt to extract the myclobutanil, tebuconazole, cyproconazole, and prothioconazole from water samples. The results showed that mono-cationic ILs had much better recovery than dicationic ILs, and mono-imidazolium IL bearing butyl groups at N-1 and N-3 sites had the best recovery. When the length of the alkyl substituent group was more than four carbons at N-3 site, the recovery decreased with increase of alkyl chain length of 1-butylimidazolium IL. The extraction efficiency order of triazoles from high to low was [BBMIm][Br], [BPMIm][Br], [BHMIm][Br], [BMIm][Br] (1-butyl-3-methylimidazolium bromide), [C 4 (BMIm) 2 ]Br 2 , [C 4 (MIm) 2 ]Br 2 . An in situ ionic liquid dispersive liquid-liquid microextraction combined with ultrasmall superparamagnetic Fe 3 O 4 was established as a pretreatment method for enrichment of triazole fungicides in water samples by using the synthetic [BBMIm][Br] as the cationic IL and used to detect analytes followed by high-performance liquid chromatography. Under the optimized conditions, the proposed method showed a good linearity within a range of 5-250 μg L -1 , with the determination coefficient (r 2 ) varying from 0.998 to 0.999. High mean enrichment factors were achieved ranging from 187 to 323, and the recoveries of the target analytes from real water samples at spiking levels of 10.0, 20.0, and 50.0 μg L -1 were between 70.1% and 115.0%. The limits of detection for the analytes were 0.74-1.44 μg L -1 , and the intra-day relative standard deviations varied from 5.23% to 8.65%. The proposed method can be further applied to analyze and monitor pesticides in other related samples. Graphical Abstract The scheme of the in-situ DLLME method for the determination of triazoles using the imidazolium-based ionic liquids.

Bronchospasm and anaphylactic shock following lidocaine aerosol inhalation in a patient with butane inhalation lung injury.

PubMed

Lee, Min-Young; Park, Kyong Ah; Yeo, So-Jeong; Kim, Shin-Hee; Goong, Hyeun-Jeong; Jang, An-Soo; Park, Choon-Sik

2011-10-01

Allergic reactions to local anesthetics are very rare and represent <1% of all adverse local anesthetics reactions. A 54-year-old man was admitted to the hospital in the winter because of shortness of breath. The patient reportedly had an inhalation lung injury due to butane gas fuel. On the fifth day, he developed an asthmatic attack and anaphylactic shock immediately after lidocaine aerosol administration to prepare for bronchoscopy to confirm an acute inhalational lung injury diagnosis. Cardiopulmonary resuscitation was performed immediately after respiratory arrest, and the patient was admitted to the intensive care unit intubated and on a ventilator. He was extubated safely on the third post-cardiopulmonary resuscitation day. These observations suggest that aerosol lidocaine anesthesia may cause airway narrowing and anaphylactic shock. Practitioners should be aware of this potential complication. We report on this case with a brief review of the literature.

Emission characteristics of VOCs emitted from consumer and commercial products and their ozone formation potential.

PubMed

Dinh, Trieu-Vuong; Kim, Su-Yeon; Son, Youn-Suk; Choi, In-Young; Park, Seong-Ryong; Sunwoo, Young; Kim, Jo-Chun

2015-06-01

The characteristics of volatile organic compounds (VOCs) emitted from several consumer and commercial products (body wash, dishwashing detergent, air freshener, windshield washer fluid, lubricant, hair spray, and insecticide) were studied and compared. The spray products were found to emit the highest amount of VOCs (~96 wt%). In contrast, the body wash products showed the lowest VOC contents (~1.6 wt%). In the spray products, 21.6-96.4 % of the VOCs were propane, iso-butane, and n-butane, which are the components of liquefied petroleum gas. Monoterpene (C10H16) was the dominant component of the VOCs in the non-spray products (e.g., body wash, 53-88 %). In particular, methanol was present with the highest amount of VOCs in windshield washer fluid products. In terms of the number of carbon, the windshield washer fluids, lubricants, insecticides, and hair sprays comprised >95 % of the VOCs in the range C2-C5. The VOCs in the range C6-C10 were predominantly found in the body wash products. The dishwashing detergents and air fresheners contained diverse VOCs from C2 to C11. Besides comprising hazardous VOCs, VOCs from consumer products were also ozone precursors. The ozone formation potential of the consumer and commercial spray products was estimated to be higher than those of liquid and gel materials. In particular, the hair sprays showed the highest ozone formation potential.

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

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.

Study of the Air-Tolerant 1,3-Diphosphacyclobutane-2,4-diyl through the Direct Arylation.

PubMed

Ito, Shigekazu

2018-04-01

Installing π-functional substituents on the skeletal phosphorus atoms of the air-tolerant 1,3-diphosphacyclobutane-2,4-diyl unit are promising for tuning the open-shell singlet P-heterocyclic chromophore. The sterically encumbered 1,3-diphosphaCycloButen-4-yl Anion (CBA), generated from the phosphorus-carbon triple bond, was available for the regioselective arylation via nucleophilic aromatic substitution (S N Ar) reaction, addition to arynes, and single-electron transfer (SET) process affording the corresponding P-arylated 1,3-diphosphacyclobutane-2,4-diyls. The photo-absorption and redox properties correlated with the effects of the aryl substituents on the 1,3-diphosphacyclobutane-2,4-diyl unit. The X-ray analyses enabled not only to discuss the metric parameters but also to visualize the radicalic electrons via the electron-density distribution analysis. The electron-donating character of the P-heterocyclic chromophores induced the p-type semiconductor behavior. Detection of hydrogen fluoride via formation of the 1λ 5 ,3λ 5 -diphosphete derivative was also developed. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of β-cyclodextrin-based hydrogel microparticles for solubility enhancement of rosuvastatin: an in vitro and in vivo evaluation

PubMed Central

Sarfraz, Rai Muhammad; Ahmad, Mahmood; Mahmood, Asif; Akram, Muhammad Rouf; Abrar, Asad

2017-01-01

The aim of this study was to enhance the solubility of rosuvastatin (RST) calcium by developing β-cyclodextrin-g-poly(2-acrylamido-2-methylpropane sulfonic acid [AMPS]) hydrogel microparticles through aqueous free-radical polymerization technique. Prepared hydrogel microparticles were characterized for percent entrapment efficiency, solubility studies, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, powder X-ray diffraction, scanning electron microscopy, zeta size and potential, swelling and release studies. Formulations (HS1–HS9) have shown entrapment efficiency between 83.50%±0.30% and 88.50%±0.25%, and optimum release was offered by formulation HS7 at both pH levels, ie, 1.2 (89%) and 7.4 (92%). The majority of microparticles had a particle size of less than 500 µm and zeta potential of −37 mV. Similarly, optimum solubility, ie, 10.66-fold, was determined at pH 6.8 as compared to pure RST calcium, ie, 7.30-fold. In vivo studies on fabricated hydrogel microparticulate system in comparison to pure drug were carried out, and better results regarding pharmacokinetic parameters were seen in the case of hydrogel microparticles. A potential approach for solubility enhancement of RST calcium and other hydrophobic moieties was successfully developed. PMID:29123380

Designing Stability into Thermally Reactive Plumbylenes.

PubMed

Bačić, Goran; Zanders, David; Mallick, Bert; Devi, Anjana; Barry, Seán T

2018-06-26

Lead analogues of N-heterocyclic carbenes (NHPbs) are the least understood members of this increasingly important class of compounds. Here we report the design, preparation, isolation, structure, volatility, and decomposition pathways of a novel aliphatic NHPb: rac- N  2 , N  3 -di- tert-butylbutane-2,3-diamido lead(II) (1Pb). The large steric bulk of the tert-butylamido moieties and rac-butane backbone successfully hinder redox decomposition pathways observed for diamidoethylene and -ethane backbone analogues, pushing the onset of thermal decomposition from below 0 °C to above 150 °C. With an exceptionally high vapor pressure of 1 Torr at 94 ± 2 °C and excellent thermal stability among Pb(II) complexes, 1Pb is a promising precursor for the chemical vapor deposition (CVD) and atomic layer deposition (ALD) of functional lead-containing materials.

Synthesis of butenes through 2-butanol dehydration over mesoporous materials produced from ferrierite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, Soyeon; Kim, Hyeonjoo; Bae, Jung A.

2012-05-20

Mesoporous materials synthesized from commercial ferrierite (MMZ-FER) were applied to butanol dehydration. The MMZ-FER was produced by disassembling ferrierite into unit structures in the presence of an alkali solution, adding a surfactant as a templating material, followed by hydrothermal treatment. The effect of the alkali/(Si+Al) ratio in the disassembling step on the characteristics of the catalyst and butanol dehydration performance were investigated. The MMZ-FER materials, synthesized in a condition in which the NaOH/(Si + Al) mole ratio in the disassembling step was 0.67 and 1.0, demonstrated similar textural properties to those of MCM-41. Many weak acid sites developed on themore » MMZ-FER(0.67) and MMZ-FER(1.0) samples, which is attributed to the creation of ferrierite-induced acid sites. The MMZ-FER materials showed excellent catalytic activity, selectivity, and stability during the dehydration of 2-butanol.« less

Cometabolism of Methyl tertiary Butyl Ether and Gaseous n-Alkanes by Pseudomonas mendocina KR-1 Grown on C5 to C8 n-Alkanes

PubMed Central

Smith, Christy A.; O'Reilly, Kirk T.; Hyman, Michael R.

2003-01-01

Pseudomonas mendocina KR-1 grew well on toluene, n-alkanes (C5 to C8), and 1° alcohols (C2 to C8) but not on other aromatics, gaseous n-alkanes (C1 to C4), isoalkanes (C4 to C6), 2° alcohols (C3 to C8), methyl tertiary butyl ether (MTBE), or tertiary butyl alcohol (TBA). Cells grown under carbon-limited conditions on n-alkanes in the presence of MTBE (42 μmol) oxidized up to 94% of the added MTBE to TBA. Less than 3% of the added MTBE was oxidized to TBA when cells were grown on either 1° alcohols, toluene, or dextrose in the presence of MTBE. Concentrated n-pentane-grown cells oxidized MTBE to TBA without a lag phase and without generating tertiary butyl formate (TBF) as an intermediate. Neither TBF nor TBA was consumed by n-pentane-grown cells, while formaldehyde, the expected C1 product of MTBE dealkylation, was rapidly consumed. Similar Ks values for MTBE were observed for cells grown on C5 to C8 n-alkanes (12.95 ± 2.04 mM), suggesting that the same enzyme oxidizes MTBE in cells grown on each n-alkane. All growth-supporting n-alkanes (C5 to C8) inhibited MTBE oxidation by resting n-pentane-grown cells. Propane (Ki = 53 μM) and n-butane (Ki = 16 μM) also inhibited MTBE oxidation, and both gases were also consumed by cells during growth on n-pentane. Cultures grown on C5 to C8 n-alkanes also exhibited up to twofold-higher levels of growth in the presence of propane or n-butane, whereas no growth stimulation was observed with methane, ethane, MTBE, TBA, or formaldehyde. The results are discussed in terms of their impacts on our understanding of MTBE biodegradation and cometabolism. PMID:14660389

Syntheses and structural characterization of iron(II) and copper(II) coordination compounds with the neutral flexible bidentate N-donor ligands

NASA Astrophysics Data System (ADS)

Beheshti, Azizolla; Lalegani, Arash; Bruno, Giuseppe; Rudbari, Hadi Amiri

2014-08-01

Two new coordination compounds [Fe(bib)2(N3)2]n(1) and [Cu2(bpp)2(N3)4] (2) with azide and flexible ligands 1,4-bis(imidazolyl)butane (bib) and 1,3-bis(3,5-dimethylpyrazolyl)propane (bpp) were prepared and structurally characterized. In the 2D network structure of 1, the iron(II) ion lies on an inversion center and exhibits an FeN6 octahedral arrangement while in the dinuclear structure of 2, the copper(II) ion adopts an FeN5 distorted square pyramid geometry. In the complex 1, each μ2-bib acts as bridging ligand connecting two adjacent iron(II) ions while in the complex 2, the bpp ligand is coordinated to copper(II) ion in a cyclic-bidentate fashion forming an eight-membered metallocyclic ring. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. Thermal analysis of polymer 1 was also studied.

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene.

PubMed

Call, Zachary; Suchewski, Meagan; Bradley, Christopher A

2017-03-20

A reliable, intermediate scale preparation of 1,2,3,4,5-pentamethylcyclopentadiene (Cp*H) is presented, based on modifications of existing protocols that derive from initial 2-bromo-2-butene lithiation followed by acid mediated dienol cyclization. The revised synthesis and purification of the ligand avoids the use of mechanical stirring while still permitting access to significant quantities (39 g) of Cp*H in good yield (58%). The procedure offers other additional benefits, including a more controlled quench of excess lithium during the production of the intermediate heptadienols and a simplified isolation of Cp*H of sufficient purity for metallation with transition metals. The ligand was subsequently used to synthesize [Cp*MCl2]2 complexes of both iridium and ruthenium to demonstrate the utility of the Cp*H prepared and purified by our method. The procedure outlined herein affords substantial quantities of a ubiquitous ancillary ligand support used in organometallic chemistry while minimizing the need for specialized laboratory equipment, thus providing a simpler and more accessible entry point into the chemistry of 1,2,3,4,5-pentamethylcyclopentadiene.

Inter-laboratory calibration of natural gas round robins for δ2H and δ13C using off-line and on-line techniques

USGS Publications Warehouse

Dai, Jinxing; Xia, Xinyu; Li, Zhisheng; Coleman, Dennis D.; Dias, Robert F.; Gao, Ling; Li, Jian; Deev, Andrei; Li, Jin; Dessort, Daniel; Duclerc, Dominique; Li, Liwu; Liu, Jinzhong; Schloemer, Stefan; Zhang, Wenlong; Ni, Yunyan; Hu, Guoyi; Wang, Xiaobo; Tang, Yongchun

2012-01-01

Compound-specific carbon and hydrogen isotopic compositions of three natural gas round robins were calibrated by ten laboratories carrying out more than 800 measurements including both on-line and off-line methods. Two-point calibrations were performed with international measurement standards for hydrogen isotope ratios (VSMOW and SLAP) and carbon isotope ratios (NBS 19 and L-SVEC CO2). The consensus δ13C values and uncertainties were derived from the Maximum Likelihood Estimation (MLE) based on off-line measurements; the consensus δ2H values and uncertainties were derived from MLE of both off-line and on-line measurements, taking the bias of on-line measurements into account. The calibrated consensus values in ‰ relative to VSMOW and VPDB are: NG1 (coal-related gas): Methane: δ2HVSMOW = − 185.1‰ ± 1.2‰, δ13CVPDB = − 34.18‰ ± 0.10‰ Ethane: δ2HVSMOW = − 156.3‰ ± 1.8‰, δ13CVPDB = − 24.66‰ ± 0.11‰ Propane: δ2HVSMOW = − 143.6‰ ± 3.3‰, δ13CVPDB = − 22.21‰ ± 0.11‰ i-Butane: δ13CVPDB = − 21.62‰ ± 0.12‰ n-Butane: δ13CVPDB = − 21.74‰ ± 0.13‰ CO2: δ13CVPDB = − 5.00‰ ± 0.12‰ NG2 (biogas): Methane: δ2HVSMOW = − 237.0‰ ± 1.2‰, δ13CVPDB = − 68.89‰ ± 0.12‰ NG3 (oil-related gas): Methane: δ2HVSMOW = − 167.6‰ ± 1.0‰, δ13CVPDB = − 43.61‰ ± 0.09‰ Ethane: δ2HVSMOW = − 164.1‰ ± 2.4‰, δ13CVPDB = − 40.24‰ ± 0.10‰ Propane: δ2HVSMOW = − 138.4‰ ± 3.0‰, δ13CVPDB = − 33.79‰ ± 0.09‰ All of the assigned values are traceable to the international carbon isotope standard of VPDB and hydrogen isotope standard of VSMOW.

Characterization of volatile aroma compounds in different brewing barley cultivars.

PubMed

Dong, Liang; Hou, Yingmin; Li, Feng; Piao, Yongzhe; Zhang, Xiao; Zhang, Xiaoyu; Li, Cheng; Zhao, Changxin

2015-03-30

Beer is a popular alcoholic malt beverage resulting from fermentation of the aqueous extract of malted barley with hops. The aroma of brewing barley impacts the flavor of beer indirectly, because some flavor compounds or their precursors in beer come from the barley. The objectives of this research were to study volatile profiles and to characterize odor-active compounds of brewing barley in order to determine the variability of the aroma composition among different brewing barley cultivars. Forty-one volatiles comprising aldehydes, ketones, alcohols, organic acids, aromatic compounds and furans were identified using solid phase microextraction combined with gas chromatography/mass spectrometry, among which aldehydes, alcohols and ketones were quantitatively in greatest abundance. Quantitative measurements performed by means of solvent extraction and calculation of odor activity values revealed that acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, hexanal, heptanal, octanal, nonanal, 3-methyl-1-butanol, cyclopentanol, 2,3-butanedione, 2,3-pentanedione, 2-heptanone, acetic acid, ethyl acetate, 2-pentylfuran and benzeneacetaldehyde, whose concentrations exceeded their odor thresholds, could be considered as odor-active compounds of brewing barley. Principal component analysis was employed to evaluate the differences among cultivars. The results demonstrated that the volatile profile based on the concentrations of aroma compounds enabled good differentiation of most barley cultivars. © 2014 Society of Chemical Industry.

Dry Reforming of Ethane and Butane with CO 2 over PtNi/CeO 2 Bimetallic Catalysts

DOE PAGES

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

2016-09-21

Dry reforming is a potential process to convert CO 2 and light alkanes into syngas (H 2 and CO), which can be subsequently transformed to chemicals and fuels. Here in this work, PtNi bimetallic catalysts have been investigated for dry reforming of ethane and butane using both model surfaces and supported powder catalysts. The PtNi bimetallic catalyst shows an improvement in both activity and stability as compared to the corresponding monometallic catalysts. The formation of PtNi alloy and the partial reduction of Ce 4+ to Ce 3+ under reaction conditions are demonstrated by in-situ Ambient Pressure X-ray Photoemission Spectroscopy (AP-XPS),more » X-ray Diffraction (XRD) and X-ray Absorption Fine Structure (XAFS) measurements. A Pt-rich bimetallic surface is revealed by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) following CO adsorption. Combined in-situ experimental results and Density Functional Theory (DFT) calculations suggest that the Pt-rich PtNi bimetallic surface structure would weaken the binding of surface oxygenates/carbon species and reduce the activation energy for C-C bond scission, leading to an enhanced dry reforming activity.« less

Dry Reforming of Ethane and Butane with CO 2 over PtNi/CeO 2 Bimetallic Catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Binhang; Yang, Xiaofang; Yao, Siyu

Dry reforming is a potential process to convert CO 2 and light alkanes into syngas (H 2 and CO), which can be subsequently transformed to chemicals and fuels. Here in this work, PtNi bimetallic catalysts have been investigated for dry reforming of ethane and butane using both model surfaces and supported powder catalysts. The PtNi bimetallic catalyst shows an improvement in both activity and stability as compared to the corresponding monometallic catalysts. The formation of PtNi alloy and the partial reduction of Ce 4+ to Ce 3+ under reaction conditions are demonstrated by in-situ Ambient Pressure X-ray Photoemission Spectroscopy (AP-XPS),more » X-ray Diffraction (XRD) and X-ray Absorption Fine Structure (XAFS) measurements. A Pt-rich bimetallic surface is revealed by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) following CO adsorption. Combined in-situ experimental results and Density Functional Theory (DFT) calculations suggest that the Pt-rich PtNi bimetallic surface structure would weaken the binding of surface oxygenates/carbon species and reduce the activation energy for C-C bond scission, leading to an enhanced dry reforming activity.« less

Evaluation of an optoacoustic based gas analysing device

NASA Astrophysics Data System (ADS)

Markmann, Janine; Lange, Birgit; Theisen-Kunde, Dirk; Danicke, Veit; Mayorov, Fedor; Eckert, Sebastian; Kettmann, Pascal; Brinkmann, Ralf

2017-07-01

The relative occurrence of volatile organic compounds in the human respiratory gas is disease-specific (ppb range). A prototype of a gas analysing device using two tuneable laser systems, an OPO-laser (2.5 to 10 μm) and a CO2-laser (9 to 11 μm), and an optoacoustic measurement cell was developed to detect concentrations in the ppb range. The sensitivity and resolution of the system was determined by test gas measurements, measuring ethylene and sulfur hexafluoride with the CO2-laser and butane with the OPO-laser. System sensitivity found to be 13 ppb for sulfur hexafluoride, 17 ppb for ethylene and <10 ppb for butane, with a resolution of 50 ppb at minimum for sulfur hexafluoride. Respiratory gas samples of 8 healthy volunteers were investigated by irradiation with 17 laser lines of the CO2-laser. Several of those lines overlap with strong absorption bands of ammonia. As it is known that ammonia concentration increases by age a separation of people <35 und >35 was striven for. To evaluate the data the first seven gas samples were used to train a discriminant analysis algorithm. The eighth subject was then assigned correctly to the group >35 years with the age of 49 years.

Interaction of cetyltrimethylammonium bromide and its gemini homologue bis(cetyldimethylammonium)butane dibromide with xanthine oxidase.

PubMed

Mir, Mohammad Amin; Khan, Javed Masood; Khan, Rizwan Hasan; Dar, Aijaz Ahmad; Rather, Ghulam Mohammad

2012-05-17

The interaction of xanthine oxidase (XO), a key enzyme in purine metabolism, with cetyltrimethylammonium bromide (CTAB) and bis(cetyldimethylammonium)butane dibromide (C16C4C16Br2) has been studied using tensiometry, spectrofluorometry, spectrophotometry, and circular dichroism at pH 7.4 and 25 °C. The tensiometric profiles of CTAB and C16C4C16Br2 in the presence of XO exhibit a single break at a lower surfactant concentration termed as C1 compared to their CMC in the buffered solution and show the existence of interaction between the surfactants and the enzyme. The results of the multitechnique approach showed that, although both CTAB as well as C16C4C16Br2 interact with the XO, C16C4C16Br2 interacts more strongly than its conventional single chain counterpart. Fluorescence and absorption measurements revealed that, compared to CTAB, C16C4C16Br2 is more effective in unfolding the enzyme. Change in XO activity by the surfactants was in concurrence with the structural alterations monitored by circular dichroism and showed structural stabilization of XO at higher surfactant concentrations, consistent with the aggregation results. This stabilization has been explained in light of strong tendency of C16C4C16Br2 for micellar growth and membrane/water stabilization of proteins by membrane-like fragments provided by higher concentrations of C16C4C16Br2 . The results are related to the stronger electrostatic and hydrophobic forces in C16C4C16Br2, owing to the presence of two charged headgroups and two hydrophobic tails.

iHWG-μNIR: a miniaturised near-infrared gas sensor based on substrate-integrated hollow waveguides coupled to a micro-NIR-spectrophotometer.

PubMed

Rohwedder, J J R; Pasquini, C; Fortes, P R; Raimundo, I M; Wilk, A; Mizaikoff, B

2014-07-21

A miniaturised gas analyser is described and evaluated based on the use of a substrate-integrated hollow waveguide (iHWG) coupled to a microsized near-infrared spectrophotometer comprising a linear variable filter and an array of InGaAs detectors. This gas sensing system was applied to analyse surrogate samples of natural fuel gas containing methane, ethane, propane and butane, quantified by using multivariate regression models based on partial least square (PLS) algorithms and Savitzky-Golay 1(st) derivative data preprocessing. The external validation of the obtained models reveals root mean square errors of prediction of 0.37, 0.36, 0.67 and 0.37% (v/v), for methane, ethane, propane and butane, respectively. The developed sensing system provides particularly rapid response times upon composition changes of the gaseous sample (approximately 2 s) due the minute volume of the iHWG-based measurement cell. The sensing system developed in this study is fully portable with a hand-held sized analyser footprint, and thus ideally suited for field analysis. Last but not least, the obtained results corroborate the potential of NIR-iHWG analysers for monitoring the quality of natural gas and petrochemical gaseous products.

OH and halogen atom influence on the variability of non-methane hydrocarbons in the Antarctic Boundary Layer

NASA Astrophysics Data System (ADS)

Read, Katie A.; Lewis, Alastair C.; Salmon, Rhian A.; Jones, Anna E.; Bauguitte, Stéphane

2007-02-01

Measurements of C2-C8 non-methane hydrocarbons (NMHCs) have been made in situ at Halley Base, Antarctica (75°35'S, 26°19'W) from February 2004 to February 2005 as part of the Chemistry of the Antarctic Boundary Layer and the Interface with Snow (CHABLIS) experiment. The data show long- and short-term variabilities in NMHCs controlled by the seasonal and geographic dependence of emissions and variation in atmospheric removal rates and pathways. Ethane, propane, iso-butane, n-butane and acetylene abundances followed a general OH-dependent sinusoidal seasonal cycle. The yearly averages were 186, 31, 3.2, 4.9 and 19 pptV, respectively, lower than those which were reported in some previous studies. Superimposed on a seasonal cycle was shorter-term variability that could be attributed to both synoptic airmass variability and localized loss processes due to other radical species. Hydrocarbon variability during periods of hour-to-day-long surface O3 depletion in late winter/early spring indicated active halogen atom chemistry estimated to be in the range 1.7 × 103-3.4 × 104 atom cm-3 for Cl and 4.8 × 106-9.6 × 107 atom cm-3 for Br. Longer-term negative deviations from sinusoidal behaviour in the late August were indicative of NMHC reaction with a persistent [Cl] of 2.3 × 103 atom cm-3. Maximum ethene and propene of 157 and 179 pptV, respectively, were observed in the late February/early March, consistent with increased oceanic biogenic emissions; however, their presence was significant year-round (June-August concentrations of 17.1 +/- 18.3 and 7.9 +/- 20.0 pptV, respectively).

Highly durable, coking and sulfur tolerant, fuel-flexible protonic ceramic fuel cells.

PubMed

Duan, Chuancheng; Kee, Robert J; Zhu, Huayang; Karakaya, Canan; Chen, Yachao; Ricote, Sandrine; Jarry, Angelique; Crumlin, Ethan J; Hook, David; Braun, Robert; Sullivan, Neal P; O'Hayre, Ryan

2018-05-01

Protonic ceramic fuel cells, like their higher-temperature solid-oxide fuel cell counterparts, can directly use both hydrogen and hydrocarbon fuels to produce electricity at potentially more than 50 per cent efficiency 1,2 . Most previous direct-hydrocarbon fuel cell research has focused on solid-oxide fuel cells based on oxygen-ion-conducting electrolytes, but carbon deposition (coking) and sulfur poisoning typically occur when such fuel cells are directly operated on hydrocarbon- and/or sulfur-containing fuels, resulting in severe performance degradation over time 3-6 . Despite studies suggesting good performance and anti-coking resistance in hydrocarbon-fuelled protonic ceramic fuel cells 2,7,8 , there have been no systematic studies of long-term durability. Here we present results from long-term testing of protonic ceramic fuel cells using a total of 11 different fuels (hydrogen, methane, domestic natural gas (with and without hydrogen sulfide), propane, n-butane, i-butane, iso-octane, methanol, ethanol and ammonia) at temperatures between 500 and 600 degrees Celsius. Several cells have been tested for over 6,000 hours, and we demonstrate excellent performance and exceptional durability (less than 1.5 per cent degradation per 1,000 hours in most cases) across all fuels without any modifications in the cell composition or architecture. Large fluctuations in temperature are tolerated, and coking is not observed even after thousands of hours of continuous operation. Finally, sulfur, a notorious poison for both low-temperature and high-temperature fuel cells, does not seem to affect the performance of protonic ceramic fuel cells when supplied at levels consistent with commercial fuels. The fuel flexibility and long-term durability demonstrated by the protonic ceramic fuel cell devices highlight the promise of this technology and its potential for commercial application.

Effectiveness of replacing catalytic converters in LPG-fueled vehicles in Hong Kong

NASA Astrophysics Data System (ADS)

Lyu, X. P.; Guo, H.; Simpson, I. J.; Meinardi, S.; Louie, P. K. K.; Ling, Z. H.; Wang, Y.; Liu, M.; Luk, C. W. Y.; Wang, N.; Blake, D. R.

2015-12-01

Many taxis and public buses are powered by liquefied petroleum gas (LPG) in Hong Kong. With more vehicles using LPG, they have become the major contributor to ambient volatile organic compounds (VOCs) in Hong Kong. An intervention program aimed to reduce the emissions of VOCs and nitrogen oxides (NOx) from LPG-fueled vehicles was implemented by the Hong Kong Government in September 2013. Long-term real-time measurements indicated that the program was remarkably effective in reducing LPG-related VOCs, NOx and nitric oxide (NO) in the atmosphere. Receptor modeling results further revealed that propane, propene, i-butane, n-butane and NO in LPG-fueled vehicle exhaust emissions decreased by 37.3 ± 0.4, 50.2 ± 0.3, 32.9 ± 0.4, 41.1 ± 0.4 and 75.9 ± 0.3 %, respectively, during the implementation of the program. In contrast, despite the reduction of VOCs and NOx, the O3 production following the program increased by 0.25 ± 0.04 ppbv h-1 (4.8 %). Moreover, the production rate of HOx decreased due to the reduction of VOCs, whereas NO reduction resulted in a more significant decrease of the HOx in destruction compared to the decrease in production, and an increase of hydroxyl (OH) and hydroperoxyl (HO2). Analysis of O3-VOCs-NOx sensitivity in ambient air indicated VOC-limited regimes in the O3 formation before and during the program. Moreover, a maximum reduction percentage of NOx (i.e., 29.4 %) and the lowest reduction ratio of VOCs / NOx (i.e., ~ 3 : 1) in LPG-fueled vehicle emissions were determined to give a zero O3 increment. The findings are of great help to future formulation and implementation of control strategies on vehicle emissions in Hong Kong.

Theoretical Kinetics Analysis for $$\\dot{H}$$ Atom Addition to 1,3-Butadiene and Related Reactions on the $$\\dot{C}$$ 4H 7 Potential Energy Surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yang; Klippenstein, Stephen J.; Zhou, Chong-Wen

The oxidation chemistry of the simplest conjugated hydrocarbon, 1,3-butadiene, can provide a first step in understanding the role of poly-unsaturated hydrocarbons in combustion and, in particular, an understanding of their contribution towards soot formation. Based on our previous work on propene and the butene isomers (1-, 2- and isobutene), it was found that the reaction kinetics of H-atom addition to the C=C double bond plays a significant role in fuel consumption kinetics and influences the predictions of high-temperature ignition delay times, product species concentrations and flame speed measurements. In this study, the rate constants and thermodynamic properties formore » $$\\dot{H}$$-atom addition to 1,3-butadiene and related reactions on the $$\\dot{C}$$ 4H 7 potential energy surface have been calculated using two different series of quantum chemical methods and two different kinetic codes. Excellent agreement is obtained between the two different kinetics codes. The calculated results including zero point energies, single point energies, rate constants, barrier heights and thermochemistry are systematically compared among the two quantum chemical methods. 1-methylallyl ($$\\dot{C}$$ 4H 71-3) and 3-buten-1- yl ($$\\dot{C}$$ 4H 71-4) radicals and C 2H 4 + $$\\dot{C}$$2H3 are found to be the most important channels and reactivity promoting products, respectively. We calculated that terminal addition is dominant (> 80%) compared to internal $$\\dot{H}$$-atom addition at all temperatures in the range 298 – 2000 K. However, this dominance decreases with increasing temperature. The calculated rate constants for the bimolecular reaction C 4H 6 + $$\\dot{H}$$ → products and C 2H 4 + $$\\dot{C}$$ 2H 3 → products are in excellent agreement with both experimental and theoretical results from the literature. For selected C 4 species the calculated thermochemical values are also in good agreement with literature data. In addition, the rate constants for H-atom abstraction by $$\\dot{H}$$ atoms have also been calculated, and it is found that abstraction from the central carbon atoms is the dominant channel (> 70%) at temperatures in the range 298 – 2000 K. Lastly, by incorporating our calculated rate constants for both H-atom addition and abstraction into our recently developed 1,3-butadiene model, we show that laminar flame speed predictions are significantly improved, emphasizing the value of this study.« less

Catalytic distillation process

DOEpatents

Smith, Jr., Lawrence A.

1982-01-01

A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C.sub.4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Catalytic distillation process

DOEpatents

Smith, L.A. Jr.

1982-06-22

A method is described for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C[sub 4] feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Rotational barriers. 1. 1,2-dihaloethanes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiberg, K.B.; Murcko, M.A.

1987-06-18

The rotational barrier about the C-C bond of 1,2-dichloroethane has been calculated by using several basis sets (4-31G, 6-31G*, 6-31+G*, and 6-31++G**) and including electron correlation. Corrections for zero-point energy differences, and the differences in enthalpy change from 0 to 298 K, were made by using the calculated geometries and vibrational frequencies. The trans/gauche energy difference was found to be 1.39 kcal/mol as compared to the observed value, 1.1 +/- 0.1 kcal/mol. The intramolecular interactions in the several rotamers are discussed. The trans/gauche energy difference for 1,2-difluoroethane also was calculated (MP3/6-311++G**) and was found to be 0.76 kcal/mol favoring themore » gauche conformer, again in good agreement with the experimental value of 0.57 +/- 0.09 kcal/mol. The trend in trans/gauche energy differences in the series n-butane, 1,2-dichloroethane, 1,2-difluoroethane is noted.« less

40 CFR 60.631 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... feedstock gas entering the natural gas processing plant. In light liquid service means that the piece of equipment contains a liquid that meets the conditions specified in § 60.485(e) or § 60.633(h)(2). In wet gas... the process. Natural gas liquids means the hydrocarbons, such as ethane, propane, butane, and pentane...

40 CFR 60.631 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... feedstock gas entering the natural gas processing plant. In light liquid service means that the piece of equipment contains a liquid that meets the conditions specified in § 60.485(e) or § 60.633(h)(2). In wet gas... the process. Natural gas liquids means the hydrocarbons, such as ethane, propane, butane, and pentane...

40 CFR 60.631 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... feedstock gas entering the natural gas processing plant. In light liquid service means that the piece of equipment contains a liquid that meets the conditions specified in § 60.485(e) or § 60.633(h)(2). In wet gas... the process. Natural gas liquids means the hydrocarbons, such as ethane, propane, butane, and pentane...

Tests for genotoxicity and mutagenicity of furan and its metabolite cis-2-butene-1,4-dial in L5178Y tk+/- mouse lymphoma cells.

PubMed

Kellert, Marco; Brink, Andreas; Richter, Ingrid; Schlatter, Josef; Lutz, Werner K

2008-12-08

Furan is found in various food items and is cytotoxic and carcinogenic in the liver of rats and mice. Metabolism of furan includes the formation of an unsaturated dialdehyde, cis-2-butene-1,4-dial (BDA). In view of the multifunctional electrophilic reactivity of BDA, adduct formation with protein and DNA may explain some of the toxic effects. Short-term tests for genotoxicity of furan in mammalian cells are inconclusive, little is known for BDA. We investigated BDA generated by hydrolysis of 2,5-diacetoxy-2,5-dihydrofuran for genotoxicity in L5178Y tk+/- mouse lymphoma cells using standard procedures for the comet assay, the micronucleus test, and the mouse lymphoma thymidine kinase gene mutation assay, using 4-h incubation periods. Cytotoxicity was remarkable: cell viability at concentrations>or=50 microM was reduced to <50%. In the dose range up to 25 microM, viability was >90%. Measures of comet-tail length and thymidine-kinase mutant frequency were increased 1.6- and 2.4-fold above control, respectively. Analysis of three fully independent replicates with a linear mixed-effects model showed a highly significant increase with concentration for both endpoints. Compared to methyl methanesulfonate used as a positive control, BDA was of similar potency with respect to genotoxicity, but it was much more cytotoxic. Furan added to cell cultures at doses that resulted in time-averaged effective concentrations of up to 3100 microM was neither cytotoxic nor genotoxic. A potential cross-linking activity of BDA was investigated by checking whether gamma radiation-induced DNA migration in the comet assay could be reduced by pre-treatment with BDA. In contrast to the effect of the positive control glutaraldehyde, BDA treatment did not reduce the comet tail length. On the contrary, an increase was observed at >or=100 microM BDA, which was attributable to early apoptotic cells. Although BDA was found to be a relatively potent genotoxic agent in terms of the concentration necessary to double the background measures, cytotoxicity strongly limited the concentration range that produced interpretable results. This may explain some of the inconclusive results and indicates that non-genotoxic effects must be taken into account in the discussion of the modes of toxic and carcinogenic action of furan.

Two unexpected promiscuous activities of the iron-sulfur protein IspH in production of isoprene and isoamylene.

PubMed

Ge, Deyong; Xue, Yanfen; Ma, Yanhe

2016-05-11

Bacillus species, possessing the methylerythritol phosphate (MEP) pathway for the synthesis of isoprenoid feedstock, are the highest producers of isoprene among bacteria; however, the enzyme responsible for isoprene synthesis has not been identified. The iron-sulfur protein IspH is the final enzyme of the MEP pathway and catalyses the reductive dehydration of (E)-4-hydroxy-3-methyl-2-butenyl diphosphate (HMBPP) to form isopentenyl diphosphate and dimethylallyl diphosphate (DMAPP). In this study, we demonstrated two unexpected promiscuous activities of IspH from alkaliphilic Bacillus sp. N16-5, which can produce high levels of isoprene. Bacillus sp. N16-5 IspH could catalyse the formation of isoprene from HMBPP and the conversion of DMAPP into a mixture of 2-methyl-2-butene and 3-methyl-1-butene. Both reactions require an electron transfer system, such as that used for HMBPP dehydration. Isoprene and isoamylene synthesis in Bacillus sp. N16-5 was investigated and the reaction system was reconstituted in vitro, including IspH, ferredoxin and ferredoxin-NADP(+)-reductase proteins and NADPH. The roles of specific IspH protein residues were also investigated by site-directed mutagenesis experiments; two variants (H131N and E133Q) were found to have lost the HMBPP reductase activity but could still catalyse the formation of isoprene. Overexpression of IspH H131N in Bacillus sp. N16-5 resulted in a twofold enhancement of isoprene production, and the yield of isoprene from the strain expressing E133Q was increased 300% compared with the wild-type strain. IspH from Bacillus sp. N16-5 is a promiscuous enzyme that can catalyse formation of isoprene and isoamylene. This enzyme, especially the H131N and E133Q variants, could be used for the production of isoprene from HMBPP.

Configuration control on the shape memory stiffness of molecularly imprinted polymer for specific uptake of creatinine

NASA Astrophysics Data System (ADS)

Ang, Qian Yee; Zolkeflay, Muhammad Helmi; Low, Siew Chun

2016-04-01

In this study, sol-gel processing was proposed to prepare a creatinine (Cre)-imprinted molecularly imprinted polymer (MIP). The intermolecular interaction constituted by the cross-linkers, i.e., 2-acrylamido-2-methylpropane-sulfonic acid (AMPS) and aluminium ion (Al3+), was studied and compared in order to form a confined matrix that promises the effectiveness of molecular imprinting. In view of the shape recognition, the hydrogen bonded Cre-AMPS did not demonstrate good recognition of Cre, with Cre binding found only at 5.70 ± 0.15 mg g-1 of MIP. Whilst, MIP cross-linked using Al3+ was able to attain an excellent Cre adsorption capacity of 19.48 ± 0.64 mg g-1 of MIP via the stronger ionic interaction of Cre-Al3+. Based on the Scatchard analysis, a higher Cre concentration in testing solution required greater driving force to resolve the binding resistance of Cre molecules, so as to have a precise Cre binding with shape factor. The molecular recognition ability of Cre-MIP in present work was shape-specific for Cre as compared to its structural analogue, 2-pyrrolidinone (2-pyr), by an ideal selectivity coefficient of 6.57 ± 0.10. In overall, this study has come up with a practical approach on the preparation of MIP for the detection of renal dysfunction by point-of-care Cre testing.

Chemical modification of Nafion membranes by protic ionic liquids: the key role of ionomer-cation interactions.

PubMed

Lu, Fei; Gao, Xinpei; Xie, Shuting; Sun, Nan; Zheng, Liqiang

2014-10-21

Chemically modified Nafion composite membranes were successfully fabricated using five kinds of protic ionic liquids (PILs) with different cations, 1-butylammonium methanesulfonate (BA-MS), tributylammonium methanesulfonate (TBA-MS), 2,4,6-trimethylphenylammonium methanesulfonate (TMA-MS), butane-1,4-diammonium methanesulfonate (BDA-MS), and N-(2-aminoethyl)ethane-1,2-diammonium methanesulfonate (DETA-MS). The PIL incorporated Nafion composite membranes were characterized by impedance spectroscopy, small-angle X-ray scattering (SAXS), dynamic-mechanical analysis (DMA) and thermogravimetric analysis (TGA). In general, the Nafion/PIL composite membranes exhibit a significant increase in the ionic conductivities than Nafion under anhydrous conditions. The interactions between the Nafion ionomer and different geometric cations of PILs were also discussed by the comparison of nanostructures, dynamic-mechanical properties and thermal stabilities of the Nafion/PIL composite membranes.

1-[5-(4-Bromo­phen­yl)-3-(4-fluoro­phen­yl)-4,5-dihydro-1H-pyrazol-1-yl]butan-1-one

PubMed Central

Fun, Hoong-Kun; Loh, Wan-Sin; Sapnakumari, M.; Narayana, B.; Sarojini, B. K.

2012-01-01

In the title compound, C19H18BrFN2O, the benzene rings form dihedral angles of 5.38 (7) and 85.48 (7)° with the mean plane of the 4,5-dihydro-1H-pyrazole ring (r.m.s. deviation = 0.0849 Å), which approximates to an envelope conformation with the –CH2– group as the flap. The dihedral angle between the benzene rings is 82.86 (7)°. In the crystal, C—H⋯F and C—H⋯O hydrogen bonds link the mol­ecules to form inversion dimers and together these generate chains along [011]. The crystal packing also features C—H⋯π inter­actions. PMID:22969553

Cytotoxic and Antimicrobial Activity of Dehydrozingerone based Cyclopropyl Derivatives.

PubMed

Burmudžija, Adrijana Z; Muškinja, Jovana M; Kosanić, Marijana M; Ranković, Branislav R; Novaković, Slađana B; Đorđević, Snežana B; Stanojković, Tatjana P; Baskić, Dejan D; Ratković, Zoran R

2017-08-01

A small series of 1-acetyl-2-(4-alkoxy-3-methoxyphenyl)cyclopropanes was prepared, starting from dehydrozingerone (4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one) and its O-alkyl derivatives. Their microbiological activities toward some strains of bacteria and fungi were tested, as well as their in vitro cytotoxic activity against some cancer cell lines (HeLa, LS174 and A549). All synthesized compounds showed significant antimicrobial activity and expressed cytotoxic activity against tested carcinoma cell lines, but they showed no significant influence on normal cell line (MRC5). Butyl derivative is the most active on HeLa cells (IC 50 = 8.63 μm), while benzyl one is active against LS174 and A549 cell lines (IC 50 = 10.17 and 12.15 μm, respectively). © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Sampling, storage, and analysis of C2-C7 non-methane hydrocarbons from the US National Oceanic and Atmospheric Administration Cooperative Air Sampling Network glass flasks.

PubMed

Pollmann, Jan; Helmig, Detlev; Hueber, Jacques; Plass-Dülmer, Christian; Tans, Pieter

2008-04-25

An analytical technique was developed to analyze light non-methane hydrocarbons (NMHC), including ethane, propane, iso-butane, n-butane, iso-pentane, n-pentane, n-hexane, isoprene, benzene and toluene from whole air samples collected in 2.5l-glass flasks used by the National Oceanic and Atmospheric Administration, Earth System Research Laboratory, Global Monitoring Division (NOAA ESRL GMD, Boulder, CO, USA) Cooperative Air Sampling Network. This method relies on utilizing the remaining air in these flasks (which is at below-ambient pressure at this stage) after the completion of all routine greenhouse gas measurements from these samples. NMHC in sample aliquots extracted from the flasks were preconcentrated with a custom-made, cryogen-free inlet system and analyzed by gas chromatography (GC) with flame ionization detection (FID). C2-C7 NMHC, depending on their ambient air mixing ratios, could be measured with accuracy and repeatability errors of generally < or =10-20%. Larger deviations were found for ethene and propene. Hexane was systematically overestimated due to a chromatographic co-elution problem. Saturated NMHC showed less than 5% changes in their mixing ratios in glass flask samples that were stored for up to 1 year. In the same experiment ethene and propene increased at approximately 30% yr(-1). A series of blank experiments showed negligible contamination from the sampling process and from storage (<10 pptv yr(-1)) of samples in these glass flasks. Results from flask NMHC analyses were compared to in-situ NMHC measurements at the Global Atmospheric Watch station in Hohenpeissenberg, Germany. This 9-months side-by-side comparison showed good agreement between both methods. More than 94% of all data comparisons for C2-C5 alkanes, isoprene, benzene and toluene fell within the combined accuracy and precision objectives of the World Meteorological Organization Global Atmosphere Watch (WMO-GAW) for NMHC measurements.

Synthesis of novel acid electrolytes for phosphoric acid fuel cells

NASA Astrophysics Data System (ADS)

Adcock, James L.

1988-11-01

A 40 millimole per hour scale aerosol direct fluorination reactor was constructed. F-Methyl F-4-methoxybutanoate and F-4-methoxybutanoyl fluoride were synthesized by aerosol direct fluorination of methyl 4-methoxybutanoate. Basic hydrolysis of the perfluorinated derivatives produce sodium F-4 methoxybutanoate which was pyrolyzed to F-3-methoxy-1-propene. Purification and shipment of 33 grams of F-3-methoxy-1-propene followed. Syntheses by analogous methods allowed production and shipment of 5 grams of F-3-ethoxy 1-propene, 18 grams of F-3-(2-methoxy.ethoxy) 1-propene, and 37 grams of F-3,3-dimethyl 1-butene. Eighteen grams of F-2,2-dimethyl 1-chloropropane was produced directly and shipped. As suggested by other contractors, 5 grams of F-3-methoxy 1-iodopropane, and 5 grams of F-3-(2-methoxy.ethoxy) 1-iodopropane were produced by converting the respective precursor acid sodium salts produced for olefin synthesis to the silver salts and pyrolyzing them with iodine. Each of these compounds was prepared for the first time by the aerosol fluorination process during the course of the contract. These samples were provided to other Gas Research Institute (GRI) contractors for synthesis of perfluorinated sulfur (VI) and phosphorous (V) acids.

Vitamin B1-catalyzed acetoin formation from acetaldehyde: a key step for upgrading bioethanol to bulk C₄ chemicals.

PubMed

Lu, Ting; Li, Xiukai; Gu, Liuqun; Zhang, Yugen

2014-09-01

The production of bulk chemicals and fuels from renewable biobased feedstocks is of significant importance for the sustainability of human society. The production of ethanol from biomass has dramatically increased and bioethanol also holds considerable potential as a versatile building block for the chemical industry. Herein, we report a highly selective process for the conversion of ethanol to C4 bulk chemicals, such as 2,3-butanediol and butene, via a vitamin B1 (thiamine)-derived N-heterocyclic carbene (NHC)-catalyzed acetoin condensation as the key step to assemble two C2 acetaldehydes into a C4 product. The environmentally benign and cheap natural catalyst vitamin B1 demonstrates high selectivity (99%), high efficiency (97% yield), and high tolerance toward ethanol and water impurities in the acetoin reaction. The results enable a novel and efficient process for ethanol upgrading. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Raman spectroscopic study of reaction dynamics

NASA Astrophysics Data System (ADS)

MacPhail, R. A.

1990-12-01

The Raman spectra of reacting molecules in liquids can yield information about various aspects of the reaction dynamics. The author discusses the analysis of Raman spectra for three prototypical unimolecular reactions, the rotational isomerization of n-butane and 1,2-difluoroethane, and the barrierless exchange of axial and equatorial hydrogens in cyclopentane via pseudorotation. In the first two cases the spectra are sensitive to torsional oscillations of the gauche conformer, and yield estimates of the torsional solvent friction. In the case of cyclopentane, the spectra can be used to discriminate between different stochastic models of the pseudorotation dynamics, and to determine the relevant friction coefficients.

Arctic springtime observations of volatile organic compounds during the OASIS-2009 campaign

NASA Astrophysics Data System (ADS)

Hornbrook, Rebecca S.; Hills, Alan J.; Riemer, Daniel D.; Abdelhamid, Aroob; Flocke, Frank M.; Hall, Samuel R.; Huey, L. Gregory; Knapp, David J.; Liao, Jin; Mauldin, Roy L.; Montzka, Denise D.; Orlando, John J.; Shepson, Paul B.; Sive, Barkley; Staebler, Ralf M.; Tanner, David. J.; Thompson, Chelsea R.; Turnipseed, Andrew; Ullmann, Kirk; Weinheimer, Andrew J.; Apel, Eric C.

2016-08-01

Gas-phase volatile organic compounds (VOCs) were measured at three vertical levels between 0.6 m and 5.4 m in the Arctic boundary layer in Barrow, Alaska, for the Ocean-Atmosphere-Sea Ice-Snowpack (OASIS)-2009 field campaign during March-April 2009. C4-C8 nonmethane hydrocarbons (NMHCs) and oxygenated VOCs (OVOCs), including alcohols, aldehydes, and ketones, were quantified multiple times per hour, day and night, during the campaign using in situ fast gas chromatography-mass spectrometry. Three canister samples were also collected daily and subsequently analyzed for C2-C5 NMHCs. The NMHCs and aldehydes demonstrated an overall decrease in mixing ratios during the experiment, whereas acetone and 2-butanone showed increases. Calculations of time-integrated concentrations of Br atoms, ∫[Br]dt, yielded values as high as (1.34 ± 0.27) × 1014 cm-3 s during the longest observed ozone depletion event (ODE) of the campaign and were correlated with the steady state Br calculated at the site during this time. Both chlorine and bromine chemistry contributed to the large perturbations on the production and losses of VOCs. Notably, acetaldehyde, propanal, and butanal mixing ratios dropped below the detection limit of the instrument (3 parts per trillion by volume (pptv) for acetaldehyde and propanal, 2 pptv for butanal) during several ODEs due to Br chemistry. Chemical flux calculations of OVOC production and loss are consistent with localized high Cl-atom concentrations either regionally or within a very shallow surface layer, while the deeper Arctic boundary layer provides a continuous source of precursor alkanes to maintain the OVOC mixing ratios.

Investigation of potential interferences in the detection of atmospheric ROx radicals by laser-induced fluorescence under dark conditions

NASA Astrophysics Data System (ADS)

Fuchs, H.; Tan, Z.; Hofzumahaus, A.; Broch, S.; Dorn, H.-P.; Holland, F.; Künstler, C.; Gomm, S.; Rohrer, F.; Schrade, S.; Tillmann, R.; Wahner, A.

2015-11-01

Direct detection of highly reactive, atmospheric hydroxyl radicals (OH) is widely accomplished by laser-induced fluorescence (LIF) instruments. The technique is also suitable for the indirect measurement of HO2 and RO2 peroxy radicals by chemical conversion to OH. It requires sampling of ambient air into a low pressure cell, where OH fluorescence is detected after excitation by 308 nm laser radiation. Although the residence time of air inside the fluorescence cell is typically only on the order of milliseconds, there is potential that additional OH is internally produced, which would artificially increase the measured OH concentration. Here, we present experimental studies investigating potential interferences in the detection of OH and peroxy radicals for the LIF instruments of Forschungszentrum Jülich for nighttime conditions. For laboratory experiments, the inlet of the instrument was overflown by excess synthetic air containing one or more reactants. In order to distinguish between OH produced by reactions upstream of the inlet and artificial signals produced inside the instrument, a chemical titration for OH was applied. Additional experiments were performed in the simulation chamber SAPHIR where simultaneous measurements by an open-path differential optical absorption spectrometer (DOAS) served as reference for OH to quantify potential artifacts in the LIF instrument. Experiments included the investigation of potential interferences related to the nitrate radical (NO3, N2O5), related to the ozonolysis of alkenes (ethene, propene, 1-butene, 2,3-dimethyl-2-butene, α-pinene, limonene, isoprene), and the laser photolysis of acetone. Experiments studying the laser photolysis of acetone yield OH signals in the fluorescence cell, which are equivalent to 0.05 × 106 cm-3 OH for a mixing ratio of 5 ppbv acetone. Under most atmospheric conditions, this interference is negligible. No significant interferences were found for atmospheric concentrations of reactants during ozonolysis experiments. Only for α-pinene, limonene, and isoprene at reactant concentrations which are orders of magnitude higher than in the atmosphere artificial OH could be detected. The value of the interference depends on the turnover rate of the ozonolysis reaction. For example, an apparent OH concentration of approximately 1 × 106 cm-3 is observed, if 5.8 ppbv limonene reacts with 600 ppbv ozone. Experiments with the nitrate radical NO3 reveal a small interference signal in the OH, HO2 and RO2 detection. Dependencies on experimental parameters point to artificial OH formation by surface reactions at the chamber walls or in molecular clusters in the gas expansion. The signal scales with the presence of NO3 giving equivalent radical concentrations of 1.1 × 105 cm-3 OH, 1 × 107 cm-3 HO2, and 1.7 × 107 cm-3 RO2 per 10 pptv NO3.

40 CFR 80.1235 - What gasoline is subject to the benzene requirements of this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... blendstock or finished gasoline to produce gasoline. (2) Oxygenate added to PCG downstream of the refinery... downstream of the refinery or importer that produced or imported PCG adds oxygenate to such product, it shall... credit generation under this subpart. (3) Butane added to finished gasoline, RBOB, CBOB downstream of the...

A chiral diamine: practical implications of a three-stereoisomer cocrystallization.

PubMed

Dolinar, Brian S; Samedov, Kerim; Maloney, Andrew G P; West, Robert; Khrustalev, Victor N; Guzei, Ilia A

2018-01-01

A brief comparison of seven straightforward methods for molecular crystal-volume estimation revealed that their precisions are comparable. A chiral diamine, N 2 ,N 3 -bis[2,6-bis(propan-2-yl)phenyl]butane-2,3-diamine, C 28 H 44 N 2 , has been used to illustrate the application of the methods. Three stereoisomers of the diamine cocrystallize in the centrosymmetric space group P2 1 /c with Z' = 1.5. The molecules occupying general positions are RR and SS, whereas that residing on an inversion center is meso. This is one of only ten examples of three stereoisomers with two asymmetric atoms cocrystallizing together reported to the Cambridge Structural Database (CSD). The conformations of the SS/RR and meso molecules differ considerably and lead to statistically significantly different C(asymmetric)-C(asymmetric) bond lengths in the diastereomers. An advanced Python script-based CSD searching technique for chiral compounds is presented.

Impact of higher alcohols blended in gasoline on light-duty vehicle exhaust emissions.

PubMed

Ratcliff, Matthew A; Luecke, Jon; Williams, Aaron; Christensen, Earl; Yanowitz, Janet; Reek, Aaron; McCormick, Robert L

2013-12-03

Certification gasoline was splash blended with alcohols to produce four blends: ethanol (16 vol%), n-butanol (17 vol%), i-butanol (21 vol%), and an i-butanol (12 vol%)/ethanol (7 vol%) mixture; these fuels were tested in a 2009 Honda Odyssey (a Tier 2 Bin 5 vehicle) over triplicate LA92 cycles. Emissions of oxides of nitrogen, carbon monoxide, non-methane organic gases (NMOG), unburned alcohols, carbonyls, and C1-C8 hydrocarbons (particularly 1,3-butadiene and benzene) were determined. Large, statistically significant fuel effects on regulated emissions were a 29% reduction in CO from E16 and a 60% increase in formaldehyde emissions from i-butanol, compared to certification gasoline. Ethanol produced the highest unburned alcohol emissions of 1.38 mg/mile ethanol, while butanols produced much lower unburned alcohol emissions (0.17 mg/mile n-butanol, and 0.30 mg/mile i-butanol); these reductions were offset by higher emissions of carbonyls. Formaldehyde, acetaldehyde, and butyraldehyde were the most significant carbonyls from the n-butanol blend, while formaldehyde, acetone, and 2-methylpropanal were the most significant from the i-butanol blend. The 12% i-butanol/7% ethanol blend was designed to produce no increase in gasoline vapor pressure. This fuel's exhaust emissions contained the lowest total oxygenates among the alcohol blends and the lowest NMOG of all fuels tested.

Evaluation of C4 diphosphine ligands in rhodium catalysed methanol carbonylation under a syngas atmosphere: synthesis, structure, stability and reactivity of rhodium(I) carbonyl and rhodium(III) acetyl intermediates.

PubMed

Lamb, Gareth; Clarke, Matthew; Slawin, Alexandra M Z; Williams, Bruce; Key, Lesley

2007-12-21

The carbonylation of methanol to acetic acid is a hugely important catalytic process, and there are considerable cost and environmental advantages if a process could be designed that was tolerant of hydrogen impurities in the CO feed gas, while eliminating by-products such as propionic acid and acetaldehyde altogether. This paper reports on an investigation into the application of rhodium complexes of several C(4) bridged diphosphines, namely BINAP, 1,4-bis(diphenylphosphino)butane (dppb), bis(diphenylphosphino)xylene (dppx) and 1,4-bis(dicyclohexylphosphino)butane (dcpb) as catalysts for hydrogen tolerant methanol carbonylation. An investigation into the structure, reactivity and stability of pre-catalysts and catalyst resting states of these complexes has also been carried out in order to understand the observations in catalysis. Rh(I) carbonyl halide complexes of each of the ligands have been prepared from both [Rh(2)(CO)(4)Cl(2)] and dimeric mu-Cl-[Rh(L)Cl](2) complexes. These Rh(I) carbonyl complexes are either dimeric with bridging phosphine ligands (dppb, dcpb, dppx) or monomeric chelate complexes. The reaction of the complexes with methyl iodide at 140 degrees C has been studied, which has revealed clear differences in the stability of the corresponding Rh(III) complexes. Surprisingly, the dimeric Rh(I) carbonyls react cleanly with MeI with rearrangement of the diphosphine to a chelate co-ordination mode to give stable Rh(III) acetyl complexes. The Rh acetyls for L=dppb and dppx have been fully characterised by X-ray crystallography. During the catalytic studies, the more rigid dppx and BINAP ligands were found to be nearly 5 times more hydrogen tolerant than [Rh(CO)(2)I(2)](-), as revealed by by-product analysis. The origin of this hydrogen tolerance is explained based on the differing reactivities of the Rh acetyls with hydrogen gas, and by considering the structure of the complexes.

Deprotonation of a Seemingly Hydridic Diborane(6) To Build a B-B Bond.

PubMed

Kaese, Thomas; Budy, Hendrik; Bolte, Michael; Lerner, Hans-Wolfram; Wagner, Matthias

2017-06-19

Deprotonation of the doubly arylene-bridged diborane(6) derivative 1H 2 with (Me 3 Si) 3 CLi or (Me 3 Si) 2 NK gives the B-B σ-bonded species M[1H] in essentially quantitative yields (THF, room temperature; M=Li, K, arylene=4,4'-di-tert-butyl-2,2'-biphenylylene). With nBuLi as the base, the yield of Li[1H] drops to 20 % and the 1,1-bis(9-borafluorenyl)butane Li[2H] is formed as a side product (30 %). In addition to the 1,1-butanediyl fragment, the two boron atoms of Li[2H] are linked by a μ-H bridge. In the closely related molecule Li[3H], the corresponding μ-H atom can be abstracted with (Me 3 Si) 3 CLi to afford the B-B-bonded conjugated base Li 2 [3] (THF, 150 °C; 15 %). Li[1H] and Li[2H] were characterized by NMR spectroscopy and X-ray crystallography. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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

NASA Astrophysics Data System (ADS)

Ning, Zhi; Wubulihairen, Maimaitireyimu; Yang, Fenhuan

2012-12-01

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

A new method of cannabis ingestion: the dangers of dabs?

PubMed

Loflin, Mallory; Earleywine, Mitch

2014-10-01

A new method for administering cannabinoids, called butane hash oil ("dabs"), is gaining popularity among marijuana users. Despite press reports that suggest that "dabbing" is riskier than smoking flower cannabis, no data address whether dabs users experience more problems from use than those who prefer flower cannabis. The present study aimed to gather preliminary information on dabs users and test whether dabs use is associated with more problems than using flower cannabis. Participants (n=357) reported on their history of cannabis use, their experience with hash oil and the process of "dabbing," reasons for choosing "dabs" over other methods, and any problems related to both flower cannabis and butane hash oil. Analyses revealed that using "dabs" created no more problems or accidents than using flower cannabis. Participants did report that "dabs" led to higher tolerance and withdrawal (as defined by the participants), suggesting that the practice might be more likely to lead to symptoms of addiction or dependence. The use of butane hash oil has spread outside of the medical marijuana community, and users view it as significantly more dangerous than other forms of cannabis use. Published by Elsevier Ltd.

Infrared absorption of 1-chloro-2-methyl-2-propyl [⋅C(CH3)2CH2Cl] and 2-chloro-2-methylpropyl [⋅CH2C(CH3)2Cl] radicals produced in the addition reactions of Cl with isobutene (i-C4H8) in solid para-hydrogen.

PubMed

Chou, Ching-Yin; Lee, Yuan-Pern

2016-10-07

The addition reactions of chlorine atom with isobutene (i-C 4 H 8 ) in solid para-hydrogen (p-H 2 ) were investigated with infrared (IR) absorption spectra. When a p-H 2 matrix containing Cl 2 and isobutene was irradiated with ultraviolet light at 365 nm, intense lines in a set at 534.5, 1001.0, 1212.9, 1366.0, 2961.6, and 2934.7 cm -1 , and several weaker others due to the 1-chloro-2-methyl-2-propyl radical, ⋅ C(CH 3 ) 2 CH 2 Cl, and those in a second set including intense ones at 642.7, 799.2, 1098.2, 1371.8, and 3027.3 cm -1 due to the 2-chloro-2-methylpropyl radical, ⋅ CH 2 C(CH 3 ) 2 Cl, appeared; the ratio of ⋅ C(CH 3 ) 2 CH 2 Cl to ⋅ CH 2 C(CH 3 ) 2 Cl was approximately (3 ± 1):1. The observed wavenumbers and relative intensities agree with the vibrational wavenumbers and IR intensities predicted with the B3PW91/aug-cc-pVTZ method. That the Cl atom adds to both carbons of the C=C bond of isobutene with the terminal site slightly favored is consistent with the energies of products predicted theoretically, but is in contrast to the reaction of Cl + propene in solid p-H 2 in which the addition of Cl to mainly the central C atom was previously reported. The role of the p-H 2 matrix in affecting the reaction paths is discussed. Absorption lines of the complex i-C 4 H 8 ⋅Cl 2 and the dichloro-product anti-1,2-dichloro-2-methylpropane, a-CH 2 ClCCl(CH 3 ) 2 , are also characterized.

Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

DOE PAGES

Rotavera, Brandon; Zádor, Judit; Welz, Oliver; ...

2014-09-19

The product formation from R + O 2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO 2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O 2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positivemore » dependence on temperature over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O 2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.« less

Development of segmented polyurethane elastomers with low iodine content exhibiting radiopacity and blood compatibility.

PubMed

Dawlee, S; Jayabalan, Muthu

2011-10-01

Biofunctionally active and inherently radiopaque polymers are the emerging need for biomedical applications. Novel segmented polyurethane elastomer with inherent radiopacity was prepared using aliphatic chain extender 2,3-diiodo-2-butene-1,4-diol, polyol polytetramethylene glycol and 4,4'-methylenebis(phenyl isocyanate) (MDI) for blood compatible applications. Aliphatic polyurethane was also prepared using hexamethylene diisocyanate for comparison. X-ray analysis of the polyurethanes revealed good radiopacity even at a relatively low concentration of 3% iodine in aromatic polyurethane and 10% in aliphatic polyurethane. The polyurethanes also possessed excellent thermal stability. MDI-based polyurethane showed considerably higher tensile strength than the analogous HDI-based polyurethane. MDI-based aromatic polyurethane exhibited a dynamic surface morphology in aqueous medium, resulting in the segregation of hydrophilic domains which was more conducive to anti-thrombogenic properties. The polyurethane was cytocompatible with L929 fibroblast cells, non-hemolytic, and possessed good blood compatibility.

Capillary Columns with a Sorbent Based on Functionalized Poly(1-Trimethylsilyl-1-Propyne) for the Elution Analysis of Natural Gas

NASA Astrophysics Data System (ADS)

Yakovleva, E. Yu.; Patrushev, Yu. V.; Pai, Z. P.

2018-05-01

The chromatographic properties of capillary columns prepared using functionalized poly(1- trimethylsilyl-1-propyne) (PTMSP) are evaluated and compared with the performance of a commercial column with divinylbenzene polymer sorbent. The loading capacity of a PTMSP column with dimensions of 30 m × 0.53 mm × 0.8 μm is shown to be about 2.5 times higher than that of a divinylbenzene polymer column with a diameter of 0.32 mm and a film thickness of 10 μm. The increased value of the background current for PTMSP columns at 220°C is explained by the presence of non-polar bulky substituents in the polymer chain. Differences in the order of elution are found for the following pairs of compounds: acetylene-ethylene; ethane-water; butene-1-isobutane; and sulfur dioxide-carbonyl sulfide. On a column with the functionalized PTMC, analysis of a mixture composition close to natural gas is found to be complete within 27 min.

KINETIC ANALYSIS OF ISOBUTENE/BUTENE ALKYLATION OVER ULTRASTABLE H-Y ZEOLITE. (R824729)

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...

AtomicNuclearProperties

Science.gov Websites

) Polytrifluorochloroethylene [C2F3Cl]n Polyvinylacetate [CH2CHOCOCH3]n Polyvinyl alcohol (C2H3-O-H)n Polyvinyl butyral [C8H1302 other materal for properties of interest in high-energy physics: stopping power (<-dE/dx>) tables (C10H16O) Aniline (C6H5NH2) Anthracene (C14H10) Benzene C6H6 Butane (C4H10) n-Butyl alcohol (C4H9OH) Carbon

Synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid vinyl-ACCA) derivatives: key intermediates for the preparation of inhibitors of the hepatitis C virus NS3 protease.

PubMed

Beaulieu, Pierre L; Gillard, James; Bailey, Murray D; Boucher, Colette; Duceppe, Jean-Simon; Simoneau, Bruno; Wang, Xiao-Jun; Zhang, Li; Grozinger, Karl; Houpis, Ioannis; Farina, Vittorio; Heimroth, Heidi; Krueger, Thomas; Schnaubelt, Jürgen

2005-07-22

(1R,2S)-1-Amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is a key building block in the synthesis of potent inhibitors of the hepatitis C virus NS3 protease such as BILN 2061, which was recently shown to dramatically reduce viral load after administration to patients infected with HCV genotype 1. We have developed a scalable process that delivers derivatives of this unusual amino acid in >99% ee. The strategy was based on the dialkylation of a glycine Schiff base using trans-1,4-dibromo-2-butene as an electrophile to produce racemic vinyl-ACCA, which was subsequently resolved using a readily available, inexpensive esterase enzyme (Alcalase 2.4L). Factors that affect diastereoselection in the initial dialkylation steps were examined and the conditions optimized to deliver the desired diastereomer selectively. Product inhibition, which was encountered during the enzymatic resolution step, initially resulted in prolonged cycle times. Enrichment of racemic vinyl-ACCA through a chemical resolution via diastereomeric salt formation or the use of forcing conditions in the enzymatic reaction both led to improvements in throughput and the development of a viable process. The chemistry described herein was scaled up to produce multikilogram quantities of this building block.

Carbonyl atmospheric reaction products of aromatic hydrocarbons in ambient air

NASA Astrophysics Data System (ADS)

Obermeyer, Genevieve; Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

To convert gaseous carbonyls to oximes during sampling, an XAD-4 resin denuder system pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and followed by analysis with methane positive chemical ionization gas chromatography/mass spectrometry was used to measure carbonyls in ambient air samples in Riverside, CA. In conjunction with similar analyses of environmental chamber OH radical-initiated reactions of o- and p-xylene, 1,2,4-trimethylbenzene, ethylbenzene, 4-hydroxy-2-butanone and 1,4-butanediol, we identified benzaldehyde, o-, m- and p-tolualdehyde and acetophenone and the dicarbonyls glyoxal, methylglyoxal, biacetyl, ethylglyoxal, 1,4-butenedial, 3-hexene-2,5-dione, 3-oxo-butanal, 1,4-butanedial and malonaldehyde in the ambient air samples. As discussed, these carbonyls and dicarbonyls can be formed from the OH radical-initiated reactions of aromatic hydrocarbons and other volatile organic compounds emitted into the atmosphere, and we conclude that in situ atmospheric formation is a major source of these carbonyls in our Riverside, CA, ambient air samples.

Testing of Monitoring Devices for JP-4 Releases in the Subsurface

DTIC Science & Technology

1990-04-01

tests conducted to study the effectiveness, advantages , and limitations of a set of devices. All of the devices (except FiberChem) evaluated are...1,000 ppm and 1 percent butane standards ( Alltech Associates, Inc., Deerfield, Illinois). b. Temperature Program Analysis Two different temperature...in place. The advantage of having the probe is that we did not have to calculate or measure the liquid volume displaced by the probe. The accuracy of

Geometry at the aliphatic tertiary carbon atom: computational and experimental test of the Walsh rule.

PubMed

Böhm, Stanislav; Exner, Otto

2004-02-01

The geometrical parameters of molecules of 2-substituted 2-methylpropanes and 1-substituted bicyclo[2.2.2]octanes were calculated at the B3LYP/6-311+G(d,p) level. They agreed reasonably well with the mean crystallographic values retrieved from the Cambridge Structural Database for a set of diverse non-cyclic structures with a tertiary C atom. The angle deformations at this C atom produced by the immediately bonded substituent are also closely related to those observed previously in benzene mono derivatives (either as calculated or as derived from crystallographic data). The calculated geometrical parameters were used to test the classical Walsh rule: It is evidently true that an electron-attracting substituent increases the proportion of C-atom p-electrons in the bond to the substituent and leaves more s-electrons to the remaining bonds; as a consequence the C-C-C angles at a tertiary carbon are widened and the C-C bonds shortened. However, this rule describes only part of the reality since the bond angles and lengths are controlled by other factors as well, for instance by steric crowding. Another imperfection of the Walsh rule is that the sequence of substituents does not correspond to their electronegativities, as measured by any known scale; more probably it is connected with the inductive effect, but then only very roughly.

More environment-friendly and safer working gas mixtures for Bakelite RPCs operated in streamer mode

NASA Astrophysics Data System (ADS)

Zhang, Qingmin; Lv, Zhipeng; Lv, Jinge; Zhang, Jiawen; Xu, Jilei; Ning, Zhe

2017-08-01

This paper presents experimental results of RPCs performances with different working gas mixtures. Owing to Freon's high global warming potential, its threat to RPCs aging and its large consumption in large particle physics experiments, studies to minimize the concentration of HFC-134A, and even its complete replacement, have been undertaken. In addition, the reduction of iso-butane is also a favorable strategy, due to the flammability level of the gas mixture. Freon-less working gas mixture of Ar/HFC-134A/i-C4H10/CO2=20/0/8/72 was chosen with plateau efficiency of 86.3% and noise rate of 0.61 Hz/cm2. For working gas with lower ratio of Freon, Ar/HFC-134A/i-C4H10/CO2=20/20/8/52 was suggested with plateau efficiency of 91.0% and noise rate of 0.19 Hz/cm2, in which Freon was decreased by 22% compared to the BESIII RPC gas mixture. Furthermore, iso-butane was decreased to 6% with RPC's efficiency of 90% and noise rate of 0.20 Hz/cm2 achieved. Finally, the explanation of RPC's different performances at various working gas mixtures has been validated by the investigation of secondary streamers. This study will be helpful for RPC's application in future large particle physics experiments, in which RPCs can run in streamer mode.

Tuning the oxidative power of free iron-sulfur clusters.

PubMed

Lang, Sandra M; Zhou, Shaodong; Schwarz, Helmut

2017-03-15

The gas-phase reactions between a series of di-iron sulfur clusters Fe 2 S x + (x = 1-3) and the small alkenes C 2 H 4 , C 3 H 6 , and C 4 H 8 have been investigated by means of Fourier-transform ion-cyclotron resonance mass spectrometry. For all studied alkenes, the reaction efficiency is found to increase in the order Fe 2 S + < Fe 2 S 2 + < Fe 2 S 3 + . In particular, Fe 2 S + and Fe 2 S 2 + only form simple association products, whereas the sulfur-rich Fe 2 S 3 + is able to dehydrogenate propene and 2-butene via desulfurization of the cluster and formation of H 2 S. This indicates an increased propensity to induce oxidation reactions, i.e. oxidative power, of Fe 2 S 3 + that is attributed to an increased formal oxidation state of the iron atoms. Furthermore, the ability of Fe 2 S 3 + to activate and dissociate the C-H bonds of the alkenes is observed to increase with increasing size of the alkene and thus correlates with the alkene ionization energy.

Customization of copolymers to optimize selectivity and yield in polymer-driven antibody purification processes.

PubMed

Capito, Florian; Skudas, Romas; Stanislawski, Bernd; Kolmar, Harald

2013-01-01

This manuscript describes customization of copolymers to be used for polymer-driven protein purification in bioprocessing. To understand how copolymer customization can be used for fine-tuning, precipitation behavior was analyzed for five target antibodies (mAbs) and BSA as model impurity protein, at ionic strength similar to undiluted cell culture fluid. In contrast to the use of standardized homopolymers, customized copolymers, composed of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and 4-(acryloylamino)benzoic acid (ABZ), exhibited antibody precipitation yields exceeding 90%. Additionally, copolymer average molecular weight (Mw ) was varied and its influence on precipitation yield and contaminant coprecipitation was investigated. Results revealed copolymer composition as the major driving force for precipitation selectivity, which was also dependent on protein hydrophobicity. By adjusting ABZ content and Mw of the precipitant for each of the mAbs, conditions were found that allowed for high precipitation yield and selectivity. These findings may open up new avenues for using polymers in antibody purification processes. © 2013 American Institute of Chemical Engineers.

Identification, preparation and UHPLC determination of process-related impurity in zolmitriptan.

PubMed

Douša, Michal; Gibala, Petr; Rádl, Stanislav; Klecán, Ondřej; Mandelová, Zuzana; Břicháč, Jiří; Pekárek, Tomáš

2012-01-25

A new impurity was detected and determined using gradient ion-pair UHPLC method with UV detection in zolmitriptan (ZOL). Using MS, NMR and IR study the impurity was identified as (4S,4'S)-4,4'-(2,2'-(4-(dimethylamino)butane-1,1-diyl)bis(3-(2-(dimethylamino) ethyl)-1H-indole-5,2-diyl))bis(methylene)di(oxazolidin-2-one) (ZOL-dimer). The standard of ZOL-dimer was consequently prepared via organic synthesis followed by semipreparative HPLC purification. The UHPLC method was optimized in order to selectively detect and quantify other known and unknown process-related impurities and degradation products of ZOL as well. The presented method which was validated with respect to linearity, accuracy, precision and selectivity has an advantage of a very quick UHPLC chromatographic separation (less than 7 min including re-equilibration time) and therefore is highly suitable for routine analysis of related substances and stability studies of ZOL. Copyright © 2011 Elsevier B.V. All rights reserved.

Phase equilibrium measurements on twelve binary mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giles, N.F.; Wilson, H.L.; Wilding, W.V.

1996-11-01

Phase equilibrium measurements have been performed on twelve binary mixtures. The PTx method was used to obtain vapor-liquid equilibrium data for the following binary systems at two temperatures each: ethanethiol + propylene; nitrobenzene + methanol; pyridine + ethyl acetate; octane + tert-amyl methyl ether; diisopropyl ether + butane; 1,3-dichloro-2-propanol + epichlorohydrin; 2,3-dichloro-1-propanol + epichlorohydrin; 2,3-epoxy-1-propanol + epichlorohydrin; 3-chloro-1,2-propanediol + epichlorohydrin; methanol + hydrogen cyanide. For these systems, equilibrium vapor and liquid phase compositions were derived from the PTx data using the Soave equation of state to represent the vapor phase and the Wilson, NRTL, or Redlich-Kister activity coefficient model tomore » represent the liquid phase. The infinite dilution activity coefficient of methylamine in N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone-rich half of the binary. Liquid-liquid equilibrium studies were made on the triethylene glycol + 1-pentene system at two temperatures by directly analyzing samples taken from each liquid phase.« less

Gas-Phase Dimerization of Ethylene under Mild Conditions Catalyzed by MOF Materials Containing (bpy)Ni II Complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madrahimov, Sherzod T.; Gallagher, James R.; Zhang, Guanghui

2015-10-09

NU-1000-(bpy)Ni-II, a highly porous MOF material possessing well-defined (bpy)Ni-II moieties, was prepared through solvent-assisted ligand incorporation (SALI). Treatment with Et2AlCl affords a single-site catalyst with excellent catalytic activity for ethylene dimerization (intrinsic activity for butenes that is up to an order of magnitude higher than the corresponding (bpy)NiCl2 homogeneous analogue) and stability (can be reused at least three times). The high porosity of this catalyst results in outstanding levels of activity at ambient temperature in gas-phase ethylene dimerization reactions, both under batch and continuous flow conditions.

Regioselective alkane hydroxylation with a mutant CYP153A6 enzyme

DOEpatents

Koch, Daniel J.; Arnold, Frances H.

2013-01-29

Cytochrome P450 CYP153A6 from Myobacterium sp. strain HXN1500 was engineered using in-vivo directed evolution to hydroxylate small-chain alkanes regioselectively. Mutant CYP153A6-BMO1 selectively hydroxylates butane and pentane at the terminal carbon to form 1-butanol and 1-pentanol, respectively, at rates greater than wild-type CYP153A6 enzymes. This biocatalyst is highly active for small-chain alkane substrates and the regioselectivity is retained in whole-cell biotransformations.

Effective Subcritical Butane Extraction of Bifenthrin Residue in Black Tea.

PubMed

Zhang, Yating; Gu, Lingbiao; Wang, Fei; Kong, Lingjun; Qin, Guangyong

2017-03-30

As a natural and healthy beverage, tea is widely enjoyed; however, the pesticide residues in tea leaves affect the quality and food safety. To develop a highly selective and efficient method for the facile removal of pesticide residues, the subcritical butane extraction (SBE) technique was employed, and three variables involving temperature, time and extraction cycles were studied. The optimum SBE conditions were found to be as follows: extraction temperature 45 °C, extraction time 30 min, number of extraction cycles 1, and in such a condition that the extraction efficiency reached as high as 92%. Further, the catechins, theanine, caffeine and aroma components, which determine the quality of the tea, fluctuated after SBE treatment. Compared with the uncrushed leaves, pesticide residues can more easily be removed from crushed leaves, and the practical extraction efficiency was 97%. These results indicate that SBE is a useful method to efficiently remove the bifenthrin, and as appearance is not relevant in the production process, tea leaves should first be crushed and then extracted in order that residual pesticides are thoroughly removed.

Sulfonated macro-RAFT agents for the surfactant-free synthesis of cerium oxide-based hybrid latexes.

PubMed

Garnier, Jérôme; Warnant, Jérôme; Lacroix-Desmazes, Patrick; Dufils, Pierre-Emmanuel; Vinas, Jérôme; van Herk, Alex

2013-10-01

Three types of amphiphatic macro-RAFT agents were employed as compatibilizers to promote the polymerization reaction at the surface of nanoceria for the synthesis of CeO2-based hybrid latexes. Macro-RAFT copolymers and terpolymers were first synthesized employing various combinations of butyl acrylate as a hydrophobic monomer and acrylic acid (AA) and/or 2-acrylamido-2-methylpropane sulfonic acid (AMPS) as hydrophilic monomers. After characterizing the adsorption of these macro-RAFT agents at the cerium oxide surface by UV-visible spectrometry, emulsion copolymerization reactions of styrene and methyl acrylate were then carried out in the presence of the surface-modified nanoceria. Dynamic Light Scattering and cryo-Transmission Electron Microscopy were employed to confirm the hybrid structure of the final CeO2/polymer latexes, and proved that the presence of acrylic acid units in amphiphatic macro-RAFT agents enabled an efficient formation of hybrid structures, while the presence of AMPS units, when combined with AA units, resulted in a better distribution of cerium oxide nanoclusters between latex particles. Copyright © 2013 Elsevier Inc. All rights reserved.

Development of three stable isotope dilution assays for the quantitation of (E)-2-butenal (crotonaldehyde) in heat-processed edible fats and oils as well as in food.

PubMed

Granvogl, Michael

2014-02-12

Three stable isotope dilution assays (SIDAs) were developed for the quantitation of (E)-2-butenal (crotonaldehyde) in heat-processed edible fats and oils as well as in food using synthesized [¹³C₄]-crotonaldehyde as internal standard. First, a direct headspace GC-MS method, followed by two indirect methods on the basis of derivatization with either pentafluorophenylhydrazine (GC-MS) or 2,4-dinitrophenylhydrazine (LC-MS/MS), was developed. All methods are also suitable for the quantitation of acrolein using the standard [¹³C₃]-acrolein. Applying these three methods on five different types of fats and oils varying in their fatty acid compositions revealed significantly varying crotonaldehyde concentrations for the different samples, but nearly identical quantitative data for all methods. Formed amounts of crotonaldehyde were dependent not only on the type of oil, e.g., 0.29-0.32 mg/kg of coconut oil or 33.9-34.4 mg/kg of linseed oil after heat-processing for 24 h at 180 °C, but also on the applied temperature and time. The results indicated that the concentration of formed crotonaldehyde seemed to be correlated with the amount of linolenic acid in the oils. Furthermore, the formation of crotonaldehyde was compared to that of its homologue acrolein, demonstrating that acrolein was always present in higher amounts in heat-processed oils, e.g., 12.3 mg of crotonaldehyde/kg of rapeseed oil in comparison to 23.4 mg of acrolein/kg after 24 h at 180 °C. Finally, crotonaldehyde was also quantitated in fried food, revealing concentrations from 12 to 25 μg/kg for potato chips and from 8 to 19 μg/kg for donuts, depending on the oil used.

Syntheses and structural characterization of mercury (II) coordination polymers with neutral bidentate flexible pyrazole-based ligands

NASA Astrophysics Data System (ADS)

Lalegani, Arash; Khaledi Sardashti, Mohammad; Salavati, Hossein; Asadi, Amin; Gajda, Roman; Woźniak, Krzysztof

2016-03-01

Mercury(II) coordination compounds [Hg(μ-bbd)(μ-SCN)4]n(1) and [Hg(bpp)(SCN)2] (2) were synthesized by using the neutral flexible bidentate N-donor ligands 1,4-bis(3,5-dimethypyrazol-1-yl)butane (bbd) and 1,3-bis(3,5-dimethylpyrazolyl)propane (bpp), NCS- ligand and appropriate mercury(II) salts. Compound 1 forms a polymeric network with moieties which are connected by SCN groups and the mercury ions present as HgN3S2 trigonal bipyramides. The crystal structure of 2 is build of monomers and the mercury(II) ion adopts an HgN2S2 tetrahedral geometry. In the complex 1, each bbd acts as bridging ligand connecting Hg(μ-SCN)4 ions, while in the complex 2, the bpp ligand is coordinated to an mercury(II) ion in a cyclic-bidentate fashion forming an eight-membered metallocyclic ring. Moreover, in the tetrahedral structure of 2, the neutral molecules form a 1D chain structure through the C-H···N hydrogen bonds, whereas in 1 no hydrogen bonds are observed. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction.

Synthesis of 2,3-trans-3,4-cis- and 2,3-trans-3,4-trans-2,3,4-triphenyltetrahydrofurans.

PubMed

Munshi, K L; Dikshit, D K; Kapil, R S; Anand, N

1974-04-01

The synthesis of 2,3-trans-3,4-cis- and 2,3-trans-3,4-trans-2,3,4-triphenyltetrahydrofurans was undertaken because these compounds incorportae the essential structural features of certain 2,3-diphenyl-benzofurans and 1,2,3-triphenylalkanones reported earlier to have marked antifertility activity. The synthesis of the 2 tetrahydrofurans was achieved by the cyclization of corresponding 2,3,4-triphenylbutane-1,4-diols upon heating with dimethyl sulfoxide (DMSO). The butane 1,4-diols were in turn prepared either by direct litium aluminum hydride (LAH) reduction of methyl 3-benzoyl-2,3-diphenylpropionates or by conversion of these propionates to delta-3,4-butryrolactones followed by LAH reduction. The propionates were prepared from the Fiedel-Crafts reaction of 2,3-diphenylsuccinic anhydride with benzene. Tetrahydrofurans were tested for their antiimplantation activity in rats. 2,3-trans-3,4-cis-2,4-diphenyl-3-p -(beta-pyrrolidinoethoxy) phenyltetrahydrofuran oxalate was found to inhibit implantation completely at 50 mg/kg, but was inefective at a lower dose.

Microbial Oxidation of Natural Gas in a Plume Emanating from the Coal Oil Point Seep Field

NASA Astrophysics Data System (ADS)

Mendes, S. D.; Valentine, D. L.; Perez, C.; Scarlett, R.

2012-12-01

The hydrocarbon seep field at Coal Oil Point, off the coast of Santa Barbara, California, releases > 1010 g of thermogenic natural gas each year. Gases emitted from Coal Oil Point include methane, ethane, propane, and butane, which are atmospheric pollutants and greenhouse gases. Even though the seeps are at water depths of only 5-80 m, much of the gas dissolves and contributes to a plume that is transported by ocean currents. While hydrocarbons can support bacterial respiration, resulting in the removal of hydrocarbon gas from the plume, the time-scale for the bacterial respiratory response is unconstrained. To track hydrocarbon respiration 3H-ethane, propane, and butane were synthesized using Grignard reagents and tritiated water with yields of >70% and applied as tracers to samples up- and down-current from the seeps at Coal Oil Point. Validation experiments conducted in September 2011 aboard the R/V Atlantis show that 3H-labeled tracers are an order of magnitude more sensitive than previous methods using stable carbon isotopes (Valentine et. al 2010), making this technique preferable in natural systems. Application of the tracers concurrent with plume tracking in July-August 2012 show ethane, propane, and butane consumption are readily inducible on a timescale of days.

Degraded protein adducts of cis-2-butene-1,4-dial are urinary and hepatocyte metabolites of furan.

PubMed

Lu, Ding; Sullivan, Mathilde M; Phillips, Martin B; Peterson, Lisa A

2009-06-01

Furan is a liver toxicant and carcinogen in rodents. On the basis of these observations and the large potential for human exposure, furan has been classified as a possible human carcinogen. The mechanism of tumor induction by furan is unknown. However, the toxicity requires cytochrome P450-catalyzed oxidation of furan. The product of this oxidation, cis-2-butene-1,4-dial (BDA), reacts readily with glutathione, amino acids, and DNA and is a bacterial mutagen in Ames assay strain TA104. Characterization of the urinary metabolites of furan is expected to provide information regarding the structure(s) of the reactive metabolite(s). Recently, several urinary metabolites have been identified. We reported the presence of a monoglutathione-BDA reaction product, N-[4-carboxy-4-(3-mercapto-1H-pyrrol-1-yl)-1-oxobutyl]-l-cysteinylglycine cyclic sulfide. Three additional urinary metabolites of furan were also characterized as follows: R-2-acetylamino-6-(2,5-dihydro-2-oxo-1H-pyrrol-1-yl)-1-hexanoic acid, N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-l-cysteine, and its sulfoxide. It was postulated that these three metabolites are derived from degraded protein adducts. However, the possibility that these metabolites result from the reaction of BDA with free lysine and/or cysteine was not ruled out. In this latter case, one might predict that the reaction of thiol-BDA with free lysine would not occur exclusively on the epsilon-amino group. Reaction of BDA with N-acetylcysteine or GSH in the presence of lysine indicated that both the alpha- and the epsilon-amino groups of lysine can be modified by thiol-BDA. The N-acetylcysteine-BDA-N-acetyllysine urinary metabolites were solely linked through the epsilon-amino group of lysine. A GSH-BDA-lysine cross-link was a significant hepatocyte metabolite of furan. In this case, the major product resulted from reaction with the epsilon-amino group of lysine; however, small amounts of the alpha-amino reaction product were also observed. Western analysis of liver and hepatocyte protein extracts using anti-GSH antibody indicated that GSH was covalently linked to proteins in tissues or cells exposed to furan. Our data support the hypothesis that GSH-BDA can react with either free lysine or protein lysine groups. These data suggest that there are multiple pathways by which furan can modify cellular nucleophiles. In one pathway, BDA reacts directly with proteins to form cysteine-lysine reaction products. In another, BDA reacts with GSH to form GSH-BDA conjugates, which then react with cellular nucleophiles like free lysine or lysine moieties in proteins. Both pathways will give rise to N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-l-cysteine. Given the abundance of these metabolites in urine of furan-treated rats, these pathways appear to be major pathways of furan biotransformation in vivo.

Degraded protein adducts of cis-2-butene-1,4-dial are urinary and hepatocyte metabolites of furan

PubMed Central

Lu, Ding; Sullivan, Mathilde M.; Phillips, Martin B.; Peterson, Lisa A.

2009-01-01

Furan is a liver toxicant and carcinogen in rodents. Based on these observations and the large potential for human exposure, furan has been classified as a possible human carcinogen. The mechanism of tumor induction by furan is unknown. However, the toxicity requires cytochrome P450 catalyzed oxidation of furan. The product of this oxidation, cis-2-butene-1,4-dial (BDA), reacts readily with glutathione, amino acids and DNA and is a bacterial mutagen in Ames assay strain TA104. Characterization of the urinary metabolites of furan is expected to provide information regarding the structure(s) of the reactive metabolite(s). Recently, several urinary metabolites have been identified. We reported the presence of a mono-glutathione-BDA reaction product, N-[4-carboxy-4-(3-mercapto-1H-pyrrol-1-yl)-1-oxobutyl]-L-cysteinylglycine cyclic sulfide. Three additional urinary metabolites of furan were also characterized: R-2-acetylamino-6-(2,5-dihydro-2-oxo-1H-pyrrol-1-yl)-1-hexanoic acid, N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-L-cysteine and its sulfoxide. It was postulated that these three metabolites are derived from degraded protein adducts. However, the possibility that these metabolites result from reaction of BDA with free lysine and/or cysteine was not ruled out. In this latter case, one might predict that the reaction of thiol-BDA with free lysine would not occur exclusively on the ε-amino group. Reaction of BDA with N-acetylcysteine or GSH in the presence of lysine indicated that both the α- and ε-amino groups of lysine can be modified by thiol-BDA. The N-acetylcysteine-BDA-N-acetyllysine urinary metabolites were solely linked through the ε-amino group of lysine. A GSH-BDA-lysine crosslink was a significant hepatocyte metabolite of furan. In this case, the major product resulted from reaction with the ε-amino group of lysine, however, small amounts of the α-amino reaction product were also observed. Western analysis of liver and hepatocyte protein extracts using anti-GSH antibody indicated that GSH was covalently linked to proteins in tissues or cells exposed to furan. Our data support the hypothesis that GSH-BDA can react with either free lysine or protein lysine groups. These data suggest that there are multiple pathways by which furan can modify cellular nucleophiles. In one pathway, BDA reacts directly with proteins to form cysteine-lysine reaction products. In another, BDA reacts with GSH to form GSH-BDA conjugates which then reacts with cellular nucleophiles like free lysine or lysine moieties in proteins. Both pathways will give rise to N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-L-cysteine. Given the abundance of these metabolites in urine of furan-treated rats, these pathways appear to be major pathways of furan biotransformation in vivo. PMID:19441776

Catalytic hydrolysis of cellulose into furans

NASA Astrophysics Data System (ADS)

Shi, Chengmei; Tao, Furong; Cui, Yuezhi

2016-12-01

Chromium chloride in 4-(3-methylimidazolium-1-yl)butane-1-sulfonic acid hydrogen sulfate (IL-1) was found to effectively catalyze the hydrolysis of microcrystalline cellulose (MCC) at 150°C for 300 min to achieve 87.8% conversion to a slate of products. With a catalytic amount of CrCl3, the yields of 5-hydroxymethyl furfural (HMF) and furfural were up to 32.4 and 15.2%, respectively, small molecules levulinic acid (LA, 10.8%) and the total reducing sugars (TRS, 10.7%) were also generated. Through LC-MSD analysis and mass spectra, dimer of furan compounds as the main by-products were speculated, and the components of gas products were methane, ethane, CO, CO2, and H2. We suggested that IL-1 and CrCl3 exhibited a coordination interaction; the formation of the intermediate via the hydride shift played a key role in the formation of HMF. The catalyst was recycled and exhibited constant activity for five successive trials.

Investigation of potential interferences in the detection of atmospheric ROx radicals by laser-induced fluorescence under dark conditions

NASA Astrophysics Data System (ADS)

Fuchs, Hendrik; Tan, Zhaofeng; Hofzumahaus, Andreas; Broch, Sebastian; Dorn, Hans-Peter; Holland, Frank; Künstler, Christopher; Gomm, Sebastian; Rohrer, Franz; Schrade, Stephanie; Tillmann, Ralf; Wahner, Andreas

2016-04-01

Direct detection of highly reactive, atmospheric hydroxyl radicals (OH) is widely accomplished by laser-induced fluorescence (LIF) instruments. The technique is also suitable for the indirect measurement of HO2 and RO2 peroxy radicals by chemical conversion to OH. It requires sampling of ambient air into a low-pressure cell, where OH fluorescence is detected after excitation by 308 nm laser radiation. Although the residence time of air inside the fluorescence cell is typically only on the order of milliseconds, there is potential that additional OH is internally produced, which would artificially increase the measured OH concentration. Here, we present experimental studies investigating potential interferences in the detection of OH and peroxy radicals for the LIF instruments of Forschungszentrum Jülich for nighttime conditions. For laboratory experiments, the inlet of the instrument was over flowed by excess synthetic air containing one or more reactants. In order to distinguish between OH produced by reactions upstream of the inlet and artificial signals produced inside the instrument, a chemical titration for OH was applied. Additional experiments were performed in the simulation chamber SAPHIR where simultaneous measurements by an open-path differential optical absorption spectrometer (DOAS) served as reference for OH to quantify potential artifacts in the LIF instrument. Experiments included the investigation of potential interferences related to the nitrate radical (NO3, N2O5), related to the ozonolysis of alkenes (ethene, propene, 1-butene, 2,3-dimethyl-2-butene, α-pinene, limonene, isoprene), and the laser photolysis of acetone. Experiments studying the laser photolysis of acetone yield OH signals in the fluorescence cell, which are equivalent to 0.05 × 106 cm-3 OH for a mixing ratio of 5 ppbv acetone. Under most atmospheric conditions, this interference is negligible. No significant interferences were found for atmospheric concentrations of reactants during ozonolysis experiments. Only for propene, α-pinene, limonene, and isoprene at reactant concentrations, which are orders of magnitude higher than in the atmosphere, could artificial OH be detected. The value of the interference depends on the turnover rate of the ozonolysis reaction. For example, an apparent OH concentration of approximately 1 × 106 cm-3 is observed when 5.8 ppbv limonene reacts with 600 ppbv ozone. Experiments with the nitrate radical NO3 reveal a small interference signal in the OH, HO2, and RO2 detection. Dependencies on experimental parameters point to artificial OH formation by surface reactions at the chamber walls or in molecular clusters in the gas expansion. The signal scales with the presence of NO3 giving equivalent radical concentrations of 1.1 × 105 cm-3 OH, 1 × 107 cm-3 HO2, and 1.7 × 107 cm-3 RO2 per 10 pptv NO3.

Influence of Crystal Expansion/Contraction on Zeolite Membrane Permeation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorenson, Stephanie G; Payzant, E Andrew; Noble, Richard D

X-ray diffraction was used to measure the unit cell parameters of B-ZSM-5, SAPO-34, and NaA zeolite powders as a function of adsorbate loading at 303 K, and in one case, at elevated temperatures. Most adsorbates expanded the zeolite crystals below saturation loading at 303 K: n-hexane and SF6 in B-ZSM-5, methanol and CO2 in SAPO-34, and methanol in NaA zeolite. As the loadings increased, the crystals expanded more. Changes in the unit cell volumes of B-ZSM-5 and SAPO-34 zeolite powders correlated with changes in permeation through zeolite membranes defects. When the zeolite crystals expanded or contracted upon adsorption, the defectmore » sizes decreased or increased. In B-ZSM-5 membranes, the fluxes through defects decreased dramatically when n-hexane or SF6 adsorbed. In contrast, i-butane adsorption at 303 K contracted B-ZSM-5 crystals at low loadings and expanded them at higher loadings. Correspondingly, the flux through B-ZSM-5 membrane defects increased at low i-butane loadings and decreased at high loading because the defects increased in size at low loading and decreased at high loadings. At 398 K and 473 K, n-hexane expanded the B-ZSM-5 unit cell more as the temperature increased from 303 to 473 K. The silicalite-1 and B-ZSM-5 unit cell volumes expanded similarly upon n-hexane adsorption at 303 K; boron substitution had little effect on volume expansion.« less

Conversion of 2,3-butanediol to 2-butanol, olefins and fuels

DOEpatents

Lilga, Michael A.; Lee, Guo-Shuh; Lee, Suh-Jane

2016-12-13

Embodiments of an integrated method for step-wise conversion of 2,3-butanediol to 2-butanol, and optionally to hydrocarbons, are disclosed. The method includes providing an acidic catalyst, exposing a composition comprising aqueous 2,3-butanediol to the acidic catalyst to produce an intermediate composition comprising methyl ethyl ketone, providing a hydrogenation catalyst that is spatially separated from the acidic catalyst, and subsequently exposing the intermediate composition to the hydrogenation catalyst to produce a composition comprising 2-butanol. The method may further include subsequently exposing the composition comprising 2-butanol to a deoxygenation catalyst, and deoxygenating the 2-butanol to form hydrocarbons. In some embodiments, the hydrocarbons comprise olefins, such as butenes, and the method may further include subsequently exposing the hydrocarbons to a hydrogenation catalyst to form saturated hydrocarbons.

77 FR 3750 - Notice of Intent To Grant a Partially Exclusive License; Cobalt Technologies, Inc.

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-25

... described in the following: patent application 61/562231: Water and Contaminants Removal From Butanol...-Butene, filed on July 29, 2009.// patent application 12/769757: Turbine and Diesel Fuels and Methods of... Oligomerization of Olefin Feedstocks for the Production of Turbine and Diesel Fuels, filed on April 27, 2011...

Suicide Inhibitors of Reverse Transcriptase in the Therapy of AIDS and Other Retroviruses

DTIC Science & Technology

1989-07-01

Acquired Immun Deficiency Syndrome (AIDS) (7-8). The most recent evaluation of the AIDS epidemic in the U.S. (4) indicates that the currer total of...are shown below. One of the first, [N-(L-3-tran carboxyxiran-2-carbonyl)-L-leucyl]-amido (4-guanido) butane was isolated from Asperg /II japonicus and...risk of acquired immune deficiency syndrome (AIDS). Science. 2.4: 497- 500 (1983). 9. Kopkrowski H., De Freitas E.C., Harper M.E., Woliheim S.M

Synthesis of hydrocarbons by CO2 fluid conversion with hydrogen: Experimental modeling at 7.8 GPa and 1350°C

NASA Astrophysics Data System (ADS)

Sokol, A. G.; Tomilenko, A. A.; Bul'bak, T. A.; Sobolev, N. V.

2017-12-01

Synthesis of hydrocarbons by the interaction of a CO2 fluid with hydrogen mantle domains has been simulated in an experiment at 7.8 GPa and 1350°C. The synthesized fluid contains mainly aldehydes; lower amounts of ketones, alcohols, esters, and ethers; as well as noticeable amounts of isobutane and butane, alkenes, arenes, and polycyclic aromatic and heterocyclic hydrocarbons. The fluid is compositionally close to volatiles found in inclusions from mantle olivines and picroilmenites.

Ethylene polymerization on a SiH4-modified Phillips catalyst: detection of in situ produced α-olefins by operando FT-IR spectroscopy.

PubMed

Barzan, Caterina; Groppo, Elena; Quadrelli, Elsje Alessandra; Monteil, Vincent; Bordiga, Silvia

2012-02-21

Ethylene polymerization on a model Cr(II)/SiO(2) Phillips catalyst modified with gas phase SiH(4) leads to a waxy product containing a bimodal MW distribution of α-olefins (M(w) < 3000 g mol(-1)) and a highly branched polyethylene, LLDPE (M(w) ≈ 10(5) g mol(-1), T(m) = 123 °C), contrary to the unmodified catalyst which gives a linear and more dense PE, HDPE (M(w) = 86,000 g mol(-1) (PDI = 7), T(m) = 134 °C). Pressure and temperature resolved FT-IR spectroscopy under operando conditions (T = 130-230 K) allows us to detect α-olefins, and in particular 1-hexene and 1-butene (characteristic IR absorption bands at 3581-3574, 1638 and 1598 cm(-1)) as intermediate species before their incorporation in the polymer chains. The polymerization rate is estimated, using time resolved FT-IR spectroscopy, to be 7 times higher on the SiH(4)-modified Phillips catalyst with respect to the unmodified one.

Environmental Restoration - Expedient Methods and Technologies: A User Guide with Case Studies

DTIC Science & Technology

1998-03-01

benzene, high fructose corn syrup , raw molasses, butane gas, sodium benzoate, or acetate. Enhanced anaerobic biodegradation of jet fuels in ground water...appendix discusses technology applications that are deemed impractical because of high cost, difficulty of use, or other factors. Also included is a...conversations with knowledgeable 1 Technologically sophisticated processes are not addressed in this study because of high cost, which includes the engineering

The rabbit liver microsomal biotransformation of 1,1-dialkylethylenes: enantioface selection of epoxidation and enantioselectivity of epoxide hydrolysis.

PubMed

Bellucci, G; Chiappe, C; Cordoni, A; Marioni, F

1994-01-01

The rabbit liver microsomal biotransformation of alpha-methylstyrene (1a), 2-methyl-1-hexene (1b), 2,4,4-trimethyl-1-pentene (1c), and 1,3,3-trimethyl-1-butene (1d) has been investigated with the aim at establishing the enantioface selection of the cytochrome P-450-promoted epoxidation of the double bond and the enantioselectivity of microsomal epoxide hydrolase(mEH)-catalyzed hydrolysis of the resulting epoxides. GLC on a Chiraldex G-TA (ASTEC) column was used to determine the enantiomeric composition of the products. The epoxides 2 first produced in incubations carried out in the presence of an NADPH regenerating system were not detected, being rapidly hydrolyzed by mEH to diols 3. The enantiomeric composition of the latter showed that no enantioface selection occurred in the epoxidation of 1c and 1d, and a very low (8%) ee of the (R)-epoxide was formed from 1b. Incubation of racemic epoxides 2b-d with the microsomal fraction showed that the mEH-catalyzed hydrolysis of 2c and 2d was practically nonenantioselective, while that of 2b exhibited a selectivity E = 4.9 favoring the hydrolysis of the (S)-enantiomer. A comparison of these results with those previously obtained for linear and branched chain alkyl monosubstituted oxiranes shows that the introduction of the second alkyl substituent suppresses the selectivity of the mEH reaction of the latter and reverses that of the former substrates.

Extended reaction scope of thiamine diphosphate dependent cyclohexane-1,2-dione hydrolase: from C-C bond cleavage to C-C bond ligation.

PubMed

Loschonsky, Sabrina; Wacker, Tobias; Waltzer, Simon; Giovannini, Pier Paolo; McLeish, Michael J; Andrade, Susana L A; Müller, Michael

2014-12-22

ThDP-dependent cyclohexane-1,2-dione hydrolase (CDH) catalyzes the CC bond cleavage of cyclohexane-1,2-dione to 6-oxohexanoate, and the asymmetric benzoin condensation between benzaldehyde and pyruvate. One of the two reactivities of CDH was selectively knocked down by mutation experiments. CDH-H28A is much less able to catalyze the CC bond formation, while the ability for CC bond cleavage is still intact. The double variant CDH-H28A/N484A shows the opposite behavior and catalyzes the addition of pyruvate to cyclohexane-1,2-dione, resulting in the formation of a tertiary alcohol. Several acyloins of tertiary alcohols are formed with 54-94 % enantiomeric excess. In addition to pyruvate, methyl pyruvate and butane-2,3-dione are alternative donor substrates for CC bond formation. Thus, the very rare aldehyde-ketone cross-benzoin reaction has been solved by design of an enzyme variant. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New Formulation for the Viscosity of n-Butane

NASA Astrophysics Data System (ADS)

Herrmann, Sebastian; Vogel, Eckhard

2018-03-01

A new viscosity formulation for n-butane, based on the residual quantity concept, uses the reference equation of state by Bücker and Wagner [J. Phys. Chem. Ref. Data 35, 929 (2006)] and is valid in the fluid region from the triple point to 650 K and to 100 MPa. The contributions for the zero-density viscosity and for the initial-density dependence were separately developed, whereas those for the critical enhancement and for the higher-density terms were pretreated. All contributions were given as a function of the reciprocal reduced temperature τ, while the last two contributions were correlated as a function of τ and of the reduced density δ. The different contributions were based on specific primary data sets, whose evaluation and choice were discussed in detail. The final formulation incorporates 13 coefficients derived employing a state-of-the-art linear optimization algorithm. The viscosity at low pressures p ≤ 0.2 MPa is described with an expanded uncertainty of 0.5% (coverage factor k = 2) for temperatures 293 ≤ T/K ≤ 626. The expanded uncertainty in the vapor phase at subcritical temperatures T ≥ 298 K as well as in the supercritical thermodynamic region T ≤ 448 K at pressures p ≤ 30 MPa is estimated to be 1.5%. It is raised to 4.0% in regions where only less reliable primary data sets are available and to 6.0% in ranges without any primary data, but in which the equation of state is valid. A weakness of the reference equation of state in the near-critical region prevents estimation of the expanded uncertainty in this region. Viscosity tables for the new formulation are presented in Appendix B for the single-phase region, for the vapor-liquid phase boundary, and for the near-critical region.

21 CFR 184.1005 - Acetic acid.

Code of Federal Regulations, 2014 CFR

2014-04-01

... synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived from ethylene, liquid phase oxidation of butane, and reaction of carbon monoxide with methanol derived from...

Quantifying Interfacial pH Variation at Molecular Length Scales Using a Concurrent Non-Faradaic Reaction.

PubMed

Ryu, Jaeyune; Wuttig, Anna; Surendranath, Yogesh

2018-05-15

We quantify changes in the interfacial pH local to the electrochemical double layer during electrocatalysis, using a concurrent non-faradaic probe reaction. In the absence of electrocatalysis, nanostructured Pt/C surfaces mediate the reaction of H2 with cis-2-butene-1,4-diol to form a mixture of 1,4-butanediol and n-butanol with a selectivity that is linearly dependent on the bulk solution pH. We show that kinetic branching occurs from a common surface-bound intermediate, ensuring that this probe reaction is uniquely sensitive to the interfacial pH within molecular length scales of the surface. We use the pH-dependent selectivity of this reaction to track changes in interfacial pH during concurrent hydrogen oxidation electrocatalysis and find that the local pH can vary dramatically, > 3 units, relative to the bulk value even at modest current densities in well-buffered electrolytes. This work highlights the key role that interfacial pH variation plays in modulating inner-sphere electrocatalysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect temperature of supercritical CO2 fluid extraction on phytochemical analysis and antioxidant activity of Zingiber officinale Roscoe

NASA Astrophysics Data System (ADS)

Sondari, Dewi; Irawadi, Tun Tedja; Setyaningsih, Dwi; Tursiloadi, Silvester

2017-11-01

Supercritical fluid extraction of Zingiber officinale Roscoe has been carried out at a pressure of 16 MPa, with temperatures between 20-40 °C, during extraction time of 6 hours and the flow rate of CO2 fluid 5.5 ml/min. The result of supercritical method was compared with the extraction maceration using a mixture of water and ethanol (70% v/v) for 24 hours. The main content in ginger that has a main role as an antioxidant is a gingerol compound that can help neutralize the damaging effects caused by free radicals in the body, as anti-coagulant, and inhibit the occurrence of blood clots. This study aims to determine the effect of temperature on chemical components contained in rough extract of Zingiber officinale Roscoe and its antioxidant activity, total phenol and total flavonoid content. To determine the chemical components contained in the crude extract of Zingiber officinale Roscoe extracted by supercritical fluid and maceration extraction, GC-MS analysis was performed. Meanwhile, the antioxidant activity of the extract was evaluated based on a 2.2-diphenyl-1-picrylhydrazyl (DPPH) free radical damping method. The results of the analysis show that the result of ginger extract by using the supercritical CO2 extraction method has high antioxidant activity than by using maceration method. The highest total phenol content and total flavonoids were obtained on ginger extraction using supercritical CO2 fluid extraction, indicating that phenol and flavonoid compounds contribute to antioxidant activity. Chromatographic analysis showed that the chemical profile of ginger extract containing oxygenated monoterpenes, monoterpene hydrocarbons, sesquiterpene hydrocarbons, oxygenated monoterpene gingerol and esters. In supercritical fluid extraction, the compounds that can be identified at a temperature of 20-40 °C contain 27 compounds, and 11 compounds from the result of maceration extract. The main component of Zingiber officinale Roscoe extracted using supercritical fluid at a temperature of 40 °C is Hexanal (6.04%), Butan-2-one, 4-(3-hydroxy-2-methoxyphenyl) (27.95%), [6]-Paradol (0.73%), Gingerol (8.22%), Bis (2-ethylhexyl) phthalate (1.62%), α-Citral (12.14%) and α-zingiberene (2.90%). The main component extracts of Zingiber officinale Roscoe by maceration is Hexanal (10.71%), Decanal (3.74%), Butan-2-one, 4-(3-hydroxy-2-methoxyphenyl) (38.33%), Gingerol (4.56%) and Zingiberene (0.99).

Synthesis and Structure of an Extended Cluster Lead(II) Carboxylate, [Pb{(CO)(9)Co(3)(&mgr;(3)-CCO(2))}(2)](n)(). Role of Core Metals in Cluster-Derived Hydrogenation Catalysts.

PubMed

Lei, Xinjian; Shang, Maoyu; Patil, Atul; Wolf, Eduardo E.; Fehlner, Thomas P.

1996-05-22

The reaction of lead acetate with (CO)(9)Co(3)(&mgr;(3)-CCOOH) leads to the formation of [Pb{(CO)(9)Co(3)(&mgr;(3)-CCO(2))}(2)](n)(), I, in high yield. The structure of I exhibits unusual six-coordinate Pb(II) centers with two asymmetrical chelating cluster carboxylates (C(22)Co(6)PbO(22); triclinic P&onemacr;; a = 8.119(1), b = 14.346(2), c = 14.660(2) Å; alpha = 102.18(1), beta = 99.01(1), gamma = 97.30(1) degrees; Z = 2). One oxygen of each cluster carboxylate ligand bridges between adjacent lead atoms such that a chainlike extended structure is found in the solid state without the presence of solvent or water. I is converted stepwise on pyrolysis into two metastable forms of solid materials (designated LT and HT), each of which has been characterized spectroscopically. The hydrogenation of 2-butenal as a test reaction shows that the LT catalyst exhibits selectivities similar to previous LT materials derived from other cobalt cluster metal carboxylates and that the HT material is totally inactive. The observed release of the lead core metal under HT activation conditions totally inactivates the catalyst and demonstrates exposure of the core metal in the HT form of these novel catalysts.

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.

21 CFR 184.1005 - Acetic acid.

Code of Federal Regulations, 2012 CFR

2012-04-01

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

21 CFR 184.1005 - Acetic acid.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

Volatiles from roasted byproducts of the poultry-processing industry.

PubMed

Wettasinghe, M; Vasanthan, T; Temelli, F; Swallow, K

2000-08-01

Volatiles of roasted chicken breast muscle and byproducts, such as backbones, breastbones, spent bones, and skin, were investigated. Total volatile concentrations ranged from 2030 ppb in the roasted backbones to 4049 ppb in the roasted skin. The major classes of volatile compounds detected in roasted samples were aldehydes (648-1532 ppb) and alcohols (336-1006 ppb). Nitrogen- and/or sulfur-containing compounds were also detected in appreciable quantities (161-706 ppb) in all samples. For all samples, hexanal and 2-methyl-2-buten-1-ol were dominant among the aldehydes and alcohols, respectively. Among the nitrogen- and sulfur-containing compounds, Maillard reaction products, such as tetrahydropyridazines, piperidines, and thiazoles, were the major contributors to the total volatile content in all samples. The composition of volatiles observed in roasted byproducts was markedly different from that of the roasted breast muscle. Therefore, the blending of the byproducts in appropriate proportions or blending of volatile flavor extracts from different byproducts may be necessary to obtain an aroma that mimics roasted chicken aroma.

Purification and characterization of two enone reductases from Saccharomyces cerevisiae.

PubMed

Wanner, P; Tressl, R

1998-07-01

Two enone reductases catalyzing irreversibly the enantioselective reduction of alpha,beta-unsaturated carbonyls have been purified 165-fold and 257-fold, respectively, from the cytosolic fraction of Saccharomyces cerevisiae by means of streptomycin sulfate treatment, Sephadex G-25 filtration, DEAE-Sepharose CL-6B chromatography, blue Sepharose CL-6B chromatography and Superdex 200 preparation-grade filtration. One enzyme (E I) was NADPH-dependent, showed a molecular mass of 75 kDa and decomposed under denaturing electrophoretic conditions into two subunits of 34 kDa and 37 kDa. The other enzyme (E II) was NADH linked and the molecular mass estimated by means of Superdex 200 preparation-grade filtration, was 130 kDa. The enzyme decomposed into subunits of 56 kDa and 64 kDa on SDS/PAGE. Both enzymes were most active at pH 4.8 and accepted 1-octen-3-one, 1-hexen-3-one, 3-alken-2-ones, 4-alken-3-ones, 2-cyclohexen-1-ones, 2-alkenals, 2,4-alkadienals, 2-phenyl-2-alkenals, and 2-alkyl-2-alkenals as substrates. Both enzymes showed their highest activities with 1-hexen-3-one and 1-octen-3-one, respectively. The Km values for 1-octen-3-one were estimated as 0.54 mM (E I) and 0.20 mM (E II), respectively. Both enzymes catalyzed the enantioselective reduction of cis- and trans-2-phenyl-2-butenal into (R)-2-phenylbutanal.

Three-Dimensional Conformation of Folded Polymers in Single Crystals

NASA Astrophysics Data System (ADS)

Hong, You-lee; Yuan, Shichen; Li, Zhen; Ke, Yutian; Nozaki, Koji; Miyoshi, Toshikazu

2015-10-01

The chain-folding mechanism and structure of semicrystalline polymers have long been controversial. Solid-state NMR was applied to determine the chain trajectory of 13C CH3 -labeled isotactic poly(1-butene) (i PB 1 ) in form III chiral single crystals blended with nonlabeled i PB 1 crystallized in dilute solutions under low supercooling. An advanced 13C - 13C double-quantum NMR technique probing the spatial proximity pattern of labeled 13C nuclei revealed that the chains adopt a three-dimensional (3D) conformation in single crystals. The determined results indicate a two-step crystallization process of (i) cluster formation via self-folding in the precrystallization stage and (ii) deposition of the nanoclusters as a building block at the growth front in single crystals.

Shock tube study of the fuel structure effects on the chemical kinetic mechanisms responsible for soot formation, part 2

NASA Technical Reports Server (NTRS)

Frenklach, M.; Clary, D. W.; Ramachandra, M. K.

1985-01-01

Soot formation in oxidation of allene, 1,3-butadiene, vinylacetylene and chlorobenzene and in pyrolysis of ethylene, vinylacetylene, 1-butene, chlorobenzene, acetylen-hydrogen, benzene-acetylene, benzene-butadiene and chlorobenzene-acetylene argon-diluted mixtures was studied behind reflected shock waves. The results are rationalized within the framework of the conceptual models. It is shown that vinylacetylene is much less sooty than allene, which indicates that conjugation by itself is not a sufficient factor for determining the sooting tendency of a molecule. Structural reactivity in the context of the chemical kinetics is the dominant factor in soot formation. Detailed chemical kinetic modeling of soot formation in pyrolysis of acetylene is reported. The main mass growth was found to proceed through a single dominant route composed of conventional radical reactions. The practically irreversible formation reactions of the fused polycyclic aromatics and the overshoot by hydrogen atom over its equilibrium concentration are the g-driving kinetic forces for soot formation.

Crystal and molecular structures of sixteen charge-assisted hydrogen bond-mediated diisopropylammonium salts from different carboxylic acids

NASA Astrophysics Data System (ADS)

Lin, Zhihao; Hu, Kaikai; Jin, Shouwen; Ding, Aihua; Wang, Yining; Dong, Lingfeng; Gao, Xingjun; Wang, Daqi

2017-10-01

Cocrystallization of the commonly available organic amine, diisopropylamine, with a series of carboxylic acids gave a total of sixteen molecular salts with the compositions: diisopropylaminium 2-methyl-2-phenoxypropanate [(Hdpa)+ · (mpa-), mpa- = 2-methyl-2-phenoxypropanoate] (1), diisopropylaminium 2-methyl-2-(naphthalen-2-yloxy)-propionate [(Hdpa)+ · (npa-), npa- = 2-methyl-2-(naphthalen-2-yloxy)-propionate] (2), diisopropylaminium indole-3-acetate [(Hdpa)+ · (iaa-), iaa- = indole-3-acetate] (3), diisopropylaminium 4-chlorophenoxyacetate [(Hdpa)+ · (cpa-), cpa- = 4-chlorophenoxyacetate] (4), diisopropylaminium 2,4-dichlorophenoxyacetate [(Hdpa)+ · (dcpa-), dcpa- = 2,4-dichlorophenoxyacetate] (5), diisopropylaminium 4-hydroxybenzoate [(Hdpa)+ · (hba-), hba- = 4-hydroxybenzoate] (6), diisopropylaminium 4-aminobenzoate [(Hdpa)+ · (aba-), aba- = 4-aminobenzoate] (7), tetra(diisopropylaminium) tetra(1-hydroxy-2-naphthoate) trihydrate [(Hdpa)44+ · (2-hnpa)44- · 3H2O, 2-hnpa = 1-hydroxy-2-naphthoate] (8), diisopropylaminium 2-hydroxy-3-naphthoate [(Hdpa)+ · (3-hnpa-), 3-hnpa- = 2-hydroxy-3-naphthoate] (9), diisopropylaminium 5-bromosalicylate [(Hdpa)+ · (bsa-), bsa- = 5-bromosalicylate] (10), diisopropylaminium 3,5-dinitrobenzoate [(Hdpa)+ · (dna-), dna- = 3,5-dinitrobenzoate] (11), diisopropylaminium 3,5-dinitrosalicylate [(Hdpa)+ · (3,5-dns-), 3,5-dns- = 3,5-dinitrosalicylate] (12), tetra(diisopropylaminium) bis(m-phthalate) monohydrate [(Hdpa+)4 · (mpta2-)2 · H2O, mpta2- = m-phthalate] (13), bis(diisopropylaminium) dihydrogen 1,2,3,4-butane tetracarboxylate [(Hdpa+)2 · (H2Bta2-), H2Bta2- = dihydrogen 1,2,3,4-butane tetracarboxylate] (14), bis(diisopropylaminium) mucate [(Hdpa+)2 · (muc2-), muc2- = mucate] (15), and diisopropylaminium hydrogen 1,2-phenylenediacetate [(Hdpa) · (Hpda-), Hpda- = hydrogen 1,2-phenylenediacetate] (16). The sixteen salts have been characterised by XRD technique, IR, and elemental analysis, and the melting points of all the salts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the sixteen investigated crystals the NH groups in the diisopropylamine are protonated when the carboxylic acids are deprotonated, and the crystal packing is interpreted in terms of the strong charge-assisted Nsbnd H⋯O hydrogen bond formation between the ammonium and the deprotonated COOH groups. Except the Nsbnd H⋯O hydrogen bond, the Osbnd H⋯O hydrogen bonds (charge assisted or neutral) were also found at the salts 6, 8, 9, 10, 12, 13, 14, 15, and 16. Further analysis of the crystal packing of the salts indicated that a different family of additional CHsbnd O/CH2sbnd O/CH3sbnd O, CH-π/CH3-π, CH3-Cπ, N-π, and π-π associations contribute to the stabilization and expansion of the total structures. For the coexistence of the various weak interactions these structures adopted homo or hetero supramolecular synthons or both.

Ultrahigh and High Resolution Structures and Mutational Analysis of Monomeric Streptococcus pyogenes SpeB Reveal a Functional Role for the Glycine-rich C-terminal Loop

DOE Office of Scientific and Technical Information (OSTI.GOV)

González-Páez, Gonzalo E.; Wolan, Dennis W.

2012-09-05

Cysteine protease SpeB is secreted from Streptococcus pyogenes and has been studied as a potential virulence factor since its identification almost 70 years ago. Here, we report the crystal structures of apo mature SpeB to 1.06 {angstrom} resolution as well as complexes with the general cysteine protease inhibitor trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and a novel substrate mimetic peptide inhibitor. These structures uncover conformational changes associated with maturation of SpeB from the inactive zymogen to its active form and identify the residues required for substrate binding. With the use of a newly developed fluorogenic tripeptide substrate to measure SpeB activity, we determined IC{sub 50}more » values for trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and our new peptide inhibitor and the effects of mutations within the C-terminal active site loop. The structures and mutational analysis suggest that the conformational movements of the glycine-rich C-terminal loop are important for the recognition and recruitment of biological substrates and release of hydrolyzed products.« less

Aerobic oxidation of cyclic amines to lactams catalyzed by ceria-supported nanogold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dairo, Taiwo O.; Nelson, Nicholas C.; Slowing, Igor I.

Here, the oxidative transformation of cyclic amines to lactams, which are important chemical feedstocks, is efficiently catalyzed by CeO 2-supported gold nanoparticles (Au/CeO 2) and Aerosil 200 in the presence of an atmosphere of O 2. The complete conversion of pyrrolidine was achieved in 6.5 h at 160 °C, affording a 97 % yield of the lactam product 2-pyrrolidone (γ-butyrolactam), while 2-piperidone (δ-valerolactam) was synthesized from piperidine (83 % yield) in 2.5 h. Caprolactam, the precursor to the commercially important nylon-6, was obtained from hexamethyleneimine in 37 % yield in 3 h. During the oxidation of pyrrolidine, two transient species,more » 5-(pyrrolidin-1-yl)-3,4-dihydro-2H-pyrrole (amidine-5) and 4-amino-1-(pyrrolidin-1-yl)butan-1-one, were observed. Both of these compounds were oxidized to 2-pyrrolidone under catalytic conditions, indicating their role as intermediates in the reaction pathway. In addition to the reactions of cyclic secondary amines, Au/CeO 2 also efficiently catalyzes the oxidation of N-methyl cyclic tertiary amines to the corresponding lactams at 80 and 100 °C.« less

Aerobic oxidation of cyclic amines to lactams catalyzed by ceria-supported nanogold

DOE PAGES

Dairo, Taiwo O.; Nelson, Nicholas C.; Slowing, Igor I.; ...

2016-09-23

Here, the oxidative transformation of cyclic amines to lactams, which are important chemical feedstocks, is efficiently catalyzed by CeO 2-supported gold nanoparticles (Au/CeO 2) and Aerosil 200 in the presence of an atmosphere of O 2. The complete conversion of pyrrolidine was achieved in 6.5 h at 160 °C, affording a 97 % yield of the lactam product 2-pyrrolidone (γ-butyrolactam), while 2-piperidone (δ-valerolactam) was synthesized from piperidine (83 % yield) in 2.5 h. Caprolactam, the precursor to the commercially important nylon-6, was obtained from hexamethyleneimine in 37 % yield in 3 h. During the oxidation of pyrrolidine, two transient species,more » 5-(pyrrolidin-1-yl)-3,4-dihydro-2H-pyrrole (amidine-5) and 4-amino-1-(pyrrolidin-1-yl)butan-1-one, were observed. Both of these compounds were oxidized to 2-pyrrolidone under catalytic conditions, indicating their role as intermediates in the reaction pathway. In addition to the reactions of cyclic secondary amines, Au/CeO 2 also efficiently catalyzes the oxidation of N-methyl cyclic tertiary amines to the corresponding lactams at 80 and 100 °C.« less

Distribution, abundance and carbon isotopic composition of gaseous hydrocarbons in Big Soda Lake, Nevada: An alkaline, meromictic lake

USGS Publications Warehouse

Oremland, R.S.; Des Marais, D.J.

1983-01-01

Distribution and isotopic composition (??13C) of low molecular weight hydrocarbon gases were studied in Big Soda Lake (depth = 64 m), an alkaline, meromictic lake with permanently anoxic bottom waters. Methane increased with depth in the anoxic mixolimnion (depth = 20-35 m), reached uniform concentrations (55 ??M/l) in the monimolimnion (35-64 m) and again increased with depth in monimolimnion bottom sediments (>400 ??M/kg below 1 m sub-bottom depth). The ??13C[CH4] values in bottom sediment below 1 m sub-bottom depth (<-70 per mil) increased with vertical distance up the core (??13C[CH4] = -55 per mil at sediment surface). Monimolimnion ??13C[CH4] values (-55 to -61 per mil) were greater than most ??13C[CH4] values found in the anoxic mixolimnion (92% of samples had ??13C[CH4] values between -20 and -48 per mil). No significant concentrations of ethylene or propylene were found in the lake. However ethane, propane, isobutane and n-butane concentrations all increased with water column depth, with respective maximum concentrations of 260, 80, 23 and 22 nM/l encountered between 50-60 m depth. Concentrations of ethane, propane and butanes decreased with depth in the bottom sediments. Ratios of CH4 [C2H6 + C3H8] were high (250-620) in the anoxic mixolimnion, decreased to ~161 in the monimolimnion and increased with depth in the sediment to values as high as 1736. We concluded that methane has a biogenic origin in both the sediments and the anoxic water column and that C2-C4 alkanes have biogenic origins in the monimolimnion water and shallow sediments. The changes observed in ??13C[CH4] and CH4 (C2H6 + C3H8) with depth in the water column and sediments are probably caused by bacteria] processes. These might include anaerobic methane oxidation and different rates of methanogenesis and C2 to C4 alkane production by microorganisms. ?? 1983.

High temperature set retarded well cement compositions and methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vinson, E.F.; Brothers, L.E.; Bour, D.L.

1991-03-05

This patent describes a set retarded cement composition which is substantially non-thinning at high temperatures. It comprises: hydraulic cement; sufficient water to form a pumpable slurry; a set retarder comprising at least one member selected from the group consisting of a copolymer of 2-acrylamido, 2-methylpropane sulfonic acid (AMPS) and acrylic acid having an average molecular weight below about 5000 and comprising from about 40 to about 60 mole percent AMPS, the copolymer being present in an amount in the range of from about 0.1 to about 5% by weight of cement, lignosulfonates present in an amount in the range ofmore » from about 0.1 to about 5% by weight of cement, borates present in an amount in the range of from about 0.2 to about 5% by weight of cement and organic acids present in an amount of from about 0.2 to about 5% by weight of cement; and a galactomannan gum which has been treated with a hydrophobing agent selected from the group consisting of potassium pyroantimonate present on the gum in an amount of from about 0.001 to about 0.3 percent by weight of the gum and compounds capable of liberating borate ions when added to water present on the gum in an amount of from about 0.5 to about 1.0 percent by weight of the gum, whereby the hydration rate of the gum is retarded at temperatures below about 120 degrees F. and at pH levels above about 10, but the hydration rate increases at temperatures above about 120 degrees F., the treated gum being present in the composition in an amount of at least about 0.5% by weight of cement.« less

Characteristics of atmospheric non-methane hydrocarbons during haze episode in Beijing, China.

PubMed

Guo, Songjun; Tan, Jihua; Duan, Jingchun; Ma, Yongliang; Yang, Fumo; He, Kebin; Hao, Jimin

2012-12-01

This study firstly focused on non-methane hydrocarbons (NMHCs) during three successive days with haze episode (16-18 August 2006) in Beijing. Concentrations of alkanes, alkenes, aromatic hydrocarbons, and ethyne all peaked at traffic rush hour, implying vehicular emission; and alkanes also peaked at non-traffic rush hour in the daytime, implying additional source. Especially, alkanes and aromatics clearly showed higher levels in the nighttime than that in the daytime, implying their active photochemical reactions in the daytime. Correlation coefficients (R (2)) showed that propane, n-butane, i-butane, ethene, propene, and benzene correlated with ethyne (R (2) = 0.61-0.66), suggesting that their main source is vehicular emission; 2-methylpentane and n-hexane correlated with i-pentane (R (2) = 0.61-0.64), suggesting that gasoline evaporation is their main source; and ethylbezene, m-/p-xylene, and o-xylene correlated with toluene (R (2) = 0.60-0.79), suggesting that their main source is similar to that of toluene (e.g., solvent usage). The R (2) of ethyne, i-pentane, and toluene with total NMHCs were 0.58, 0.76, and 0.60, respectively, indicating that ambient hydrocarbons are associated with vehicular emission, gasoline evaporation, and solvent usage. The sources of other hydrocarbons (e.g., ethane) might be natural gas leakage, biogenic emission, or long-range transport of air pollutants. Measured higher mean B/T ratio (0.78 ± 0.27) was caused by the more intensive photochemical activity of toluene than benzene, still indicating the dominant emission from vehicles.

Dinuclear NHC-palladium complexes containing phosphine spacers: synthesis, X-ray structures and their catalytic activities towards the Hiyama coupling reaction.

PubMed

Yang, Jin; Li, Pinhua; Zhang, Yicheng; Wang, Lei

2014-05-21

Six dinuclear N-heterocyclic carbene (NHC) palladium complexes, [PdCl2(IMes)]2(μ-dppe) (1), [PdCl2(IPr)]2(μ-dppe) (2), [PdCl2(IMes)]2(μ-dppb) (3), [PdCl2(IPr)]2(μ-dppb) (4), [PdCl2(IMes)]2(μ-dpph) (5), and [PdCl2(IPr)]2(μ-dpph) (6) [IMes = N,N'-bis-(2,4,6-trimethylphenyl)imidazol-2-ylidene; IPr = N,N'-bis-(2,6-di(iso-propyl)phenyl)imidazol-2-ylidene; dppe = 1,2-bis(diphenylphosphino)ethane, dppb = 1,4-bis(diphenylphosphino)butane; and dpph = 1,6-bis(diphenylphosphino)hexane], have been synthesized through bridge-cleavage reactions of chloro-bridged dimeric compounds, [Pd(μ-Cl)(Cl)(NHC)]2, with the corresponding diphosphine ligands. The obtained compounds were fully characterized by (1)H NMR, (13)C NMR and (31)P NMR spectroscopy, FT-IR, elemental analysis and single-crystal X-ray crystallography. Moreover, further explorations of the catalytic potential of the dinuclear carbene palladium complexes as catalysts for the Pd-catalyzed transformations have been performed under microwave irradiation conditions, and the complexes exhibited moderate to good catalytic activity in the Hiyama coupling reaction of trimethoxyphenylsilane with aryl chlorides.

Structure-property evolution during polymer crystallization

NASA Astrophysics Data System (ADS)

Arora, Deepak

The main theme of this research is to understand the structure-property evolution during crystallization of a semicrystalline thermoplastic polymer. A combination of techniques including rheology, small angle light scattering, differential scanning calorimetry and optical microscopy are applied to follow the mechanical and optical properties along with crystallinity and the morphology. Isothermal crystallization experiments on isotactic poly-1-butene at early stages of spherulite growth provide quantitative information about nucleation density, volume fraction of spherulites and their crystallinity, and the mechanism of connecting into a sample spanning structure. Optical microscopy near the fluid-to-solid transition suggests that the transition, as determined by time-resolved mechanical spectroscopy, is not caused by packing/jamming of spherulites but by the formation of a percolating network structure. The effect of strain, Weissenberg number (We ) and specific mechanical work (w) on rate of crystallization (nucleation followed by growth) and on growth of anisotropy was studied for shear-induced crystallization of isotactic poly-1-butene. The samples were sheared for a finite strain at the beginning of the experiment and then crystallized without further flow (Janeschitz-Kriegl protocol). Strain requirements to attain steady state/leveling off of the rate of crystallization were found to be much larger than the strain needed to achieve steady state of flow. The large strain and We>1 criteria were also observed for morphological transition from spherulitic growth to oriented growth. An apparatus for small angle light scattering (SALS) and light transmission measurements under shear was built and tested at the University of Massachusetts Amherst. As a new development, the polarization direction can be rotated by a liquid crystal polarization rotator (LCPR) with a short response time of 20 ms. The experiments were controlled and analyzed with a LabVIEW(TM) based code (LabVIEW(TM) 7.1) in real time. The SALS apparatus was custom built for ExxonMobil Research in Clinton NJ.

Chemoselective Hydrogenation with Supported Organoplatinum(IV) Catalyst on Zn(II)-Modified Silica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Camacho-Bunquin, Jeffrey; Ferrandon, Magali; Sohn, Hyuntae

For this research, well-defined organoplatinum(IV) sites were grafted on a Zn(II)-modified SiO 2 support via surface organometallic chemistry in toluene at room temperature. Solid-state spectroscopies including XAS, DRIFTS, DRUV–vis, and solid-state (SS) NMR enhanced by dynamic nuclear polarization (DNP), as well as TPR-H 2 and TEM techniques revealed highly dispersed (methylcyclopentadienyl)methylplatinum(IV) sites on the surface ((MeCp)PtMe/Zn/SiO 2, 1). In addition, computational modeling suggests that the surface reaction of (MeCp)PtMe 3 with Zn(II)-modified SiO 2 support is thermodynamically favorable (ΔG = -12.4 kcal/mol), likely due to the increased acidity of the hydroxyl group, as indicated by NH 3-TPD and DNP-enhanced 17O{more » 1H} SSNMR. In situ DRIFTS and XAS hydrogenation experiments reveal the probable formation of a surface Pt(IV)-H upon hydrogenolysis of Pt-Me groups. The heterogenized organoplatinum(IV)-hydride sites catalyze the selective partial hydrogenation of 1,3-butadiene to butenes (up to 95%) and the reduction of nitrobenzene derivatives to anilines (up to 99%) with excellent tolerance of reduction-sensitive functional groups (olefin, carbonyl, nitrile, halogens) under mild reaction conditions.« less

Chemoselective Hydrogenation with Supported Organoplatinum(IV) Catalyst on Zn(II)-Modified Silica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Camacho-Bunquin, Jeffrey; Ferrandon, Magali; Sohn, Hyuntae

Well-defined organoplatinum(IV) sites were grafted on a Zn(II)-modified SiO2 support via surface organometallic chemistry in toluene at room temperature. Solid-state spectroscopies including XAS, DRIFTS, DRUV-Vis, and solid-state (SS)NMR enhanced by dynamic nuclear polarization (DNP), as well as TPR-H2 and TEM techniques revealed highly dispersed (methylcyclopentadi-enyl)methylplatinum(IV) sites on the surface ((MeCp)PtMe/Zn/SiO2, 1). In addition, computational modelling suggests that the surface reaction of (MeCp)PtMe3 with Zn(II)-modified SiO2 support is thermodynamically favorable (ΔG = -12.4 kcal/mol), likely due to the increased acidity of the hydroxyl group, as confirmed by NH3-TPD and DNP-enhanced 17O{1H} SSNMR. In situ DRIFTS and XAS hydrogenation experiments reveal themore » formation of a surface Pt(IV)-H upon hydrogenolysis of Pt-Me groups. The heterogenized organoplatinum(IV)-H sites catalyze the selective partial hydrogenation of 1,3-butadiene to butenes (up to 95%) and the reduction of nitrobenzene derivatives to anilines (up to 100%) with excellent tolerance of reduction-sensitive func-tional groups (olefin, carbonyl, nitrile, halogens) under mild reaction conditions.« less

Chemoselective Hydrogenation with Supported Organoplatinum(IV) Catalyst on Zn(II)-Modified Silica

DOE PAGES

Camacho-Bunquin, Jeffrey; Ferrandon, Magali; Sohn, Hyuntae; ...

2018-02-27

For this research, well-defined organoplatinum(IV) sites were grafted on a Zn(II)-modified SiO 2 support via surface organometallic chemistry in toluene at room temperature. Solid-state spectroscopies including XAS, DRIFTS, DRUV–vis, and solid-state (SS) NMR enhanced by dynamic nuclear polarization (DNP), as well as TPR-H 2 and TEM techniques revealed highly dispersed (methylcyclopentadienyl)methylplatinum(IV) sites on the surface ((MeCp)PtMe/Zn/SiO 2, 1). In addition, computational modeling suggests that the surface reaction of (MeCp)PtMe 3 with Zn(II)-modified SiO 2 support is thermodynamically favorable (ΔG = -12.4 kcal/mol), likely due to the increased acidity of the hydroxyl group, as indicated by NH 3-TPD and DNP-enhanced 17O{more » 1H} SSNMR. In situ DRIFTS and XAS hydrogenation experiments reveal the probable formation of a surface Pt(IV)-H upon hydrogenolysis of Pt-Me groups. The heterogenized organoplatinum(IV)-hydride sites catalyze the selective partial hydrogenation of 1,3-butadiene to butenes (up to 95%) and the reduction of nitrobenzene derivatives to anilines (up to 99%) with excellent tolerance of reduction-sensitive functional groups (olefin, carbonyl, nitrile, halogens) under mild reaction conditions.« less

The effect of functionalized polycarboxylate structures as corrosion inhibitors in a simulated concrete pore solution

NASA Astrophysics Data System (ADS)

Fazayel, A. S.; Khorasani, M.; Sarabi, A. A.

2018-05-01

In this study, the effects of polycarboxylate derivatives with different comonomers and functional groups on the control or reduction of corrosion in steel specimens were evaluated through electrochemical impedance spectroscopy (EIS) and potentiodynamic analysis. A highly alkaline contaminated concrete pore solution (CPS) containing chlorides was used to simulate the pitting corrosion, and according to the results, the mechanism of inhibitive action was determined. Both the inhibition efficiency and pitting corrosion inhibition of methacrylate-copolymers were in the order of poly methacrylate-co acrylamide > poly methacrylate-co-2-acrylamido-2 methylpropane sulfonic acid > poly methacrylate-co-hydroxyethyl methacrylate. In addition, the corrosion potential of steel specimens in all studied concentrations of NaCl with different concentrations of polymethacrylate-co acrylamide (as the best inhibitor in this study) in saturated Ca(OH)2 solution showed almost an identical trend. Polymethacrylic acid-co-acrylamide showed a 92.35% inhibitor efficiency in the saturated Ca(OH)2 solution containing 1.8 wt.% chlorides and could effectively reduce the corrosion rate. Even at 3.5 wt.% of NaCl, this inhibitor could remarkably reduce the destructive effect of chloride ion attacks on the steel surface and passive film. The inhibition effect of these polymeric inhibitors seemed to be due to the formation of a barrier layer on the metal surface, approved by the well-known adsorption mechanism of organic molecules at the metal/solution interface. The results of SEM, EDS and AFM investigations were also in agreement with the outcomes of electrochemical studies.

Interactions of anesthetics with the water-hexane interface. A molecular dynamics study

NASA Technical Reports Server (NTRS)

Chipot, C.; Wilson, M. A.; Pohorille, A.

1997-01-01

The free energy profiles characterizing the transfer of nine solutes across the liquid-vapor interfaces of water and hexane and across the water-hexane interface were calculated from molecular dynamics simulations. Among the solutes were n-butane and three of its halogenated derivatives, as well as three halogenated cyclobutanes. The two remaining molecules, dichlorodifluoromethane and 1,2-dichloroperfluoroethane, belong to series of halo-substituted methanes and ethanes, described in previous studies (J. Chem. Phys. 1996, 104, 3760; Chem. Phys. 1996, 204, 337). Each series of molecules contains structurally similar compounds that differ greatly in anesthetic potency. The accuracy of the simulations was tested by comparing the calculated and the experimental free energies of solvation of all nine compounds in water and in hexane. In addition. the calculated and the measured surface excess concentrations of n-butane at the water liquid-vapor interface were compared. In all cases, good agreement with experimental results was found. At the water-hexane interface, the free energy profiles for polar molecules exhibited significant interfacial minima, whereas the profiles for nonpolar molecules did not. The existence of these minima was interpreted in terms of a balance between the free energy contribution arising from solute-solvent interactions and the work to form a cavity that accommodates the solute. These two contributions change monotonically, but oppositely, across the interface. The interfacial solubilities of the solutes, obtained from the free energy profiles, correlate very well with their anesthetic potencies. This is the case even when the Meyer-Overton hypothesis, which predicts a correlation between anesthetic potency and solubility in oil, fails.

Climatic factors directly impact the volatile organic compound fingerprint in green Arabica coffee bean as well as coffee beverage quality.

PubMed

Bertrand, B; Boulanger, R; Dussert, S; Ribeyre, F; Berthiot, L; Descroix, F; Joët, T

2012-12-15

Coffee grown at high elevations fetches a better price than that grown in lowland regions. This study was aimed at determining whether climatic conditions during bean development affected sensory perception of the coffee beverage and combinations of volatile compounds in green coffee. Green coffee samples from 16 plots representative of the broad range of climatic variations in Réunion Island were compared by sensory analysis. Volatiles were extracted by solid phase micro-extraction and the volatile compounds were analysed by GC-MS. The results revealed that, among the climatic factors, the mean air temperature during seed development greatly influenced the sensory profile. Positive quality attributes such as acidity, fruity character and flavour quality were correlated and typical of coffees produced at cool climates. Two volatile compounds (ethanal and acetone) were identified as indicators of these cool temperatures. Among detected volatiles, most of the alcohols, aldehydes, hydrocarbons and ketones appeared to be positively linked to elevated temperatures and high solar radiation, while the sensory profiles displayed major defects (i.e. green, earthy flavour). Two alcohols (butan-1,3-diol and butan-2,3-diol) were closely correlated with a reduction in aromatic quality, acidity and an increase in earthy and green flavours. We assumed that high temperatures induce accumulation of these compounds in green coffee, and would be detected as off-flavours, even after roasting. Climate change, which generally involves a substantial increase in average temperatures in mountainous tropical regions, could be expected to have a negative impact on coffee quality. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mid-infrared surface transmitting and detecting quantum cascade device for gas-sensing

PubMed Central

Harrer, Andreas; Szedlak, Rolf; Schwarz, Benedikt; Moser, Harald; Zederbauer, Tobias; MacFarland, Donald; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Lendl, Bernhard; Strasser, Gottfried

2016-01-01

We present a bi-functional surface emitting and surface detecting mid-infrared device applicable for gas-sensing. A distributed feedback ring quantum cascade laser is monolithically integrated with a detector structured from a bi-functional material for same frequency lasing and detection. The emitted single mode radiation is collimated, back reflected by a flat mirror and detected by the detector element of the sensor. The surface operation mode combined with the low divergence emission of the ring quantum cascade laser enables for long analyte interaction regions spatially separated from the sample surface. The device enables for sensing of gaseous analytes which requires a relatively long interaction region. Our design is suitable for 2D array integration with multiple emission and detection frequencies. Proof of principle measurements with isobutane (2-methylpropane) and propane as gaseous analytes were conducted. Detectable concentration values of 0–70% for propane and 0–90% for isobutane were reached at a laser operation wavelength of 6.5 μm utilizing a 10 cm gas cell in double pass configuration. PMID:26887891

25 CFR 700.105 - Utility charges.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Policies and Instructions Definitions § 700.105 Utility charges. Utility charges means the cost for heat, lighting, hot water, electricity, natural gas, butane, propane, wood, coal or other fuels water, sewer and...

Volatile compound profile of sous-vide cooked lamb loins at different temperature-time combinations.

PubMed

Roldán, Mar; Ruiz, Jorge; Del Pulgar, José Sánchez; Pérez-Palacios, Trinidad; Antequera, Teresa

2015-02-01

Lamb loins were subjected to sous-vide cooking at different combinations of temperature (60 and 80°C) and time (6 and 24h) to assess the effect on the volatile compound profile. Major chemical families in cooked samples were aliphatic hydrocarbons and aldehydes. The volatile compound profile in sous-vide cooked lamb loin was affected by the cooking temperature and time. Volatile compounds arising from lipid oxidation presented a high abundance in samples cooked at low or moderate cooking conditions (60°C for 6 and 24h, 80°C for 6h), while a more intense time and temperature combination (80°C for 24h) resulted on a higher concentration of volatile compounds arising from Strecker degradations of amino acids, as 2-methylpropanal and 3-methylbutanal. Therefore, sous-vide cooking at moderately high temperatures for long times would result in the formation of a stronger meaty flavor and roast notes in lamb meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1996-12-31

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