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Sample records for butane 2-methylpropane 1-butene

  1. Viscosities of binary mixtures of toluene with butan-1-ol and 2-methylpropan-2-ol

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    VASILE DUMITRESCU

    2005-11-01

    Full Text Available The viscosities of binary liquid mixtures of toluene with butan-1-ol and 2-methylpropan-2-ol have been determined at 298.15, 303.15, 308.15, 313.15 and 318.15 K over the whole concentration range. The Hind, Grunberg–Nissan, Wijk, Auslander and McAllister models were used to calculate the viscosity coefficients and these were compared with the experimental data for the mixtures. Excess viscosities were also calculated and fitted to the Redlich–Kister equation. Various thermodynamic properties of viscous flow activation were determined and their variations with composition are discussed.

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

    Science.gov (United States)

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

    2015-11-11

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

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

    Science.gov (United States)

    Chin, Chih-Hao; Lee, Shih-Huang

    2012-01-01

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

  4. Henry's law constants and infinite dilution activity coefficients of propane, propene, butane, isobutane, 1-butene, isobutene, trans-2-butene, and 1,3-butadiene in 1-pentanol, 2-pentanol, and 3-pentanol

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    Miyano, Yoshimori [Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajimacho, Kurashiki 712-8505 (Japan)]. E-mail: miyano@chem.kusa.ac.jp

    2005-05-15

    Henry's law constants and infinite dilution activity coefficients of propane, propene, butane, isobutane, 1-butene, isobutene, trans-2-butene, and 1,3-butadiene in 1-pentanol, 2-pentanol in the temperature range of (250 to 330) K and 3-pentanol in the temperature range of (260 to 330) K were measured by a gas stripping method. A rigorous formula for evaluating the Henry's law constants from the gas stripping measurements was used for the data reduction of these highly volatile mixtures. The uncertainty is about 2% for the Henry's law constants and 3% for the estimated infinite dilution activity coefficients. In the evaluation of the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and Pointing correction factor cannot be neglected, especially at higher temperatures. The estimated uncertainty of the infinite dilution activity coefficients includes 1% for nonideality.

  5. Enthalpies and entropies of vaporization of propan-2-ol-2-methylpropan-1-ol solutions

    Science.gov (United States)

    Baev, A. A.; Baev, A. K.

    2014-03-01

    P-T-x dependences are measured for the solutions of a propan-2-ol-2-methylpropan-1-ol binary system and the enthalpies and entropies of vaporization are determined. Dimerization in propan-2-ol and 2-methylpropan-1-ol is rationalized and the contribution from energy introduced by isostructural methyl groups to the enthalpy of vaporization is determined. Structural and energy analyses of solutions with networks of specific interactions are performed. The formation of heterodimers in solutions and vapors with reduced hydrogen bond energies and specific interactions with the 2 s 2(C) unshared electron pairs of the carbon atoms of terminal methyl groups in ethyl and propyl fragments of propan-2-ol and 2-methylpropan-1-ol, respectively, is substantiated. The hydrogen bond energy of heterodimers is estimated.

  6. 2-[(5-Chloro-2-oxidobenzylideneazaniumyl]-2-methylpropane-1,3-diol

    Directory of Open Access Journals (Sweden)

    Dong-Yue Wang

    2012-02-01

    Full Text Available The title compound, C11H14ClNO3, was prepared by the condensation of equimolar quantities of 5-chlorosalicylaldehyde and 2-amino-2-methylpropane-1,3-diol in methanol. In the crystal, it exists in the zwitterionic form, with nominal proton transfer from the phenol group to the imine N atom. This results in the formation of an intramolecular N—H...O hydrogen bond, which generates an S(6 ring. Intermolecular O—H...O hydrogen bonds arise from the hydroxy groups, forming (001 sheets.

  7. Synthesis and properties of poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid)/PbS hybrid composite

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    Preda, N., E-mail: nicol@infim.ro [National Institute of Materials Physics, Multifunctional Materials and Structures Laboratory, P.O. Box MG-7, 77125 Bucharest (Romania); Rusen, E. [University Politehnica Bucharest, Department of Polymer Science, Calea Victoriei No. 71101, Bucharest (Romania); Musuc, A. [Institute of Physical Chemistry, 060021 Bucharest (Romania); Enculescu, M.; Matei, E. [National Institute of Materials Physics, Multifunctional Materials and Structures Laboratory, P.O. Box MG-7, 77125 Bucharest (Romania); Marculescu, B. [University Politehnica Bucharest, Department of Polymer Science, Calea Victoriei No. 71101, Bucharest (Romania); Fruth, V. [Institute of Physical Chemistry, 060021 Bucharest (Romania); Enculescu, I. [National Institute of Materials Physics, Multifunctional Materials and Structures Laboratory, P.O. Box MG-7, 77125 Bucharest (Romania)

    2010-08-15

    The synthesis of a new hybrid composite based on PbS nanoparticles and poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid) [P(MMA-AMPSA)] copolymer is reported. The chemical synthesis consists in two steps: (i) a surfactant-free emulsion copolymerization between methyl methacrylate and 2-acrylamido-2-methylpropane sulfonic acid and (ii) the generation of PbS particles in the presence of the P(MMA-AMPSA) latex, from the reaction between lead nitrate and thiourea. The composite was studied by scanning electron microscopy (SEM), X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The microstructure observed using SEM proves that the PbS nanoparticles are well dispersed in the copolymer matrix. The X-ray diffraction measurements demonstrate that the PbS nanoparticles have a cubic rock salt structure. It was also found that the inorganic semiconductor nanoparticles improve the thermal stability of the copolymer matrix.

  8. Crystal structure of 1-(5-amino-2H-tetrazol-2-yl-2-methylpropan-2-ol

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    Hyun Sik Park

    2015-12-01

    Full Text Available The title compound, C5H11N5O, crystallized with two independent molecules in the asymmetric unit. The two molecules differ in the orientation of the 2-methylpropan-2-ol unit, with the hydroxy H atoms pointing in opposite directions. In the crystal, molecules are linked via O—H...O and N—H...O hydrogen bonds, forming ribbons propagating along [10-1]. The ribbons are linked via N—H...N hydrogen bonds, forming a three-dimensional structure.

  9. Production of propene from 1-butene metathesis reaction on tungsten based heterogeneous catalysts

    Institute of Scientific and Technical Information of China (English)

    Huijuan Liu; Ling Zhang; Xiujie Li; Shengjun Huang; Shenglin Liu; Wenjie Xin; Sujuan Xie; Longya Xu

    2009-01-01

    A new propene production route from 1-butene metathesis has been developed on heterogeneous 10WO_3/Al_2O_3-HY catalysts with different HY contents. It is found that the catalysts play bi-functionally first for the isomerization of 1-butene to 2-butene and then for the cross-metathesis between 1-butene and 2-butene to propene and 2-pentene. The combination of HY zeolite and Al_2O_3 is prerequisite for the production of propene. The propene yield keeps increasing with the HY content in the range of 10-70 wt%,where 10WO_3/Al_2O_3-70HY exhibits the highest propene yield. The MS-H_2-TPR and MS-O_2-TPO characterizations indicate that the increase of HY content in the catalysts weakens the interaction between W species and supports,whereas enhance the probability of coking on the metal species and acid sites.

  10. Continuous gas-phase hydroformylation of 1-butene using supported ionic liquid phase (SILP) catalysts

    DEFF Research Database (Denmark)

    Haumann, Marco; Dentler, Katharina; Joni, Joni;

    2007-01-01

    The concept of supported ionic liquid phase (SILP) catalysis has been extended to 1-butene hydroformylation. A rhodium-sulfoxantphos complex was dissolved in [BMIM][n-C8H17OSO3] and this solution was highly dispersed on silica. Continuous gas-phase experiments in a fixed-bed reactor revealed...

  11. Synthesis, Characterization, and Highly Selective Ethylene Dimerization to 1-Butene of [O-NX]Ni(II) Complexes

    Institute of Scientific and Technical Information of China (English)

    许崇杰; 沈琪; 孙秀丽; 唐勇

    2012-01-01

    A series of nickel(II) complexes have been synthesized and characterized. Molecular structure analysis exhibits that a square planar geometry around nickel is adopted. Upon activation with MAO, these nickel(II) complexes are efficient in catalyzing the ethylene dimerization, providing 1-butene with an activity of up to 1.4 ×10^7 g/(molohoatm). The heteroatoms of the sidearm in the complexes were proved to have great impact on the activity and selectivity of 1-butene.

  12. Study of poly (acrylamide-co-2-acrylamido-2-methylpropane sulfonic acid) hydrogel using gamma radiation initiation

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    Zhang, C.; Easteal, A.J. [The University of Auckland, Auckland (New Zealand). Department of Chemistry

    1998-12-31

    Full text: Poly (acrylamide-co-2-acrylamido-2-methylpropane sulfonic acid ) (PAAM-co-AMPS) polyelectrolyte hydrogels were formed by using {gamma}-radiation to initiate polymerization and cross-linking. The dependence of chain growth and cross-linking of liquid-like gel on absorbed dose was observed by viscosity measurement. It was found that the viscosity of liquid-like gel increased non-linearly with increasing radiation dose. Crosslinking took place at about 2,300 Gy. It was noted that an ageing effect occurred, such that the viscosity of liquid-like gels decreased significantly on standing. X-ray diffraction revealed that after dehydration the dried gels were amorphous, suggesting that radiation polymerization occurs by random initiation and propagation. Differential scanning calorimetry (DSC) indicated a clear distinction between the thermal behaviour of the homopolymer gels formed by irradiation, and the behaviour of the copolymer gels. PAAM-co-AMPS gels have enhanced thermal stability in comparison to PAAM and PAMPS. The melting points of water in the gels initially increase with increasing dose, and decrease slightly at very high radiation dose. Those trends can be explained by the variation in the numbers of solute molecules or ions in the gels with absorbed dose. Melting points of water in gels can be used for observation of the polymerization process associated with irradiation. Copolymer composition (expressed by either f{sub 1} (AAM molal fraction ) or f{sub 2} (AMPS molal fraction) ) associated with radiation dose was determined by both elemental analysis and FTIR. Both methods show that f{sub 1} increases to a maximum with increasing dose, and subsequently decreases. It is concluded that PAAM-co-AMPS hydrogels were synthesised successfully by gamma radiation initiation, and that copolymer compositions are dependent on radiation dose

  13. Production of propylene from 1-butene on highly active "bi-functional single active site" catalyst: Tungsten carbene-hydride supported on alumina

    KAUST Repository

    Mazoyer, Etienne

    2011-12-02

    1-Butene is transformed in a continuous flow reactor over tungsten hydrides precursor W-H/Al2O3, 1, giving a promising yield into propylene at 150 °C and different pressures. Tungsten carbene-hydride single active site operates as a "bi-functional catalyst" through 1-butene isomerization on W-hydride and 1-butene/2-butenes cross-metathesis on W-carbene. This active moiety is generated in situ at the initiation steps by insertion of 1-butene on tungsten hydrides precursor W-H/Al2O3, 1 followed by α-H and β-H abstraction. © 2011 American Chemical Society.

  14. Shear effects on crystallization behaviors and structure transitions of isotactic poly-1-butene

    DEFF Research Database (Denmark)

    Li, Jingqing; Guan, Peipei; Zhang, Yao;

    2014-01-01

    Different melt pre-shear conditions were applied to isotactic poly-1-butene (iP-1-B) and the effect on the crystallization behaviors and the crystalline structure transitions of iP-1-B were investigated. The polarized optical microscope observations during isothermal crystallization process...... crystalline structures. With the melt pre-shear rate increasing, the lattice spaces of the crystallites decreased and the long period, L, and the amorphous layer thickness, La, along the equator direction increased slightly, but L and La along the meridian direction was not affected by melt pre-shear flow....... Though the orientated crystalline structures existed in the iP-1-B samples, no accelerating effect on crystal transition from II to I was found. Importantly, the final crystalline structures of iP-1-B in form I was found tunable under different melt pre-shear conditions, even though...

  15. Effect of molecular weight on the crystallization kinetics of isostatic poly(1-butene)

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    Cortazar, M.; Guzman, G.M.

    1982-03-12

    Isothermal crystallization of isotactic poly(1-butene) fractions by calorimetry and microscopy was studied for a range of molecular weights from 96 000 to 964 000. An Avrami exponent of 2 was found indicating a two-dimensional growth rate of the crystal, following a predetermined nucleation mode, proving that such an exponent is independent of both temperature and molecular weight. The temperature and molecular weight dependence of the growth rate of spherulites and overall crystallization rates was analyzed by means of the theoretical expression given by Hoffman and Lauritzen. The product of the lateral and basal surface free energies of the crystallites, sigma x sigma/sub e/, increases with molecular weight and approaches its limiting values when a certain molecular weight is attained.

  16. Experimental and modeling study of the oxidation of n- and iso-butanal

    KAUST Repository

    Veloo, Peter S.

    2013-09-01

    Understanding the kinetics of large molecular weight aldehydes is essential in the context of both conventional and alternative fuels. For example, they are key intermediates formed during the low-temperature oxidation of hydrocarbons as well as during the high-temperature oxidation of oxygenated fuels such as alcohols. In this study, an experimental and kinetic modeling investigation of n-butanal (. n-butyraldehyde) and iso-butanal (. iso-butyraldehyde or 2-methylpropanal) oxidation kinetics was performed. Experiments were performed in a jet stirred reactor and in counterflow flames over a wide range of equivalence ratios, temperatures, and pressures. The jet stirred reactor was utilized to observe the evolution of stable intermediates and products for the oxidation of n- and iso-butanal at elevated pressures and low to intermediate temperatures. The counterflow configuration was utilized for the determination of laminar flame speeds. A detailed chemical kinetic interpretative model was developed and validated consisting of 244 species and 1198 reactions derived from a previous study of the oxidation of propanal (propionaldehyde). Extensive reaction pathway and sensitivity analysis was performed to provide detailed insight into the mechanisms governing low-, intermediate-, and high-temperature reactivity. The simulation results using the present model are in good agreement with the experimental laminar flame speeds and well within a factor of two of the speciation data obtained in the jet stirred reactor. © 2013 The Combustion Institute.

  17. Catalytic cracking of 1-butene to propylene by Ag modified HZSM-5

    Institute of Scientific and Technical Information of China (English)

    Rongrong Zhang; Zhengbao Wang

    2015-01-01

    Silver modified HZSM-5 (AgHZ) zeolite catalysts were prepared by ion exchange method and their catalytic properties in the 1-butene cracking reaction were measured. The catalysts were characterized by infrared spec-troscopy with pyridine adsorption (Py-IR), N2 adsorption and X-ray diffraction (XRD). The effects of Ag loading and steaming treatment on catalytic performances were studied. It is found that the activity of HZSM-5 (HZ) cat-alyst significantly decreases with the steaming time, whereas AgHZ catalysts show stable activity in the steaming time of 24–48 h and their activities increase with the Ag loading. When the steaming time is 24–48 h, the yield of propylene over HZ catalyst significantly decreases, whereas it is stable over AgHZ catalysts. The AgHZ catalysts with Ag loadings of 0.28%–0.43%(by mass) show similar propylene yields (~30%), which are higher than that over the AgHZ catalyst with a Ag loading of 0.55%(by mass). These results indicate that the steam-treated AgHZ catalysts with optimum Ag loadings have higher yield of propylene and are more stable than the steam-treated HZ catalyst. The regeneration stability measurement in butene cracking also shows that the AgHZ catalyst steam-treated under a suitable condition has better stability than the HZ catalyst.

  18. Cell cycle specificity of cytogenetic damage induced by 3,4-epoxy-1- butene.

    Science.gov (United States)

    Kligerman, A D; Doerr, C L; Tennant, A H

    1999-07-21

    3,4-epoxy-1-butene (EB), a primary metabolite of butadiene, is a direct-acting "S-dependent" genotoxicant that can induce sister chromatid exchanges (SCEs) and chromosome aberrations (CAs) in cycling cells in vitro. However, EB is almost inactive when splenic or peripheral blood lymphocytes are exposed at the G(0) stage of the cell cycle. To investigate whether repair of DNA lesions is responsible for the lack of cytogenetic responses seen after G(0) treatments, we used cytosine arabinoside (ara-C) to inhibit DNA polymerization during DNA repair. If enough repairable lesions are present, double-strand breaks should accumulate and form chromosome-type ("S-independent") deletions and exchanges. This is exactly what occurred. EB induced chromosome deletions and dicentrics at the first division following treatment, when the EB exposure was followed by ara-C. Without ara-C treatment, there was no induction of CAs. These experiments indicate that the relatively low levels of damage induced by EB in G(0) lymphocytes are removed by DNA repair prior to DNA synthesis and thus, before the production of SCEs or chromatid-type aberrations.

  19. Synthesis and Evaluation of Poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene/Magnetite Nanoparticle Composites as Corrosion Inhibitors for Steel

    Directory of Open Access Journals (Sweden)

    Gamal A. El-Mahdy

    2014-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  1. Excess enthalpies from displacement calorimetry excess enthalpies for 1,1,1- trichloroethane+carbon tetrachloride and 2-chloro-2-methylpropane+carbon tetrachloride at 298.15 K

    NARCIS (Netherlands)

    Miltenburg, J.C. van der; Obbink, J.H.; Meijer, E.L.

    1979-01-01

    Excess enthalpies HE are reported for the 1,1,1-trichloroethane+carbon tetrachloride and 2-chloro-2-methylpropane+carbon tetrachloride systems. The results are fitted to the formula HE = x(1−x)Σiai(1−2x)i.

  2. Selective hydrogenation of 1,3-butadiene in presence of 1-butene under liquid phase conditions with NiPd/Al^sub 2^O3 catalysts

    National Research Council Canada - National Science Library

    Franklin J Méndez; Roger Solano; Yanet Villasana; Julia Guerra; Susana Curbelo; Marcel Inojosa; Claudio Olivera-Fuentes; Joaquín L Brito

    2016-01-01

      The catalytic performance of Al2O3-supported monometallic and bimetallic catalysts in selective hydrogenation of 1,3-butadiene in the presence of 1-butene under liquid phase conditions was studied...

  3. 2-(Cyclohexylamino)-1-(4-cyclopentylpiperazin-1-yl)-2-methylpropan-1-one, a novel compound with neuroprotective and neurotrophic effects in vitro.

    Science.gov (United States)

    Elbrønd-Bek, H; Wellejus, A; Kelly, N M; Weidner, M S; Jørgensen, S H

    2011-11-01

    Focusing on development of novel drug candidates for the treatment of neurodegenerative diseases, we developed and synthesized a new compound, 2-(cyclohexylamino)-1-(4-cyclopentylpiperazin-1-yl)-2-methylpropan-1-one (amido-piperizine 1). The compound demonstrated robust neuroprotective properties after both glutamate excitotoxicity and peroxide induced oxidative stress in primary cortical cultures. Furthermore, amido-piperizine 1 was found to significantly induce neurite outgrowth in vitro which could suggest central reparative and regenerative potential of the compound. With these potential beneficial effects in CNS, the ability of the amido-piperizine 1 to penetrate the blood-brain barrier was tested using MDR1-MDCK cells. Amido-piperizine 1 was found not to be a P-gp substrate and to have a high blood-brain barrier penetration potential, indicating excellent availability to the CNS. Moreover, amido-piperizine 1 had a fast metabolic clearance rate in vitro, suggesting that parenteral in vivo administration seems preferable. As an attempt to elucidate a possible mechanism of action, we found that amido-piperizine 1 bound in nano-molar range to the sigma-1 receptor, which could explain the observed neuroprotective and neurotrophic properties, and with a 100-fold lower affinity to the sigma-2 receptor. These results propose that amido-piperizine 1 may hold promise as a drug candidate for the treatment of stroke/traumatic brain injury or other neurodegenerative diseases.

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

    Science.gov (United States)

    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.

  5. Biocompatibility of polypropylene non-woven fabric membrane via UV-induced graft polymerization of 2-acrylamido-2-methylpropane sulfonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Song Lingjie [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhao Jie; Yang Huawei; Jin Jing; Li Xiaomeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2011-10-15

    This work described the graft polymerization of a sulfonic acid terminated monomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), onto the surface of polypropylene non-woven (NWF PP) membrane by O{sub 2} plasma pretreatment and UV-induced photografting method. The chemical structure and composition of the modified surfaces were analyzed by FTIR-ATR and XPS, respectively. The wettability was investigated by water contact angle and equilibrium water adsorption. And the biocompatibility of the modified NWF PP membranes was evaluated by protein adsorption and platelet adhesion. It was found that the graft density increased with prolonging UV irradiation time and increasing AMPS concentration; the water contact angles of the membranes decreased from 124{sup o} to 26{sup o} with the increasing grafting density of poly(AMPS) from 0 to 884.2 {mu}g cm{sup -2}, while the equilibrium water adsorption raised from 5 wt% to 75 wt%; the protein absorption was effectively suppressed with the introduction of poly(AMPS) even at the low grafting density (132.4 {mu}g cm{sup -2}); the number of platelets adhering to the modified membrane was dramatically reduced when compared with that on its virgin surface. These results indicated that surface modification of NWF PP membrane with AMPS was a facile approach to construct biocompatible surface.

  6. Temperature-dependent absorption cross-section measurements of 1-butene (1-C4H8) in VUV and IR

    KAUST Repository

    Es-sebbar, Et-touhami

    2013-01-01

    Vacuum ultraviolet (VUV) and infrared (IR) absorption cross-section measurements of 1-butene (1-C4H8; CH2=CHCH2CH3; Butylene) are reported over the temperature range of 296-529K. The VUV measurements are performed between 115 and 205nm using synchrotron radiation as a tunable VUV light source. Fourier Transform Infrared (FTIR) spectroscopy is employed to measure absorption cross-section and band strengths in the IR region between 1.54 and 25μm (~6500-400cm-1). The measured room-temperature VUV and IR absorption cross-sections are compared with available literature data and are found to be in good agreement. The oscillator strength for the electronic transition (A1A\\'→X1A\\') around 150-205nm is determined to be 0.32±0.01.The gas temperature has a strong effect on both VUV and IR spectra. Measurements made in the VUV region show that the peak value of the band cross-section decreases and the background continuum increases with increasing gas temperature. This behavior is due to a change in the rotational and vibrational population distribution of 1-butene molecule. Similar changes in rotational population are observed in the IR spectra. Moreover, variation of the IR spectra with temperature is used to measure the enthalpy difference between syn and skew conformations of 1-butene and is found to be 0.24±0.03. kcal/mol, which is in excellent agreement with values reported in the literature. The measurements reported in this work will provide the much-needed spectroscopic information for the development of high-temperature quantitative diagnostics in combustion applications and validation of atmospheric chemistry models of extra-solar planets. © 2012 Elsevier Ltd.

  7. 信息动态%Polymerization of 1-butene with spherical MgCI2-supported catalyst

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The activity of the spherical MgCl2-supported catalyst for 1-butene polymerization reached 607 g/g and the isotacticity index of poly(l-butene) prepared with the catalyst attained 82.3% under the following optimal conditions: triethyl aluminum as cocatalyst, molar ratio of Al to Ti 300, polymerization pressure 0.10 MPa, polymerization temperature 30 ℃, hydrogen 3 mL, molar ratio of cyclohexyl methyl dimethoxy s/lane (CHMMS) to Al 0.033 and reaction time 2 hr. The ranking of external electron donors could be expressed in descending order on the basis of either the catalyst activity as CHMMS, dieyclopentyl dimethoxy silane(DCPMS), diisobutyl dimethoxy silane(DIBMS), diisopropyl dimethoxy silane(DIPMS) and diphenyl dimethoxy silane(DDS), or the isotacticity index of poly(l-butene) as DCPMS, DIPMS, DIBMS, CHMMS and DDS.

  8. Influence of phosphorous addition on Bi3Mo2Fe1 oxide catalysts for the oxidative dehydrogenation of 1-butene

    KAUST Repository

    Park, Jung-Hyun

    2016-01-22

    Bi3Mo2Fe1Px oxide catalysts were prepared by a co-precipitation method and the influence of phosphorous content on the catalytic performance in the oxidative dehydrogenation of 1-butene was investigated. The addition of phosphorous up to 0.4mole ratio to Bi3Mo2Fe1 oxide catalyst led to an increase in the catalytic performance; however, a higher phosphorous content (above P=0.4) led to a decrease of conversion. Of the tested catalysts, Bi3Mo2Fe1P0.4 oxide catalyst exhibited the highest catalytic performance. Characterization results showed that the catalytic performance was related to the quantity of a π-allylic intermediate, facile desorption behavior of adsorbed intermediates and ability for re-oxidation of catalysts. © 2015 Korean Institute of Chemical Engineers, Seoul, Korea

  9. Grafting of diethyl maleate and maleic anhydride onto styrene-b-(ethylene-co-1-butene)-b-styrene triblock copolymer (SEBS)

    NARCIS (Netherlands)

    Picchioni, F.; Ghetti, S.; Passaglia, E.; Ruggeri, G.

    2000-01-01

    In this paper a study of the bulk functionalization of styrene-b-(ethylene-co-1-butene)-b-styrene triblock copolymer (SEBS) with diethyl maleate (DEM) or maleic anhydride (MAH) and dicumyl peroxide (DCP) as initiator in a Brabender mixer is described. The determination of the functionalization degre

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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...

  12. Effect of Polymerization Conditions on Thermal and Mechanical Properties of Ethylene/1-Butene Copolymer Made with Ziegler-Natta Catalysts

    Directory of Open Access Journals (Sweden)

    Mostafizur Rahaman

    2014-01-01

    Full Text Available The effect of polymerization conditions on thermal and mechanical properties of ethylene/1-butene copolymers synthesized through titanium-magnesium-supported Ziegler-Natta catalysts was studied. The increase in hydrogen pressure leads to a decrease in molecular weight (MW, storage modulus, and melting temperature. However, it yields an increase in molecular weight distribution (MWD, tan⁡δ, % crystallinity, tensile modulus, yield stress, and strain at break. The effects of ethylene pressure and polymerization temperature on the copolymer MW, MWD and thermal and mechanical properties have been investigated. However, the impacts of ethylene pressure and polymerization temperature on copolymer modulus, tensile strength, % crystallinity, crystallization peak temperature, yield stress, strain at break, and yield strain are marginal. The hydrogen pressure plays a major role in controlling the copolymer properties because it acts as an efficient chain transfer agent during polymerization reaction. The MW is the key parameter that influences flow activation energy. However, the other mechanical, dynamic mechanical, and thermal properties not only depend on MW but are also influenced by other parameters.

  13. ROLE AND IMPORTANCE OF RADIUS OF GYRATION OF CHAINS IN THE MELT IN THE CRYSTALIZATION OF POLY(1-BUTENE)

    Institute of Scientific and Technical Information of China (English)

    Qiang Fu; G.Strobl

    2002-01-01

    Crystallization in polymer systems actually is a process that transfers the entangled melts into a semi-crystalline layered structure. Whether or not a chain disentangles may result in different crystallization mechanism. When compared to the crystal thickness (dc), the volume occupied by the chain in the melt, i.e., the radius of gyration (Rg), plays a very important role in polymer crystallization. When dc ≤ Rg, crystallization does not necessitate a chain disentangling. The entanglements are just shifted into the amorphous regions. However, as dc>Rg, i.e., as the crystal thickness gets larger than the radius of gyration of the chain in the melt, it becomes necessary for a chain to disentangle. Then a change of crystallization mechanism occurs. Such change has been experimentally observed in the crystallization of poly(1-butene). A change in the crystal morphologies from spherulite to quadrangle, is seen via PLM, as crystallization temperatures increase.Even more, such a change is molecular weight dependent, and shifts to lower temperature as molecular weight decreases. There exists a jump of crystal thickness and crystallinity associated with morphological change, as seen via SAXS. A change of crystallization kinetics and crystallinity is further evidenced via dilatometry. The unique feature of P1b crystallization has been discussed based on the radius of gyration of chain in the melt (Rg), and very good agreement is obtained.

  14. Evaluated kinetics of terminal and non-terminal addition of hydrogen atoms to 1-alkenes: a shock tube study of H + 1-butene.

    Science.gov (United States)

    Manion, Jeffrey A; Awan, Iftikhar A

    2015-01-22

    Single-pulse shock tube methods have been used to thermally generate hydrogen atoms and investigate the kinetics of their addition reactions with 1-butene at temperatures of 880 to 1120 K and pressures of 145 to 245 kPa. Rate parameters for the unimolecular decomposition of 1-butene are also reported. Addition of H atoms to the π bond of 1-butene results in displacement of either methyl or ethyl depending on whether addition occurs at the terminal or nonterminal position. Postshock monitoring of the initial alkene products has been used to determine the relative and absolute reaction rates. Absolute rate constants have been derived relative to the reference reaction of displacement of methyl from 1,3,5-trimethylbenzene (135TMB). With k(H + 135TMB → m-xylene + CH3) = 6.7 × 10(13) exp(-3255/T) cm(3) mol(-1) s(-1), we find the following: k(H + 1-butene → propene + CH3) = k10 = 3.93 × 10(13) exp(-1152 K/T) cm(3) mol(-1) s(-1), [880-1120 K; 145-245 kPa]; k(H + 1-butene → ethene + C2H5) = k11 = 3.44 × 10(13) exp(-1971 K/T) cm(3) mol(-1) s(-1), [971-1120 K; 145-245 kPa]; k10/k11 = 10((0.058±0.059)) exp [(818 ± 141) K/T), 971-1120 K. Uncertainties (2σ) in the absolute rate constants are about a factor of 1.5, while the relative rate constants should be accurate to within ±15%. The displacement rate constants are shown to be very close to the high pressure limiting rate constants for addition of H, and the present measurements are the first direct determination of the branching ratio for 1-olefins at high temperatures. At 1000 K, addition to the terminal site is favored over the nonterminal position by a factor of 2.59 ± 0.39, where the uncertainty is 2σ and includes possible systematic errors. Combining the present results with evaluated data from the literature pertaining to temperatures of <440 K leads us to recommend the following: k∞(H + 1-butene → 2-butyl) = 1.05 × 10(9)T(1.40) exp(-366/T) cm(3) mol(-1) s(-1), [220-2000 K]; k∞(H + 1-butene → 1

  15. AA/AMPS水凝胶的交联聚合反应动力学及其机理%Crosslink Polymerization Kinetics and Mechanism of Hydrogels Composed of Acrylic Acid and 2-Acrylamido-2-methylpropane Sulfonic Acid

    Institute of Scientific and Technical Information of China (English)

    廖列文; 岳航勃; 崔英德

    2011-01-01

    Crosslink polymerization kinetics of poly(acrylic acid-co-2-acrylamido-2-methylpropane sulfonic acid),AA/AMPS hydrogels, was investigated by using dilatometry in the presence of sodium persulfate as initiator and N,N'-methylene bis(acrylamide) as crosslinker. It was found that the reaction for the cross/ink polymerization of AA/AMPS hydrogels had orders of 0.58, 1.14, and 0.86 with respect to the initiator, AMPS, and AA, respectively.From the Arrhenius plots, the activation energy of the crossLink polymerization was found to be about 140 and 89 kJ·mol-1 in the presence and absence of the crosslinker, respectively, in the temperature range from 45 to 65 ℃. It was noted that the crosslinker had effects on the reaction order of the initiator and the activation energy due to the formation of cross-linked networks, which was verified by Fourier transfer infrared (FTLR) spectrum. To further confirm the influences of the cross-linked network structure on kinetic parameters of the crosslink polymerization, a mechanism was proposed, which highlights the different termination routes between free radical polymerization and crosslink polymerization. These results suggest that dilatometry provides a convenient tool for crosslink polymerization study, and confirm that the cross-linked networks are formed in the crosslink polymerization.

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

    Science.gov (United States)

    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.

  17. Microbiology: Deep-sea secrets of butane metabolism

    Science.gov (United States)

    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

  18. 2-Methylpropan-2-aminium 2-(methoxycarbonylbenzoate

    Directory of Open Access Journals (Sweden)

    Jian Li

    2011-10-01

    Full Text Available In the title compound, C4H12N+·C9H7O4−, two C atoms and the N atom of the cation lie on a mirror plane, while all the atoms of the anion are disordered about a mirror plane. In the crystal, N—H...O hydrogen bonds link the components into chains along [010]. In the anion, the mean planes of the methoxycarbonyl and carboxylate groups form dihedral angles of 83.0 (2 and 83.2 (2°, respectively, with the aromatic ring.

  19. 3,4-Epoxy-1-butene, a reactive metabolite of 1,3-butadiene, induces somatic mutations in Xpc-null mice.

    Science.gov (United States)

    Wickliffe, J K; Galbert, L A; Ammenheuser, M M; Herring, S M; Xie, J; Masters, O E; Friedberg, E C; Lloyd, R S; Ward, J B

    2006-01-01

    Xpc-null (Xpc-/-) mice, deficient in the global genome repair subpathway of nucleotide excision repair (NER-GGR), were exposed by intraperitoneal (i.p.) injection to a 300 mg/kg mutagenic dose of 3,4-epoxy-1-butene (EB), to investigate NER's potential role in repairing butadiene (BD) epoxide DNA lesions. Mutagenic sensitivity was assessed using the Hprt assay. Xpc-/- mice were significantly more sensitive to EB exposure, exhibiting an average 2.8-fold increase in Hprt mutant frequency (MF) relative to those of exposed Xpc+/+ (wild-type) mice. As a positive control for NER-GGR, additional mice were exposed by i.p. injection to a 150 mg/kg mutagenic dose of benzo[a]pyrene (B[a]P). The Xpc-/- mice had MFs 2.9-fold higher than those of exposed Xpc+/+ mice. These results suggest that NER-GGR plays a role in recognizing and repairing some of the DNA adducts formed following in vivo exposure to EB. Additional research is needed to examine the response of Xpc-/- mice, as well as other NER-deficient strains, to inhaled BD. Furthermore, it is likely that alternative DNA repair pathways also are involved in restoring genomic integrity compromised by BD-epoxide DNA damage. Collaborative studies are currently underway to address these critical issues.

  20. Metathesis of 1-Butene to Propene over Mo/Al2O3@SBA-15: Influence of Alumina Introduction Methods on Catalytic Performance.

    Science.gov (United States)

    Zhang, Dazhou; Li, Xiujie; Liu, Shenglin; Zhu, Xiangxue; Chen, Fucun; Xu, Longya

    2015-08-01

    A series of Mo-based catalysts for 1-butene metathesis to propene were prepared by supporting Mo species on SBA-15 premodified with alumina. The effects of the method of introduction of the alumina guest to the host SBA-15 on the location of the Mo species and the corresponding metathesis activity were studied. As revealed by N2 adsorption isotherms and TEM results, well-dispersed alumina was formed on the pore walls of SBA-15 if the ammonia/water vapor induced hydrolysis (NIH) method was employed. The Mo species preferentially interacted with alumina instead of SBA-15, as evidenced by X-ray photoelectron spectroscopy, time-of-flight secondary-ion mass spectrometry, and IR spectroscopy of adsorbed pyridine. Furthermore, new Brønsted acid sites favorable for the dispersion of the Mo species and low-temperature metathesis activity were generated as a result of the effective synergy between the alumina and SBA-15. The Mo/Al2O3@SBA-15 catalyst prepared by the NIH method showed higher metathesis activity and stability under the conditions of 120 °C, 0.1 MPa, and 1.5 h(-1) than catalysts prepared by other methods.

  1. Study on reaction process for oxidative dehydrogenation of 1-butene to butadiene%1-丁烯氧化脱氢制丁二烯反应过程研究

    Institute of Scientific and Technical Information of China (English)

    张梁; 田靖; 刘兵

    2015-01-01

    The reaction process of 1-butene oxidative dehydrogenation to butadiene over catalyst HS-2 in an isothermal integral fixed bed reactor was studied, and the effects of feedstock composition and reaction conditions on the conversion of 1-butene and selectivity of butadiene were investigated.The results indicated that the conversion of 1-butene first increased then remained nearly constant and the selectivity of butadiene almost kept unchanged with increasing temperature; the conversion of 1-butene gradually increased and the selectivity of butadiene declined insignificantly with increasing mole ratio of oxygen to 1-butene; the conversion of 1-butene decreased slightly with increasing mole ratio of water to 1-butene which had little effect on the selectivity of butadiene;iron-based catalyst HS-2 could be used in a wide temperature scope, so it would be suitable for the adiabatic reactor; and the mixed butenes containing 1-butene and 2-butene could be selected as reactant.%在320~560℃,0.06MPa~0.1MPa(g),氧烯比和水烯比(物质的量比)分别为0.55~0.85、11~20的条件下,使用自制丁烯氧化脱氢HS-2型催化剂在等温积分反应器中,研究了1-丁烯生成丁二烯的反应过程,并考察了原料丁烯组成及操作条件对丁烯转化率、丁二烯选择性的影响。实验结果表明:随着温度的升高,1-丁烯转化率先增加后基本保持不变,丁二烯的选择性基本不变;随着氧烯比的升高,1-丁烯转化率渐渐增大,丁二烯选择性随着氧烯比的升高,下降不明显;水烯比对丁二烯选择性影响不大,水烯比升高使得1-丁烯转化率略有降低;铁系催化剂HS-2的活性温度区间较宽,可适用于绝热反应器;丁烯原料可选1-丁烯和2-丁烯(顺、反丁烯)混合物。

  2. The Effect of Sulfate Ion on the Isomerization of n-Butane to iso-Butane

    Institute of Scientific and Technical Information of China (English)

    Sugeng Triwahyono; Zalizawati Abdullah; Aishah Abdul Jalil

    2006-01-01

    The effect of sulfate ion (SO24-) loading on the properties of Pt/SO24--ZrO2 and on the catalytic isomerization of n-butane to iso-butane was studied. The catalyst was prepared by impregnation of Zr(OH)4 with H2SO4 and platinum solution followed by calcination at 600 ℃. Ammonia TPD and FT-IR were used to confirm the distribution of acid sites and the structure of the sulfate species. Nitrogen physisorption and X-ray diffraction were used to confirm the physical structures of Pt/SO24--ZrO2. XRD pattern showed that the presence of sulfate ion stabilized the metastable tetragonal phase of zirconia and hindered the transition of amorphous phase to monoclinic phase of zirconia. Ammonia TPD profiles indicated the distributions of weak and medium acid sites observed on 0.1 N and 1.0 N sulfate in the loaded catalysts. The addition of 2.0 N and 4.0 N sulfate ion generated strong acid site and decreased the weak and medium acid sites. However, the XRD results and the specific surface area of the catalysts indicated that the excessive amount of sulfate ion collapsed the structure of the catalyst. The catalysts showed high activity and stability for isomerization of n-butane to iso-butane at 200 ℃ under hydrogen atmosphere. The conversion of n-butane to iso-butane per specific surface area of the catalyst increased with the increasing amount of sulfate ion owing to the existence of the bidentate sulfate and/or polynucleic sulfate species ((ZrO)2SO2), which acts as an active site for the isomerization.

  3. N′-(Butan-2-ylidenefuran-2-carbohydrazide

    Directory of Open Access Journals (Sweden)

    He-ping Li

    2010-10-01

    Full Text Available The title Schiff base compound, C9H12N2O2, was obtained from a condensation reaction of butan-2-one and furan-2-carbohydrazide. The furan ring and the hydrazide fragment are roughly planar, the largest deviation from the mean plane being 0.069 (2Å, but the butanylidene group is twisted slightly with respect to this plane by a dihedral angle of 5.2 (3°. In the crystal, intermolecular N—H...O hydrogen bonds link pairs of inversion-related molecules, forming dimers of R22(8 graph-set motif.

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

    Science.gov (United States)

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

    2016-01-01

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

  5. Binuclear metal carbonyl DAB complexes X. Activation of h2-C=N coordinated DAB ligands towards C-C bond formation with alkynes. The X-ray structure of {2-phenyl-3-(tert-butylamino)-4-(tertbutyl-imino)-1-butene-1-yl}Ru2(CO)5. Application to the catalytic cyclotrimerization of alkynes

    NARCIS (Netherlands)

    Koten, G. van; Staal, L.H.; Vrieze, K.; Santen, B. van; Stam, C.H.

    1981-01-01

    Ru,(CO),(DAB) (DAB = 1,4-diazabutadiene) complexes react with alkynes forming RU,(CO)~(AIB) complexes (AIB = 3-amino-4-imino-1-buten-1-ylI)n. these products the DAB ligand and the alkyne are coupled via a C-C bond. The molecular structure of these complexes has been determined by a single-crystal X-

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

    CERN Document Server

    Salazar, M A; Atchison, W; Armijo, E; Bartos, Yu; García, F; Randolph, B; Sheppard, M G

    2001-01-01

    Summary form only given, as follows. A hydrogen rich, low density liquid, contained within the internal volume of a cylindrical liner, was requested of the Polymers and Coatings Group (MST-7) of the Los Alamos Materials Science Division for one of the last liner driven experiments conducted on the Los Alamos Pegasus facility. The experiment required massive tungsten glide planes for inertial confinement of the liner fill media during implosion. Shallow sinusoidal perturbations were machined on the inside surface of the liner to seed instabilities, also true of the previous experiments. Butane was selected for a relatively low equilibrium vapor pressure, a practical attribute for use in the Pegasus vacuum power flow channel. Butane safety topics at Pegasus will be addressed. Glide planes were sealed to the liner by use of butane compatible o-rings. A sintered form of tungsten was used for the glide planes to facilitate machining the relatively complex shapes that were required. Porosity of the tungsten was sea...

  7. French butane propane committee. 2003 activity report; Comite Francais du Butane et du Propane. Rapport d'activite 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-05-01

    This activity report presents the 2003 status of the actions carried out by the French butane and propane committee (CFBP) for the development of the liquefied petroleum gas (LPG) industry in France. While the past year has seen the butane, propane and LPG-fuel sales following the decay started 4 years ago, in 2004 the CFBP has reinforced its actions of public information about the LPG energy choice and has carried out several projects in order to improve the safety of LPG tanks and storage facilities, one of the first concern of LPG industry. (J.S.)

  8. 球形MgCl2载体催化剂催化1-丁烯聚合%Polymerization of 1-butene with spherical MgCl2-supported catalyst

    Institute of Scientific and Technical Information of China (English)

    任笑飞; 任合刚; 白鹏; 杨敏; 吴之禄; 郝月梅; 刘宾元

    2012-01-01

    在以三乙基铝(AlEt3)为助催化剂、n(AD/n(Ti)为300、聚合压力为0.10 MPa、聚合温度为30℃、通人氢气3 mL、环己基甲基二甲氧基硅烷(CHMMS)与Al的摩尔比为0.033、聚合2h的条件下,球形MgCl2载体催化剂的活性为607g/g,聚1-丁烯的等规指数为82.3%.依催化剂活性大小,外给电子体的顺序为:CHMMS,二环戊基二甲氧基硅烷(DCPMS),二异丁基二甲氧基硅烷(DIBMS),二异丙基二甲氧基硅烷(DIPMS),二苯基二甲氧基硅烷(DDS);依聚1-丁烯等规指数大小,外给电子体的顺序为DCPMS.DIPMS,DIBMS,CHMMS,DDS.%The activity of the spherical MgCl2-supported catalyst for 1-butene polymerization reached 607 g/g and the isotacticity index of poly( 1-butene) prepared with the catalyst attained 82.3% under the following optimal conditions: triethyl aluminum as cocatalyst, molar ratio of Al to Ti 300, polymerization pressure 0.10 MPa, polymerization temperature 30℃, hydrogen 3 mL, molar ratio of cyclohexyl methyl dimethoxy silane (CHMMS) to Al 0.033 and reaction time 2 hr. The ranking of external electron donors could be expressed in descending order on the basis of either the catalyst activity as CHMMS, dicyclopentyl dimethoxy silane (DCPMS), diisobutyl dimethoxy silane (DIBMS), diisopropyl dimethoxy silane (DIPMS) and diphenyl dimethoxy silane(DDS), or the isotacticity index of poly(l-butene) as DCPMS, DIPMS, DIBMS, CHMMS and DDS.

  9. Elimination of butanal from odorous air by a labscale biofilter

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Vriens, L.; Verachtert, H.

    1991-01-01

    Butanal was chosen as a model compound for testing the performance of biofilters. It's a member of an important class of odour compounds released by waste water treatment plants of animal rendering and food processing industry. The influence of nutrient supplementation has been investigated using tw

  10. Elimination of butanal from odorous air by a labscale biofilter

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Vriens, L.; Verachtert, H.

    1991-01-01

    Butanal was chosen as a model compound for testing the performance of biofilters. It's a member of an important class of odour compounds released by waste water treatment plants of animal rendering and food processing industry. The influence of nutrient supplementation has been investigated using tw

  11. Elimination of butanal from odorous air by a labscale biofilter

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Vriens, L.; Verachtert, H.

    1991-01-01

    Butanal was chosen as a model compound for testing the performance of biofilters. It's a member of an important class of odour compounds released by waste water treatment plants of animal rendering and food processing industry. The influence of nutrient supplementation has been investigated using

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

    Science.gov (United States)

    Mo, Yirong

    2010-04-16

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

  13. Antioxidant properties of oxime 3-(phenylhydrazono) butan-2-one

    Energy Technology Data Exchange (ETDEWEB)

    Puntel, Gustavo Orione; Gubert, Priscila; Teixeira Rocha, Joao Batista; Pereira, Maria Ester; Soares, Felix A.A. [Universidade Federal de Santa Maria, Departamento de Quimica, Centro de Ciencias Naturais e Exatas, Santa Maria, RS (Brazil); Peres, Gisele Louro; Santana Carratu, Vanessa [Fundacao Universidade de Rio Grande, Departamento de Quimica, Rio Grande, RS (Brazil); Bresolin, Leandro [Universidade Federal do Acre, Cruzeiro do Sul, AC (Brazil)

    2008-10-15

    Oximes are a class of compounds normally used to reverse the acetylcholinesterase (AChE) inhibition caused by organophosphates (OPs). Conversely, researches focusing on the possible antioxidant properties of these compounds are lacking in the literature. The aim of this study was to investigate the potential antioxidant and toxic properties of 3-(phenylhydrazono) butan-2-one oxime in mice. In vitro, hydrogen peroxide-induced lipid peroxidation was decreased by low concentrations of the oxime (0.1-1.0{mu}M); (P<0.05). Similarly, lipoperoxidation induced by malonate and iron (Fe{sup 2+}) was significantly decreased by the oxime (0.4-1.0 {mu}M) (P<0.05). Oxime pre-treatment did not modify the basal peroxidation level nor prevented the induced lipid peroxidation determined ex-vivo. The present results suggest that 3-(phenylhydrazono) butan-2-one oxime could be a good antioxidant compound. The absence of toxicity signs after in vivo administration of 3-(phenylhydrazono) butan-2-one oxime to mice may indicate that it could be a safe drug for further studies. (orig.)

  14. 不同模板剂合成的 SAPO -34分子筛催化丁烯裂解%Catalytic cracking of 1-butene over SAPO-34 molecular sieves synthesized by different templates

    Institute of Scientific and Technical Information of China (English)

    胡云峰; 胡影; 陈焕

    2015-01-01

    Currently,the demand for propene is rising because of downstream products. It is important to improve the production capacity of propene. SAPO-34 with eight-membered ring channel can effectively improve the selectivity to low carbon olefin,especially the selectivity to propene. In this paper,SAPO-34 molecular sieves were synthesized by using diethylamine(DEA),tetraethylammonium hydroxide(TEAOH) and DEA + TEAOH as the templates,and characterized by XRD,NH3-TPD and SEM. The influence of the templates on the catalytic properties of SAPO-34 molecular sieves for 1-butene catalytic cracking was investigated in a fixed bed reactor. The results indicated that templates had the important influence on particle size,acid strength,acid amounts and catalytic properties. The sample prepared with TEAOH as the template had the least acid amount and the weakest acid strength. The sample synthesized with DEA template possessed the most acid amount and the strongest acid strength. The double templates exhibited additive effect. In 1-butene catalytic cracking reaction,the less the amount of acid sites and the weaker the acidity of SAPO-34 molecular sieve,the higher the selectivity to propene. The highest yield of propene was 33. 61% .%受下游产品的影响,丙烯需求量逐年上升,提高丙烯生产能力显得尤为重要。SAPO -34分子筛具有八元环孔道结构,在丁烯裂解中可有效提高低碳烯烃选择性,尤其是丙烯选择性。以二乙胺、四乙基氢氧化铵和二乙胺+四乙基氢氧化铵为模板剂合成 SAPO -34分子筛,采用 XRD、NH3- TPD 和 SEM 等进行表征,并在固定床反应器上考察模板剂对分子筛催化性能的影响。结果表明,模板剂种类对制备的 SAPO -34分子筛的晶粒大小、酸强度、酸量以及催化性能有重要影响。以四乙基氢氧化铵为模板剂合成的分子筛酸量最少,酸性最弱;以二乙胺为模板剂合成的分子筛酸量最大且

  15. French butane propane committee. 2004 activity report; Comite francais du butane et du propane. Rapport d'activite 2004

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This activity report presents the French butane-propane committee (CFBP), an association for the promotion of liquefied petroleum gases (LPG), the characteristics of LPG fuels, the LPG market and its evolution, the CFBP's missions and the 2004 highlights: representation of subscribing companies, participation to standardization works, making techniques and regulations change, improving the safety of equipments and installations, training and information, promoting LPG products. (J.S.)

  16. French butane propane committee. 2003 activity report; Comite francais du butane et du propane. Rapport d'activite 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This activity report presents the French butane-propane committee (CFBP), an association for the promotion of liquefied petroleum gases (LPG), the characteristics of LPG fuels, the LPG market and its evolution, the CFBP's missions and the 2003 highlights: representation of subscribing companies, participation to standardization works, making techniques and regulations change, improving the safety of equipments and installations, training and information, promoting LPG products. (J.S.)

  17. 2,3-Bis[(3-methylbiphenyl-4-ylimino]butane

    Directory of Open Access Journals (Sweden)

    Jingjing Chen

    2014-04-01

    Full Text Available The title compound, C30H28N2, is a product of the condensation reaction of 2-methyl-4-phenylaniline and butane-2,3-dione. The molecule lies on a crystallographic inversion centre. The C=N bond has an E conformation. The dihedral angle between the two benzene rings of the 4-phenyl-2-methylphenyl group is 29.19 (76°. The 1,4-diazabutadiene plane makes an angle of 70.1 (10° with the N-bonded methylphenyl ring and an angle of 81.08 (97° with the terminal phenyl group.

  18. Effects of dimethyl ether on n-butane oxidation

    OpenAIRE

    Bekat, Tuğçe; İnal, Fikret

    2014-01-01

    Dimethyl ether (DME) is the simplest ether and it is used as an alternative fuel or fuel additive to reduce toxic emissions from combustion processes. The effects of DME on n-butane oxidation were investigated for two different concentrations of DME in the fuel mixture (i.e., 20% and 50%) and two different fuel-rich equivalence ratios (i.e., 2.6 and 3.0) using detailed chemical kinetic modeling. Reactor model was selected as atmospheric-pressure, adiabatic, tubular reactor, operated under lam...

  19. 球形MgCl2载体催化剂催化1-丁烯聚合%Polymerization of 1-butene with spherical MgCl2-supported catalyst

    Institute of Scientific and Technical Information of China (English)

    任笑飞; 任合刚; 白鹏; 杨敏; 吴之禄; 郝月梅; 刘宾元

    2011-01-01

    在以三乙基铝(AlEt3)为助催化剂、n(Al)/n(Ti)为300、聚合压力为0.10 MPa、聚合温度为30℃、通入氢气3 mL、环己基甲基二甲氧基硅烷(CHMMS)与Al的摩尔比为0.033、聚合2h的条件下,球形MgCl2载体催化刺的活性为607g/g,聚1-丁烯的等规指数为82.3%.依催化剂活性大小,外给电子体的顺序为:CHMMS,二环戊基二甲氧基硅烷(DCPMS),二异丁基二甲氧基硅烷(DIBMS),二异丙基二甲氧基硅烷(DIPMS),二苯基二甲氧基硅烷(DDS);依聚1-丁烯等规指数大小,外给电子体的顺序为DCPMS,DIPMS,DIBMS,CHMMS,DDS.%The activity of the spherical MgCl2-supported catalyst for 1-butene polymerization reached 607 g/g and the isotacticity index of poly(l-butene) prepared with the catalyst attained 82.3% under the following optimal conditions: triethyl aluminum as cocatalyst, molar ratio of Al to Ti 300, polymerization pressure 0.10 MPa, polymerization temperature 30 ℃, hydrogen 3 mL, molar ratio of cyclohexyl methyl dimethoxy silane (CHMMS) to Al 0.033 and reaction time 2 hr. The ranking of external electron donors could be expressed in descending order on the basis of either the catalyst activity as CHMMS, dicyclopentyl dimethoxy silane(DCPMS), diisobutyl dimethoxy silane(DIBMS), diisopropyl dimethoxy silane(DIPMS) and diphenyl dimethoxy silane(DDS), or the isotacticity index of poly(l-butene) as DCPMS, DIPMS, DIBMS, CHMMS and DDS.

  20. Oxidative cracking of n-butane over various silica packings; Kakushu shirika sonzaika deno n-butan no sanka bunkai hanno

    Energy Technology Data Exchange (ETDEWEB)

    Wakui, K.; Sato, K.; Sawada, G.; Shiozawa, K.; Matano, K. [Japan chemical Industry Association, Tokyo (Japan); Suzuki, K.; Hayakawa, T.; Murata, K.; Yoshimura, Y.; Mizukami, F. [National Institute of Materials and Chemical Research, Ibaraki (Japan)

    2000-07-01

    In order to study the difference between catalytic and non-catalytic oxidative cracking of n-butane, the oxidative cracking over carious silica was investigated in the temperature range of 600-700 degree C. The reactions were conducted with molecular oxygen, nitrogen, and n-butane using a fixed bed reactor loaded with various silica packings. Homogeneous radical reaction in the gas phase proceeded farther in an empty silica tube reactor and the highest conversion of n-butane was attained. With the loading of various silica packings, the conversion of n-butane was lowered; however, the conversion obtained using amorphous silica was quite different from that obtained using crystalline silica such as quartz sand or silicalite. The radical reaction was not suppressed so much by amorphous silica packing as by crystalline silica packing, and the n-butane conversion was as high as that in the empty tube reactor without silica packing. It was considered that the surface OH groups on the amorphous silica are involved in the radical chain reactions of the oxidative cracking. Ethylene, propylene, and butanes were obtained as major products and the selectivity of light olefins was high (700 degree C, about 75 % at 45 % conversion) compared with that obtained using other oxides. (author)

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

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

    2011-01-01

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

  3. Comparison of conversion and deposit formation of ethanol and butane under SOFC conditions

    Science.gov (United States)

    Gupta, Gaurav K.; Dean, Anthony M.; Ahn, Kipyung; Gorte, Raymond J.

    This paper explores the gas-phase kinetics of butane and ethanol conversion as well as the propensity for molecular-weight growth and deposit formation in the non-catalytic regions of a solid oxide fuel cell (SOFC). Experiments are done where the fuel flows through a quartz reactor heated by a furnace. The primary observables are the extent of fuel conversion and the amount of deposit formed on a YSZ disk placed at the end of the furnace. Experiments are performed at 700, 750 and 800 ° C. The residence times in the hot zone varied from 2 to 4 s. Ethanol is more reactive than butane, and almost all the ethanol is reacted at 750 ° C whereas butane is completely reacted at 800 ° C. Deposit formation is much larger for butane. These results are compared to predictions of a detailed kinetic model. Model predictions for the extent of fuel conversion and molecular-weight growth are in good agreement with the data for both fuels. Butane is predicted to be converted to the lighter hydrocarbons methane, ethylene, propylene and ethane. Hydrogen is also a significant product, especially at higher temperatures. For ethanol, the product distribution is different with lower amounts of hydrocarbons while substantial quantities of water, ethylene, CO and H 2 are predicted. In ethanol pyrolysis there is no significant production of species with more than two carbon atoms, whereas propylene production is significant in butane pyrolysis. Modeling results suggest this is a major reason for increased deposit formation with butane. Equilibrium calculations demonstrate that both the butane and ethanol systems are far removed from equilibrium.

  4. Combustion Characteristics of Butane Porous Burner for Thermoelectric Power Generation

    Directory of Open Access Journals (Sweden)

    K. F. Mustafa

    2015-01-01

    Full Text Available The present study explores the utilization of a porous burner for thermoelectric power generation. The porous burner was tested with butane gas using two sets of configurations: single layer porcelain and a stacked-up double layer alumina and porcelain. Six PbSnTe thermoelectric (TE modules with a total area of 54 cm2 were attached to the wall of the burner. Fins were also added to the cold side of the TE modules. Fuel-air equivalence ratio was varied between the blowoff and flashback limit and the corresponding temperature, current-voltage, and emissions were recorded. The stacked-up double layer negatively affected the combustion efficiency at an equivalence ratio of 0.20 to 0.42, but single layer porcelain shows diminishing trend in the equivalence ratio of 0.60 to 0.90. The surface temperature of a stacked-up porous media is considerably higher than the single layer. Carbon monoxide emission is independent for both porous media configurations, but moderate reduction was recorded for single layer porcelain at lean fuel-air equivalence ratio. Nitrogen oxides is insensitive in the lean fuel-air equivalence ratio for both configurations, even though slight reduction was observed in the rich region for single layer porcelain. Power output was found to be highly dependent on the temperature gradient.

  5. Effective Subcritical Butane Extraction of Bifenthrin Residue in Black Tea

    Directory of Open Access Journals (Sweden)

    Yating Zhang

    2017-03-01

    Full Text Available 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.

  6. Easy to use plastic optical fiber-based biosensor for detection of butanal.

    Directory of Open Access Journals (Sweden)

    Nunzio Cennamo

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

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

    Science.gov (United States)

    Jorgensen, William L.

    1982-12-01

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

  8. Structure–Activity Correlations for TON, FER, and MOR in the Hydroisomerization of n-Butane

    NARCIS (Netherlands)

    Pieterse, Johannis A.Z.; Seshan, K.; Lercher, Johannes A.

    2000-01-01

    n-Butane hydroconversion was studied over (Pt-loaded) molecular sieves with TON, FER, and MOR morphology. The conversion occurs via a complex interplay of mono- and bimolecular bifunctional acid mechanism and monofunctional platinum-catalyzed hydrogenolysis. Hydroisomerization occurs bimolecularly a

  9. Draft Genome Sequence of Propane- and Butane-Oxidizing Actinobacterium Rhodococcus ruber IEGM 231

    OpenAIRE

    Ivshina, Irena B.; Kuyukina, Maria S.; Krivoruchko, Anastasiya V.; Barbe, Valérie; Fischer, Cécile

    2014-01-01

    We report a draft genome sequence of Rhodococcus ruber IEGM 231, isolated from a water spring near an oil-extracting enterprise (Perm region, Russian Federation). This sequence provides important insights into the genetic mechanisms of propane and n-butane metabolism, organic sulfide and beta-sitosterol biotransformation, glycolipid biosurfactant production, and heavy metal resistance in actinobacteria.

  10. Draft Genome Sequence of Propane- and Butane-Oxidizing Actinobacterium Rhodococcus ruber IEGM 231.

    Science.gov (United States)

    Ivshina, Irena B; Kuyukina, Maria S; Krivoruchko, Anastasiya V; Barbe, Valérie; Fischer, Cécile

    2014-12-11

    We report a draft genome sequence of Rhodococcus ruber IEGM 231, isolated from a water spring near an oil-extracting enterprise (Perm region, Russian Federation). This sequence provides important insights into the genetic mechanisms of propane and n-butane metabolism, organic sulfide and beta-sitosterol biotransformation, glycolipid biosurfactant production, and heavy metal resistance in actinobacteria.

  11. The effect of nutrient supplementation on the biofiltration removal of butanal in contaminated air

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Vriens, L.; Verachtert, H.

    1993-01-01

    Butanal is one of the odorous compounds produced in the animal-rendering and food-processing industries and also in sewage-treatment plants. It shows the necessity for complementing such plants with systems for off-gas treatment. Biofiltration using simple packing material was tested for the removal

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

    Science.gov (United States)

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

    2008-11-27

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

  13. Reduction of NO by n-butane in a JSR: experiments and kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Dagaut, P.; Luche, J.; Cathonnet, M. [CNRS Laboratoire de Combustion et Systemes Reactifs, Orleans (France)

    2000-06-01

    A study of the reduction of nitric oxide (NO) by n-butane, in simulated conditions of a reburning zone, has been undertaken in a fused silica jet-stirred reactor operating at 1 atm. The temperatures ranged from 1100 to 1450 K, the initial mole fraction of NO was 1000 ppm, and that of n-butane was 2000-2200 ppm. The equivalence ratio was varied from 0.68 to 2. It was demonstrated that the reduction of NO varies as the temperature and that for a given temperature, a maximum NO reduction occurs, slightly above stoichiometric conditions. Generally, the present results follow those obtained in previous studies involving simple hydrocarbons or natural gas as reburn-fuel. The oxidation of n-butane was also studied without NO in the same conditions of temperature, pressure, and residence time. A detailed chemical kinetic modeling of the present experiments was performed using an updated and improved kinetic scheme (892 reversible reactions and 113 species). An overall reasonable agreement between the present data and the modeling was obtained. Furthermore, the proposed kinetic mechanism can be successfully used to model the reduction of NO by ethane, ethylene, a natural gas blend (methane-ethane 10:1), acetylene, propene and propane. According to this study, NO reduction by n-butane mainly occurs via reaction with ketenyl radical (HCCO). 16 refs., 6 figs.

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

    Science.gov (United States)

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

    2014-12-10

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

  15. Selective conversion of butane into liquid hydrocarbon fuels on alkane metathesis catalysts

    KAUST Repository

    Szeto, Kaï Chung

    2012-01-01

    We report a selective direct conversion of n-butane into higher molecular weight alkanes (C 5+) by alkane metathesis reaction catalysed by silica-alumina supported tungsten or tantalum hydrides at moderate temperature and pressure. The product is unprecedented, asymmetrically distributed towards heavier alkanes. This journal is © 2012 The Royal Society of Chemistry.

  16. Dehydroisomerization of n-Butane over Pt–ZSM5: II. Kinetic and Thermodynamic Aspects

    NARCIS (Netherlands)

    Pirngruber, G.D.; Seshan, K.; Lercher, J.A.

    2000-01-01

    A kinetic model is applied to describe the dehydroisomerization of n-butane to isobutene over Pt–ZSM5. It is compared with experimental data and used to show how a combination of kinetics and thermodynamics affects the obtained yields. High temperatures reduced the selectivity to by-product formatio

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

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

    2013-09-01

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

  20. Selective oxidation of carbon monoxide in the presence of butane and maleic anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Corbin, D.R.; Bonifaz, C. (DuPont Company, Wilmington, DE (United States))

    1994-03-01

    The selective oxidation of carbon monoxide in the presence of butane and maleic anhydride has been studied over platinum- and palladium-containing zeolites as well as palladium-on-silica (Pd/SiO[sub 2]) catalysts. The results show that although a zeolite support is needed in many systems to effect a kinetic control to improve selectivity, thermodynamic control using Pd([approximately]2-4 ppm)/SiO[sub 2] is sufficient to give the desired selectivities in this system. In addition, a palladium-containing vanadium-phosphate catalyst was prepared that showed complete oxidation of carbon monoxide, conversion of butane to maleic anhydride, and no observable decomposition of the maleic anhydride. 14 refs., 4 tabs.

  1. High-pressure cloud point data for the system glycerol + olive oil + n-butane + AOT

    Directory of Open Access Journals (Sweden)

    J. P. Bender

    2008-09-01

    Full Text Available This work reports high-pressure cloud point data for the quaternary system glycerol + olive oil + n-butane + AOT surfactant. The static synthetic method, using a variable-volume view cell, was employed for obtaining the experimental data at pressures up to 27 MPa. The effects of glycerol/olive oil concentration and surfactant addition on the pressure transition values were evaluated in the temperature range from 303 K to 343 K. For the system investigated, vapor-liquid (VLE, liquid-liquid (LLE and vapor-liquid-liquid (VLLE equilibrium were recorded. It was experimentally observed that, at a given temperature and surfactant content, an increase in the concentration of glycerol/oil ratio led to a pronounced increase in the slope of the liquid-liquid coexistence curve. A comparison with results reported for the same system but using propane as solvent showed that much lower pressure transition values are obtained when using n-butane.

  2. The liquid phase oxidation of n-butane: a search for plausible mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, C.C. [Celanese Ltd., TX (United States). Corpus Christi Technical Center

    1998-12-31

    This articles deals with an approach that has given some key information about the mechanisms of the liquid phase oxidation of butane to acetic acid. This procedure has been developed over the last 34 years; however, much of what will be discussed represents a synthesis of previous insights. Many of the observations are relatively recent and have not been previously published. In principle, this approach should be applicable to many oxidation processes. (orig.)

  3. n-Butane Oxidation over γ-Al2O3 Supported Vanadium Phosphate Catalysts

    Institute of Scientific and Technical Information of China (English)

    Y.H.Taufiq-Yap; L.K.Leong; R.Irmawati

    2007-01-01

    Four vanadium phosphate catalysts supported on γ-Al2O3(20 wt%)were synthesized via 75 h)at 673 K in a reaction flow of n-butane/air mixture.The samples calcined for 6 and 10 h produced only a single phase of(VO)2P2O7.However,the VOPO4 phase(β-VOPO4)was detected and became more prominent with only a minor pyrophosphate peaks were found after 30 h of calcination.All these pyrophosphate peaks disappeared after 75 h of calcination.The formation of V5+ phase Was also observed in the SEM micrographs.The redox properties and the nature of oxidants of the catalysts employed in this study were investigated by H2-TPR analysis.Selective oxidation of n-butane to maleic anhydride (MA) over these catalysts shows that the percentage of n-butane conversion decreases with the transformation of the catalysts from V4+ to V5+ phases.An appropriate ratio of V5+/V4+ can enhance the performance of the VPO catalyst.However,a higher amount of V5+ and its associated oxygen species are responsible to promote the MA selectivity.

  4. Liquidlike nature of crystalline n-butane and n-pentane films studied by time-of-flight secondary ion mass spectrometry.

    Science.gov (United States)

    Souda, Ryutaro

    2009-12-03

    Crystallization of vapor-deposited thin films of n-butane and n-pentane has been investigated using temperature-programmed time-of-flight secondary ion mass spectrometry. The morphology of thin n-butane (n-pentane) films changes at around the calorimetric crystallization temperature of 65 K (85 K) as a result of crystallization of the supercooled liquid. The morphology of the crystal grains of n-butane changes at 85 K; the butane molecules permeate through porous amorphous-solid-water films above this temperature. The crystal grains of n-pentane are smaller in size than those of n-butane, forming a smoother crystalline film. However, the crystalline n-pentane film dewets abruptly at higher temperatures, depending on the film thickness. The liquidlike nature of crystalline n-pentane (n-butane) is attributable to premelting (coexisting second liquid).

  5. Influence of Tungsten Loadings on the 1-Butene Metathesis Reaction over W/SiO2/Al2O3 Catalysts%钨含量对W/SiO2/Al2O3催化剂上1-丁烯自歧化反应的影响

    Institute of Scientific and Technical Information of China (English)

    柳娜; 张辉; 薛念华; 丁维平

    2015-01-01

    A series of W/SiO2/Al2O3 catalysts with various tungsten loadings were synthesized via the impregnation method. The as-synthesized catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, H2 temperature-programmed reduction (H2-TPR), and NH3 temperature-programmed desorption (NH3-TPD). The results reveal that the tungsten loadings were crucial to the dispersion and reducibility of the tungsten oxide species and the acidity of catalysts. The catalytic performances were also investigated during the metathesis of 1-butene to propene. Amongst these catalysts, W/SiO2/Al2O3 with a tungsten mass fraction of 6.0%gave the highest activity and stability during the 1-butene metathesis reaction. The excel ent catalytic performance of the catalyst containing a tungsten mass fraction of 6.0%is attributed to its moderate dispersion, suitable reducibility of the WOx species and suitable acidity. We speculate that these factors are favorable for the formation of active centers for olefin metathesis.%采用浸渍法制备了一系列钨负载量不同的W/SiO2/Al2O3催化剂.采用X射线衍射(XRD)、激光拉曼(Raman)光谱、紫外-可见(UV-Vis)光谱、氢气程序升温还原(H2-TPR)和氨程序升温脱附(NH3-TPD)等技术对催化剂进行了表征.实验结果表明:钨的负载量对催化剂上氧化钨物种的分散程度、还原性以及催化剂的酸性有非常重要的影响.对该类催化剂上1-丁烯自歧化反应进行了详细考察,结果表明:当钨的质量分数为6.0%时, W/SiO2/Al2O3催化剂表现出最佳的歧化活性和稳定性.原因在于6.0%的钨负载量可以使催化剂上氧化钨物种具有中等程度的分散性、合适的还原性,并且使催化剂具有一定程度的酸性,这些因素有利于在催化剂上形成烯烃歧化活性位.

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

    Science.gov (United States)

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

    2015-04-21

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

  7. Crystal structure of 1-(piperidin-1-yl)butane-1,3-dione.

    Science.gov (United States)

    Schwierz, Markus; Görls, Helmar; Imhof, Wolfgang

    2014-12-01

    In the title compound, C9H15NO2, the piperidine ring exhibits a chair conformation. The butane-dione subunit exhibits a conformation with the ketone C atom in an eclipsed position with respect to the amide carbonyl group. In the crystal, a two-dimensional layered arrangement is formed by hydrogen bonds of the C-H⋯O type between the methyl group and the exocyclic methyl-ene unit as donor sites and the amide carbonyl O atom as the acceptor of a bifurcated hydrogen bond. These layers are oriented parallel to the ab plane.

  8. Ozone Activated Cool Diffusion Flames of Butane Isomers in a Counterflow Facility

    KAUST Repository

    Al Omier, Abdullah Abdulaziz

    2017-04-01

    Proceeding from the aim to reduce global pollution emissions from the continuous burning of hydrocarbons stimulated by increasing energy demand, more efficient and ultra-low emissions’ combustion concepts such as the homogenous charge compression ignition engines (HCCI) have been developed. These new engines rely on the low temperature chemistry (LTC) combustion concept. A detailed investigation of the properties of cool flames, governed by LTC, is essential for the design of these new engines. The primary goal of this work was to build a fundamental counterflow experiment for cool flames studies in a diffusive system, to better understand combustion in LTC engines. The project was intended to provide a basic understanding of the low-temperature reactivity and cool flames properties of butane isomers under atmospheric pressure conditions. This was achieved by establishing self-sustaining cool flames through a novel technique of ozone addition to an oxygen stream in a non-premixed counterflow model. The ignition and extinction limits of butane isomers’ cool flames have been investigated under a variety of strain rates. Results revealed that establishment of cool flames are favored at lower strain rates. Iso-butane was less reactive than n-butane by showing higher ignition and extinction limits. Ozone addition showed a significant influence on cool flame ignition and sustenance; it was found that increasing ozone concentration in the oxidizer stream dramatically increased the reactivity of both fuels. Results showed increased fuel reactivity as the temperature of the fuel stream outlet increased. 4 A numerical analysis was performed to simulate ignition and extinction of the cool flame in diffusive systems. The results revealed that ignition and extinction limits of cool flames are predominantly governed by LTC. The model qualitatively captured experimental trends for both fuels; however, it overpredicted both ignition and extinction limits under all strain rates

  9. Selective Oxidation of n-Butane over VPO Catalyst Modified by Different Additives

    Institute of Scientific and Technical Information of China (English)

    Hong Liang; Daiqi Ye

    2005-01-01

    A series of vanadyl pyrophosphate catalyst (VPO) modified by different additives have been prepared with the aim to study the performance for selective conversion of n-butane to maleic anhydride(MA). The addition of various promoters improved the catalytic performance remarkably on both activity and selectivity. The correlation of activity and selectivity of the catalysts with their structure has been discussed. The increase in BET surface areas and surface redox sites leads to an enhanced activity. However,good selectivity can only be obtained on those surfaces with suitable surface acid sites.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tsz-Keung, Cheung; d`Itri, J.L.; Lange, F.C.; Gates, B.C. [Univ. of California, Davis, CA (United States)

    1995-12-31

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

  11. 6-Methyl-1,3,5-triazine-2,4-diamine butane-1,4-diol monosolvate

    Directory of Open Access Journals (Sweden)

    Rajni M. Bhardwaj

    2012-12-01

    Full Text Available The title co-crystal, C4H7N5·C4H10O2, crystallizes with one molecule of 6-methyl-1,3,5-triazine-2,4-diamine (DMT and one molecule of butane-1,4-diol in the asymmetric unit. The DMT molecules form ribbons involving centrosymmetric R22(8 dimer motifs between DMT molecules along the c-axis direction. These ribbons are further hydrogen bonded to each other through butane-1,4-diol, forming sheets parallel to (121.

  12. Effect of tellurium promoter on vanadium phosphate catalyst for partial oxidation of n-butane

    Institute of Scientific and Technical Information of China (English)

    Y. H. Taufiq-Yap; S. Nor Asrina; G. J. Hutchings; N. F. Dummer; J. K. Bartley

    2011-01-01

    Te-promoted (1%) vanadium phosphate catalyst (VPDTe) was prepared via VOPO4·2H2O by calcining its precursor VOHPO4·0·5H2O in a flow of n-b(u)ane/air.VPDTe catalyst has resulted a higher existence of V5+ phase with V5+/V4+ ratio of 0.23.SEM micrographs show that Te addition altered the arrangement of the platelets from "rose-like" clusters to layer with irregular shape.Te addition has also markedly lowered the reduction activation energies of the vanadium phosphate catalyst as revealed by TPR profile.The amount of active oxygen species associated with V4+ phase of the Te promoted catalyst was significantly higher than those of the unpromoted catalyst.These observations suggest that high mobility and availability of reactive oxygen species contributed to the enhancement of n-butane conversion up to 80% at 673 K,while only 47% over unpromoted catalyst (2400 h-1,1.7% n-butane in air).

  13. Pipeline design software and the simulation of liquid propane/butane-light oils pipeline operations

    Energy Technology Data Exchange (ETDEWEB)

    Peters, J. [Monenco AGRA Inc., Calgary, Alberta (Canada)

    1996-12-31

    A comprehensive and integrated suite of computer software routines has been developed to simulate the flow of liquids in pipelines. The fluid properties module accommodates Newtonian and non-Newtonian liquids or mixtures including corrections for changes in properties with temperature and pressure. The hydraulic model calculates pressure drop in single or looped pipelines based on the diameter, route (length) and profile data provided. For multi-product pipelines the hydraulics module estimates energy loss for any sequence of batches given the size and fluid properties of each batch, and the velocity in the pipeline. When the characteristics of existing or proposed pipeline pumps are included, location and size of pumps can be optimized. The effect of heat loss on pressure drop is predicted by invoking the module which calculates the fluid temperature profile based on operating conditions, fluid properties, pipe and insulation conductivity and soil heat transfer data. Modules, created to simulate heater or cooler operations, can be incorporated to compensate for changes in temperature. Input data and calculated results can be presented in a format customized by the user. The simulation software has been successfully applied to multi-product, fuel oil, and non-Newtonian emulsion pipelines. The simulation and operation of a refinery products pipeline for the transportation of propane, butane, gasline, jet and diesel batches will be discussed. The impact of high vapor pressure batches (i.e., propane and butane) on the operation of the pipeline and on the upstream and downstream facilities will be examined in detail.

  14. Synthesis, crystal structure and photochemistry of Hexakis(butan-1-aminium) heptamolybdate(VI) tetrahydrate

    Indian Academy of Sciences (India)

    SAVITA S KHANDOLKAR; ASHISH R NAIK; CHRISTIAN NÄTHER; WOLFGANG BENSCH; BIKSHANDARKOILR SRINIVASAN

    2016-11-01

    The synthesis, crystal structure, spectral characterization, photochemistry, electrochemical and thermal studies of the hexakis(butan-1-aminium) heptamolybdate(VI) tetrahydrate (1) are reported. Dissolution of a mixed mono-hepta compound (BuNH₃)₈[(Mo₇O₂₄)(MoO₄)]·3H₂O in water results in its transformation to the title compound viz., (BuNH₃)₆ [Mo₇O₂₄]·4H₂O 1 (BuNH₃ = butan-1-aminium). The structure of the title compound consists of two crystallographically unique [Mo₇O₂₄]⁶⁻ anions, twelve independent (BuNH₃)⁺ cations and eight unique lattice water molecules, all of which are interlinked with the aid of three varieties of Hbonding interactions. Solar irradiation of 1 results in the formation of a bis(μ2-oxo) bridged diheptamolybdateproduct. Electrochemical studies reveal the role of 1 in the photodimerization process. Thermal decomposition of 1 results in the formation of crystalline α-MoO₃.

  15. Synthesis and Characterization of Graft Copolymer of Dextran and 2-Acrylamido-2-methylpropane Sulphonic Acid

    Directory of Open Access Journals (Sweden)

    Venkanna Azmeera

    2012-01-01

    Full Text Available A novel biodegradable graft copolymer of dextran (Dx and 2-acrylamido-2-methyl-1-propane sulphonic acid (AMPS was synthesized by grafting poly-AMPS chains onto dextran backbone by free radical polymerization using ceric ammonium nitrate (CAN as an initiator. Different amounts of AMPS were used to synthesize four different grades of graft copolymers with different side chain lengths. These grafted polymers were characterized by elemental analysis, FTIR, 1HNMR, rheological technique, scanning electron microscopy (SEM, thermogravimetric analysis (TGA, and X-ray diffractometry (XRD. They exhibited efficient flocculation performance in kaolin suspension.

  16. Effect of Cr and Co Promoters Addition on Vanadium Phosphate Catalysts for Mild Oxidation of n-Butane

    Institute of Scientific and Technical Information of China (English)

    Yun Hin Taufiq-Yap

    2006-01-01

    In this study, Cr and Co promoted, as well as unpromoted vanadium phosphate (VPO)catalysts were synthesized by the reaction of V2O5 and o-H3PO4 in organic medium followed by calcination in n-butane/air environment at 673 K. The physico-chemical properties and the catalytic behavior were affected by the addition of Cr and Co dopants. H2-TPR was used to investigate the nature of oxidants in the unpromoted and promoted catalysts. The results showed that both the Cr and Co promoters remarkably lowered the temperature of the reduction peak associated with V5+. The amount of oxygen species originated from the active phase, V4+, removed was significantly increased for Co and Cr-promoted catalysts. Both Cr and Co dopants improve strongly the n-butane conversion without sacrificing the MA selectivity. A good correlation was observed between the amount of oxygen species removed from V4+ phase and the activity for n-butane oxidation to maleic anhydride. This suggested that V4+-O was the center for the activation of n-butane.

  17. Molecular dynamics studies of the melting of butane and hexane monolayers adsorbed on the basal-plane surface of graphite

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Newton, J. C.; Taub, H.

    1993-01-01

    The effect of molecular steric properties on the melting of quasi-two-dimensional solids is investigated by comparing results of molecular dynamics simulations of the melting of butane and hexane monolayers adsorbed on the basal-plane surface of graphite. These molecules differ only in their leng...

  18. Oxidation and combustion of fuel-rich N-butane-oxygen mixture in a standard 20-liter explosion vessel

    NARCIS (Netherlands)

    Frolov, S.M.; Basevich, V.Y.; Smetanyuk, V.A.; Belyaev, A.A.; Pasman, H.J.

    2006-01-01

    Experiments on forced ignition of extremely fuel-rich n-butane-oxygen mixture with the equivalence ratio of 23 in the standard 20-liter spherical vessel at elevated initial pressure (4.1 bar) and temperature (500 K) reveal the nonmonotonic influence of the forced ignition delay time on the maximum e

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Bücker, D.; Wagner, W.

    2006-06-01

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

  1. Phase behavior of olive and soybean oils in compressed propane and n-butane

    Directory of Open Access Journals (Sweden)

    P. M. Ndiaye

    2006-09-01

    Full Text Available The aim of this work is to report the experimental data and thermodynamic modeling of phase equilibrium of binary systems containing soybean and olive oils with propane and n-butane. Phase equilibrium experiments were carried out using the static synthetic method in a high-pressure variable-volume view cell in the temperature range from 30 to 70ºC and varying the solvent overall composition from 5 to 98 wt%. Vapor-liquid, liquid-liquid and vapor-liquid-liquid phase transitions were observed at relatively low pressures. The Peng-Robinson and the SAFT equations of state without any binary interaction parameters were employed in an attempt at representing the phase behavior of the systems. Results show the satisfactory performance of SAFT-EoS in predicting qualitatively all phase transitions reported in this work.

  2. Numerical and Experimental Study on Negative Buoyance Induced Vortices in N-Butane Jet Flames

    KAUST Repository

    Xiong, Yuan

    2015-07-26

    Near nozzle flow field in flickering n-butane diffusion jet flames was investigated with a special focus on transient flow patterns of negative buoyance induced vortices. The flow structures were obtained through Mie scattering imaging with seed particles in a fuel stream using continuous-wave (CW) Argon-ion laser. Velocity fields were also quantified with particle mage velocimetry (PIV) system having kHz repetition rate. The results showed that the dynamic motion of negative buoyance induced vortices near the nozzle exit was coupled strongly with a flame flickering instability. Typically during the flame flickering, the negative buoyant vortices oscillated at the flickering frequency. The vortices were distorted by the flickering motion and exhibited complicated transient vortical patterns, such as tilting and stretching. Numerical simulations were also implemented based on an open source C++ package, LaminarSMOKE, for further validations.

  3. Quantum Chemical Calculations of the Structure, Property and Stability of Penta-coordinated Carbonium Ions Derived from Normal Butane

    Institute of Scientific and Technical Information of China (English)

    Tao Haiqiao; Long Jun; Zhou Han; Xie Chaogang; Dai Zhenyu; Wei Xiaoli

    2009-01-01

    The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane, the energy increases in the following order: C2HC3C1HC2>C2HH>C1HH. The stability of the penta-enordinated carbonium ions may be explained by the electron distribution in the three-center-two-electron bonds. The delocalization of the penta-eoordinated carbonium ion CHC with three-center-two-electron bonds on positive charges was stronger than that of the penta-coordinated carbonium ion CHH with three-center-two-electron bonds and its stability was higher than that of the penta-coordinated earbonium ion CHH with three-center-two-electron bonds.

  4. Quasielastic neutron scattering and molecular dynamics simulation studies of the melting transition in butane and hexane monolayers adsorbed on graphite

    DEFF Research Database (Denmark)

    Hervig, K.W.; Wu, Z.; Dai, P.

    1997-01-01

    Quasielastic neutron scattering experiments and molecular dynamics (MD) simulations have been used to investigate molecular diffusive motion near the melting transition of monolayers of flexible rod-shaped molecules. The experiments were conducted on butane and hexane monolayers adsorbed on an ex......Quasielastic neutron scattering experiments and molecular dynamics (MD) simulations have been used to investigate molecular diffusive motion near the melting transition of monolayers of flexible rod-shaped molecules. The experiments were conducted on butane and hexane monolayers adsorbed...... comparison with experiment, quasielastic spectra calculated from the MD simulations were analyzed using the same models and fitting algorithms as for the neutron spectra. This combination of techniques gives a microscopic picture of the melting process in these two monolayers which is consistent with earlier...

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

    Science.gov (United States)

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

    2005-02-01

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

  6. Biocatalytic hydroxylation of n-butane with in situ cofactor regeneration at low temperature and under normal pressure

    Directory of Open Access Journals (Sweden)

    Svenja Staudt

    2012-02-01

    Full Text Available The hydroxylation of n-alkanes, which proceeds in the presence of a P450-monooxygenase advantageously at temperatures significantly below room temperature, is described. In addition, an enzymatic hydroxylation of the “liquid gas” n-butane with in situ cofactor regeneration, which does not require high-pressure conditions, was developed. The resulting 2-butanol was obtained as the only regioisomer, at a product concentration of 0.16 g/L.

  7. Samarium-modified vanadium phosphate catalyst for the selective oxidation of n-butane to maleic anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hua-Yi [State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Wang, Hai-Bo [Fushun Res InstPetr& Petrochem, Fushun, 113001 (China); Liu, Xin-Hua; Li, Jian-Hui; Yang, Mei-Hua [State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Huang, Chuan-Jing, E-mail: huangcj@xmu.edu.cn [State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Weng, Wei-Zheng [State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Wan, Hui-Lin, E-mail: hlwan@xmu.edu.cn [State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China)

    2015-10-01

    Graphical abstract: The addition of a small amount of Sm into VPO catalyst brought about great changes in its physicochemical properties such as surface area, surface morphology, phase composition and redox property, thus leading to a higher catalytic performance in the selective oxidation of n-butane to maleic anhydride, as compared to the undoped VPO catalyst. - Highlights: • The addition of Sm leads to great changes in the structure of VPO catalyst. • Sm improves performance of VPO for oxidation of n-butane to maleic anhydride. • Catalytic performance is closely related to structure of VPO catalyst. - Abstract: A series of samarium-modified vanadium phosphate catalysts were prepared and studied in selective oxidation of n-butane to maleic anhydride. The catalytic evaluation showed that Sm modification significantly increased the overall n-butane conversion and intrinsic activity. N{sub 2}-adsorption, XRD, SEM, Raman, XPS, EPR and H{sub 2}-TPR techniques were used to investigate the intrinsic difference among these catalysts. The results revealed that the addition of Sm to VPO catalyst can increase the surface area of the catalyst, lead to a significant change in catalyst morphology from plate-like structure into rosette-shape clusters, and largely promote the formation of (VO){sub 2}P{sub 2}O{sub 7}. All of these were related to the different catalytic performance of Sm-doped and undoped VPO catalysts. The roles of the different VOPO{sub 4} phases and the influence of Sm were also described and discussed.

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

    Science.gov (United States)

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

    2016-11-01

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

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

    Science.gov (United States)

    Balabin, Roman M

    2009-02-12

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

  10. Conversion of n-Butane to iso-Butene on Gallium/HZSM-5 Catalysts

    Directory of Open Access Journals (Sweden)

    S.M. Gheno

    2002-07-01

    Full Text Available The conversion of n-butane to iso-butene on gallium/HZSM-5 catalysts at 350ºC and WHSV=2.5h8-1 was studied. The catalysts were prepared by ion exchange from a Ga(NO32 solution and further submitted to calcination in air at 530ºC. TEM analysis with an EDAX detector and TPR-H2 data showed that after calcination the Ga species were present mainly as Ga2O3, which are reduced to Ga2O at temperatures near 610ºC. The specific acid activity (SAA of the catalysts increased with the increase in aluminum content in the zeolite, and for a fixed Si/Al ratio, the SAA increased with Ga content. Values for specific hydro/dehydrogenation activity (SH/DHA were significantly higher than those for SAA, indicating that the catalytic process is controlled by the kinetics on acid sites. Moreover, the production of iso-butene with a selectivity higher than 25% was a evidence that in gallium/HZSM-5-based catalysts the rate of the hydrogenation reaction is lower than that of the dehydrogenation reaction; this behavior confirmed the dehydrogenation nature of gallium species, thereby showing great promise for iso-butene production.

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

    Science.gov (United States)

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

    2016-12-07

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

  12. Measurements and modelling of phase behaviour and viscosity of a heavy oil-butane system

    Energy Technology Data Exchange (ETDEWEB)

    Yazdani, A.; Maini, B.B. [Calgary Univ., AB (Canada)

    2007-07-01

    Solvent based recovery processes are environmentally friendly alternatives for thermal techniques. Information on the phase behavior of the heavy oil/solvent system is needed for numerical simulation and feasibility studies of these processes. However, the lack of experimental data for such systems in the literature has been problematic. Solvent/oil mixtures that are evaluated within the context of the vapour extraction (VAPEX) process, require accurate description of the system's pressure, volume, and temperature (PVT) properties. This paper presented the results of a study that designed an experimental set-up and conducted several experiments in order to obtain the required PVT information. The paper presented the results of the PVT experiments conducted with the Frog-Lake heavy oil/butane system that was used in VAPEX experiments reported previously by the authors. The experimental measurements included the solvent fractions in the oil, mixture density and mixture viscosity at different saturation pressures. Using the phase behavior package WINPROP, the PVT results were modeled and an equation of state (EOS) was tuned for simulating the experimental behavior of the system. The viscosity measurements were compared with the predictions of several available correlations. It was concluded that the predicted values of EOS for density and saturation pressure were in agreement with the obtained experimental data and that a mixing type relationship was found to be adequate for describing the viscosity of heavy oil - solvent mixtures. 12 refs., 4 tabs., 10 figs.

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

    Science.gov (United States)

    Sironi, Luca; Amadasi, Alberto; Zoja, Riccardo

    2016-09-01

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

  14. User characteristics and effect profile of Butane Hash Oil: An extremely high-potency cannabis concentrate.

    Science.gov (United States)

    Chan, Gary C K; Hall, Wayne; Freeman, Tom P; Ferris, Jason; Kelly, Adrian B; Winstock, Adam

    2017-09-01

    Recent reports suggest an increase in use of extremely potent cannabis concentrates such as Butane Hash Oil (BHO) in some developed countries. The aims of this study were to examine the characteristics of BHO users and the effect profiles of BHO. Anonymous online survey in over 20 countries in 2014 and 2015. Participants aged 18 years or older were recruited through onward promotion and online social networks. The overall sample size was 181,870. In this sample, 46% (N=83,867) reported using some form of cannabis in the past year, and 3% reported BHO use (n=5922). Participants reported their use of 7 types of cannabis in the past 12 months, the source of their cannabis, reasons for use, use of other illegal substances, and lifetime diagnosis for depression, anxiety and psychosis. Participants were asked to rate subjective effects of BHO and high potency herbal cannabis. Participants who reported a lifetime diagnosis of depression (OR=1.15, p=0.003), anxiety (OR=1.72, pcannabis. BHO users also reported stronger negative effects and less positive effects when using BHO than high potency herbal cannabis (pcannabis. Copyright © 2017. Published by Elsevier B.V.

  15. Partial Oxidation of n-Butane over a Sol-Gel Prepared Vanadium Phosphorous Oxide

    Directory of Open Access Journals (Sweden)

    Juan M. Salazar

    2013-01-01

    Full Text Available Vanadium phosphorous oxide (VPO is traditionally manufactured from solid vanadium oxides by synthesizing VOHPO4∙0.5H2O (the precursor followed by in situ activation to produce (VO2P2O7 (the active phase. This paper discusses an alternative synthesis method based on sol-gel techniques. Vanadium (V triisopropoxide oxide was reacted with ortho-phosphoric acid in an aprotic solvent. The products were dried at high pressure in an autoclave with a controlled excess of solvent. This procedure produced a gel of VOPO4 with interlayer entrapped molecules. The surface area of the obtained materials was between 50 and 120 m2/g. Alcohol produced by the alkoxide hydrolysis reduced the vanadium during the drying step, thus VOPO4 was converted to the precursor. This procedure yielded non-agglomerated platelets, which were dehydrated and evaluated in a butane-air mixture. Catalysts were significantly more selective than the traditionally prepared materials with similar intrinsic activity. It is suggested that the small crystallite size obtained increased their selectivity towards maleic anhydride.

  16. Mechanism of n-butane hydrogenolysis promoted by Ta-hydrides supported on silica

    KAUST Repository

    Pasha, Farhan Ahmad

    2014-06-06

    The mechanism of hydrogenolysis of alkanes, promoted by Ta-hydrides supported on silica via 2 ≡ Si-O- bonds, has been studied with a density functional theory (DFT) approach. Our study suggests that the initial monohydride (≡ Si-O-)2Ta(III)H is rapidly trapped by molecular hydrogen to form the more stable tris-hydride (≡ Si-O-) 2Ta(V)H3. Loading of n-butane to the Ta-center occurs through C-H activation concerted with elimination of molecular hydrogen (σ-bond metathesis). Once the Ta-alkyl species is formed, the C-C activation step corresponds to a β-alkyl transfer to the metal with elimination of an olefin. According to these calculations, an α-alkyl transfer to the metal to form a Ta-carbene species is of higher energy. The olefins formed during the C-C activation step can be rapidly hydrogenated by both mono- and tris-Ta-hydride species, making the overall process of alkane cracking thermodynamically favored. © 2014 American Chemical Society.

  17. LIDEM unit for the production of methyl tert-butyl ether from butanes

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, M.G.; Zadvornov, M.A.

    1994-09-01

    One of the basic problems in the production of motor fuels is how to obtain high-octane unleaded gasolines that will meet today`s ecological requirements. The term {open_quotes}reformulated gasolines{close_quotes} has come into general use throughout the world to denote fuels with a certain chemical composition. These gasolines consist of preselected components; as shown by worldwide experience, they must include oxygen-containing compounds that are distinguished by high octane numbers and low reactivities. Standards in effect in the United States, Japan, and certain Western European countries require that automotive gasolines must contain at least 2-4% by weight of oxygen-containing compounds (calculated as oxygen). In the last 15 years, in order to meet these requirements, production has been set up in various countries for the manufacture of high-octane oxygen-containing components known as oxygenates. The most common of these is methyl tert-butyl ether (MTBE), obtained by etherification of isobutene by methanol. Process technology developed by this last organization was used as the basis for constructing a unit in the Nizhnekamskneftekhim Production Association and at the Mazheikyai Petroleum Refinery in Lithuania. MTBE production has been held back mainly by a shortage of isobutene, which is obtained mainly from butane-butene cuts produced in cat crackers. In order to alleviate this shortage, it has been proposed that MTBE should be obtained from saturated C{sub 4} hydrocarbons that are recovered in processing oilfield associated gas, and also in the refinery from primary distillation units, catalytic reformers, and hydrocrackers. A working design was developed in 1991-1992 by Lengiproneftekhim for a basically new combination unit designed for the processing of saturated C{sub 4} hydrocarbons, which has been termed the LIDEM unit (Leningrad - isomerization - dehydrogenation - MTBE).

  18. Chemical lumping of mechanisms generated by computer. Application to the modelling of normal butane oxidation; Globalisation chimique de mecanismes generes par ordinateur. Application a la modelisation de l`oxydation du n-butane

    Energy Technology Data Exchange (ETDEWEB)

    Bounaceur, R.; Warth, V.; Glaude, P.A.; Battin-Leclerc, F.; Scacchi, G.; Come, G.M. [Nancy-1 Univ., 54 (France); Faravelli, T.; Ranzi, E. [Politecnico di Milano, Milan (Italy)

    1996-09-01

    There is an increasing need for the development of well validated and reliable models to represent the combustion phenomena in spark ignited engines, in order to formulate gasolines which present optimal octane number properties and which lead to a minimal pollutants formation. These models require the development of chemical mechanisms, to reproduce the combustion reactions, which can be embedded in three dimensional computational fluid dynamic codes in order to be employed to model the reactive flows found in real combustion devices. At the moment, a complete mechanism for modelling the combustion of organic compounds includes several thousands of elementary reactions and thus cannot be incorporated in such codes due to the present limitations of computer hardware. This lead to an urgent need of techniques to reduce the size of complex chemical mechanisms. This paper describes a technique which permits to drastically reduce comprehensive primary mechanisms which can be obtained by computer aided design in the case of the gas-phase oxidation of alkanes. This procedures has been tested by reducing a primary mechanism which has been automatically generated in the case of the normal-butane oxidation by the software EXGAS which is developed in Nancy. The reduced mechanism thus obtained permits to obtain results very close to those computed by using the complete mechanism in the case of the modelling of the normal-butane oxidation both at low temperature between 554 and 737 K, in the negative temperature coefficient field, and at higher temperature at 937 K. In fact, the normal-butane oxidation is rather an academic example to test this method as the global number of reaction is only reduced from 1149 reactions to 971 reactions with the CO-C2 reaction base containing 781 reactions. This method will be really useful to reduce bigger mechanism contains 2141 reactions and could be reduced to around 150 reactions. The further problem will also to be able to reduce the CO

  19. Catalytic Performance of Bare Supporters and Supported KVO3 Catalysts for Cracking n-Butane to Produce Light Olefins

    Institute of Scientific and Technical Information of China (English)

    LuJiangyin; ZhaoZhen; XuChunming; ZhangPu

    2005-01-01

    Supported KVO3 catalysts were prepared by impregnating different kinds of.supporters (α-Al2O3,γ-Al2O3 and SiO2 powders) with a KVO3 solution. The activity of the bare supporters and supported catalysts were evaluated in a continuous micro-reactivity test unit, with n-butane as a raw material. The results show that KVO3 has no catalytic activity, but it can increase the selectivity to light olefins. The supporter of γ-Al2O3 has good catalytic performance for nbutane cracking when the reaction temperature is below 700℃.

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

    Science.gov (United States)

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

    2015-06-25

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

  1. Species active in the selective catalytic reduction of no with iso-butane on iron-exchanged ZSM-5 zeolites

    Directory of Open Access Journals (Sweden)

    M. S. Batista

    2005-09-01

    Full Text Available Fe-ZSM-5 catalysts were prepared by ion exchange in aqueous medium or in the solid state and tested in the catalytic reduction of NO with iso-butane. X-ray powder diffraction (XRD, atomic absorption spectroscopy (AAS, electron paramagnetic resonance spectroscopy (EPR, X-ray absorption spectroscopy (XANES, EXAFS, temperature-programmed reduction by H2 (H2-TPR and Mössbauer spectroscopy (MÖS-S were used for sample characterisation. Irrespective of the method used in catalyst preparation, EPR, XANES and MÖS-S showed Fe atoms in the oxidation state of 3+. MÖS-S and H2-TPR data on Fe-ZSM-5 prepared by ion exchange in the solid state allowed quantification of a lower hematite (Fe2O3 concentration and a higher proportion of Fe cations than samples prepared in an aqueous medium. In all the catalysts studied these Fe cations were the active sites in the reduction of NO to N2 and in the oxidation of iso-butane. It is further suggested that coordination of Fe species is another important aspect to be considered in their behaviour.

  2. Does Phenoloxidase Contributed to the Resistance? Selection with Butane-Fipronil Enhanced its Activities from Diamondback Moths

    Science.gov (United States)

    Liu, Shouzhu; Niu, Hongtao; Xiao, Ting; Xue, Chaobin; Liu, Zhongde; Luo, Wanchun

    2009-01-01

    Using microtitration method, the relationship between Phenoloxidase activity and the resistance of the diamondback moth Plutella xylostella (Linnaeus) to the novel insecticide butane-fipronil was determined in vitro. After selection of the tenth-generation by butane-fipronil, the resistance of the fourth instar larvae was increased 83.80-fold as compared to the susceptible strain. Phenoloxidase activity of the resistant strain (POr) was 1.29-fold higher than the susceptible one (POs). However, the Km and optimum pH values were similar in resistant and susceptible strains, which were 1.11 mM and 6.5, respectively. Both POr and POs have maximum stability at pH values less than 7.0, although POs was less stable at lower pH values than POr. In addition, the thermal stabilities of the two phenoloxidase were very similar. It is suggested that PO may play an important role in the increasing resistance of pests to pesticides. PMID:19401784

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

    Science.gov (United States)

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

    2016-05-01

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

  4. Syngas production from butane using a flame-made Rh/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Hotz, Nico; Stutz, Michael J.; Poulikakos, Dimos [Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zurich, CH-8092 Zurich (Switzerland); Loher, Stefan; Stark, Wendelin J. [Functional Materials Laboratory, Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8092 Zurich (Switzerland)

    2007-05-11

    The capability of flame-made Rh/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} nanoparticles catalyzing the production of H{sub 2}- and CO-rich syngas from butane was investigated for different Rh loadings (0-2.0 wt% Rh) and two different ceramic fibers (Al{sub 2}O{sub 3}/SiO{sub 2} and SiO{sub 2}) as plugging material in a packed bed reactor for a temperature range from 225 to 750 C. The main goal of this study was the efficient processing of butane at temperatures between 500 and 600 C for a micro-intermediate-temperature SOFC system. Our results showed that Rh/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} nanoparticles offer a very promising material for butane-to-syngas conversion with complete butane conversion and a hydrogen yield of 77% at 600 C. The catalytic performance of packed beds strongly depended on the use of either Al{sub 2}O{sub 3}/SiO{sub 2} or SiO{sub 2} fiber plugs. This astonishing effect could be attributed to the interplay of homogeneous and heterogeneous chemical reactions during the high-temperatures within the reactor. (author)

  5. Mechanosynthesis and mechanochemical treatment of bismuth doped vanadium phosphorus oxide catalysts for the partial oxidation of n-butane to maleic anhydride

    Institute of Scientific and Technical Information of China (English)

    Y H.Taufiq-Yap; Y C.Wong; Y Kamiya; W.J.Tang

    2008-01-01

    Three Bi-doped vanadyl pyrophosphate catalysts were prepared via dihydrate route(VPD method),which consisted of different preparation methods including mechanosvnthesis,mechanochemical treatment,and the conventional reflux method.The catalysts produced by the above three methods were characterized by x-ray diffraction(XRD),scanning electron microscopy(SEM),and temperature programmed reduction(TPR).Catalytic evaluation for the partial oxidation of n-butane to maleic anhydride (MA) was also carried out.The XRD patterns of all the Bi-doped catalysts showed the main peaks of pyrophosphate phase.Lower intensity peaks were observed for the mechanochemically treated Bi-doped catalyst(VPDBiMill)with two additional small DeakS corresponding to the presence of a small amount of V5+ phase.The TPR profiles showed that the highest amount of active oxygen species.i.e.V4+-O- pair,responsible for n-butane activation,was removed from VPDBiMill.Furthermore.from the catalytic test results.the graph of selectivity to MA as a function of the conversion of n-butane demonstrated that VPDBiMill was the most selective catalyst.This suggests that the mechanochemical treatment of vanadium phosphate catalyst(VPDBiMill)is a potential method to improve the catalytic properties for the partial oxidation of n-butane to maleic anhydride.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2011-04-15

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2011-11-01

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

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

    Science.gov (United States)

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

    2013-06-01

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

  12. Catalytic Dehydrogenation of n-Butane over V/SiO2 Catalyst: A Comparison with Cr/SiO2 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Xu Yuebing; Fu Wenting; Lu Jiangyin; Wang Jide

    2008-01-01

    V/SiO2 catalysts compared to Cr/SiO2 catalysts were studied for dehydrogenation of n-butane to butenes.Several methods for characterization of catalysts such as FT-IR,UV-vis and Raman spectroscopies were used.Some differences between two catalysts were showed,including the performances of catalysts,distribution of products and mechanism of reactions.The results showed that prepared catalysts with 12m% of active component loading all demonstrated best conversion of n-butane to butene at a reaction temperature of around 590℃.Two different reaction mechanisms were mentioned to well explain why iso-butene was produced on V/SiO2 catalysts but not on Cr/SiO2 catalysts.

  13. (R,R)-Butane-2,3-diol dehydrogenase from Bacillus clausii DSM 8716(T): Cloning and expression of the bdhA-gene, and initial characterization of enzyme.

    Science.gov (United States)

    Muschallik, Lukas; Molinnus, Denise; Bongaerts, Johannes; Pohl, Martina; Wagner, Torsten; Schöning, Michael J; Siegert, Petra; Selmer, Thorsten

    2017-09-20

    The gene encoding a putative (R,R)-butane-2,3-diol dehydrogenase (bdhA) from Bacillus clausii DSM 8716(T) was isolated, sequenced and expressed in Escherichia coli. The amino acid sequence of the encoded protein is only distantly related to previously studied enzymes (identity 33-43%) and exhibited some uncharted peculiarities. An N-terminally StrepII-tagged enzyme variant was purified and initially characterized. The isolated enzyme catalyzed the (R)-specific oxidation of (R,R)- and meso-butane-2,3-diol to (R)- and (S)-acetoin with specific activities of 12U/mg and 23U/mg, respectively. Likewise, racemic acetoin was reduced with a specific activity of up to 115U/mg yielding a mixture of (R,R)- and meso-butane-2,3-diol, while the enzyme reduced butane-2,3-dione (Vmax 74U/mg) solely to (R,R)-butane-2,3-diol via (R)-acetoin. For these reactions only activity with the co-substrates NADH/NAD(+) was observed. The enzyme accepted a selection of vicinal diketones, α-hydroxy ketones and vicinal diols as alternative substrates. Although the physiological function of the enzyme in B. clausii remains elusive, the data presented herein clearly demonstrates that the encoded enzyme is a genuine (R,R)-butane-2,3-diol dehydrogenase with potential for applications in biocatalysis and sensor development. Copyright © 2017. Published by Elsevier B.V.

  14. A Novel Way to Prepare γ-Al2O3 Supported SO42-/ZrO2 Solid Superacid Catalysts for n-Butane Isomerization

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Highly active solid superacid catalysts for n-butane isomerization, SZ/Al2O3-P, were prepared by supporting SO42-/ZrO2 (SZ) on γ-Al2O3 carrier using a precipitation method.The activities of some catalysts were enhanced significantly.The activity of the most active sample, 60%SZ/Al2O3-P, was even about 2 times more active than that of the SZ catalyst.

  15. Comparative Study of Molecular Interactions in Binary Liquid Mixtures of 4 –Methyl-2-pentanoneWith Butan-2-One, Furfuraldehyde, Cyclohexanone At 308 K

    Directory of Open Access Journals (Sweden)

    D. Ubagaramary

    2016-03-01

    Full Text Available Molecular interaction studies using ultrasonic technique in the binary liquid mixtures of 4 –Methyl-2-pentanone With Butan-2-One,Furfuraldehyde and Cyclohexanonehas been carried out at different temperature. Using the measured values of ultrasonic velocity, density and viscosity, acoustical parameters and their excess values are evaluated. From these excess parametersare used to discussing about the nature and strength of the interactions in these binary systems.

  16. Effects of Calcination Temperature on the Acidity and Catalytic Performances of HZSM-5 Zeolite Catalysts for the Catalytic Cracking of n-Butane

    Institute of Scientific and Technical Information of China (English)

    Jiangyin Lu; Zhen Zhao; Chunming Xu; Aijun Duan; Pu Zhang

    2005-01-01

    The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total acid amounts, their density and the amount of B-type acid of HZSM-5 catalysts rapidly decreased, while the amounts of L-type acid had almost no change and thus the ratio of L/B was obviously enhanced with the increase of calcination temperature (excluding 800 ℃). The catalytic performances of modified HZSM-5 catalysts for the cracking of n-butane were also investigated. The main properties of these catalysts were characterized by means of XRD, N2 adsorption at low temperature, NH3-TPD, FTIR of pyridine adsorption and BET surface area measurements. The results showed that HZSM-5 zeolite pretreated at 800 ℃ had very low catalytic activity for n-butane cracking. In the calcination temperature range of 500-700 ℃, the total selectivity to olefins, propylene and butene were increased with the increase of calcination temperature, while, the selectivity for arene decreased with the calcination temperature.The HZSM-5 zeolite calcined at 700 ℃ produced light olefins with high yield, at the reaction temperature of 650 ℃ the yields of total olefins and ethylene were 52.8% and 29.4%, respectively. Besides, the more important role is that high calcination temperature treatment improved the duration stability of HZSM-5zeolites. The effect of calcination temperature on the physico-chemical properties and catalytic performance of HZSM-5 for cracking of n-butane was explored. It was found that the calcination temperature had large effects on the surface area, crystallinity and acid properties of HZSM-5 catalyst, which further affected the catalytic performance for n-butane cracking.

  17. Effects of Light Rare Earth on Acidity and Catalytic Performance of HZSM-5 Zeolite for Catalytic Cracking of Butane to Light Olefins

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaoning; Zhao Zhen; Xu Chunming; Duan Aijun; Zhang Li; Jiang Guiyuan

    2007-01-01

    The effects of rare earth (RE) on the structure, acidity, and catalytic performance of HZSM-5 zeolite were investigated. A series of RE/HZSM-5 catalysts, containing 7.54% RE (RE=La, Ce, Pr, Nd, Sm, Eu or Gd), were prepared by the impregnation of the ZSM-5 type zeolites (Si/Al=64:1) with the corresponding RE nitrate aqueous solutions. The catalysts were characterized by means of FT-IR, UV-Vis, NH3-TPD, and IR spectroscopy of adsorbed pyridine. The catalytic performances of the RE/HZSM-5 for the catalytic cracking of mixed butane to light olefins were also measured with a fixed bed microreactor. The results revealed that the addition of light rare earth metal on the HZSM-5 catalyst greatly enhanced the selectivity to olefins, especially to propylene, thus increasing the total yield of olefins in the catalytic cracking of butane. Among the RE-modified HZSM-5 samples, Ce/HZSM-5 gave the highest yield of total olefins, and Nd/HZSM-5 gave the highest yield of propene at a reaction temperature of 600℃. The presence of rare earth metal on the HZSM-5 sample, not only modified the acidic properties of HZSM-5 including the amount of acid sites and acid type, that is, the ratio of L/B (Lewis acid/Bronsted acid), but also altered the basic properties of it, which in turn promoted the catalytic performance of HZSM-5 for the catalytic cracking of butane.

  18. An Experimental Measurement on Laminar Burning Velocities and Markstein Length of Iso-Butane-Air Mixtures at Ambient Conditions

    Directory of Open Access Journals (Sweden)

    Yousif Alaeldeen Altag

    2016-01-01

    Full Text Available In the present work, experimental investigation on laminar combustion of iso-butane-air mixtures was conducted in constant volume explosion vessel. The experiments were conducted at wide range of equivalence ratios ranging between Ф = 0.6 and 1.4 and atmospheric pressure of 0.1 MPa and ambient temperature of 303K. Using spherically expanding flame method, flame parameters including stretched, unstretched flame propagation speeds, laminar burning velocities and Markstein length were calculated. For laminar burning velocities the method of error bars of 95% confidence level was applied. In addition, values of Markstein lengths were measured in wide range of equivalence ratios to study the influence of stretch rate on flame instability and burning velocity. It was found that the stretched flame speed and laminar burning velocities increased with equivalence ratios and the peak value was obtained at equivalence ratio of Ф = 1.1. The Markstein length decreased with the increases in equivalence ratios, which indicates that the diffusion thermal flame instability increased at high equivalence ratios in richer mixture side. However, the total deviations in the laminar burning velocities have discrepancies of 1.2-2.9% for all investigated mixtures.

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

    KAUST Repository

    Choi, Byungchul

    2010-12-01

    The autoignition characteristics of laminar lifted flames of methane, ethylene, ethane, and n-butane fuels have been investigated experimentally in coflow air with elevated temperature over 800. K. The lifted flames were categorized into three regimes depending on the initial temperature and fuel mole fraction: (1) non-autoignited lifted flame, (2) autoignited lifted flame with tribrachial (or triple) edge, and (3) autoignited lifted flame with mild combustion. For the non-autoignited lifted flames at relatively low temperature, the existence of lifted flame depended on the Schmidt number of fuel, such that only the fuels with Sc > 1 exhibited stationary lifted flames. The balance mechanism between the propagation speed of tribrachial flame and local flow velocity stabilized the lifted flames. At relatively high initial temperatures, either autoignited lifted flames having tribrachial edge or autoignited lifted flames with mild combustion existed regardless of the Schmidt number of fuel. The adiabatic ignition delay time played a crucial role for the stabilization of autoignited flames. Especially, heat loss during the ignition process should be accounted for, such that the characteristic convection time, defined by the autoignition height divided by jet velocity was correlated well with the square of the adiabatic ignition delay time for the critical autoignition conditions. The liftoff height was also correlated well with the square of the adiabatic ignition delay time. © 2010 The Combustion Institute.

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

    Science.gov (United States)

    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. O2 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.

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

    Science.gov (United States)

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

    2012-01-01

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

  2. 21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances... articles intended for packaging or holding food during cooking, provided that the thickness of such polymers in the form in which they contact food shall not exceed 0.1 millimeter (0.004 inch) and...

  3. Solubility parameter of poly[styrene-b-(1-butene-co-ethylene)-b-styrene

    Science.gov (United States)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

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

    Energy Technology Data Exchange (ETDEWEB)

    Falcon, J.; Ortega, J.; Gonzalez, E. [Escuela Superior de Ingenieros Industriales, Las Palmas (Spain). Laboratorio de Termodinamica y Fisicoquimica

    1996-07-01

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

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

    Science.gov (United States)

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

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

  6. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Butan-1-ol (VMSD1111, LB5188_V)

    Science.gov (United States)

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

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Butan-1-ol (VMSD1111, LB5188_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

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

    Science.gov (United States)

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

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

  8. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Butan-1-ol (VMSD1212, LB5189_V)

    Science.gov (United States)

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

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Butan-1-ol (VMSD1212, LB5189_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  9. Site-Specific Rate Constant Measurements for Primary and Secondary H- and D-Abstraction by OH Radicals: Propane and n -Butane

    KAUST Repository

    Badra, Jihad

    2014-07-03

    Site-specific rate constants for hydrogen (H) and deuterium (D) abstraction by hydroxyl (OH) radicals were determined experimentally by monitoring the reaction of OH with two normal and six deuterated alkanes. The studied alkanes include propane (C3H8), propane 2,2 D2 (CH 3CD2CH3), propane 1,1,1-3,3,3 D6 (CD 3CH2CD3), propane D8 (C3D 8), n-butane (n-C4H10), butane 2,2-3,3 D4 (CH3CD2CD2CH3), butane 1,1,1-4,4,4 D6 (CD3CH2CH2CD3), and butane D10 (C4D10). Rate constant measurements were carried out over 840-1470 K and 1.2-2.1 atm using a shock tube and OH laser absorption. Previous low-temperature data were combined with the current high-temperature measurements to generate three-parameter fits which were then used to determine the site-specific rate constants. Two primary (P1,H and P 1,D) and four secondary (S00,H, S00,D, S 01,H, and S01,D) H- and D-abstraction rate constants, in which the subscripts refer to the number of C atoms connected to the next-nearest-neighbor C atom, are obtained. The modified Arrhenius expressions for the six site-specific abstractions by OH radicals are P1,H = 1.90 × 10-18T2.00 exp(-340.87 K/T) cm 3molecule-1s-1 (210-1294 K); P1,D= 2.72 × 10-17 T1.60 exp(-895.57 K/T) cm 3molecule-1s-1 (295-1317 K); S00,H = 4.40 × 10-18 T1.93 exp(121.50 K/T) cm 3molecule-1s-1 (210-1294 K); S00,D = 1.45 × 10-20 T2.69 exp(282.36 K/T) cm 3molecule-1s-1 (295-1341 K); S01,H = 4.65 × 10-17 T1.60 exp(-236.98 K/T) cm 3molecule-1s-1 (235-1407 K); S01,D = 1.26 × 10-18 T2.07 exp(-77.00 K/T) cm 3molecule-1s-1 (294-1412 K). © 2014 American Chemical Society.

  10. Poly[aqua[μ2-1,1′-(butane-1,4-diyldiimidazole](μ2-naphthalene-1,4-dicarboxylatonickel(II

    Directory of Open Access Journals (Sweden)

    Xian-Zhi Zou

    2008-09-01

    Full Text Available In the title compound, [Ni(C12H6O4(C10H14N4(H2O]n, the coordination polyhedron around each NiII atom is a distorted cis-NiN2O4 octahedron. The naphthalene-1,4-dicarboxylate and 1,1′-(butane-1,4-diyldiimidazole ligands bridge the Ni centres to form a two-dimensional (4,4-network, and O—H...O hydrogen bonds complete the structure.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dix, Sean T. [Department of Chemical and Biomolecular Engineering; Clemson University; Clemson, USA; Scott, Joseph K. [Department of Chemical and Biomolecular Engineering; Clemson University; Clemson, USA; Getman, Rachel B. [Department of Chemical and Biomolecular Engineering; Clemson University; Clemson, USA; Campbell, Charles T. [Department of Chemistry; University of Washington; Seattle, USA

    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 O2over a model for MOF-encapsulated bimetallic nanoparticles. The model consists of a Ag3Pd(111) surface decorated with a 2-atom-thick ring of (immobile) helium atoms which creates an artificial pore of similar size to that in common MOFs, which sterically constrains the adsorbed reaction intermediates. The kinetic parameters are based on energies calculated using density functional theory (DFT). The microkinetic model was analysed at 423 K to determine the dominant pathways and which species (adsorbed intermediates and transition states in the reaction mechanism) have energies that most sensitively affect the reaction rates to the different products, using degree-of-rate-control (DRC) analysis. This analysis revealed that activation of the C–H bond is assisted by adsorbed oxygen atoms, O*. Unfortunately, O* also abstracts H from adsorbed 1-butanol and butoxy as well, leading to butanal as the only significant product. This suggested to (1) add water to produce more OH*, thus inhibiting these undesired steps which produce OH*, and (2) eliminate most of the O2pressure 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 O2was 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

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

    Science.gov (United States)

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

    1992-07-01

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

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

    Science.gov (United States)

    Gehring, Christian; Wessel, Mirja; Schaffer, Steffen

    2016-01-01

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

  14. (Vapour + liquid) equilibria of the {l_brace}trifluoromethane (HFC-23) + propane{r_brace} and {l_brace}trifluoromethane (HFC-23) + n-butane{r_brace} systems

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Mincheol; Yun, Yongju [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Shin, Moon Sam [Department of Cosmetic Science, Chungwoon University, Chungnam 350-701 (Korea, Republic of); Kim, Hwayong [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of)], E-mail: hwayongk@snu.ac.kr

    2009-12-15

    Isothermal (vapour + liquid) equilibrium data were measured for the two systems, {l_brace}trifluoromethane (HFC-23) + propane{r_brace} and {l_brace}trifluoromethane (HFC-23) + n-butane{r_brace}, at temperatures ranging from 283.15 K to 313.15 K at 10 K intervals. These experiments were performed with a circulating-type apparatus and on-line gas chromatography. Experimental data were well correlated by the Peng-Robinson equation of state using the Wong-Sandler mixing rules and the NRTL model.

  15. (Vapour + liquid) equilibria of the {l_brace}1,1-difluoroethane (HFC-152a) + n-butane (HC-600){r_brace} system

    Energy Technology Data Exchange (ETDEWEB)

    Im, Jihoon [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Lee, Gangwon [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Lee, Yong-Jin [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Kim, Hwayong [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of) ]. E-mail: hwayongk@snu.ac.kr

    2007-08-15

    Binary (vapour + liquid) equilibrium data were obtained for the {l_brace}1,1-difluoroethane (HFC-152a) + n-butane (HC-600){r_brace} system at temperatures from 313.15 K to 363.15 K. These experiments were carried out with a circulating-type apparatus with on-line gas chromatography. The experimental data were correlated well by Peng-Robinson equation of state using the Wong-Sandler mixing rules. This system shows positive azeotropic phase behaviour.

  16. Synthesis, Characterization and Thermal Decomposition Studies of Cr(III, Mn(II and Fe(III Complexes of N, N '-Bis[1,3-benzodioxol-5-ylmethylene]butane-1,4-diamine

    Directory of Open Access Journals (Sweden)

    Prasad M. Alex

    2009-01-01

    Full Text Available A bidentate Schiff base ligand namely, N,N'-bis-1,3-benzodioxol-5-ylmethylene]butane-1,4-diamine was synthesised by condensing piperonal (3,4-dioxymethylenebenzaldehyde with butane-1,4-diamine. Cr(III, Mn(II, Fe(III complexes of this chelating ligand were synthesised using acetates, chlorides, bromides, nitrates and perchlorates of these metals. The ligand and the complexes were characterised by elemental analysis, 1H NMR, UV-Vis and IR spectra, conductance and magnetic susceptibility measurements and thermogravimetric analysis. The thermograms of three complexes were analysed and the kinetic parameters for the different stages of decompositions were determined.

  17. Discussion pressure swing adsorption technology of Butane dehydrogenation tail gas extracting hydrogen%从丁烷脱氢尾气提取氢气的变压吸附方法讨论

    Institute of Scientific and Technical Information of China (English)

    屈玉玺; 迟建光

    2015-01-01

    丁烷脱氢尾气提取氢气变压吸附技术是一种新型的气体分离技术,本文探讨从丁烷脱氢尾气提取氢气的变压吸附方法。%Butane dehydrogenation tail gas extracting hydrogen pressure swing adsorption technology is a new type of gas separation technology, this paper discusses the pressure swing adsorption method of extracting hydrogen from butane dehydrogenation tail gas.

  18. The Investigation of Model of Consumers Responses to Brand Equity Based on Marketing Mix Efforts, Corporate Image and Brand Equity Relation (case stady : Butane Campany

    Directory of Open Access Journals (Sweden)

    Ahmad Sardari

    2014-07-01

    Full Text Available Abstract For keeping and continuing their perpetuity in nowadays, companies and should focus on competitive advantages and getting more consumers’ satisfaction for sale and more market shares.One of the useful tools that makes the company less vulnerable in face of market competitive activities and consumption liability and repetition is brand equity. The purpose of this paper is investigating the consumers’ responses on marketing- mix efforts, corporate image and brand equity relation using Kim & Hyun model(2011 and Buil & Martı´nez model(2013.This research is considered as applied based on goal and descriptive-survey based on data collection. Hypotheses were tested using structural equation modeling or SEM (in Lisrel and P.L.S software and consumers’ data Butane corporation productes in Tehran. Findings corroborate the positive impact of brand equity on consumers’ responses.The results of hypotheses analysis illustrate marketing- mix efforts positively impacts on brand equity and corporate image plays a significant role in creation of brand equity for Butane.So company managers should designate special places for distribution system growth, after sale services development, pricing, promotion in investment matrix for marketing mixed efforts.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Kumar, Varun; Kumar, Manoj; Shakher, Chandra

    2015-08-01

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

  1. High-valued Utilization of China Fir Sawdust Extracted Essential Oil: Preparation of Granular Activated Carbons for n-Butane Adsorption

    Institute of Scientific and Technical Information of China (English)

    ZHU Guang-zhen; DENG Xian-lun; LIU Xiao-min

    2011-01-01

    [Objective] The aim was to study on the high-valued utilization of China Fir sawdust extracted essential oil. [Method] In the field of fir essential oil extraction, the processed China fir sawdust was used to prepare low-valued products. The high-valued utilization of China fir sawdust extracted essential oil (CFSEEO), namely as a precursor to prepare granular activated carbons (GACs), was attempted. The materials were characterized by ultimate analysis, SEM and XRD. [Rusult] A butane working capacity (BWC) of 14.3 g/100 ml was obtained by using the GACs with apparent density of 0.25 g/ml. It was available to introduce the technology of extracting essential oil from the China fir sawdust (CFS) in the industrial production process of activated carbons with high BWC (12.0 -16.5 g/100 ml) and high surface area (2 000 -2 630m2/g) using phosphoric acid based on previous studies of the authors. [Conclusion] The resulting carbon prepared with the raw materials containing lower moisture exhibited a better property on n-butane adsorption.

  2. The Fabrication of Ga2O3/ZSM-5 Hollow Fibers for Efficient Catalytic Conversion of n-Butane into Light Olefins and Aromatics

    Directory of Open Access Journals (Sweden)

    Jing Han

    2016-01-01

    Full Text Available In this study, the dehydrogenation component of Ga2O3 was introduced into ZSM-5 nanocrystals to prepare Ga2O3/ZSM-5 hollow fiber-based bifunctional catalysts. The physicochemical features of as-prepared catalysts were characterized by means of XRD, BET, SEM, STEM, NH3-TPD, etc., and their performances for the catalytic conversion of n-butane to produce light olefins and aromatics were investigated. The results indicated that a very small amount of gallium can cause a marked enhancement in the catalytic activity of ZSM-5 because of the synergistic effect of the dehydrogenation and aromatization properties of Ga2O3 and the cracking function of ZSM-5. Compared with Ga2O3/ZSM-5 nanoparticles, the unique hierarchical macro-meso-microporosity of the as-prepared hollow fibers can effectively enlarge the bifunctionality by enhancing the accessibility of active sites and the diffusion. Consequently, Ga2O3/ZSM-5 hollow fibers show excellent catalytic conversion of n-butane, with the highest yield of light olefins plus aromatics at 600 °C by 87.6%, which is 56.3%, 24.6%, and 13.3% higher than that of ZSM-5, ZSM-5 zeolite fibers, and Ga2O3/ZSM-5, respectively.

  3. Partial Oxidation of Butane to Syngas over Nickel SupportedCatalysts Modified by Alkali Metal Oxide and Rare-Earth Metal Oxide

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The partial oxidation of butane (POB) to syngas over nickel supported catalysts was first investigated with a flow-reactor, TG and UVRRS. The NiO/g-Al2O3 is the most suitable for the POB among NiO/g-Al2O3, NiO/MgO and NiO/SiO2. And the reaction performance of the NiO/g-Al2O3 shows little difference from those of the nickel supported catalysts modified by alkali metal oxide and rare-earth metal oxide. However, modification with Li2O and La2O3 can suppress carbon-deposition of the NiO/g-Al2O3, which contains graphite-like species during the POB reaction.

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

    Science.gov (United States)

    Yamasaki, Yudai; Iida, Norimasa

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

  5. Synthesis and Characterization of New Macrocyclic Cu(Ⅱ)Complexes from Various Diamines, Copper(Ⅱ) Nitrate and 1,4-Bis(2-formylphenoxy)butane

    Institute of Scientific and Technical Information of China (English)

    ILHAN, Salih; TEMEL, Hamdi; KILIC, Ahmet

    2007-01-01

    Six new macrocyclic complexes were synthesized by a template reaction of 1,4-bis(2-formylphenoxy)butane with diamines and Cu(NO3)2·3H2O and their structures were proposed on the basis of elemental analysis, FT-IR,UV-Vis, magnetic susceptibility measurements, molar conductivity measurements and mass spectra. The metal to ligand molar ratios of the Cu(Ⅱ) complexes were found to be 1∶1. The Cu(Ⅱ) complexes are 1∶2 electrolytes as shown by their molar conductivities (Λm) in DMF at 10-3 mol·L-1. Due to the existence of free ions the Cu(Ⅱ)complexes are electrically conductive. Their configurations were proposed to be probably distorted octahedral.

  6. Kinetics of phosphotungstic acid catalyzed oxidation of propan-1,3-diol and butan-1,4-diol by N-chlorosaccharin

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar Singh

    2011-09-01

    Full Text Available The kinetic studies of N-chlorosaccharin (NCSA oxidation of propan-1,3-diol and butan-1,4-diol have been reported in presence of phophotungstic acid and in aqueous acetic acid medium. The reactions follow first-order in NCSA and one to zero order with respect to substrate and phosphotungstic acid. Increase in the concentration of added perchloric acid increases the rate of oxidation. A negative effect on the oxidation rate is observed for solvent whereas the ionic strength does not influence the rate of reaction. Addition of the reaction product, saccharin, exhibited retarding effect. Various activation parameters have been evaluated. The products of the reactions were identified as the corresponding aldehydes. A suitable scheme of mechanism consistent with the experimental results has been proposed.

  7. Thermodynamic Property Surfaces for Adsorption of R507A, R134a, and n -Butane on Pitch-Based Carbonaceous Porous Materials

    KAUST Repository

    Chakraborty, Anutosh

    2010-10-01

    The thermodynamic property surfaces of R507A, R134a, and n-butane on pitch-based carbonaceous porous material (Maxsorb III) are developed from rigorous classical thermodynamics and experimentally measured adsorption isotherm data. These property fields enable us to compute the entropy, enthalpy, internal energy, and heat of adsorption as a function of pressure, temperature, and the amount of adsorbate. The entropy and enthalpy maps are necessary for the analysis of adsorption cooling cycle and gas storage. We have shown here that it is possible to plot an adsorption cooling cycle on the temperature-entropy (T-s) and enthalpy-uptake (h-x) maps. Copyright © Taylor and Francis Group, LLC 2010.

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

    Science.gov (United States)

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

    2014-11-01

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

  9. Enthalpies of formation, bond dissociation energies, and molecular structures of the n-aldehydes (acetaldehyde, propanal, butanal, pentanal, hexanal, and heptanal) and their radicals.

    Science.gov (United States)

    da Silva, Gabriel; Bozzelli, Joseph W

    2006-12-07

    Aldehydes are important intermediates and products in a variety of combustion and gas-phase oxidation processes, such as in low-temperature combustion, in the atmosphere, and in interstellar media. Despite their importance, the enthalpies of formation and bond dissociation energies (BDEs) for the aldehydes are not accurately known. We have determined enthalpies of formation for acetaldehyde, propanal, and butanal from thermodynamic cycles, using experimentally measured reaction and formation enthalpies. All enthalpy values used for reference molecules and reactions were first verified to be accurate to within around 1 kcal mol-1 using high-level ab initio calculations. Enthalpies of formation were found to be -39.72 +/- 0.16 kcal mol-1 for acetaldehyde, -45.18 +/- 1.1 kcal mol-1 for propanal, and -49.27 +/- 0.16 kcal mol-1 for butanal. Enthalpies of formation for these three aldehydes, as well as for pentanal, hexanal, and heptanal, were calculated using the G3, G3B3, and CBS-APNO theoretical methods, in conjunction with bond-isodesmic work reactions. On the basis of the results of our thermodynamic cycles, theoretical calculations using isodesmic work reactions, and existing experimental measurements, we suggest that the best available formation enthalpies for the aldehydes acetaldehyde, propanal, butanal, pentanal, hexanal, and heptanal are -39.72, -45.18, -50.0, -54.61, -59.37, and -64.2 kcal mol-1, respectively. Our calculations also identify that the literature enthalpy of formation of crotonaldehyde is in error by as much as 1 kcal mol-1, and we suggest a value of -25.1 kcal mol-1, which we calculate using isodesmic work reactions. Bond energies for each of the bonds in the aldehydes up to pentanal were calculated at the CBS-APNO level. Analysis of the BDEs reveals the R-CH(2)CH=O to be the weakest bond in all aldehydes larger than acetaldehyde, due to formation of the resonantly stabilized vinoxy radical (vinyloxy radical/formyl methyl radical). It is

  10. Poly[(μ4-biphenyl-3,3′-dicarboxylatobis[μ2-1,1′-(butane-1,4-diyldiimidazole](μ2-oxalatodimanganese(II

    Directory of Open Access Journals (Sweden)

    Bao-Yong Zhu

    2010-10-01

    Full Text Available In the title coordination compound, [Mn2(C14H8O4(C2O4(C10H14N42]n, the biphenyl-3,3′-dicarboxylate and oxalate anions, both situated on inversion centres, function in a bridging mode, linking the dinuclear MnII atoms into wave-like layers. Each 1,1′-(1,4-butane-1,4-diyldiimidazole ligand coordinates to two MnII atoms located in adjacent layers via Mn—N coordination bonds, giving a three-dimensional network. As the methylene groups can bend freely relative to each other due to the C atoms connected via single bonds, the 1,1′-(butane-1,4-diyldiimidazole ligand forms an S-shaped conformation, which makes the void in the three-dimensional network distorted.

  11. Preparation and characterization of poly(2-acrylamido-2-methylpropane-sulfonic acid)/Chitosan hydrogel using gamma irradiation and its application in wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Gad, Y.H. [National Centre for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)], E-mail: yasser2uk@yahoo.com

    2008-09-15

    Radiation grafting of chitosan with 2-acrylamido-2-methyl propane sulfonic acid (AMPS) has been successfully performed. The effect of absorbed dose (kGy) and the chitosan:AMPS ratio on graft hydrogelization was studied. The structure of the prepared hydrogel was confirmed using infrared spectroscopy (IR). Thermal properties were simultaneously studied by thermogravimetric analysis (TGA). The effect of the polymerization variables on the swelling % of the prepared hydrogel was investigated. The highest equilibrium degree of swelling (38.6 g/g) and gel % (94.7%) of the prepared chitosan-AMPS hydrogel was at 40% AMPS and absorbed dose of 10 kGy. The removal of methylene blue, acid red dye, Cd (II) and Cr (III) from composed wastewater was also investigated. The effect of pH, the chitosan:AMPS ratio and the concentration of the pollutant on the adsorption process were studied.

  12. Preparation and characterization of poly(2-acrylamido-2-methylpropane-sulfonic acid)/Chitosan hydrogel using gamma irradiation and its application in wastewater treatment

    Science.gov (United States)

    Gad, Y. H.

    2008-09-01

    Radiation grafting of chitosan with 2-acrylamido-2-methyl propane sulfonic acid (AMPS) has been successfully performed. The effect of absorbed dose (kGy) and the chitosan:AMPS ratio on graft hydrogelization was studied. The structure of the prepared hydrogel was confirmed using infrared spectroscopy (IR). Thermal properties were simultaneously studied by thermogravimetric analysis (TGA). The effect of the polymerization variables on the swelling % of the prepared hydrogel was investigated. The highest equilibrium degree of swelling (38.6 g/g) and gel % (94.7%) of the prepared chitosan-AMPS hydrogel was at 40% AMPS and absorbed dose of 10 kGy. The removal of methylene blue, acid red dye, Cd (II) and Cr (III) from composed wastewater was also investigated. The effect of pH, the chitosan:AMPS ratio and the concentration of the pollutant on the adsorption process were studied.

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

    Science.gov (United States)

    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.

  14. Phase equilibrium at high pressure of heavy oil fraction in propane and n-butane; Equilibrio de fases em alta pressao de fracoes pesadas do petroleo em propano e n-butano

    Energy Technology Data Exchange (ETDEWEB)

    Canziani, Daniel B.; Ndiaye, Papa M. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil); Oliveira, Jose V. de; Corazza, Marcos L. [Universidade Regional Integrada, Erechim, RS (Brazil)

    2008-07-01

    One of the biggest challenge of the oil industry is the preparation and adequacy of existing refineries for processing of heavy oil in large quantities. Specifically aims of this work is to measure phase equilibria date at high-pressure with systems involving GOP (Heavy Gasoil), RAT (Atmospheric Residue) and Marlim (crude oil) in n-butane and propane, using the static-synthetic method. The influence of the addition of methanol on the transition pressure is also investigated. With regard to tests made with the use of methanol as a co-solvent, those with higher levels of methanol (5% in mass fraction) had presented transition pressures a little higher than systems with 1% of methanol and systems without methanol. The systems without methanol showed similar pressures. All systems are PT diagrams of the type Lower Critical Solution Temperature (LCST). Among the solvents used the n-butane shown to be the most soluble for all solutes, in particular for the RAT. With the n-butane were observed only liquid-vapour equilibria, and with propane the liquid-liquid, liquid-liquid-vapour and liquid-liquid-fluid equilibria could be observed. The system Propane-5%Methanol-GOP presented liquid-liquid-vapour transitions, indicates be a diagram of the type V (according to the classification of van Konynenburg and Scott). (author)

  15. N(1)-(quinolin-2-ylmethyl)butane-1,4-diamine, a polyamine analogue, attenuated injury in in vitro and in vivo models of cerebral ischemia.

    Science.gov (United States)

    Cen, Juan; Liu, Lu; He, Ling; Liu, Man; Wang, Chao-Jie; Ji, Bian-Sheng

    2012-11-01

    It has been widely recognized that glutamate (Glu)-induced cytotoxicity, intracellular calcium overload and excessive free radical production are the key players in the development and progression of ischemic brain injury. Since MK-801, an antagonist of N-methyl-d-aspartate (NMDA) receptor, showed many adverse reactions that hampered its clinical applications, development of safe and effective agent for the treatment of cerebral ischemia is eagerly required. This study was to investigate the effects of N(1)-(quinolin-2-ylmethyl)butane-1,4-diamine (QMA), a polyamine analogue, on the in vitro and in vivo models of cerebral ischemic damage. The results revealed that pretreatment with QMA could attenuate Glu, putrescine (Put) and oxygen-glucose deprivation (OGD)-induced cell death, lipid peroxidation as well as the elevation of reactive oxygen species (ROS) and intracellular [Ca(2+)](i) in pheochromocytoma (PC12) cells and in rat primary cortical neurons. The results also demonstrated that QMA could inhibit NMDA-mediated intracellular [Ca(2+)](i) accumulation in rat primary cortical neurons and reduce brain infarct volume in middle cerebral artery occlusion (MCAO) rats. The present report suggested that polyamines played a crucial role in the pathological processes of cerebral ischemic damage and that QMA or other novel polyamine analogues could be promising therapeutic candidates for stroke by virtue of their anti-hypoxia and antioxidation property.

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

    Science.gov (United States)

    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.

  17. Functionalization of undoped and p-doped Si (100) using atomic force microscope tips in the presence of propan-2-ol, butan-2-ol and toluene

    Science.gov (United States)

    McCausland, Jeffrey A.; Withanage, Sajeevi; Mallik, Robert R.; Lyuksyutov, Sergei F.

    2017-07-01

    A technique, based on amplitude modulation of Atomic Force Microscope (AFM) tips, in the absence of an applied bias voltage, is reported in this study. Under ambient humidity conditions, ultra-sharp n-doped silicon tips (spike radius 1 nm) oscillating at 160-250 kHz generate raised nanostructures 50-200 nm wide and 2 nm high on undoped or p-doped Si (100) surfaces pretreated with certain neat organic solvents. The solvents in the present work are propan-2-ol, butan-2-ol, or toluene. AFM is used to characterize the nanostructures which are found to be stable for at least 96 h. It is suggested that mechanical stress associated with the oscillatory Hookean energy ( 5-15 eV) of the tip promotes cleavage of residual solvent bonds on the surface. This bond cleavage, and the presence of surface defects, which may be critical in the formation of surface-solvent bonds (specifically Si-O-C or Si-C) to create the observed nanostructures, is discussed. The process described here to create raised nanostructures is distinctly different from all other reported techniques to date.

  18. Preparation of Polyvinyl Alcohol/Xylan Blending Films with 1,2,3,4-Butane Tetracarboxylic Acid as a New Plasticizer

    Directory of Open Access Journals (Sweden)

    Cun-dian Gao

    2014-01-01

    Full Text Available Miscible, biodegradable polyvinyl alcohol (PVA/xylan blending films were firstly prepared in the range of the PVA/xylan weight ratio from 1 : 2 to 3 : 1 by casting method using 1,2,3,4-butane tetracarboxylic acid (BTCA as a new plasticizer. The properties of blending films as functions of PVA/xylan weight ratio and BTCA amount were discussed. XRD and FT-IR were applied to characterize the blending films. Experimental results indicated that tensile strength (TS and elongation at break (EAB of blending films decreased along with the decrease of the PVA/xylan weight ratio. Both of TS and EAB firstly increased and then decreased as the amount of BTCA was increased. More importantly, blending films were biodegraded almost by 41% with an addition of 10% BTCA in blending films within 30 days in soil. For all hydroxyl functionalized polymers (xylan and PVA, their molecular interactions and miscibility with BTCA endowed blending films with the biocompatibility and biodegradability. Therefore, these blending films are environmentally friendly materials which could be applied as biodegradable plastics for food packaging and agricultural applications.

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

    Science.gov (United States)

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

    2015-04-01

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

  20. Preconcentration and determination of copper and cadmium ions with 1,6-bis(2-carboxy aldehyde phenoxy)butane functionalized Amberlite XAD-16 by flame atomic absorption spectrometry.

    Science.gov (United States)

    Oral, Elif V; Dolak, Ibrahim; Temel, Hamdi; Ziyadanogullari, Berrin

    2011-02-15

    A new chelating resin, covalently linked 1,6-bis(2-carboxy aldehyde phenoxy)butane with the Amberlite XAD-16 was synthesized and used for preconcentration of Cu(II) and Cd(II) prior to their determination by flame atomic absorption spectrometry (FAAS). It was characterized by elemental analyses and Fourier Transform Infrared Spectroscopy (FT-IR). Cu(II) and Cd(II) ions were quantitatively preconcentrated on minicolumn loaded with synthesised resin at pH 4.00 and 6.00, respectively. They were eluated with 5 mL of 0.5 mol L(-1) HCl. Recoveries of Cu(II) and Cd(II) were found to be 100±2.15, 100±1.40 (N=5), the limits of detection of Cu(II) and Cd(II) in the determination by FAAS (3s, N=20) were found to be 0.33 and 1.19 μg L(-1), respectively. The effect of foreign ions on the recovery has been investigated. The proposed method has been applied for the determination of Cu(II) and Cd(II) ions to the real samples collected from Tigris river water in Diyarbakir and Elaziğ cities in Turkey. Standard addition method and analysis of the certified reference material (NCS-DC 73350) was employed to check the accuracy of the method.

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

    Science.gov (United States)

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

    2016-01-14

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

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

    Science.gov (United States)

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

    2008-09-25

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

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

    Science.gov (United States)

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

    2012-11-21

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

  4. Kinetic Study on Nucleophilic Substitution Reactions of Aryl Diphenylphosphinates with Butane-2,3-dione Monoximate and Aryloxide Anions: Reaction Mechanism and Origin of the α-Effect

    Energy Technology Data Exchange (ETDEWEB)

    Um, Ik-Hwan; Han, Jeong-Yoon [Ewha Womans University, Seoul (Korea, Republic of)

    2016-08-15

    A kinetic study is reported for nucleophilic substitution reactions of X-substituted-phenyl diphenylphosphinates (3a-3f) with butane-2,3-dione monoximate (Ox{sup -}) and a series of Y-substituted-phenoxide (Y-PhO{sup -}) ions in 50 mol % H{sub 2}O/50 mol % DMSO at 25.0 ± 0.1 .deg. C. The reactions of 3a-3f with Ox{sup -} and 4-chlorophenoxide (4-ClPhO{sup -}) result in linear Brønsted-type plots with β{sub lg} = -0.70 and -0.64, respectively, a typical β{sub lg} value for reactions reported previously to proceed through a concerted mechanism. The Brønsted-type plots for the reactions of 4-chloro-2-nitrophenyl diphenylphosphinate (3a), 4-nitrophenyl diphenylphosphinate (3b), and 4-acetylphenyl diphenylphosphinate (3d) with Y-PhO{sup -} are also linear with β{sub nuc} = 0.15-0.35. The current reactions have been concluded to proceed through a concerted mechanism in which the bond formation is much less advanced than the bond rupture in the TS on the basis of the β{sub lg} and β{sub nuc} values. The α-effect observe d in this study is very small (i.e., the k{sub Ox}{sup -}/k{sub p-ClPhO{sup -}} ratio = 16.4 - 43.5) and is independent of the leaving-group basicity. It has been concluded that the α-effect shown by Ox{sup -} in the current reactions is mainly due to desolvation of Ox{sup -} in the reaction medium (ground-state contribution) rather than stabilization of the transition-state (TS contribution) on the basis of the kinetic results.

  5. Metallo-Phosphorylation of Alkynes: Reaction of Alkynes with Cp2Zr(1-butene) ( PR3 ) and Chlorophosphate

    Institute of Scientific and Technical Information of China (English)

    XI Chan-Juan; LAI Chun-Bo; CHEN Chao; HONG Xiao-Yin

    2003-01-01

    @@ Phosphorylation of alkynes is an attractive reaction for the synthesis of stereodefined alkenylphosphonates that are useful intermediates in organic synthesis. Particularly interesting and challenging reactions are those involving the region- and stereo-selective simultaneous introductions of phosphate and other functional groups to multiple carbon-carbon bonds.[1,2

  6. The membrane-associated monooxygenase in the butane-oxidizing Gram-positive bacterium Nocardioides sp. strain CF8 is a novel member of the AMO/PMO family.

    Science.gov (United States)

    Sayavedra-Soto, Luis A; Hamamura, Natsuko; Liu, Chih-Wen; Kimbrel, Jeffrey A; Chang, Jeff H; Arp, Daniel J

    2011-06-01

    The Gram-positive bacterium Nocardioides sp. strain CF8 uses a membrane-associated monooxygenase (pBMO) to grow on butane. The nucleotide sequences of the genes encoding this novel monooxygenase were revealed through analysis of a de novo assembled draft genome sequence determined by high-throughput sequencing of the whole genome. The pBMO genes were in a similar arrangement to the genes for ammonia monooxygenase (AMO) from the ammonia-oxidizing bacteria and for particulate methane monooxygenase (pMMO) from the methane-oxidizing bacteria. The pBMO genes likely constitute an operon in the order bmoC, bmoA and bmoB. The nucleotide sequence was less than 50% similar to the genes for AMO and pMMO. The operon for pBMO was confirmed to be a single copy in the genome by Southern and computational analyses. In an incubation on butane the increase of transcriptional activity of the pBmoA gene was congruent with the increase of pBMO activity and suggested correspondence between gene expression and the utilization of butane. Phylogenetic comparison revealed distant but significant similarity of all three pBMO subunits to homologous members of the AMO/pMMO family and indicated that the pBMO represents a deeply branching third lineage of this group of particulate monooxygenases. No other bmoCAB-like genes were found to cluster with pBMO lineage in phylogenetic analysis by database searches including genomic and metagenomic sequence databases. pBMO is the first example of the AMO/pMMO-like monooxygenase from Gram-positive bacteria showing similarities to proteobacterial pMMO and AMO sequences. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

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

    Science.gov (United States)

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

    2016-02-01

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

  8. 1.2.3. Synthesis and Structural Characterization of [Co0.5(bimb1.5] n·nClO4 (bimb =1,4-bis(imidazol-1-yl-butane

    Directory of Open Access Journals (Sweden)

    Xiu-Mei Li*, Jian-Ye Ji, Zhi-Tao Wang, Yan-Ling Niu

    2014-04-01

    Full Text Available Abstract: A new cobalt(II coordination polymer, namely [Co0.5 (bimb1.5]n·nClO4 (bimb =1,4-bis(imidazol-1-yl-butane  (1, has been prepared and fully characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy and X-ray powder diffraction pattern analysis (PXRD. Of the compound, the Co(II center is octahedral coordinated with bimb serving as a bridging ligand by employing six N-donor to coordinate with the Co(II center. It exbihits three-dimensional network structure via bimb ligands. Supporting information: CIF file.

  9. The α-Effect in Nucleophilic Substitution Reactions of Y-Substituted-Phenyl X-Substituted-Cinnamates with Butane-2,3-dione Monoximate

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minyoung; Son, Yujin; Um, Ikhwan [Ewha Woman' s Univ., Seoul (Korea, Republic of)

    2013-10-15

    Second-order rate constants (k{sub Ox-}) have been measured spectrophotometrically for nucleophilic substitution reactions of 4-nitrophenyl X-substituted-cinnamates (7a-7e) and Y-substituted-phenyl cinnamates (8a-8e) with butane-2,3-dione monoximate (O{sub x}{sup -}) in 80 mol % H{sub 2}O/20 mol % DMSO at 25.0 ± 0.1 .deg. C. The Hammett plot for the reactions of 7a-7e consists of two intersecting straight lines while the Yukawa-Tsuno plot exhibits an excellent linearity with ρ{sub X} = 0.85 and r = 0.58, indicating that the nonlinear Hammett plot is not due to a change in the rate-determining step but is caused by resonance stabilization of the ground state (GS) of the substrate possessing an electron-donating group (EDG). The Brφnsted-type plot for the reactions of Y-substituted-phenyl cinnamates (8a-8e) is linear with β{sub lg} = -0.64, which is typical of reactions reported previously to proceed through a concerted mechanism. The α-nucleophile (O{sub x}{sup -}) is more reactive than the reference normal-nucleophile (4-ClPhO{sup -}). The magnitude of the α-effect (i.e., the k{sub Ox-}/k{sub 4-ClPhO-} ratio) is independent of the electronic nature of the substituent X in the nonleaving group but increases linearly as the substituent Y in the leaving group becomes a weaker electron-withdrawing group (EWG). It has been concluded that the difference in solvation energy between O{sub x}{sup -} and 4-ClPhO{sup -} (i. e., GS effect) is not solely responsible for the α-effect but stabilization of transition state (TS) through a cyclic TS structure contributes also to the Y-dependent α-effect trend (i. e., TS effect)

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

    Science.gov (United States)

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

    2014-12-01

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

  11. Bipodal surface organometallic complexes with surface N-donor ligands and application to the catalytic cleavage of C-H and C-C bonds in n -Butane

    KAUST Repository

    Bendjeriou-Sedjerari, Anissa

    2013-11-27

    We present a new generation of "true vicinal" functions well-distributed on the inner surface of SBA15: [(Sî - Si-NH 2)(≡Si-OH)] (1) and [(≡Si-NH2)2] (2). From these amine-modified SBA15s, two new well-defined surface organometallic species [(≡Si-NH-)(≡Si-O-)]Zr(CH2tBu) 2 (3) and [(≡Si-NH-)2]Zr(CH2tBu) 2 (4) have been obtained by reaction with Zr(CH2tBu) 4. The surfaces were characterized with 2D multiple-quantum 1H-1H NMR and infrared spectroscopies. Energy-filtered transmission electron microscopy (EFTEM), mass balance, and elemental analysis unambiguously proved that Zr(CH2tBu)4 reacts with these vicinal amine-modified surfaces to give mainly bipodal bis(neopentyl)zirconium complexes (3) and (4), uniformly distributed in the channels of SBA15. (3) and (4) react with hydrogen to give the homologous hydrides (5) and (6). Hydrogenolysis of n-butane catalyzed by these hydrides was carried out at low temperature (100 C) and low pressure (1 atm). While (6) exhibits a bis(silylamido)zirconium bishydride, [(≡Si-NH-)2]Zr(H) 2 (6a) (60%), and a bis(silylamido)silyloxozirconium monohydride, [(≡Si-NH-)2(≡Si-O-)]ZrH (6b) (40%), (5) displays a new surface organometallic complex characterized by an 1H NMR signal at 14.46 ppm. The latter is assigned to a (silylimido)(silyloxo)zirconium monohydride, [(≡Si-Nî)(≡Si-O-)]ZrH (5b) (30%), coexistent with a (silylamido)(silyloxo)zirconium bishydride, [(≡Si-NH-)(≡Si-O-)] Zr(H)2 (5a) (45%), and a silylamidobis(silyloxo)zirconium monohydride, [(≡Si-NH-)(≡Si-O-)2]ZrH (5c) (25%). Surprisingly, nitrogen surface ligands possess catalytic properties already encountered with silicon oxide surfaces, but interestingly, catalyst (5) with chelating [N,O] shows better activity than (6) with chelating [N,N]. © 2013 American Chemical Society.

  12. Synthesis and spectral studies of macrocyclic Pb(Ⅱ), Zn(Ⅱ), Cd(II)and La(Ⅲ) complexes derived from 1,4-bis(3-aminopropoxy)butane with metal nitrate and salicylaldehyde derivatives

    Institute of Scientific and Technical Information of China (English)

    Salih Ilhan; Hamdi Temel; Salih Pasa

    2009-01-01

    Eight new macrocyclic complexes were synthesized by template reaction of 1,4-bis(3-aminopropoxy)butane with metal nitrate and 1,3-bis(2-forrnylphenyl)propane or 1,4-bis(2-formylphenyl)butane and their structures were proposed on the basis of elemental analysis, FTIR, UV-vis, molar conductivity measurements, 1H NMR and mass spectra. The metals to ligand molar ratios of the complexes were found to be 1:1. The complexes are 1:2 electrolytes for Pb(II), Zn(II) and Cd(II) complexes and 1:3 electrolytes for La(lIl) as shown by their molar conductivities (Am) in DMSO at 10-3 tool L-l. Due to the existence of free ions in these complexes,such complexes are electrically conductive. The configurations of La(Ⅲ) and Pb(U) were proposed to probably octahedral and Zn(II) and Cd(II) complexes were proposed to probably tetrahedral.

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

    Science.gov (United States)

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

    2016-08-01

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

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

    Science.gov (United States)

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

    2012-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Reineri, F.; Aime, S. [Department of Molecular Biotechnologies and Health Sciences, University of Torino, Via Nizza 52, 10123 Torino (Italy); Gobetto, R.; Nervi, C. [Department of Chemistry, University of Torino, via P. Giuria 7, 10125 Torino (Italy)

    2014-03-07

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

  16. Densities, viscosities, and ultrasonic velocity studies of binary mixtures of trichloromethane with methanol, ethanol, propan-1-ol, and butan-1-ol at T = (298.15 and 308.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, Ujjan B. [P.G. Department of Physical Chemistry, M.S.G. College, Loknete Vyankatrao Hiray Marg, Malegaon Camp, Maharashtra 423 105 (India); Hiray, Apoorva P. [P.G. Department of Physical Chemistry, M.S.G. College, Loknete Vyankatrao Hiray Marg, Malegaon Camp, Maharashtra 423 105 (India); Sawant, Arun B. [Arts, Science and Commerce College, Nampur 423 204 (India); Hasan, Mehdi [P.G. Department of Physical Chemistry, M.S.G. College, Loknete Vyankatrao Hiray Marg, Malegaon Camp, Maharashtra 423 105 (India)]. E-mail: mihasan@rediffmail.com

    2006-12-15

    Densities, viscosities, and ultrasonic velocities of binary mixtures of trichloromethane with methanol, ethanol, propan-1-ol, and butan-1-ol have been measured over the entire range of composition, at (298.15 and 308.15) K and at atmospheric pressure. From the experimental values of density, viscosity, and ultrasonic velocity, the excess molar volumes (V {sup E}), deviations in viscosity ({delta}{eta}), and deviations in isentropic compressibility ({delta}{kappa} {sub s}) have been calculated. The excess molar volumes, deviations in viscosity and deviations in isentropic compressibility have been fitted to the Redlich-Kister polynomial equation. The Jouyban-Acree model is used to correlate the experimental values of density, viscosity, and ultrasonic velocity.

  17. Synthesis of ionic liquid 1,4- (1-isopropyl-imidazole) butane bromide%离子液体1,4-二(1-异丙基咪唑)丁烷溴化物的合成研究

    Institute of Scientific and Technical Information of China (English)

    刘泓; 赵琦

    2011-01-01

    1-Isopropyl-imidazole was synthesized by reaction of isopropyl atnine with glyoxal, formaldehyde and ammonia in methanol. Bidentate ionic liquid 1,4-( 1-isopropyl-imidazole) butane bromide was synthesized by using 1-isopropyl-imidazole. The compound was confirmed by IR,'H NMR and 13C NMR.%以乙二醛、甲醛、氨水和异丙胺为原料,甲醇为溶剂,合成1-异丙基咪唑.由1-异丙基咪唑与1,4-二溴丁烷反应,合成一种二齿型离子液体1,4-二(1-异丙基眯唑)丁烷溴化物,产物经IR、1H NMR和13C NMR予以表征.

  18. catena-Poly[[[aquasilver(I]-μ-1,1′-(butane-1,4-diyldi-1H-imidazole-κ2N3:N3′] hemi(biphenyl-4,4′-dicarboxylate dihydrate

    Directory of Open Access Journals (Sweden)

    Zheyu Zhang

    2009-12-01

    Full Text Available In the title compound, {[Ag(C10H14N4(H2O](C14H8O40.5·2H2O}n, the AgI ion is three-coordinated by two N atoms from two independent 1,1′-(butane-1,4-diyldi-1H-imidazole (BBI ligands and one water O atom in a distorted T-shaped coordination geometry. The biphenyl-4,4′-dicarboxylate (BPDC dianions do not coordinate to AgI ions but act as counter-ions. The AgI ions are linked by BBI ligands, forming a zigzag chain. These chains are linked into a two-dimensional supramolecular architecture by O—H...O hydrogen-bonding interactions between water molecules and carboxylate O atoms of the BPDC dianions.

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

    OpenAIRE

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

    1991-01-01

    L'existence d'états excités dans le processus de photoionisation VUV des hydrocarbures en phase liquide - précédemment suggérée par l'observation de la loi de Stern-Volmer lors de l'interaction avec des capteurs d'électrons - est ici détectée en traçant le spectre de photoionisation VUV du cyclohexane et du diméthyl-2-2-butane purs en phase liquide. Certains des pics observés coïncident avec les états de valence et de Rydberg de ces mêmes corps en phase gaz. Il apparaît des pics supplémentair...

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

    Science.gov (United States)

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

    2014-03-07

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yan-Peng [Inner Mongolia Key Lab Chem & Phys Rare Earth Mat, College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Department of Chemistry and Chemical Engineering, Ordos College of Inner Mongolia University, Ordos 017000 (China); Department of Chemistry and Chemical Engineering, Ordos Applied Technology College, Ordos 017000 (China); Guo, Le [Department of Chemistry and Chemical Engineering, Ordos College of Inner Mongolia University, Ordos 017000 (China); Department of Chemistry and Chemical Engineering, Ordos Applied Technology College, Ordos 017000 (China); Dong, Wei; Jia, Min; Zhang, Jing-Xue; Sun, Zhong [Inner Mongolia Key Lab Chem & Phys Rare Earth Mat, College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Chang, Fei, E-mail: ndchfei@imu.edu.cn [Inner Mongolia Key Lab Chem & Phys Rare Earth Mat, College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China)

    2016-08-15

    Three new mixed-ligand metal-organic frameworks based on 5,5′-(butane-1,4- diyl)-bis(oxy)-diisophthalic acid and transitional metal cations with the help of two ancillary bridging N-donor pyridyl and imidazole linkers, [Zn(L){sub 0.5}(4,4′-bpy)]·2(H{sub 2}O) (1), [M(L){sub 0.5}(bib)]·4(H{sub 2}O) (M = Zn (2), Co (3)), (4,4′-bpy=4,4′–bipyridine, bib=1,4-bis (1H-imidazol-1-yl)-butane), have been synthesized under solvothermal conditions. Their structures and properties were determined by single-crystal and powder X-ray diffraction analyses, IR spectra, elemental analyses and thermogravimetric analyses (TGA). Compounds 1–3 display a 3D 3-fold interpenetrated frameworks linked by the L{sup 4−} ligands, ancillary N-donor linkers and the free water molecules in the crystal lattice. Topological analysis reveals that 1–3 are a (4,4)-connected bbf topology net with the (6{sup 4}·8{sup 2})(6{sup 6}) topology. The effects of the L{sup 4−} anions, the N-donor ligands, and the metal ions on the structures of the coordination polymers have been discussed. Furthermore, luminescence properties and thermogravimetric properties of these compounds were investigated. - Graphical abstract: Three new compounds of MOFs have been prepared and characterized. The luminescence properties and thermogravimetric properties of compounds were investigated. Display Omitted.

  2. Incineration of oxygenated volatile organic compounds. Experimental study and kinetic modeling of the oxidation of methyl ethyl ketone, ethyl acetate and butan-2-ol in methane flames; Incineration de composes organiques volatils oxygenes. Etude experimentale et modelisation cinetique de l'oxydation de la methyl ethyl cetone, de l'acetate d'ethyle et du butan-2-ol dans des flammes de methane

    Energy Technology Data Exchange (ETDEWEB)

    Decottignies, V.

    2000-12-01

    This work deals with the low pressure (0.05 atm) degradation of three volatile organic compounds (VOCs): methyl-ethyl-ketone, ethyl acetate and butan-2-ol, in premixed stoichiometric laminar methane flames seeded with 1 to 3% of each VOC. Molar fraction profiles of species have been obtained using microprobe sampling coupled with a gas chromatography and a mass spectroscopy analysis. Temperature profiles have been obtained using the covered thermocouple technique in the presence of the microprobe. The addition of a VOC in the initial reagents mixture leads to an increase of the quantity of intermediate hydrocarbon compounds and in particular of some soot precursor species. The degradation of VOCs leads to the formation of oxygenated intermediates like methanol, dimethyl-ether, acetaldehyde, propanal, acetone and vinyl acetate, the type of VOC having an effect on the quantities produced. The degradation of a VOC can lead to the formation of more toxic or polluting compounds (methyl vinyl ketone, acetic acid and acrolein) than the VOC itself. In the conditions of the study, the intermediate compounds are totally destructed inside the reactional area of the flame front and are no more present in the burnt gases. Sub-mechanisms of VOC oxidation have been developed using experimental observations and the most recent recommendations of the literature. These sub-mechanisms comprise 49 species involved in 241 elementary reactions. Their validation has been performed by comparing the experiment with the kinetic modeling on the molar fraction profiles of the detected species. Experimental data are well reproduced by the model for most species. The addition of a VOC inside the initial reagents mixture creates an important reactivity increase, in particular in the case of butan-2-ol seeded flames. The analysis of reactional ways has permitted to draw out the main reactions responsible for the degradation of the 3 VOCs and the ways of formation and consumption of the

  3. In-vitro cytotoxicity and cell cycle analysis of two novel bis-1,2, 4-triazole derivatives: 1,4-bis[5-(5-mercapto-1,3,4-oxadiazol-2-yl-methyl)-thio-4-(p-tolyl)-1,2,4-triazol-3-yl]-butane (MNP-14) and 1,4-bis[5-(carbethoxy-methyl)-thio-4-(p-ethoxy phenyl)-1,2,4-triazol-3-yl]-butane (MNP-16).

    Science.gov (United States)

    Purohit, Madhusudan N; Panjamurthy, Kuppusamy; Elango, Santhini; Hebbar, Karteek; Mayur, Yergeri C; Raghavan, Sathees C

    2011-11-01

    In the present study, we have tested the cytotoxic and DNA damage activity of two novel bis-1,2,4 triazole derivatives, namely 1,4-bis[5-(5-mercapto-1,3,4-oxadiazol-2-yl-methyl)-thio-4-(p-tolyl)-1,2,4-triazol-3-yl]-butane (MNP-14) and 1,4-bis[5-(carbethoxy-methyl)-thio-4-(p-ethoxy phenyl) -1,2,4-triazol-3-yl]-butane (MNP-16). The effect of these molecules on cellular apoptosis was also determined. The in-vitro cytotoxicity was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay as well as Trypan blue dye exclusion methods against human acute lymphoblastic leukemia (MOLT4) and lung cancer cells (A549). Our results showed that MNP-16 induced significant cytotoxicity (IC(50) of 3-5 μM) compared with MNP-14. The cytotoxicity induced by MNP-16 was time and concentration dependent. The cell cycle analysis by flow cytometry (fluorescence-activated cell sorting [FACS]) revealed that though there was a significant increase in the apoptotic population (sub-G(1) phase) with an increased concentration of MNP-14 and 16, there was no cell cycle arrest. Further, the comet assay results indicated considerable DNA strand breaks upon exposure to these compounds, thereby suggesting the possible mechanism of cytotoxicity induced by MNP-16. Hence, we have identified a novel molecule (MNP-16) which could be of great clinical relevance in cancer therapeutics.

  4. Eight Zn(II) coordination networks based on flexible 1,4-di(1H-imidazol-1-yl)butane and different dicarboxylates: crystal structures, water clusters, and topologies.

    Science.gov (United States)

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

    2013-09-14

    Eight new Zn(II) coordination polymers based on flexible 1,4-di(1H-imidazol-1-yl)butane and different dicarboxylates, [Zn(dimb)(suc)·2DMF]n (1), [Zn(dimb)(mbda)·3H2O]n (2), [Zn(dimb)(adip)·DMF·2H2O]n (3), [Zn(dimb)(pma)·2.5H2O]n (4), [Zn2(dimb)(tha)2(H2O)]n (5), [Zn(dimb)(chda)·2H2O]n (6), [Zn(dimb)(obda)·DMF]n (7), [Zn(dimb)(tdga)·CH3OH]n (8) (dimb = 1,4-di(1H-imidazol-1-yl)butane, H2suc = succinic acid, H2mbda = m-benzenediacetic acid, H2adip = adipic acid, H2pma = pimelic acid, H2tha = thiophene-2,5-dicarboxylic acid, H2chda = 1,4-cyclohexanedicarboxylic acid, H2obda = o-benzenediacetic acid, H2tdga = thiodiglycolic acid; DMF = N,N'-dimethylformamide), have been synthesized and structurally characterized by single-crystal X-ray diffraction analyses, and further characterized by infrared spectra (IR), elemental analyses, powder X-ray diffractions (PXRD) and thermogravimetric analyses (TGA). Single-crystal X-ray diffraction analysis reveals that 1, 2, 4, 7 and 8 are 2D wavy 4(4)-sql networks with different dimensions of quadrilateral window units, depending on the conformation and length of dimb and dicarboxylates. Complex 3 is a 2D a 6(3)-hcb network incorporating a [Zn2(dimb)2] cyclic subunit. In complex 5, Zn(II) centers as 3-connected node are linked by dimb and tha to form a 3D 8-fold interpenetrating ThSi2 network. Complex 6 is a 4-connected noninterpenetrating cds network. Interestingly, an infinite T4(2)6(2) water tape and a D2h cyclic water tetramer are also found in complexes 2 and 3, respectively. In 1-8, all Zn(II) centers are located in a four-coordinated environment, and dimb and dicarboxylates are 2-connected linkers, but networks with diverse topologies are built, which indicates the linkage of central metal ion, the conformation of dimb and dicarboxylate have important influences on the resulting structures. Furthermore, the solid-state photoluminescence properties of the 1-8 were investigated at 298 and 77 K.

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

    NARCIS (Netherlands)

    Grunert, CM; Schweifer, J; Weinberger, P; Linert, W; Mereiter, K; Hilscher, G; Muller, M; Wiesinger, G; van Koningsbruggen, PJ

    2004-01-01

    [mu-Tris(1,4-bis(tetrazol-1-yl)butane-N4,N4')iron(II)] bis(hexafluorophosphate), [Fe(btzb)(3)](PF6)(2), crystallizes in a three-dimensional 3-fold interlocked structure featuring a sharp two-step spin-crossover behavior. The spin conversion takes place between 164 and 182 K showing a discontinuity a

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

    Science.gov (United States)

    Frenzel, Peter; Korb, Marcus; Lang, Heinrich

    2016-02-01

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

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

    Science.gov (United States)

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

    2012-02-15

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

  8. Theoretical study and design of a low-grade heat-driven pilot ejector refrigeration machine operating with butane and isobutane and intended for cooling of gas transported in a gas-main pipeline

    KAUST Repository

    Petrenko, V.O.

    2011-11-01

    This paper describes the construction and performance of a novel combined system intended for natural gas transportation and power production, and for cooling of gas transported in a gas-main pipeline. The proposed system includes a gas turbine compressor, a combined electrogenerating plant and an ejector refrigeration unit operating with a hydrocarbon refrigerant. The combined electrogenerating plant consists of a high-temperature steam-power cycle and a low-temperature hydrocarbon vapor power cycle, which together comprise a binary vapor system. The combined system is designed for the highest possible effectiveness of power generation and could find wide application in gas-transmission systems of gas-main pipelines. Application of the proposed system would enable year-round power generation and provide cooling of natural gas during periods of high ambient temperature operation. This paper presents the main results of a theoretical study and design performance specifications of a low-grade heat-driven pilot ejector refrigeration machine operating with butane and isobutane. © 2010 Elsevier Ltd and IIR. All rights reserved.

  9. 智能型AMPS/DMAEMA水凝胶的电敏感性能%Electric sensitive properties of intelligent hydrogels composed of 2-acrylamido-2-methylpropane sulfonic acid/2- (dimethylamino) ethyl methacrylate

    Institute of Scientific and Technical Information of China (English)

    岳航勃; 廖列文; 黎新明; 崔英德

    2009-01-01

    以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)为单体,N,N′-亚甲基双丙烯酰胺为交联剂,过硫酸铵和亚硫酸氢钠为氧化还原引发剂,采用水溶液聚合法制备了AMPS/DMAEMA水凝胶,考察了样品水凝胶在外加直流电场刺激下的消溶胀动力学和弯曲行为.结果表明,DMAEMA单体含量和施加电压大小对水凝胶的电敏感性能有着显著影响.用一级动力学方程能够较好地描述水凝胶在接触电压刺激下的消溶胀过程.在非接触电压刺激下,单体摩尔比,n(AMPS):n(DMAEMA)=9:1的水凝胶向负极弯曲;单体摩尔比n(AMPS):n(DMAEMA)=5:5的水凝胶向正极弯曲;单体摩尔比n(AMPS):n(DMAEMA)=7:3的水凝胶随着非接触电压的增大,出现先向负极弯曲,后向正极弯曲的现象.

  10. Obtenção do 2-etóxi-2-metilpropano grau analítico a partir do produto comercial Production of analytical grade 2-ethoxy-2-methylpropane from a commercial product

    Directory of Open Access Journals (Sweden)

    Vanessa Venturi

    2010-01-01

    Full Text Available Ethyl tert-butyl ether (ETBE is produced by commercial processes to a purity of up to 96%. In recent years, several companies have started to produce ETBE, increasing the demand for standards with higher grades of purity in the area of production control and final product certification. The present work involved the development of a purification protocol for obtaining high purity ETBE from the commercial product used in the formulation of automotive gasolines, using a spinning band distillation column. The ETBE thus produced showed a purity of over 99.5%, its main contaminant being its isomer, ethyl-sec-butyl ether (ESBE.

  11. Synthesis of (Z)-1-bromo-2-methy1-1-butene%(Z)-1-溴-2-甲基-1-丁烯的合成

    Institute of Scientific and Technical Information of China (English)

    吴磊; 叶和珏; 肖定军

    2004-01-01

    以丁酮为原料,与由亚磷酸三乙酯和氯乙酸乙酯反应得到的二乙氧基磷酰基乙酸乙酯进行Wittig-Horner反应后,再经碱性水解、溴加成反应和脱溴脱羧反应制得(z)-1-溴-2-甲基-1-丁烯,总收率53.2%(以丁酮计).

  12. 吸附法脱除异戊烷中的3-甲基丁烯%Purification of Isopentane Containing 3-Methyl-1-Butene Through Adsorption

    Institute of Scientific and Technical Information of China (English)

    王丹丹; 徐军; 孟长功

    2010-01-01

    采用水溶液离子交换法制备了AgY和AgMOR分子筛吸附剂,在固定床中考察了分子筛吸附剂种类及吸附温度、床层高度、原料气流量等条件对脱除异戊烷中的3-甲基丁烯效果的影响.实验结果表明,AgY和AgMOR分子筛保持原有的骨架结构;AgY分子筛可作为脱除异戊烷中3-甲基丁烯的吸附剂;在20 ℃、0.1 MPa、原料气流量为40 mL/min时,经过两次离子交换的AgY(2)分子筛吸附剂的饱和吸附量为115 mg/g; 在固定床中,不可利用床层高度(LUB)与原料气流量有关,与床层高度无关,但只有当床层高度超过LUB时,才有吸附效果;AgY分子筛吸附剂可脱附再生18次.

  13. 纯载体和担载KVO3催化剂裂解正丁烷制低碳烯烃的研究%Catalytic Performance of Bare Supporters and Supported KVO3 Catalysts for Cracking n-Butane to Produce Light Olefins

    Institute of Scientific and Technical Information of China (English)

    陆江银; 赵震; 徐春明; 张璞

    2005-01-01

    Supported KVO3 catalysts were prepared by impregnating different kinds of supporters (α-Al2O3, γ-A12O3 and SiO2 powders) with a KVO3 solution. The activity of the bare supporters and supported catalysts were evaluated in a continuous micro-reactivity test unit, with n-butane as a raw material. The results show that KVO3 has no catalytic activity, but it can increase the selectivity to light olefins. The supporter of α-Al2O3 has good catalytic performance for nbutane cracking when the reaction temperature is below 700℃.

  14. Synthesis, structure and properties of a new three-dimensional interpenetrated metal-organic framework with 3,3'-azodibenzoic acid (H2azdc) and 1,4-bis(1H-imidazol-1-yl)butane (bimb): {[Cd(azdc)(bimb)2]·H2O}n.

    Science.gov (United States)

    Zhong, Ya-Qiang; Chen, Si-Chun; Zhang, Lei; Jing, Chu-Yue; Zhang, Kou-Lin

    2015-06-01

    A new three-dimensional interpenetrated Cd(II)-organic framework based on 3,3'-azodibenzoic acid [3,3'-(diazenediyl)dibenzoic acid, H2azdc] and the auxiliary flexible ligand 1,4-bis(1H-imidazol-1-yl)butane (bimb), namely poly[[bis[μ2-1,4-bis(1H-imidazol-1-yl)butane-κ(2)N(3):N(3')][μ2-3,3'-(diazenediyl)dibenzoato-κ(2)O:O']cadmium(II)] monohydrate], {[Cd(C14H8N2O4)(C10H14N2)2]·H2O}n, (1), was obtained by a typical solution reaction in mixed solvents (water and N,N'-dimethylformamide). Each Cd(II) centre is six-coordinated by two O atoms of bis-monodentate bridging carboxylate groups from two azdc(2-) ligands and by four N atoms from four bimb ligands, forming an octahedral coordination environment. The Cd(II) ions are connected by the bimb ligands, resulting in two-dimensional (4,4) layers, which are further pillared by the azdc(2-) ligands, affording a threefold interpenetrated three-dimensional α-Po topological framework with the Schläfli symbol 4(12)6(3). The thermal stability and solid-state fluorescence properties of (1) have been investigated.

  15. C-H and C-C activation of n -butane with zirconium hydrides supported on SBA15 containing N-donor ligands: [(≡SiNH-)(≡SiX-)ZrH2], [(≡SiNH-)(≡SiX-)2ZrH], and[(≡SiN=)(≡SiX-)ZrH] (X = -NH-, -O-). A DFT study

    KAUST Repository

    Pasha, Farhan Ahmad

    2014-07-01

    Density functional theory (DFT) was used to elucidate the mechanism of n-butane hydrogenolysis (into propane, ethane, and methane) on well-defined zirconium hydrides supported on SBA15 coordinated to the surface via N-donor surface pincer ligands: [(≡SiNH-)(≡SiO-)ZrH2] (A), [(≡SiNH-)2ZrH2] (B), [(≡SiNH-)(≡SiO-) 2ZrH] (C), [(≡SiNH-)2(≡SiO-)ZrH] (D), [(≡SiN=)(≡Si-O-)ZrH] (E), and [(≡SiN=)(≡SiNH-)ZrH] (F). The roles of these hydrides have been investigated in C-H/C-C bond activation and cleavage. The dihydride A linked via a chelating [N,O] surface ligand was found to be more active than B, linked to the chelating [N,N] surface ligand. Moreover, the dihydride zirconium complexes are also more active than their corresponding monohydrides C-F. The C-C cleavage step occurs preferentially via β-alkyl transfer, which is the rate-limiting step in the alkane hydrogenolysis. The energetics of the comparative pathways over the potential energy surface diagram (PES) reveals the hydrogenolysis of n-butane into propane and ethane. © 2014 American Chemical Society.

  16. (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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  17. Crystal structure of poly[[μ-1,1′-(butane-1,4-diylbis(1H-benzimidazole-κ2N3:N3′]{μ-4,4′-[1,4-phenylenebis(oxy]dibenzoato-κ4O,O′:O′′,O′′′}cobalt(II

    Directory of Open Access Journals (Sweden)

    Chen Xie

    2015-06-01

    Full Text Available In the title compound, [Co(C20H12O6(C18H18N4]n, the CoII atom, located on a twofold rotation axis, is hexacoordinated to four O from two bis-bidentate 4,4′-[phenylenebis(oxy]dibenzoate (L ligands and two N atoms from two 1,1′-(butane-1,4-diylbis(1H-benzimidazole (bbbm ligands, forming a distorted octahedral cis-N2O4 coordination environment. Polymeric zigzag chains along [102] are built up by the bridging L ligands. These chains are additionally connected by the bbbm ligands to produce a two-dimensional coordination polymer parallel too (010.

  18. Response surface optimization and identification of isothiocyanates produced from broccoli sprouts.

    Science.gov (United States)

    Guo, Qianghui; Guo, Liping; Wang, Zhiying; Zhuang, Yan; Gu, Zhenxin

    2013-12-01

    Isothiocyanates (ITCs) are proved as one of natural anticarcinogenic compounds, which are produced from the decomposition of glucosinolates by myrosinase. The present study optimized the enzymolysis conditions (pH, addition of EDTA and ascorbic acid) for ITCs production from glucosinolates in broccoli sprouts using response surface methodology. ITCs production was clearly enhanced by a suitable pH, addition content of EDTA and ascorbic acid. The optimal enzymolysis conditions were determined to be adding EDTA 0.02 mmol and 0.16 mg ascorbic acid to 4 ml of the homogenized phosphate-citrate buffer solution (pH 4.00). ITCs profiles were identified and seven kinds of individual ITCs were detected, among which sulforaphane accounted the most. Four kinds of individual ITCs including isobutyl isothiocyanate, 4-isothiocyanato-1-butene, 1-isothiocyanato-3-methyl-butane and 1-isothiocyanato-butane are firstly reported in broccoli sprouts.

  19. Identification and Quantitation of Volatile Organic Compounds in Poly(methyl methacrylate) Kitchen Utensils by Headspace Gas Chromatography/Mass Spectrometry.

    Science.gov (United States)

    Ohno, Hiroyuki; Mutsuga, Motoh; Kawamura, Yoko

    2014-01-01

    A headspace GC/MS method was developed for identification and quantitation of residual volatile organic compounds in poly(methyl methacrylate) (PMMA) kitchen utensils. A sample was cut into small pieces, then N,N-dimethylacetamide was added in a headspace vial and sealed. After storing for more than 1 day at room temperature, the vial was incubated for 1 h at 90°C, and the headspace gas was analyzed by GC/MS. In 24 PMMA kitchen utensils, 16 volatile organic compounds including methyl methacrylate, methyl acrylate, toluene, 2-methyl-1-butene, 2-methyl-2-butene, 2-methylpropanal, methyl propionate, methyl isobutyrate, trans-3-heptene, heptane, cis-3-heptene, trans-2-heptene, cis-2-heptene, 2,4,4-trimethyl-1-pentene, 2,4,4-trimethyl-2-pentene, and 1-octene were identified and quantitated. These 15 volatile compounds except methyl methacrylate were found for the first time in PMMA kitchen utensils. Recovery rates from spiked samples were 97.4-104.0% with CV values of 2.8-9.6%. Samples contained 190-7900 μg/g of methyl methacrylate, 26-810 μg/g of methyl acrylate, and 2-1300 μg/g of toluene; other compounds were at levels less than 100 μg/g. Methyl methacrylate was the main monomer of PMMA and methyl acrylate was a comonomer; toluene should be used as a solvent.

  20. Mechanism of Graft Polymerization of Methyl Methacrylate-Acrylonitrile onto Poly (ethene-co-1-butene)%PEB/MMA-AN悬浮接枝共聚反应机理

    Institute of Scientific and Technical Information of China (English)

    熊凯; 朱勇平; 王霞; 王炼石; 蔡彤曼; 张安强; 曾祥斌

    2012-01-01

    研究了乙烯-1-丁烯共聚物(PEB)弹性体与甲基丙烯酸甲酯(MMA)-丙烯腈(AN)悬浮接枝共聚反应行为及接枝共聚产物对SAN树脂增韧作用随反应时间的变化规律,用凝胶渗透色谱法和傅里叶变换红外光谱法对接枝共聚产物进行了表征,分析了接枝共聚反应机理,推算了接枝链分子量.结果表明,体系首先发生链增长自由基向PEB转移终止形成非接枝共聚物(MANL)和PEB大分子自由基引发单体共聚形成接枝链(g-MAN)的反应,接枝反应结束后体系发生明显的非接枝共聚形成非接枝共聚物(MANH)的反应;MANL的分子量低于g-MAN的分子量,而g-MAN的分子量明显低于MANH的分子量;在接枝共聚过程中发生已接枝和未接枝PEB断链并随机再接生成多嵌段共聚物的副反应;在反应初期,接枝链的AN单元含量接近于非接枝共聚物的AN单元含量,在反应中后期前者远低于后者.%The effects of reaction time on reaction behavior of suspension grafting copolymerization of methyl methacrylate(MMA)-acrylonitrile( AN) onto poly(ethene-co-l-butene) (PEB) and toughening effect of PEB-g-MAN on SAN resin were investigated. The grafting polymerization product was characterized by GPC and FTTR analysis, the grafting copolymerization mechanism was investigated and the formula of calculating molecular weight of grafted chain was established. The results show that firstly the polymerization is mainly forming non-grafted copolymer with low molecular weight( MANL) of the transferring terminating polymerization of chain propagating free radicals and forming the grafted chains(g-MAN) of the transferring graft polymerization, and then the polymerization is mainly forming non-grafted copolymer with high molecular weight( MANH) of bimolecular terminating polymerization of chain propagating free radicals; molecular weight of MANL is less than that of g-M AN and molecular weight of g-M AN is less than that of MANH; there exist chain scission and random regrafting of the backbone of PEB-g-MAN and ungrafted PEB which result in the production of multi-block polymer of PEB and PEB-g-MAN during the grafting copolymerization; mass fraction of AN unit in grafted chain is close to mass fraction of AN unit in non-grafted copolymer in the initial stage and the former is much less than the later in the later stage.

  1. 催化裂化轻汽油中3-甲基-1-丁烯加氢异构化反应%Hydroisomerization reaction of 3-methyl-1-butene in catalytic cracking light gasoline

    Institute of Scientific and Technical Information of China (English)

    张斌; 王洪山; 李吉春; 孙世林; 张松显; 任海鸥; 薛英芝

    2010-01-01

    以催化裂化全馏分汽油中分离出低于70℃的轻汽油为原料,采用镍基LNEH-1催化剂,研究了加氢和异构化反应规律.结果表明,在反应温度为60℃,氧气/原料油(体积比)为30,反应压力为1.5 MPa,进料空速为2 h-1的条件下,轻汽油中二烯烃质量分数从0.34%降低到0,加氢转化率达到100%;3-甲基-1-丁烯异构转化率为86.25%;叔碳烯烃质量分数由19.43%增到21.00%.

  2. The study of portable direct-flame solid oxide fuel cell (DF-SOFC) stack with butane fuel%以丁烷为燃料的便携直接火焰固体氧化物燃料电池堆的研究

    Institute of Scientific and Technical Information of China (English)

    王宇光; 孙良良; 罗凌虹; 吴也凡; 刘丽丽; 石纪军

    2014-01-01

    In this study, a portable direct-flame solid oxide fuel cell ( DF-SOFC ) stack has been demonstrta ed using the conventional butane gas as fuel.The stack is oc nstructed yb bundles of the 3 sni gle cells in a series with conventional Ni/YSZ anode.The fuel cell structure and performance are characterized by scanning electron microscopy ( SEM) and elecrt ochemical workstation, respectively.The er sults show that the stack presents an open cicr uit voltage ( OCV) of about 2.1 V and ano utput power of 0.24 W, which powers an USB fan in 4 h.The cell voltage is quite stable for 4 h, moreover, no cra bno ed positino is found in the anode lya er.This indicates that the DF-SOFC stack can be used for portable applications.%以丁烷液化气为燃料,以固体氧化物燃料电池为电源,可以进行全天候的充电,是未来理想的充电模式。研究了以丁烷为燃料的可以便携的直接火焰燃料电池堆。该电池结构和电性能分别用扫描电子显微镜SEM和电化学工作站进行了表征。该电池堆由3片以Ni/YSZ为阳极支撑形的单电池构成。该电池堆操作开路电压为21.V,最大输出功率为0.24 W,可带动小风扇连续运行超过4h。运行4h后电池阳极没有积炭发生,说明该电池可以连续运行多个小时,可用作便携充电电源。

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

    Science.gov (United States)

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

    2004-01-12

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

  4. Volatile compounds of Domiati cheese made from buffaloe's milk with different fat content.

    Directory of Open Access Journals (Sweden)

    El-Mageed, Magda A. Abd

    1997-12-01

    Full Text Available Buffaloe's milk was manufactured to Domiati cheese with different fat content in the cheese milk (1%, 3.5% and 7%. Results obtained during the ripening period revealed that the low fat cheese (Karish is not able to long period storage, while half cream cheese had a good quality and flavour along the ripening period. The full cream cheese did not exceed the first month of ripening, then it deteriorated. The main components found were acrolein (propenal, heptanal, acetone, butan-2 one, ethanol, butan-2 ol, 2-methylpropan- 1-ol, 3-methyl butan-1-ol, ethyl propionate, propyl propionate, pentane and octane. Methyl mercaptan, methyl thiopropionate, and dimethyl trisulfide together with propyl butyrate, were existed in the samples which are characterized as bad cheese samples. Most of the previous compounds were developed after 1 month of ripening period.

    La leche de búfalo fue procesada para obtener queso Domiati con diferente contenido graso en la cuajada (1%, 3.5% y 7%. Los resultados obtenidos durante el período de maduración revelaron que el queso con bajo contenido en grasa (Karish no permite un largo período de almacenamiento, mientras que el queso con un contenido medio en grasa tuvo una buena calidad y flavor durante el período de maduración. El queso con alto contenido graso no duró más que el primer mes de maduración, deteriorándose posteriormente. Los principales componentes encontrados fueron acroleína (propenal, heptanal, acetona, butan-2-ona, etanol, butan-2-ol, 2- metil-propan-1-ol, 3 metil butan-1-ol, propionato de etilo, propionate de propilo, pentano y octano. Metil mercaptol, tiopropionato de metilo y trisulfuro de dimetilo Junto con butirato de propilo se encontraron en muestras que fueron caracterizadas como muestras de quesos malos. La mayoría de los compuestos anteriores se produjeron después de un mes de período de maduración.

  5. 聚丙烯酰胺-co-2-丙烯酰胺基-2-甲基丙磺酸凝胶催化合成乙酸正丁酯%Application of Poly(acrylamide-co-2-acrylamido-2-methylpropane sulfonicacid) Hydrogel in Synthesis of N-butyacetate

    Institute of Scientific and Technical Information of China (English)

    孟艳华; 潘春跃; 谭海军

    2009-01-01

    采用聚丙烯酰胺-co-2-丙烯酰胺基-2-甲基丙磺酸(AAm-co-AMPS)凝胶代替传统酸性催化剂催化酯化反应,期望能够在反应过程中分离副产物-水,提高酯化率.考察凝胶在纯水中的溶胀性能,并以乙酸正丁酯合成为模板来考察凝胶的催化性能和在反应过程中分离水的作用.研究表明:凝胶相对于氨基磺酸具有较好的催化活性;反应的酯化率主要与凝胶的加入量有关,在100℃,催化剂加入量为1.8 g,反应3.6 h,酯化率达到78.2%.该凝胶催化剂通过简单的处理重复利用4次,催化活性几乎不变.

  6. A dinuclear end-on azide-bridged copper(II) compound with weak antiferromagnetic interaction - Synthesis, characterization, magnetism and X-ray structure of bis[(μ-azido-κN1)-(azido-κN1)(1,3-bis(benzimidazol-2-yl)-2-methylpropane)copper(II)

    Science.gov (United States)

    van Albada, Gerard A.; Mutikainen, Ilpo; Roubeau, Olivier; Reedijk, Jan

    2013-03-01

    The centrosymmetric dinuclear compound of formula [Cu(μ-N3-κN1)(N3-κN1)(bbmp)]2 is reported. Synthesis, characterization, physical properties are determined in detail, together with its 3D structure. The dinuclear end-on azide-bridged copper(II) compound displays a weak antiferromagnetic interaction, despite the fact that the magnetic orbitals overlap. The Cu-Cu contact distance is 3.1867(8) Å, while the Cu-Nazide-Cu angle is 103.41(14)°. The IR spectra of the azido ligands are as expected for such coordinated azides.

  7. Liquid butane fuel injection for internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, R.L.; Brunges, V.E.; Bisel, H.I.

    1991-07-30

    This patent describes an internal combustion engine powered by a fuel of liquefied petroleum gas. It comprises at least one cylinder head which includes an intake port region communicating with a combustion chamber through an intake valve; a fuel injection rail including at least one fuel injector, all injectors operably connected to all intake port regions with one intake region connected to one injector whereby fuel may be injected into the intake regions; a conduit connecting the container to the injection rail; means for pumping the fuel from the injection rail and maintaining the fuel at a temperature below a temperature value and pressure above a pressure value required to sustain the fuel in a liquid state whereby the fuel in the liquid state is transferred from the storage container to the rail.

  8. Genotoxicity of alkene epoxides in human peripheral blood mononuclear cells and HL60 leukaemia cells evaluated with the comet assay.

    Science.gov (United States)

    Fabiani, Roberto; Rosignoli, Patrizia; De Bartolomeo, Angelo; Fuccelli, Raffaela; Morozzi, Guido

    2012-08-30

    Volatile organic compounds (VOCs) exert their carcinogenic activity through the production of epoxide metabolites. Because of their high reactivity some epoxides are also produced in the chemical industry for the synthesis of other compounds. Therefore, human exposure to VOCs epoxides does occur and may be an important human health concern. In this study, the in vitro genotoxic potential of epoxides originating from 1,3-butadiene (3,4-epoxy-1-butene: EB; 1,2:3,4-diepoxybutane: DEB), isoprene (3,4-epoxy-2-methyl-1-butene: IO), styrene (styrene-7,8-oxide: SO), propylene (propylene oxide: PO) and 1-butene (1,2-epoxy-butane: BO) in human peripheral blood mononuclear cells (PBMCs) and promyelocytic leukaemia cells (HL60) was measured with the comet assay (single-cell gel electrophoresis, SCGE). The effect of inclusion of foetal calf serum (FCS, 5%) in the cell-culture medium and different durations of exposure (2h, 24h) were also investigated. All epoxides tested produced DNA damage in a concentration range that did not reduce cell viability. HL60 cells were more resistant than PBMCs to the DNA damage induced by the different epoxides. With the exception of IO, the treatment for 24h resulted in an increase of DNA damage. FCS slightly protected PBMCs from the genotoxic effects induced by IO and BO, whilst no such effect was noted for the other compounds. Overall, the dose-dependent effects that were seen allowed us to define a genotoxicity scale for the different epoxides as follows: SO>EB>DEB>IO>PO>BO, which is in partial agreement with the International Agency for Research on Cancer (IARC) classification of the carcinogenic hazards.

  9. Sum Frequency Generation Vibrational Spectroscopy of 1,3-Butadiene Hydrogenation on 4 nm Pt@SiO 2 , Pd@SiO 2 , and Rh@SiO 2 Core–Shell Catalysts

    KAUST Repository

    Krier, James M.

    2015-01-14

    © 2014 American Chemical Society. 1,3-Butadiene (1,3-BD) hydrogenation was performed on 4 nm Pt, Pd, and Rh nanoparticles (NPs) encapsulated in SiO2 shells at 20, 60, and 100 °C. The core-shells were grown around polyvinylpyrrolidone (PVP) coated NPs (Stöber encapsulation) prepared by colloidal synthesis. Sum frequency generation (SFG) vibrational spectroscopy was performed to correlate surface intermediates observed in situ with reaction selectivity. It is shown that calcination is effective in removing PVP, and the SFG signal can be generated from the metal surface. Using SFG, it is possible to compare the surface vibrational spectrum of Pt@SiO2 (1,3-BD is hydrogenated through multiple paths and produces butane, 1-butene, and cis/trans-2-butene) to Pd@SiO2 (1,3-BD favors one path and produces 1-butene and cis/trans-2-butene). In contrast to Pt@SiO2 and Pd@SiO2, SFG and kinetic experiments of Rh@SiO2 show a permanent accumulation of organic material.

  10. Pharmacophore Model Generation Based on Pyrrolidine-and Butane-derived CCR5 Antagonists%基于吡咯烷与正丁烷类衍生物CCR5拮抗剂的药效团模型构建

    Institute of Scientific and Technical Information of China (English)

    孔韧; 徐雪梅; 陈慰祖; 王存新; 胡利明

    2007-01-01

    A three-dimensional pharmacophore model was developed for a considerable number of pyrrolidinebased and butane-based chemokine (C-C motif) receptor 5(CCR5) antagonists, which can block the entry of human immunodeficiency virus type 1 (HIV-1) by inhibiting the interaction of HIV-1 envelope protein and CCR5. The pharmacophore model was generated using a training set consisting of 25 carefully selected antagonists with the diverse molecular architecture and bioactivity, as required by the Catalyst/HypoGen program. The activity of the training set molecules expressed in IC50 (half-inhibitory concentration) covered from 0.06 to 10000 nmol· L-1.The most predictive pharmacophore model (Hypo 1), consisting of two positive ionizable points and three hydrophobic groups, had a correlation of 0.924 and a root mean square of 1.068, and a cost difference of 63.67 bits between the null cost and the total cost. The model was applied in predicting the activity of 74 compounds as a test set. The results indicated that the model was able to provide clear guidelines and accurate activity prediction for novel antagonist design.%吡咯烷与正丁烷类CCR5(化学趋化因子受体5)拮抗剂可通过抑制人类免疫缺陷病毒(HIV-1)包膜蛋白与CCR5的相互作用而阻断病毒进入细胞.本文使用已知拮抗剂结构和活性信息构建了一个三维药效团模型.按照Catalyst/HypoGen模块的要求,选择了25个结构和活性均具备差异性的分子作为药效团产生的训练集.其中训练集分子以IC50值表示的生物活性值跨度为0.06到10000 nmol·L-1.最好的药效团模型(Hypo 1)由两个正离子化特征以及三个疏水特征组成,训练集预测相关系数为0.924,均方根偏差为1.068.模型用于预测由74个分子组成的测试集化合物活性,结果表明模型可以提供较好的活性预测结果并用于新的拮抗剂的设计.

  11. Inhibitory Potency of 4-Carbon Alkanes and Alkenes toward CYP2E1 Activity

    Science.gov (United States)

    Hartman, Jessica H.; Miller, Grover P.; Boysen, Gunnar

    2016-01-01

    CYP2E1 has been implicated in the bioactivation of many small molecules into reactive metabolites which form adducts with proteins and DNA, and thus a better understanding of the molecular determinants of its selectivity are critical for accurate toxicological predictions. In this study, we determined the potency of inhibition of human CYP2E1 for various 4-carbon alkanes, alkenes and alcohols. In addition, known CYP2E1 substrates and inhibitors including 4-methylpyrazole, aniline, and dimethylnitrosamine were included to determine their relative potencies. Of the 1,3-butadiene-derived metabolites studied, 3,4-epoxy-1-butene was the strongest inhibitor with an IC50 of 110 μM compared to 1700 μM and 6600 μM for 1,2-butenediol and 1,2:3,4-diepoxybutane, respectively. Compared to known inhibitors, inhibitory potency of 3,4-epoxy-1-butene is between 4-methylpyrazole (IC50 = 1.8 μM) and dimethylnitrosamine (IC50 = 230 μM). All three butadiene metabolites inhibit CYP2E1 activity through a simple competitive mechanism. Among the 4-carbon compounds studied, the presence and location of polar groups seems to influence inhibitory potency. To further examine this notion, the investigation was extended to include structurally and chemically similar analogs, including propylene oxide and various butane alcohols. Those results demonstrated preferential recognition of CYP2E1 toward the type and location of polar and hydrophobic structural elements. Taken together, CYP2E1 metabolism may be modified in vivo by exposure to 4-carbon compounds, such as drugs, and nutritional constituents, a finding that highlights the complexity of exposure to mixtures. PMID:24561005

  12. Structure Sensitivity in Pt Nanoparticle Catalysts for Hydrogenation of 1,3-Butadiene: In Situ Study of Reaction Intermediates Using SFG Vibrational Spectroscopy

    KAUST Repository

    Michalak, William D.

    2013-01-31

    The product selectivity during 1,3-butadiene hydrogenation on monodisperse, colloidally synthesized, Pt nanoparticles was studied under reaction conditions with kinetic measurements and in situ sum frequency generation (SFG) vibrational spectroscopy. SFG was performed with the capping ligands intact in order to maintain nanoparticle size by reduced sintering. Four products are formed at 75 C: 1-butene, cis-2-butene, trans-2-butene, and n-butane. Ensembles of Pt nanoparticles with average diameters of 0.9 and 1.8 nm exhibit a ∼30% and ∼20% increase in the full hydrogenation products, respectively, as compared to Pt nanoparticles with average diameters of 4.6 and 6.7 nm. Methyl and methylene vibrational stretches of reaction intermediates observed under working conditions using SFG were used to correlate the stable reaction intermediates with the product distribution. Kinetic and SFG results correlate with previous DFT predictions for two parallel reaction pathways of 1,3-butadiene hydrogenation. Hydrogenation of 1,3-butadiene can initiate with H-addition at internal or terminal carbons leading to the formation of 1-buten-4-yl radical (metallocycle) and 2-buten-1-yl radical intermediates, respectively. Small (0.9 and 1.8 nm) nanoparticles exhibited vibrational resonances originating from both intermediates, while the large (4.6 and 6.7 nm) particles exhibited vibrational resonances originating predominately from the 2-buten-1-yl radical. This suggests each reaction pathway competes for partial and full hydrogenation and the nanoparticle size affects the kinetic preference for the two pathways. The reaction pathway through the metallocycle intermediate on the small nanoparticles is likely due to the presence of low-coordinated sites. © 2012 American Chemical Society.

  13. 由MCl2(M=Zn,Cd)与咪唑-4,5-二羧酸和1,4-双(咪唑-1-基)丁烷构筑的两个二重穿插二维配位聚合物的合成、结构和性质%Synthesis, Structure and Properties of Two Two-Fold Interpenetrating 2D Coordination Polymers Constructed from MCl2 (M=Zn, Cd) with Imidazole-4,5-dicarboxylic Acid and 1,4-Bis(imidazol-1-yl)butane

    Institute of Scientific and Technical Information of China (English)

    刘宏文; 卢文贯

    2011-01-01

    以2∶1∶4物质的量比的咪唑4,5-二羧酸(H3IDC),1,4-双(咪唑-1-基)丁烷(bib)和ZnCl2或CdCl2为反应物,在水热条件下分别得到了1个二重穿插的二维锌(Ⅱ)配位聚合物{[Zn2(IDC)(bib)C1]· H2O}n (1)和1个二重穿插的二维镉(Ⅱ)配位聚合物[Cd2(HIDC)(bib)1.5Cl2]n(2).用元素分析、红外光谱以及单晶X-射线衍射结构分析对它们的组成和结构进行了表征,并对它们的热稳定性和荧光性质进行了初步的研究.%Two-fold interpenetrating 2D Zinc (II) coordination polymer {[Zn2(IDC)(bib)Cl]-H2O}n (1) and 2D cadmium(II) coordination polymer [Cd2(HIDC)(bib)I.5Cl2]n (2) (H3IDC=imidazole-4,5-dicarboxylic acid, bib=l,4-bis (imidazol-l-yl)butane) were obtained by the hydrothermal reactions of HJDC, bib and ZnCl2 or CdCl2 with 2:1:4 mole ratio, respectively. Their composition and structures were determined by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction analysis. Their thermal stabilities and luminescent properties were investigated as well. CCDC: 772780, 1; 772781, 2.

  14. French Committee of Butane and Propane. 2005 activity report; Comite francais du butane et du propane. Rapport d'activite 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This document presents the 2005 highlights of the French LPG fuels industry: 1 - presentation of the CFBP association and promotion of the LPG industry; 2 - information about the LPG fuels advantages; 3 - LPG market; 4 - CFBP's commitments for end-users, professionals and public authorities: energy efficiency improvement, environment protection, energy supply of French rural towns, safety improvements. (J.S.)

  15. French Committee of Butane and Propane. 2006 activity report; Comite francais du butane et du propane. Rapport d'activite 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This document presents the 2006 highlights of the French LPG fuels industry: 1 - presentation of the CFBP association and promotion of the LPG industry; 2 - share of LPG fuels in the French energy mix; 3 - improvement of energy efficiency in the residential sector; 4 - advantages of LPG fuels; 5 - safety aspects. (J.S.)

  16. Bis(2-hydroxy-benzaldehyde oxime) O,O'-butane-1,4-diyldicarbonyl ether.

    Science.gov (United States)

    Etemadi, Bijan; Kia, Reza; Sharghi, Hashem; Hosseini Sarvari, Mona

    2009-05-20

    The mol-ecule of the title compound, C(20)H(20)N(2)O(6), lies across a crystallographic inversion centre, the asymmetric unit comprising one half-mol-ecule. An intra-molecular O-H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. Pairs of inter-molecular C-H⋯O hydrogen bonds link neighbouring mol-ecules into a layer with R(2) (2)(38) ring motif. The crystal structure is further stabilized by the inter-molecular C-H⋯π inter-actions.

  17. Bis(2-hydroxy­benzaldehyde oxime) O,O′-butane-1,4-diyldicarbonyl ether

    Science.gov (United States)

    Etemadi, Bijan; Kia, Reza; Sharghi, Hashem; Hosseini Sarvari, Mona

    2009-01-01

    The mol­ecule of the title compound, C20H20N2O6, lies across a crystallographic inversion centre, the asymmetric unit comprising one half-mol­ecule. An intra­molecular O—H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. Pairs of inter­molecular C—H⋯O hydrogen bonds link neighbouring mol­ecules into a layer with R 2 2(38) ring motif. The crystal structure is further stabilized by the inter­molecular C—H⋯π inter­actions. PMID:21583166

  18. Bis(2-hydroxybenzaldehyde oxime O,O′-butane-1,4-diyldicarbonyl ether

    Directory of Open Access Journals (Sweden)

    Bijan Etemadi

    2009-06-01

    Full Text Available The molecule of the title compound, C20H20N2O6, lies across a crystallographic inversion centre, the asymmetric unit comprising one half-molecule. An intramolecular O—H...N hydrogen bond generates a six-membered ring, producing an S(6 ring motif. Pairs of intermolecular C—H...O hydrogen bonds link neighbouring molecules into a layer with R22(38 ring motif. The crystal structure is further stabilized by the intermolecular C—H...π interactions.

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

    Science.gov (United States)

    1978-09-01

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

  20. Cascade anionotropy of the halogen in 3-acetoxy-4-bromo(chloro)-2-methyl-1-butanes

    Energy Technology Data Exchange (ETDEWEB)

    Gevorkyan, A.A.; Kazaryan, P.I.; Avakyan, S.V.

    1987-10-20

    The authors determined that the title compounds, which contain the halogen at the homoallylic position, undergo anionotropy without skeletal isomerization when heated or under the influence of acidic catalysts. Temperature ranges for the bromine and chlorine variants of the compounds were established. Gas-liquid chromatography was used along with IR and NMR spectroscopy to identify the compounds. Chemical shifts and spin-spin coupling constants were analyzed.

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

    Science.gov (United States)

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

    1991-08-01

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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  4. C2-C10 hydrocarbon emissions from a boreal wetland and forest floor

    Directory of Open Access Journals (Sweden)

    H. Hellén

    2006-01-01

    Full Text Available Emissions of various C2-C10 hydrocarbons (VOCs and halogenated hydrocarbons (VHOCs from a boreal wetland and a Scots pine forest floor in south-western Finland were measured by the static chamber technique. Isoprene was the main non-methane hydrocarbon emitted by the wetland, but small emissions of ethene, propane, propene, 1-butene, 2-methylpropene, butane, pentane and hexane were also detected. The isoprene emission from the wetland was observed to follow the commonly-used isoprene emission algorithm. The mean emission potential of isoprene was 224 µg m-2 h-1 for the whole season. This is lower than the emission potentials published earlier; that is probably at least partly due to the cold and cloudy weather during the measurements. No emissions were detected of monoterpenes or halogenated hydrocarbons from the wetland. The highest hydrocarbon emissions from the Scots pine forest floor were measured in spring and autumn. However, only a few measurements were conducted during summer. The main compounds emitted were monoterpenes. Isoprene emissions were negligible. The total monoterpene emission rates varied from zero to 373 µg m-2 h-1. The results indicated that decaying plant litter may be the source for these emissions. Small emissions of chloroform (100-800 ng m-2 h-1, ethene, propane, propene, 2-methylpropene, cis-2-butene, pentane, hexane and heptane were detected. Comparison with Scots pine emissions showed that the forest floor may be an important monoterpene source, especially in spring.

  5. A New Process for Maleic Anhydride Synthesis from a Renewable Building Block: The Gas-Phase Oxidehydration of Bio-1-butanol.

    Science.gov (United States)

    Pavarelli, Giulia; Velasquez Ochoa, Juliana; Caldarelli, Aurora; Puzzo, Francesco; Cavani, Fabrizio; Dubois, Jean-Luc

    2015-07-01

    We investigated the synthesis of maleic anhydride by oxidehydration of a bio-alcohol, 1-butanol, as a possible alternative to the classical process of n-butane oxidation. A vanadyl pyrophosphate catalyst was used to explore the one-pot reaction, which involved two sequential steps: 1) 1-butanol dehydration to 1-butene, catalysed by acid sites, and 2) the oxidation of butenes to maleic anhydride, catalysed by redox sites. A non-negligible amount of phthalic anhydride was also formed. The effect of different experimental parameters was investigated with chemically sourced 1-butanol, and the results were then confirmed by using genuinely bio-sourced 1-butanol. In the case of bio-1-butanol, however, the purity of the product remarkably affected the yield of maleic anhydride. It was found that the reaction mechanism includes the oxidation of butenes to crotonaldehyde and the oxidation of the latter to either furan or maleic acid, both of which are transformed to produce maleic anhydride.

  6. Surface study of mixtures containing cyclic ethers and isomeric chlorobutanes

    Energy Technology Data Exchange (ETDEWEB)

    Royo, F.M. [Departamento de Quimica Organica-Quimica Fisica, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Villares, A. [Departamento de Quimica Organica-Quimica Fisica, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Martin, S. [Departamento de Quimica Organica-Quimica Fisica, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Giner, B. [Departamento de Quimica Organica-Quimica Fisica, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Lafuente, C. [Departamento de Quimica Organica-Quimica Fisica, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain)]. E-mail: celadi@unizar.es

    2007-05-15

    Experimental surface tensions and the corresponding surface tensions deviations for the mixtures containing 1,3-dioxolane or 1,4-dioxane and 1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane or 2-chloro-2-methylpropane, measured with a drop volume tensiometer, are reported at the temperatures of 298.15 K and 313.15 K. The excess surface concentrations of isomeric chlorobutanes are also evaluated using a monolayer model.

  7. Energy barriers for the addition of H, *CH3, and *C2H5 to *CH2=CHX [X = H, CH3, OH] and for H-atom addition to RCH=O [R = H, CH3, *C2H5, n-C3H7]: implications for the gas-phase chemistry of enols.

    Science.gov (United States)

    Simmie, John M; Curran, Henry J

    2009-07-09

    Although enols have been identified in alcohol and other flames and in interstellar space and have been implicated in the formation of carboxylic acids in the urban troposphere in the past few years, the reactions that give rise to them are virtually unknown. To address this data deficit, particularly with regard to biobutanol combustion, we have carried out a number of ab initio calculations with the multilevel methods CBS-QB3 and CBS-APNO to determine the activation enthalpies for methyl addition to the CH(2) group of CH(2)=CHX where X = H, OH, and CH(3). These average at 26.3 +/- 1.0 kJ mol(-1) and are not influenced by the nature of X; addition to the CHX end is energetically costlier and does show the influence of group X = OH and CH(3). Replacing the attacking methyl radical by ethyl makes very little difference to addition at CH(2) and follows the same trend of a higher barrier for addition to the CH(OH) end. In the case of H-addition it is more problematic to draw general conclusions since the DFT-based methodology, CBS-QB3, struggles to locate transition states for some reactions. However, the increase in barrier heights in reaction at the CHX end in comparison to addition at the methylene end is evident. For hydrogen atom reaction with the carbonyl group in the compounds methanal, ethanal, propanal, and butanal we see that for addition at the O-center the barrier heights of ca. 38 kJ mol(-1) are not influenced by the nature of the alkyl group whereas addition at the C-center is different on going from H --> alkyl but seems to be invariant at 20 kJ mol(-1) once alkylated. Rate constants for H-atom elimination from 1-hydroxyethyl, 1-hydroxypropyl, and 1-hydroxybutyl radicals, valid over the range 800-2000 K, are reported. These demonstrate that enols are more prevalent than previously suspected and that 1-buten-1-ol should be almost as abundant as its isomeric aldehyde 1-butanal during the combustion of 1-butanol and that this will also be the case for

  8. Hydrogen Abstraction from Hydrocarbons by NH2.

    Science.gov (United States)

    Siddique, Kamal; Altarawneh, Mohammednoor; Gore, Jeff; Westmoreland, Phillip R; Dlugogorski, Bogdan Z

    2017-03-23

    This contribution investigates thermokinetic parameters of bimolecular gas-phase reactions involving the amine (NH2) radical and a large number of saturated and unsaturated hydrocarbons. These reactions play an important role in combustion and pyrolysis of nitrogen-rich fuels, most notably biomass. Computations performed at the CBS-QB3 level and based on the conventional transition-state theory yield potential-energy surfaces and reaction rate constants, accounting for tunnelling effects and the presence of hindered rotors. In an analogy to other H abstraction systems, we demonstrate only a small influence of variational effects on the rate constants for selected reaction. The studied reactions cover the abstraction of hydrogen atoms by the NH2 radical from the C-H bonds in C1-C4 species, and four C5 hydrocarbons of 2-methylbutane, 2-methyl-1-butene, 3-methyl-1-butene, 3-methyl-2-butene, and 3-methyl-1-butyne. For the abstraction of H from methane, in the temperature windows 300-500 and 1600-2000 K, the calculated reaction rate constants concur with the available experimental measurements, i.e., kcalculated/kexperimetal = 0.3-2.5 and 1.1-1.4, and the previous theoretical estimates. Abstraction of H atom from ethane attains the ratio of kcalculated/kexperimetal equal to 0.10-1.2 and 1.3-1.5 over the temperature windows of available experimental measurements, i.e., 300-900 K and 1500-2000 K, respectively. For the remaining alkanes (propane and n-butane), the average kexperimental/kcalculated ratio remains 2.6 and 1.3 over the temperature range of experimental data. Also, comparing the calculated standard enthalpy of reaction (ΔrH°298) with the available experimental measurements for alkanes, we found the mean unsigned error of computations as 3.7 kJ mol(-1). This agreement provides an accuracy benchmark of our methodology, affording the estimation of the unreported kinetic parameters for H abstractions from alkenes and alkynes. On the basis of the Evans

  9. 2,2′-{1,1′-[Butane-1,4-diylbis(oxynitrilo]diethylidyne}di-1-naphthol

    Directory of Open Access Journals (Sweden)

    Wen-Kui Dong

    2009-06-01

    Full Text Available The title compound, C28H28N2O4, was synthesized by the reaction of 2-acetyl-1-naphthol with 1,4-bis(aminooxybutane in ethanol. The molecule, which lies about an inversion centre, adopts a linear structure, in which the oxime groups and naphthalene ring systems assume an anti conformation. The intramolecular interplanar distance between parallel naphthalene rings is 1.054 (3 Å. Intramolecular O—H...N hydrogen bonds are formed between the oxime nitrogen and hydroxy groups.

  10. Crystal structure of 2,2-di-chloro-1-(piperidin-1-yl)butane-1,3-dione.

    Science.gov (United States)

    Schwierz, Markus; Görls, Helmar; Imhof, Wolfgang

    2015-01-01

    In the title compound, C9H13Cl2NO2, the piperidine ring shows a chair conformation and the O-C-C-O torsion angle between the carbonyl groups is 183.6 (4)°. In the crystal, mol-ecules are linked into an infinite layer along the ab plane by a bifurcated C-H⋯O hydrogen bond between the carbonyl O atom adjacent to the methyl group and one of the methyl-ene groups next to nitro-gen and an additional hydrogen bond of the C-H⋯Cl type. These layers are connected into a three-dimensional supra-molecular arrangement by O⋯Cl contacts [2.8979 (12) and 3.1300 (12) Å].

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

    Science.gov (United States)

    1978-09-15

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

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

    Science.gov (United States)

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

    2012-01-01

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

  13. 4,4′-[Butane-1,4-diylbis(nitrilo­methyl­idyne)]dibenzonitrile

    Science.gov (United States)

    Fun, Hoong-Kun; Kia, Reza; Kargar, Hadi

    2008-01-01

    The title Schiff base compound, C20H18N4, lies across a crystallographic inversion centre and adopts E configurations with respect to the C=N bonds. The asymmetric unit of the compound is composed of one half-mol­ecule. The imino group is coplanar with the benzene ring. Within the mol­ecule, the planar units are parallel but extend in opposite directions from the methyl­ene bridge. In the crystal structure, neighbouring mol­ecules are linked together by weak inter­molecular C—H⋯N hydrogen bonds involving the cyano N atoms. These form ten-membered rings, generating R 2 2(10) ring motifs, and link the mol­ecules along the c axis. PMID:21201826

  14. Monolayer behaviour of chiral compounds at the air-water interface: 4-hexadecyloxy-butane-1,2-diol

    DEFF Research Database (Denmark)

    Rietz, R.; Rettig, W.; Brezesinski, G.;

    1996-01-01

    . The isotherms depend only slightly on chirality. Above the transition pressure pi(c) condensed domains with a polygonal shape are formed. In all cases the domains start to destabilize from the notch. The branches of the S-enantiomer turn only clockwise, whereas domains of the mixtures show branches which turn...

  15. CCDC 1010347: Experimental Crystal Structure Determination : (butane-1,4-diylbis(di-t-butylphosphine))-(trifluoromethanesulfonato)-palladium trifluoromethanesulfonate

    KAUST Repository

    Roesle, Philipp

    2015-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  16. Design-theoretical study of cascade CO2 sub-critical mechanical compression/butane ejector cooling cycle

    KAUST Repository

    Petrenko, V.O.

    2011-11-01

    In this paper an innovative micro-trigeneration system composed of a cogeneration system and a cascade refrigeration cycle is proposed. The cogeneration system is a combined heat and power system for electricity generation and heat production. The cascade refrigeration cycle is the combination of a CO2 mechanical compression refrigerating machine (MCRM), powered by generated electricity, and an ejector cooling machine (ECM), driven by waste heat and using refrigerant R600. Effect of the cycle operating conditions on ejector and ejector cycle performances is studied. Optimal geometry of the ejector and performance characteristics of ECM are determined at wide range of the operating conditions. The paper also describes a theoretical analysis of the CO2 sub-critical cycle and shows the effect of the MCRM evaporating temperature on the cascade system performance. The obtained data provide necessary information to design a small-scale cascade system with cooling capacity of 10 kW for application in micro-trigeneration systems. © 2010 Elsevier Ltd and IIR. All rights reserved.

  17. A Unique Equation to Estimate Flash Points of Selected Pure Liquids Application to the Correction of Probably Erroneous Flash Point Values

    Science.gov (United States)

    Catoire, Laurent; Naudet, Valérie

    2004-12-01

    several flash points have been reported erroneously, whatever the reason, in one or several reference compilations. In the following lists, the currently accepted flash points for bold compounds err, or probably err, on the hazardous side by at least 10 °C and for the nonbolded compounds, the currently accepted flash points err, or probably err, on the nonhazardous side by at least 10 °C: bicyclohexyl, sec-butylamine, tert-butylamine, 2-cyclohexen-1-one, ethanethiol, 1,3-cyclohexadiene, 1,4-pentadiene, methyl formate, acetonitrile, cinnamaldehyde, 1-pentanol, diethylene glycol, diethyl fumarate, diethyl phthalate, trimethylamine, dimethylamine, 1,6-hexanediol, propylamine, methanethiol, ethylamine, bromoethane, 1-bromopropane, tert-butylbenzene, 1-chloro-2-methylpropane, diacetone alcohol, diethanolamine, 2-ethylbutanal, and formic acid. For some other compounds, no other data than the currently accepted flash points are available. Therefore, it cannot be assessed that these flash point data are erroneous but it can be stated that they are probably erroneous. At least, they need experimental re-examination. They are probably erroneous by at least 15 °C: 1,3-cyclopentadiene, di-tert-butyl sulfide, dimethyl ether, dipropyl ether, 4-heptanone, bis(2-chloroethyl)ether, 1-decanol, 1-phenyl-1-butanone, furan, ethylcyclopentane, 1-heptanethiol, 2,5-hexanediol, 3-hexanone, hexanoic acid methyl ester, 4-methyl-1,3-pentadiene, propanoyl chloride, tetramethylsilane, thiacyclopentane, 1-chloro-2-methyl-1-propene, trans-1,3-pentadiene, 2,3-dimethylheptane, triethylenetetramine, methylal, N-ethylisopropylamine, 3-methyl-2-pentene, and 2,3-dimethyl-1-butene.

  18. Conjugation of isoprene monoepoxides with glutathione, catalyzed by α, μ, π and θ-class glutathione S-transferases of rat and man

    NARCIS (Netherlands)

    Bogaards, J.J.P.; Venekamp, J.C.; Salmon, F.G.C.; Bladeren, P.J. van

    1999-01-01

    In the present study, the enzymatic conjugation of the isoprene monoepoxides 3,4 epoxy-3-methyl-1-butene (EPOX-I) and 3,4-epoxy-2-methyl-1-butene (EPOX-II) with glutathione was investigated, using purified glutathione S-transferases (GSTs) of the α, μ, π and θ-class of rat and man. HPLC analysis of

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    L. Kaser

    2012-10-01

    Full Text Available 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

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

    Directory of Open Access Journals (Sweden)

    L. Kaser

    2013-03-01

    Full Text Available 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

  3. Bis-butanediol-mercapturic acid (bis-BDMA) as a urinary biomarker of metabolic activation of butadiene to its ultimate carcinogenic species.

    Science.gov (United States)

    Kotapati, Srikanth; Sangaraju, Dewakar; Esades, Amanda; Hallberg, Lance; Walker, Vernon E; Swenberg, James A; Tretyakova, Natalia Y

    2014-06-01

    Human carcinogen 1,3-butadiene (BD) undergoes metabolic activation to 3,4-epoxy-1-butene (EB), hydroxymethylvinyl ketone (HMVK), 3,4-epoxy-1,2-butanediol (EBD) and 1,2,3,4-diepoxybutane (DEB). Among these, DEB is by far the most genotoxic metabolite and is considered the ultimate carcinogenic species of BD. We have shown previously that BD-exposed laboratory mice form 8- to 10-fold more DEB-DNA adducts than rats exposed at the same conditions, which may be responsible for the enhanced sensitivity of mice to BD-mediated cancer. In the present study, we have identified 1,4-bis-(N-acetyl-L-cystein-S-yl)butane-2,3-diol (bis-BDMA) as a novel DEB-specific urinary biomarker. Isotope dilution high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry was employed to quantify bis-BDMA and three other BD-mercapturic acids, 2-(N-acetyl-L-cystein-S-yl)-1-hydroxybut-3-ene/1-(N-acetyl-L-cystein-S-yl)-2-hydroxy-but-3-ene (MHBMA, from EB), 4-(N-acetyl-L-cystein-S-yl)-1,2-dihydroxybutane (DHBMA, from HMVK) and 4-(N-acetyl-L-cystein-S-yl)-1,2,3-trihydroxybutane (THBMA, from EBD), in urine of confirmed smokers, occupationally exposed workers and BD-exposed laboratory rats. Bis-BDMA was formed in a dose-dependent manner in urine of rats exposed to 0-200 p.p.m. BD by inhalation, although it was a minor metabolite (1%) as compared with DHBMA (47%) and THBMA (37%). In humans, DHBMA was the most abundant BD-mercapturic acid excreted (93%), followed by THBMA (5%) and MHBMA (2%), whereas no bis-BDMA was detected. These results reveal significant differences in metabolism of BD between rats and humans.

  4. Natural gas and blends oxidation and ignition: Experiments and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Y.; Dagaut, P.; Cathonnet, M.; Boettner, J.C. [CNRS, Orleans (France); Bachman, J.S.; Carlier, P. [Gaz de France, La Plaine-Saint-Denis (France)

    1994-12-31

    The kinetics of the oxidation of natural gas and blends (CH{sub 4}/C{sub 2}H{sub 6}, CH{sub 4}/C{sub 3}H{sub 8}, CH{sub 4}/C{sub 2}H{sub 6}/C{sub 3}H{sub 8}) has been studied in a jet-stirred reactor (800 {<=} T/K {<=} 1240, 1 {<=} P/atm {<=} 10, 0.1 {<=} equivalence ratio {<=} 1.5). The concentration profiles of reactants, intermediates, and products measured in a jet-stirred reactor (JSR) have been used to validate a detailed kinetic reaction mechanism. Literature ignition delay times measured in shock tube have also been modeled. A generally good agreement between the data and the model is found. The same mechanism has also been used to successfully represent the oxidation of methane, ethyne, ethene, ethane, propene, propane, n-butane, and 1-butene in various conditions including JSR, shock tube, and flame. The present study clearly shows the importance of trace hydrocarbons in the oxidation of methane. The computations indicate that the oxidation of methane is initiated by its reaction with O{sub 2} when no other hydrocarbon is present. In natural gas and blends, higher hydrocarbons react before methane, leading to the formation of OH, H, and O radicals, which in turn initiate methane oxidation. This work demonstrates that methane cannot be used safely to represent the kinetics of natural gas combustion. However, simple blends like methane-propane or methane-ethane-propane could be used.

  5. Zum konformationsverhalten einiger halogenalkane

    Science.gov (United States)

    Müller, R.; Fruwert, J.; Geiseler, G.

    1981-01-01

    The rotational isomerism of 1-bromopropane, 1-chloro-2-methylpropane and 1-bromo-2-methylpropane has been studied in the liquid phase by infrared spectroscopy. For the corresponding conformers the enthalpy differences were obtained from the temperature dependences of the intensities of the CX-stretching and some CCC-deformation vibrations. It was found that only the CX-stretching vibrations are suitable for enthalpy determinations. In the liquid phase those conformers with a gauche position of the methyl group and halogen atom are slightly preferred.

  6. Molecular and vibrational structure of thiosulfonate S-esters

    DEFF Research Database (Denmark)

    Luu, Thi Xuan Thi; Duus, Fritz; Spanget-Larsen, Jens

    2013-01-01

    S-methyl methanethiosulfonate (1), S-ethyl ethanethiosulfonate (2), S-isopropyl propane-2-thiosulfonate (3), S-tert-butyl 2-methylpropane-2-thiosulfonate (4), and S-phenyl benzenethiosulfonate (5) were investigated by FTIR spectroscopy in liquid solution and by quantum chemical calculations (B3LY...

  7. CARBONYL STRETCHING FREQUENCY-CHARACTERISTICS FOR THE STRONGLY HYDROPHOBIC SOLUTE, N-CYCLOHEXYL-2-PYRROLIDONE IN BINARY AQUEOUS MIXTURES AT 298.15-K - EVIDENCE FOR A 2-DOMAIN MODEL FOR 2-BUTOXYETHANOL WATER MIXTURES

    NARCIS (Netherlands)

    ENGBERTS, JBFN; PERJESSY, A; BLANDAMER, MJ; EATON, G

    1992-01-01

    Infrared spectra are reported in the C=O stretching region for N-cyclohexyl-2-pyrrolidone (NCP) in D2O as a function of the mole fraction of added cosolvents. As the solvent composition is changed by adding methanol, ethanol and 2-methylpropan-2-ol, the spectra reveal the presence of two types of hy

  8. 2005 Science and Technology for Chem-Bio Information Systems (S and T CBIS) volume 3 Thursday

    Science.gov (United States)

    2005-10-28

    Chemicals (TICs) in SCIPUFF , Douglas S Burns, Veeradej Chynwat, Jeffrey J Piotrowski, Kia Tavares, and Floyd Wiseman, ENSCO, Inc. Chemical and...Industrial Chemicals (TICs) in SCIPUFF Douglas S Burns, Veeradej Chynwat, Jeffrey J Piotrowski, Kia Tavares, and Floyd Wiseman ENSCO, Inc. Science and...in SCIPUFF – Chemistry of 1-butene – Derivation of keff, Xeff – Parameter Space • Results – Model output • Decay of TICs (1-Butene, Methylpropene

  9. Butane-1,2,3,4-tetraol-based amphiphilic stereoisomers for membrane protein study: importance of chirality in the linker region

    DEFF Research Database (Denmark)

    Das, Manabendra; Du, Yang; Mortensen, Jonas S.

    2017-01-01

    of the targeted membrane proteins depending on the chirality of the linker region. These findings indicate an important role for detergent stereochemistry in membrane protein stabilization. In addition, we generally observed enhanced detergent efficacy with increasing alkyl chain length, reinforcing...

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

    Science.gov (United States)

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

    2010-05-01

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

  11. Effect Of Dyeing On Wrinkle Properties Of Cotton Cross-Linked By Butane Tetracarboxylic Acid (BTCA In Presence Of Titanium Dioxide (TiO2 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hezavehi Emadaldin

    2015-06-01

    Full Text Available This study evaluates the wrinkle behaviour and wrinkle resistant properties of cotton fabrics dyed by Direct Blue 2B in the presence and absence of nano-TiO2 particles. A finishing process on samples was performed before dyeing by means of 1,2,3,4-butanetetracarboxylic acid (BTCA and sodium hypophosphite (SHP using a pad dry cure method. Such experiments as wrinkle recovery test (AATCC-128, water drop test and dye fastness determination (ISO 105-C01 were conducted to understand how current treatment impacted the cotton fabrics’ properties. Finally, samples were characterised using the X-ray diffractometery method to scrutinise how crystallinity changes and dominates the structural parameter (wrinkle behaviour of cotton fabrics. Furthermore, scanning electron microscopy (SEM was used to visualise the surface variations of the samples before and after dyeing process. The results showed that the wrinkle resistant of cross-linked fabrics have been improved after direct dyeing. Furthermore, levelness dyeing and good fastness properties of dyes on cross-linked fabrics were observed.

  12. (Butane-1,2,3,4-tetraol-κ3O1,O2,O3(ethanol-κOtris(nitrato-κ2O,O′holmium(III

    Directory of Open Access Journals (Sweden)

    Jin-Guang Wu

    2013-03-01

    Full Text Available In the title HoIII–erythritol complex, [Ho(NO33(C4H10O4(C2H5OH], the HoIII cation is chelated by a tridentate erythritol ligand and three bidentate nitrate anions. An ethanol molecule further coordinates the HoIII cation, completing the irregular O10 coordination geometry. In the crystal, an extensive O—H...O hydrogen-bond network links the molecules into a three-dimensional supramolecular structure.

  13. 纽甜原料3,3-二甲基丁醛的合成进展%Progress on Synthesis of 3,3-Dimethyl Butanal

    Institute of Scientific and Technical Information of China (English)

    华文松; 万屹东; 潘春; 芮新生

    2008-01-01

    纽甜(Neotame)是一种新型的二肤类强力甜味剂,系阿斯巴甜的衍生物。纽甜在稳定性和使用成本方面均优于阿斯巴甜,问世以来深受世界食品界的关注。2002年7月,FDA正式批准纽甜在食品中使用。我国也于2003年4月批准纽甜在各种食品中使用,按生产需要量添加。纽甜具有甜度高、甜味纯正、稳定性好等特点,应用范围十分广泛。

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

    Science.gov (United States)

    Gainsford, Graeme J; Hinkley, Simon

    2013-06-01

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

  15. Promotional Effect of Bismuth as Dopant in Bi-Doped Vanadyl Pyrophosphate Catalysts for Selective Oxidation of n-Butane to Maleic Anhydride

    Institute of Scientific and Technical Information of China (English)

    Y.H.Taufiq-Yap; Y.Kamiya; K.P.Tan

    2006-01-01

    Bismuth-promoted (1% and 3%) vanadyl pyrophosphate catalysts were prepared by refluxing creased the surface area and lowered the overall V oxidation state. Profiles of temperature programmed reduction (TPR) in H2 show a significant shift of the maxima of major reduction peaks to lower temperatures for the Bi-promoted catalysts. A new peak was also observed at the low temperature region for the catalyst with 3% of Bi dopant. The addition of Bi also increased the total amount of oxygen removed from the catalysts. The reduction pattern and reactivity information provide fundamental insight into the catalytic properties of the catalysts. Bi-promoted catalysts were found to be highly active (71% and 81%conversion for 1% and 3% Bi promoted catalysts, respectively, at 703 K), as compared to the unpromoted material (47% conversion). The higher activity of the Bi-promoted catalysts is due to that these catalysts possess highly active and labile lattice oxygen. The better catalytic performance can also be attributed to the larger surface area.

  16. Butane-1,2,3,4-tetraol-based amphiphilic stereoisomers for membrane protein study: importance of chirality in the linker region

    DEFF Research Database (Denmark)

    Das, Manabendra; Du, Yang; Mortensen, Jonas S.;

    2016-01-01

    Amphiphile selection is a crucial step in membrane protein structural and functional study. As conventional detergents have limited scope and utility, novel agents with enhanced efficacy need to be developed. Although a large number of novel agents have been reported, so far there has been no sys...

  17. 萃取精馏分离丁烷/丁烯%Selection of solvents for separating butane and butene by extractive distillation

    Institute of Scientific and Technical Information of China (English)

    雷志刚; 许峥; 周晓颖; 廖波; 易波

    2000-01-01

    介绍了两种分离丁烷/丁烯的方法,即乙腈(ACN)法和二甲基甲酰胺 (DMF) 法.对两种工艺流程进行了计算对比,DMF 法工艺流程比ACN 法简单,只需3个塔.计算结果表明,DMF法再沸器和冷凝器能耗分别比ACN法降低33.7%和22.7%,选择DMF法萃取精馏分离丁烷/丁烯效果较好.

  18. Carbon Aerogel-Supported Pt Catalysts for the Hydrogenolysis and Isomerization of n-Butane: Influence of the Carbonization Temperature of the Support and Pt Particle Size

    Directory of Open Access Journals (Sweden)

    Marta B. Dawidziuk

    2012-10-01

    Full Text Available Carbon aerogels prepared at different carbonization temperatures and with varying mesopore volumes were used as supports for Pt catalysts to study the n-C4H10/H2 reaction. Mean Pt particle size depended on the mesopore volume of the support, showing a linear decrease when the mesopore volume increased. The turnover frequency (TOF for hydrogenolysis was much higher than for isomerization in catalysts supported on carbon aerogels obtained at 900–950 °C. However, both TOF values were similar in catalysts supported on the carbon aerogel obtained at 500 °C. TOF for hydrogenolysis and isomerization were related to the mean Pt particle size in catalysts supported on carbon aerogels obtained at 900–950 °C. In addition, both reactions showed a compensation effect between the activation energy and pre-exponential factor, indicating that they have the same intermediate, i.e., the chemisorbed dehydrogenated alkane.

  19. 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

    Science.gov (United States)

    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.

  20. Mid-IR Absorption Cross-Section Measurements of Hydrocarbons

    KAUST Repository

    Alrefae, Majed Abdullah

    2013-05-01

    Laser diagnostics are fast-response, non-intrusive and species-specific tools perfectly applicable for studying combustion processes. Quantitative measurements of species concentration and temperature require spectroscopic data to be well-known at combustion-relevant conditions. Absorption cross-section is an important spectroscopic quantity and has direct relation to the species concentration. In this work, the absorption cross-sections of basic hydrocarbons are measured using Fourier Transform Infrared (FTIR) spectrometer, tunable Difference Frequency Generation laser and fixed wavelength helium-neon laser. The studied species are methane, methanol, acetylene, ethylene, ethane, ethanol, propylene, propane, 1-butene, n-butane, n-pentane, n-hexane, and n-heptane. The Fourier Transform Infrared (FTIR) spectrometer is used for the measurements of the absorption cross-sections and the integrated band intensities of the 13 hydrocarbons. The spectral region of the spectra is 2800 – 3400 cm-1 (2.9 – 3.6 μm) and the temperature range is 673 – 1100 K. These valuable data provide huge opportunities to select interference-free wavelengths for measuring time-histories of a specific species in a shock tube or other combustion systems. Such measurements can allow developing/improving chemical kinetics mechanisms by experimentally determining reaction rates. The Difference Frequency Generation (DFG) laser is a narrow line-width, tunable laser in the 3.35 – 3.53 μm wavelength region which contains strong absorption features for most hydrocarbons due to the fundamental C-H vibrating stretch. The absorption cross-sections of propylene are measured at seven different wavelengths using the DFG laser. The temperature range is 296 – 460 K which is reached using a Reflex Cell. The DFG laser is very attractive for kinetic studies in the shock tube because of its fast time response and the potential possibility of making species-specific measurements. The Fixed wavelength

  1. Complex Hydrocarbon Chemistry in Interstellar and Solar System Ices Revealed: A Combined Infrared Spectroscopy and Reflectron Time-of-flight Mass Spectrometry Analysis of Ethane (C2H6) and D6-Ethane (C2D6) Ices Exposed to Ionizing Radiation

    Science.gov (United States)

    Abplanalp, Matthew J.; Kaiser, Ralf I.

    2016-08-01

    The irradiation of pure ethane (C2H6/C2D6) ices at 5.5 K, under ultrahigh vacuum conditions was conducted to investigate the formation of complex hydrocarbons via interaction with energetic electrons simulating the secondary electrons produced in the track of galactic cosmic rays. The chemical modifications of the ices were monitored in situ using Fourier transform infrared spectroscopy (FTIR) and during temperature-programmed desorption via mass spectrometry exploiting a quadrupole mass spectrometer with electron impact ionization (EI-QMS) as well as a reflectron time-of-flight mass spectrometer coupled to a photoionization source (PI-ReTOF-MS). FTIR confirmed previous ethane studies by detecting six molecules: methane (CH4), acetylene (C2H2), ethylene (C2H4), the ethyl radical (C2H5), 1-butene (C4H8), and n-butane (C4H10). However, the TPD phase, along with EI-QMS, and most importantly, PI-ReTOF-MS, revealed the formation of at least 23 hydrocarbons, many for the first time in ethane ice, which can be arranged in four groups with an increasing carbon-to-hydrogen ratio: C n H2n+2 (n = 3, 4, 6, 8, 10), C n H2n (n = 3-10), {{{C}}}n{{{H}}}2n-2 (n = 3-10), and {{{C}}}n{{{H}}}2n-4 (n = 4-6). The processing of simple ethane ices is relevant to the hydrocarbon chemistry in the interstellar medium, as ethane has been shown to be a major product of methane, as well as in the outer solar system. These data reveal that the processing of ethane ices can synthesize several key hydrocarbons such as C3H4 and C4H6 isomers, which ha­ve been found to synthesize polycyclic aromatic hydrocarbons like indene (C9H8) and naphtha­lene (C10H8) in the ISM and in hydrocarbon-rich atmospheres of planets and their moons such as Titan.

  2. catena-Poly[{μ3-4,4′,6,6′-tetrabromo-2,2′-[butane-1,4-diylbis(nitrilomethanylylidene]diphenolato}{μ2-4,4′,6,6′-tetrabromo-2,2′-[butane-1,4-diylbis(nitrilomethanylylidene]diphenolato}dicopper(II

    Directory of Open Access Journals (Sweden)

    Hadi Kargar

    2012-07-01

    Full Text Available The asymmetric unit of the title coordination polymer consists of a dinuclear neutral complex molecule of formula [Cu2(C18H14Br4N2O22]n. One of the CuII ions is coordinated in a distorted square-planar geometry, whereas the other is coordinated in a distorted square-pyramidal geometry, the long apical Cu—O bond [2.885 (4 Å] of the square-pyramidal coordination being provided by a symmetry-related O atom creating a one-dimensional polymer along [010]. π–π stacking interactions [centroid–centroid distance = 3.783 (4 Å] and short interchain Br...Br interactions [3.6142 (12–3.6797 (12 Å] are observed.

  3. Debaryomyces hansenii strains differ in their production of flavor compounds in a cheese-surface model

    DEFF Research Database (Denmark)

    Gori, Klaus; Sørensen, Louise Marie; Petersen, Mikael Agerlin

    2012-01-01

    Flavor production among12 strains of Debaryomyces hansenii when grown on a simple cheese model mimicking a cheese surface was investigated by dynamic headspace sampling followed by gas chromatography-mass spectrometry. The present study confirmed that D. hansenii possess the ability to produce...... important cheese flavor compounds, primarily branched-chain aldehydes and alcohols, and thus important for the final cheese flavor. Quantification of representative aldehydes (2-Methylpropanal, 3-Methylbutanal) and alcohols (2-Methyl-1-propanol, 3-Methyl-1-butanol, and 3-Methyl-3-buten-1-ol) showed...... that the investigated D. hansenii strains varied significantly with respect to production of these flavor compounds. Contrary to the alcohols (2-Methyl-1-propanol,3-Methyl-1-butanol, and3-Methyl-3-buten-1-ol), the aldehydes (2-Methylpropanal, 3-Methylbutanal) were produced by the D. hansenii strains in concentrations...

  4. 煤制烯烃混合碳四的利用探讨%The Utilization of Coal-based Mixed C4

    Institute of Scientific and Technical Information of China (English)

    姜涛; 兰秀菊

    2011-01-01

    煤制烯烃的重要副产品是混合碳四.通过对煤基混合碳四中主要成分丁烯-1和丁烯-2的用途讨论,综述了利用其生产石油树脂、乙烯、丙烯、丁烯-1、己烯-1、甲乙酮、聚丁烯-1,2-丙基庚醇等不同反应途径的工艺流程、反应原理及工业化进程.得出其最有前途的利用方向是生产丁烯-1、己烯-1、聚丁烯-1、2-丙基庚醇.%The utilization of 1-Butene and 2-Butene which are the major components of the coal-based mixed C4′s was discussed in this paper. Some conclusions were reached, i.e. they can be used to produce resin, ethylene, propylene,1-Butene, 1-hexylene, methyl-ethyl ketone, poly( 1-butene)resin or 2-propyheptanol products. Especially ,they are used to produce 1-Butene, 1-hexylene, poly( 1-butene)resin or 2-propyheptanol products.

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

    Directory of Open Access Journals (Sweden)

    Schubert Jochen

    2008-11-01

    Full Text Available Abstract Background The aim of this work was to confirm the existence of volatile organic compounds (VOCs specifically released or consumed by lung cancer cells. Methods 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. Results 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. Conclusion 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.

  6. Insights into the deactivation mechanism of supported tungsten hydride on alumina (W-H/Al2O3) catalyst for the direct conversion of ethylene to propylene

    KAUST Repository

    Mazoyer, Etienne

    2014-04-01

    Tungsten hydride supported on alumina prepared by the surface organometallic chemistry method is an active precursor for the direct conversion of ethylene to propylene at low temperature and pressure. An extensive contact time study revealed that the dimerization of ethylene to 1-butene is the primary and also the rate limiting step. The catalytic cycle further involves isomerization of 1-butene to 2-butene, followed by cross-metathesis of ethylene and 2-butene to yield propylene with high selectivity. The deactivation mechanism of this reaction has been investigated. The used catalyst was extensively examined by DRIFTS, solid-state NMR, EPR, UV-Vis, TGA and DSC techniques. It was found that a large amount of carbonaceous species, which were due to side reaction like olefin polymerization took place with time on stream, significantly hindering the dimerization of ethylene to 1-butene and therefore the production of propylene. Crown Copyright © 2014 Published by Elsevier B.V. All rights reserved.

  7. Partial amination of cationic exchange resins and its application in the hydration of butene

    Institute of Scientific and Technical Information of China (English)

    Deren Fang; Wanzhong Ren; Hongying Lü; Hongtao Yang

    2012-01-01

    In this work,the amination of sulfonated polystyrene resin with alkyl secondary amine is investigated.The catalytic activities of the modified resins are determined through the hydration of 1-butene.The optimum chain length and the best range of amination rate are determined.It is found that the single-pass conversion of 1-butene was raised 2% on average,and the relative activity was increased over 30% after modification.A hypothesis about the enhancement of catalytic activities by the inclusion of alkyl chain to wrap up the butene molecule is proposed.

  8. Synthesis of amphiphilic diblock copolymer for surface modification of Ethylene-Norbornene copolymers

    DEFF Research Database (Denmark)

    Levinsen, Simon; Svendsen, Winnie Edith; Horsewell, Andy

    2014-01-01

    -norbornene copolymer TOPAS. Through matching of the radius of gyration for the model polymer and TOPAS the miscibility was achieved. The poly(ethylene-1-butene) polymer was synthesized from a hydrogenated anionic polymerized polybutadiene polymer. As hydrophilic block poly(ethylene oxide) was subsequently added also...... consisting of a bulk material compatible block and a hydrophilic block. To utilize the possibility of incorporating diblock copolymers into ethylenenorbornene copolymers, we have in this work developed a model poly(ethylene-1-butene) polymer compatible with the commercial available ethylene...

  9. catena-Poly[copper(II-{μ3-4,4′-dibromo-2,2′-[butane-1,4-diylbis(nitrilomethanylylidene]diphenolato-κ4N,O:N′,O′:O′}

    Directory of Open Access Journals (Sweden)

    Hadi Kargar

    2011-04-01

    Full Text Available The asymmetric unit of the title coordination polymer, [Cu(C18H16Br2N2O2]n, consists of a Schiff base complex in which a crystallographic twofold rotation axis bisects the central C—C bonds of the n-butyl spacers of the designated Schiff base ligands, making symmetry-related dimer units, which are twisted around CuII atoms in a bis-bidentate coordination mode. In the crystal, these dimeric units are connected through Cu—O bonds, forming one-dimensional coordination polymers, which propagate along [001]. The CuII atom adopts a square-based pyramidal coordination geometry, being coordinated by two N and two O atoms of symmetry-related ligands and by a third O atom of a neighboring complex. Furthermore, intermolecular π–π interactions [centroid–centroid distance = 3.786 (2 Å] and C—H...O interactions stabilize the crystal packing.

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

    Energy Technology Data Exchange (ETDEWEB)

    Obuseng, Veronica; Nareetsile, Florence [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana); Kwaambwa, Habauka M., E-mail: hmkwaambwa@yahoo.com [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana)

    2012-06-12

    Highlights: Black-Right-Pointing-Pointer Materials are effective and selective in simultaneous removal of heavy metal ions. Black-Right-Pointing-Pointer Use of composite adsorbent of both materials may result in more effective material. Black-Right-Pointing-Pointer Seeds biomass has various functional groups involves in metal removal. Black-Right-Pointing-Pointer Attainment of sorption equilibrium is rapid for the seeds biomass. Black-Right-Pointing-Pointer Seeds biomass effectiveness is not affected over wide effective pH range. - Abstract: Uptake for lead, copper, cadmium, nickel and manganese from aqueous solution using the Moringa oleifera seeds biomass (MOSB) and amine-based ligand (ABL) was investigated. Experiments on two synthetic multi-solute systems revealed that MOSB performed well in the biosorption and followed the decreasing orders Pb(II) > Cu(II) > Cd(II) > Ni(II) > Mn(II) and Zn(II) > Cu(II) > Ni(II). The general trend of the heavy metal ions uptake by the amine-based ligand followed decreased in the order Mn > Cd > Cu > Ni > Pb, which is the reverse trend for what was observed for MOSB. Comparing the single- and multi-metal solutions, there was no clear effect in the biosorption capacity of MOSB suggesting the presence of sufficient active binding sites for all metal ions studied. The MOSB performance is also not affected by pH in the range 3.5-8.

  11. [(2R,3S-Butane-1,2,3,4-tetraol-κ3O1,O2,O3](ethanol-κOtris(nitrato-κ2O,O′samarium(III

    Directory of Open Access Journals (Sweden)

    Jun-Hui Xue

    2013-04-01

    Full Text Available The title SmIII–erythritol complex, [Sm(NO33(C2H6O(C4H10O4], is isotypic with its Nd, Eu, Y, Gd, Tb and Ho analogues. The SmIII cation exhibits a coordination number of ten and is chelated by a tridentate erythritol ligand and three bidentate nitrate anions. It is additionally coordinated by an O atom of an ethanol molecule, completing an irregular coordination sphere. The Sm—O bond lengths range from 2.416 (2 to 2.611 (2 Å. In the crystal, extensive O—H...O hydrogen bonding involving all hydroxy groups and some of the nitrate O atoms links the molecules into a three-dimensional network.

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

    Science.gov (United States)

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

    2017-04-01

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

  13. The Study on The Determination of The Content of Aerosol Frankincense Rheumatism Propelled by Propane-Butane%丙丁烷-乳香风湿气雾剂含量测定方法的研究

    Institute of Scientific and Technical Information of China (English)

    林文辉; 万来鸿; 林广怡; 林柳清

    2007-01-01

    目的:建立乳香风湿气雾剂(以丙丁烷替代氯氟化碳类CFCs作为环保型抛射剂)的含量测定方法,为本品抛射剂CFCs替代研究提供依据.方法:采用气相色谱法[1]测定乳香风湿气雾剂中主要成份水杨酸甲酯的含量.结果与结论:水杨酸甲酯平均回收率为99.865,RSD=0.51%.含量测定方法简便、准确、重现性好,丙丁烷等辅料对水杨酸甲酯含量测定无干扰.可用于乳香风湿气雾剂质量控制.

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

    Science.gov (United States)

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

    2012-06-12

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

  15. CTAB/正丁醇/异辛烷反胶团法纯化α-淀粉酶%Purification of α-amylase by using CTAB/n-butane/isooctane reversed micelles system

    Institute of Scientific and Technical Information of China (English)

    吴雅睿; 刘建; 李宇亮; 林舒

    2007-01-01

    以CTAB/正丁醇/异辛烷构成反胶团系统,通过反胶团萃取方式纯化精制α-淀粉酶.最佳反应条件为:萃取温度40℃,水相组成为NaCl 0.03 mol/L,pH 12.0,有机相:无机相=1:2,振荡时间10 min;反萃取最佳条件为:温度60℃,水相组成为KCl 3 mol/L,pH 4.0,有机相:无机相=2:1,反萃取振荡时间10 min.在上述条件下,经过一个萃取与反萃取循环后,α-淀粉酶的萃取率最高可达90.78%.

  16. catena-Poly[{μ3-4,4′,6,6′-tetra­bromo-2,2′-[butane-1,4-diylbis(nitrilo­methan­ylyl­idene)]diphenolato}{μ2-4,4′,6,6′-tetra­bromo-2,2′-[butane-1,4-diylbis(nitrilo­methanylyl­idene)]dipheno­lato}dicopper(II)

    Science.gov (United States)

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

    2012-01-01

    The asymmetric unit of the title coordination polymer consists of a dinuclear neutral complex mol­ecule of formula [Cu2(C18H14Br4N2O2)2]n. One of the CuII ions is coordinated in a distorted square-planar geometry, whereas the other is coordinated in a distorted square-pyramidal geometry, the long apical Cu—O bond [2.885 (4) Å] of the square-pyramidal coordination being provided by a symmetry-related O atom creating a one-dimensional polymer along [010]. π–π stacking inter­actions [centroid–centroid distance = 3.783 (4) Å] and short inter­chain Br⋯Br inter­actions [3.6142 (12)–3.6797 (12) Å] are observed. PMID:22807712

  17. 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 Click here for additional data file. Click here for additional data file. Click here for additional data file.

    Science.gov (United States)

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

    2017-01-01

    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.

  18. Controlled Functionalization of Olefin/styrene Copolymers through Free Radical Processes

    NARCIS (Netherlands)

    Passaglia, Elisa; Aglietto, Mauro; Ciardelli, Francesco; Picchioni, Francesco

    2000-01-01

    The functionalization of styrene-b-(ethylene-co-1-butene)-b-styrene triblock copolymer (SEBS) and styrene-co-butadiene (SBR) random copolymer by free radical processes is presented. SEBS was functionalized in the melt with diethyl maleate (DEM) and dicumyl peroxide (DCP) as initiator. The functional

  19. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    NARCIS (Netherlands)

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing

  20. Regiospecific synthesis of 2-substituted 4-methyl-3,6-dihydro-2h-pyrans

    Energy Technology Data Exchange (ETDEWEB)

    Kazaryan, P.I.; Avakyan, O.V.; Avakyan, S.V.; Gevorkyan, A.A.

    1986-03-01

    The chloroalkylation of 3-halo-2-methyl-1-buten-4-ols was used to synthesize 4,5-dihalo-4-methyl-2-substituted tetrahydropyrans, which were converted regio-specifically to 3,6-dihydropyrans by reaction with magnesium. A similar reaction with zinc dust gave mixtures of 3,6- and 5,6-dihydropyrans.

  1. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    NARCIS (Netherlands)

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing

  2. Discovery of novel (4-piperidinyl)-piperazines as potent and orally active acetyl-CoA carboxylase 1/2 non-selective inhibitors: F-Boc and triF-Boc groups are acid-stable bioisosteres for the Boc group.

    Science.gov (United States)

    Chonan, Tomomichi; Wakasugi, Daisuke; Yamamoto, Daisuke; Yashiro, Miyoko; Oi, Takahiro; Tanaka, Hiroaki; Ohoka-Sugita, Ayumi; Io, Fusayo; Koretsune, Hiroko; Hiratate, Akira

    2011-03-01

    Novel (4-piperidinyl)-piperazine derivatives were synthesized and evaluated as ACC1/2 non-selective inhibitors. Optimization of the substituents on the nitrogen of the piperidine ring led to the identification of the fluorine substituted tert-butoxycarbonyl group. Advanced analog, 1,1,1-trifluoro-2-methylpropan-2-yl 4-{4-[(2-amino-6-methyl-1-benzothiophen-3-yl)carbonyl]piperazin-1-yl}piperidine-1-carboxylate (12c) showed potent inhibitory activities in enzyme-assay and cell-based assays. Compound 12c also exhibited reduction of hepatic de novo fatty acid synthesis in rats after oral administration.

  3. Experimental and Predicted Viscosities of Binary Mixtures Containing Chlorinated and Oxygenated Compounds

    Science.gov (United States)

    Montaño, D.; Artigas, H.; Royo, F. M.; Lafuente, Carlos

    2013-01-01

    This study presents the viscosities, both kinematic and dynamic, of binary mixtures of 1-chlorobutane, 2-chlorobutane, or 1-chloro-2-methylpropane with butyl ethyl ether or methyl tert-butyl ether from T = 283.15 K to T = 313.15 K at atmospheric pressure as a function of composition. Kinematics viscosities were measured using an Ubbelohde viscometer. The dynamic viscosities were obtained from experimental kinematic viscosities and previously reported density data. The viscosity results have been employed to check the reliability of the Wu-UNIFAC method.

  4. Quantification of aroma compounds in Parmigiano Reggiano cheese by a dynamic headspace gas chromatography-mass spectrometry technique and calculation of odor activity value.

    Science.gov (United States)

    Qian, Michael; Reineccius, G A

    2003-03-01

    Potentially important aroma compounds in Parmigiano Reggiano cheese were quantified. Free fatty acids were isolated with ion-exchange chromatography and quantified by gas chromatography. Neutral aroma compounds were quantified with a purge-trap/gas chromatography-mass spectrometry with selective mass ion technique. Odor activity values were calculated based on sensory thresholds reported in literature. The calculated odor activity values suggest that 3-methylbutanal, 2-methylpropanal, 2-methylbutanal, dimethyl trisulfide, diacetyl, methional, phenylacetaldehyde, ethyl butanoate, ethyl hexanoate, ethyl octanoate, acetic, butanoic, hexanoic, and octanoic acids are the most important aroma contributors to Parmigiano Reggiano cheese.

  5. Protection of Petroleum Pipeline Carbon Steel Alloys with New Modified Core-Shell Magnetite Nanogel against Corrosion in Acidic Medium

    Directory of Open Access Journals (Sweden)

    Gamal A. El Mahdy

    2013-01-01

    Full Text Available New method was used to prepare magnetite nanoparticle based on reduction of Fe(III ions with potassium iodide to produce Fe3O4 nanoparticle. The prepared magnetite was stabilized with cross-linked polymer based on 2-acrylamido-2-methylpropane sulfonic acid (AMPS to prepare novel core-shell nanogel. In this respect, Fe3O4/poly(2-acrylamido-2-methylpropane sulfonic acid (PAMPS magnetic nanogels with controllable particle size produced via free aqueous polymerization at 65°C have been developed for the first time. The polymer was crosslinked in the presence of N,N-methylenebisacrylamide (MBA as a crosslinker and potassium peroxydisulfate (KPS as redox initiator system. The structure and morphology of the magnetic nanogel were characterized by Fourier transform infrared spectroscopy (FTIR and transmission and scanning electron microscopy (TEM and SEM. The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS. The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations. The results showed that the nanogel particles act as mixed inhibitors. EIS data revealed that Rct increases with increasing inhibitor concentration.

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

    Science.gov (United States)

    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.

  7. Structure-guided engineering of Lactococcus lactis alcohol dehydrogenase LlAdhA for improved conversion of isobutyraldehyde to isobutanol

    KAUST Repository

    Liu, Xiang

    2013-03-01

    We have determined the X-ray crystal structures of the NADH-dependent alcohol dehydrogenase LlAdhA from Lactococcus lactis and its laboratory-evolved variant LlAdhA(RE1) at 1.9Å and 2.5Å resolution, respectively. LlAdhA(RE1), which contains three amino acid mutations (Y50F, I212T, and L264V), was engineered to increase the microbial production of isobutanol (2-methylpropan-1-ol) from isobutyraldehyde (2-methylpropanal). Structural comparison of LlAdhA and LlAdhA(RE1) indicates that the enhanced activity on isobutyraldehyde stems from increases in the protein\\'s active site size, hydrophobicity, and substrate access. Further structure-guided mutagenesis generated a quadruple mutant (Y50F/N110S/I212T/L264V), whose KM for isobutyraldehyde is ∼17-fold lower and catalytic efficiency (kcat/KM) is ∼160-fold higher than wild-type LlAdhA. Combining detailed structural information and directed evolution, we have achieved significant improvements in non-native alcohol dehydrogenase activity that will facilitate the production of next-generation fuels such as isobutanol from renewable resources.

  8. Synthesis and evaluation of iron-doped titania/silane based hydrogel for the adsorptional photocatalytic degradation of Victoria blue under visible light.

    Science.gov (United States)

    Anirudhan, Thayyath S; Divya, Peethambaran L; Nima, Jayachandran; Sandeep, Sadanandan

    2014-11-15

    Novel photocatalyst, poly(itaconic acid-co-2-acrylamido-2-methylpropane-1-sulfonic acid) iron doped titania/silane was successfully prepared by the polymerization of iron doped titania/silane and two functional monomers, itaconic acid and 2-acrylamido-2-methylpropane-1-sulfonic acid in aqueous solution using ethylene glycol dimethacrylate as cross-linker and benzoylperoxide as initiator. The sample was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Diffuse reflectance spectroscopy (DRS) techniques. Effects of various factors like pH, adsorbent dose, contact time, and ionic strength on the adsorption capacity of photocatalyst for Victoria blue (VB) were studied by batch adsorption experiments. The kinetic data were found to follow pseudo-second-order kinetic model with low chi square, χ(2) values and R(2) values closer to unity. The equilibrium data were in well agreement with Langmuir isotherm model and maximum adsorption capacity was found to be 153.89 mg/g. The swelling capacity of the adsorbent with changes in pH, time and temperature was also investigated. The kinetics of photocatalytic degradation of VB by the photocatalyst found to follow first-order kinetics. The regeneration and repeated use of photocatalyst were also examined upto four cycles. The prepared photocatalyst was found to be efficient photocatalyst-cum-adsorbent for the degradation of VB from aqueous solutions under solar light.

  9. Novel negatively-charged membrane adsorbers made using combination of photopolymerization and immersion precipitation

    Directory of Open Access Journals (Sweden)

    Tomković Tanja

    2016-01-01

    Full Text Available A novel method combining a traditional immersion precipitation process for making membranes with photopolymerization and crosslinking of functional monomers included in the casting solution was used to prepare asymmetric polyethersulfone membranes with submicron particles incorporating glycidyl methacrylate copolymer. In order to introduce sulfonic groups epoxide rings of glycidyl methacrylate were opened using two methods. The first method was functionalization with sodium sulfite, and the second method was functionalization with sulfuric acid and then grafting with 2-acrylamido-2-methylpropane sulfonic acid. Obtained membranes were characterized using infrared spectroscopy, conductometric titration and water permeability measurements. Scanning electron microscopy and atomic force microscopy were used to investigate the surface morphology and topology of membrane. Dynamic adsorption of Rhodamine B as a model dye was used to demonstrate suitability of these novel membranes for membrane adsorption since the adsorption capacity for dye cations was much better for both functionalized membrane with sodium sulfite and grafted membrane with 2-acrylamido-2-methylpropane sulfonic acid compared to the nonfunctionalized membrane. [Projekat Ministarstva nauke Republike Srbije, br. TR32008 and III 43009

  10. The driving force role of ruthenacyclobutanes

    KAUST Repository

    Vummaleti, Sai V. C.

    2015-02-07

    DFT calculations have been used to determine the thermodynamic and kinetic preference for ruthenacyclobutanes resulting from the experimentally proposed interconversion pathways (olefin and alkylidene rotations) through the investigation of cross-metathesis reaction mechanism for neutral Grubbs catalyst, RuCl2(=CHEt)NHC (A), with ethylene and 1-butene as the substrates. Our results show that although the proposed interconversions are feasible due to the predicted low energy barriers (2-6 kcal/mol), the formation of ruthenacyclobutane is kinetically favored over the competitive reactions involving alkylidene rotations. In comparison with catalyst A, the reaction energy profile for cationic Piers catalyst [RuCl2(=CHPCy3)NHC+] (B) is more endothermic in nature with both ethylene and 1-butene substrates.

  11. Data Gap Analysis and Database Expansion of Parameters for Munitions Constitutents

    Science.gov (United States)

    2005-12-01

    toluidinoanthraquinone (PTA) solvent green 3 128-80-3 biocides/dyes 14 1-butanol 71-36-3 alchohols /ketones 15 1-butene 106-98-9 hydrocarbons 16 1-chloro-2-methylbenzene...More information about the mechanisms and models of bioaccumulation can be found in Jager and Hamers (1997). The currently used regression equations...of the calculation methods. Air degradation is considered to be a molecular- mechanical process. The PBT profiler calculates an atmospheric half-life

  12. Data Gap Analysis and Database Expansion of Parameters for Munitions Constituents

    Science.gov (United States)

    2005-12-01

    toluidinoanthraquinone (PTA) solvent green 3 128-80-3 biocides/dyes 14 1-butanol 71-36-3 alchohols /ketones 15 1-butene 106-98-9 hydrocarbons 16 1-chloro-2...parameters. More information about the mechanisms and models of bioaccumulation can be found in Jager and Hamers (1997). The currently used regression...explanation of the calculation methods. Air degradation is considered to be a molecular- mechanical process. The PBT profiler calculates an atmospheric

  13. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    OpenAIRE

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing sulfonated units were prepared by blending styrene-block-butadiene-block-styrene (SBS), with both sulfonated PS and sulfonated SEBS in a Brabender mixer. Such a procedure was performed as an alter...

  14. Isoprene gas phase hydrogenation catalyzed by ThNi{sub 2} and UNi{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Joaquim Badalo [Departamento de Quimica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, P-2686-953 Sacavem Codex (Portugal)], E-mail: jbranco@itn.pt; Goncalves, Antonio Pereira; Pires de Mato, Antonio [Departamento de Quimica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, P-2686-953 Sacavem Codex (Portugal)

    2008-10-06

    The study of isoprene (2-methyl-1,3-butadiene) gas phase hydrogenation on ThNi{sub 2} and UNi{sub 2} was undertaken and the effect of the 5f element on nickel catalytic behavior investigated. At nearly steady state, the reaction products were isopentane and isopentenes (2-methyl-2-butene, 2-methyl-1-butene and 3-methyl-1-butene). The total selectivity to isopentenes was higher on ThNi{sub 2} ({approx}80 mol%) than on UNi{sub 2} ({approx}50 mol%) but, in both cases lower than that on pure Ni ({approx}96 mol%). The sum of 2-methyl-2-butene + 2-methyl-1-butene selectivities (valuable products for the tert-amyl methyl ether process) was {approx}75 mol% on ThNi{sub 2}, whereas on UNi{sub 2} it was significantly lower ({approx}50 mol%). ThNi{sub 2} and UNi{sub 2} total selectivity to isopentenes is nearly time invariant. The difference of catalytic properties between ThNi{sub 2} and UNi{sub 2} can be explained by electronic transfer from the 5f element to Ni that generates an electronic density supply on nickel, which is higher on ThNi{sub 2}.

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

    Science.gov (United States)

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

    2016-04-01

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

  16. Growth of n-alkane films on a single-crystal substrate

    DEFF Research Database (Denmark)

    Wu, Z. U.; Ehrlich, S. N.; Matthies, B.

    2001-01-01

    The structure and growth mode of alkane films (n-C/sub n/H/sub 2n+2/; n=4, 6, 7) adsorbed on a Ag(111) surface have been investigated by synchrotron X-ray scattering. New models are proposed for the butane (n=4) and hexane (n=6) monolayer and butane bilayer structures. Specular reflectivity scans...

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

    DEFF Research Database (Denmark)

    Tartaglino, Ugo; Sivebæk, Ion Marius; Persson, B N J;

    2006-01-01

    isobutane. With n-butane possessing a slightly lower viscosity at high pressures, our result refutes the view that squeeze-out should be harder for higher viscosities; on the other hand our results are consistent with wear experiments in which n-butane were shown to protect steel surfaces better than...

  18. Adsorption and diffusion of alkanes in CuBTC crystals investigated using infra-red microscopy and molecular simulations

    NARCIS (Netherlands)

    Chmelik, C.; Kärger, J.; Wiebcke, M.; Caro, J.; van Baten, J.M.; Krishna, R.

    2009-01-01

    The adsorption and intra-crystalline diffusion of n-butane (nC4), iso-butane (iC4), 2-methylbutane (2MB), and 2,2-dimethylpropane (neoP) in CuBTC (Cu-3(BTC)(2) where BTC = benzene-1,3,5-tricarboxylate) has been investigated using infrared microscopy (IRM), combined with molecular simulations. Both e

  19. 钒钼复合氧化物表面上激光促进异丁烷选择氧化制甲基丙烯酸%Laser Stimulated Selective Oxidation of i-Butane to Methacrylic Acid over Mo4V6O24

    Institute of Scientific and Technical Information of China (English)

    陶跃武; 钟顺和

    2001-01-01

    用共沉淀法制备了V和Mo的复合氧化物.运用XRD、IR、TPD和LSSR技术研究了其晶体结构、表面构造、化学吸附特性和激光促进异丁烷选择氧化反应性能.结果表明:V—Mo—O的主体物相为Mo4V6O24,它具有MoO3和V2O4交替排列的层状结构;其表面上存在着Lewis碱位Mo=O和Mo—O—V键中的O2-及Lewis酸位V4+;异丁烷的2个甲基H分别吸附在2个相邻的Lewis碱位Mo=O上形成双位分子吸附态;在常压和200℃条件下,用一定频率的激光激发Mo=O键1000次,异丁烷的转化率为6.5%,其反应产物是异丁烯、甲基丙烯醛和甲基丙烯酸,其中甲基丙烯酸的选择性为78%.根据实验结果,探讨了激光促进异丁烷选择氧化为甲基丙烯酸的表面反应机理.%A Mo/V complex oxide was prepared from (NH4)6Mo7O26.4H2O andNH4VO3 by a coprecipitation method. The surface composition, structure, chemsorption and behavior of laser stimulated selective oxidation of isobutane have been investigated by XRD, IR, TPD and microreactor. The results showed that the main phase of the complex oxide is Mo4V6O24, which has a storeyed structure composed of MoO3 and V2O4. There are both Lewis base sites, O2- in the surface Mo=O or Mo—O—V bonds, and Lewis acid site, V4+ appeared on the surface of complex oxide. Two methyl hydrogens in isobutane molecule can be chemisorbed on the terminal oxygen of the neibouring Mo=O bonds on the surface of the complex oxide. Under the conditions of 0.1 MPa, 200 ℃ and 1000 times of laser excitation with 972 cm-1on the MoObonds, about 6.5% isobutane were converted to isobutene, methyl propenal and methacrylic aicd, among them 78% were the latter. A mechanism is proposed for isobutane selective oxidation.

  20. Bis(dimethyl­formamide-κO){4,4′,6,6′-tetra­chloro-2,2-[butane-1,4-di­yl(nitrilo­methanylyl­idene)]diphenolato-κ4 O,N,N′,O′}nickel(II)

    Science.gov (United States)

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

    2012-01-01

    In the title Schiff base complex, [Ni(C18H14Cl4N2O2)(C3H7NO)2], the geometry around the NiII atom is distorted octa­hedral. It is coordinated by the N2O2 donor atoms of the tetra­dentate Schiff base ligand and the O atoms of two dimethyl­formamide mol­ecules, which are cis to one another. The benzene rings are almost normal to each other [dihedral angle = 88.60 (14)°]. The various intra­molecular C—H⋯O hydrogen bonds make S(5) and S(6) ring motifs. In the crystal, mol­ecules are linked by pairs of weak C—H⋯Cl inter­actions, forming inversion dimers. PMID:22807808

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Gates, B.C.

    1996-12-31

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

  3. Characterization of the most odor-active compounds of Iberian ham headspace.

    Science.gov (United States)

    Carrapiso, Ana I; Ventanas, Jesús; García, Carmen

    2002-03-27

    Gas chromatography-olfactometry (GC-O) based on detection frequency (DF) was used to characterize the most odor-active compounds from the headspace of Iberian ham. Twenty-eight odorants were identified by GC-O on two capillary columns, including aldehydes (11), sulfur-containing compounds (7), ketones (5), nitrogen-containing compounds (2), esters (2), and an alcohol. Among them, the highest odor potencies (DF values) were found for 2-methyl-3-furanthiol, 2-heptanone, 3-methylbutanal, methanethiol, hexanal, hydrogen sulfide, 1-penten-3-one, 2-methylpropanal, ethyl 2-methylbutyrate, and (E)-2-hexenal. Nine of the 28 most odor-active compounds were identified for the first time as aroma components of dry-cured ham, including hydrogen sulfide, 1-penten-3-one, (Z)-3-hexenal, 1-octen-3-one, and the meaty-smelling compounds 2-methyl-3-furanthiol, 2-furfurylthiol, 3-mercapto-2-pentanone, 2-acetyl-1-pyrroline, and 2-propionyl-1-pyrroline.

  4. The separation and analysis of symmetric and asymmetric dimethylarginine and other hydrophilic isobaric compounds using aqueous normal phase chromatography.

    Science.gov (United States)

    Pesek, Joseph J; Matyksa, Maria T; Modereger, Brent; Hasbun, Alejandra; Phan, Vy T; Mehr, Zahra; Guzman, Mariano; Watanable, Seiichiro

    2016-04-01

    Two biologically important compounds with clinical relevance, asymmetric dimethylarginine and symmetric dimethylarginine, are analyzed using aqueous normal phase chromatography on silica hydride-based columns. Two different stationary phases were tested, a commercially available Diamond Hydride™ and a 2-acrylamido-2-methylpropane sulfonic acid experimental column. Two types of analytical protocols were investigated: analysis of the compounds when separation was achieved and analysis of the compounds with partial chromatographic separation. Urine samples from tuberculosis patients were tested for levels of asymmetric and symmetric dimethylarginine. The mass spectrometric technique of in-source fragmentation that can provide data similar to a tandem mass analyzer was evaluated as a means of identification and quantitation of the two compounds when complete separation is not achieved. This same protocol was also evaluated for two other isobaric compounds, glucose-1 and glucose-6 phohsphate, and leucine and isoleucine.

  5. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 8, Revision 3 (FGE.08Rev3): Aliphatic and alicyclic mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups from chemical

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 70 flavouring substances in the Flavouring Group Evaluation 08, Revision 3, using the Procedure in Commission Regulation (EC) No 1565/2000. For the substan......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 70 flavouring substances in the Flavouring Group Evaluation 08, Revision 3, using the Procedure in Commission Regulation (EC) No 1565....../2000. For the substances 2-methylpropane-2-thiol [FL-no: 12.174], methyl methanethiosulphonate [FL-no: 12.159], 2-methylbutane-2-thiol [FL-no: 12.172] and 2,4,4-trimethyl-1,3-oxathiane [FL-no: 16.057] there is an indication of a genotoxic potential in vitro. Therefore, in the absence of further genotoxicity data...

  6. Separation of PCR-ready DNA from dairy products using magnetic hydrophilic microspheres and poly(ethylene glycol)-NaCl water solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rittich, Bohuslav [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic)], E-mail: rittich@sci.muni.cz; Spanova, Alena [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Salek, Petr [Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Nemcova, Petra [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Trachtova, Stepanka [Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Horak, Daniel [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, CZ-162 06 Prague (Czech Republic)

    2009-05-15

    Carboxyl group-containing magnetic nonporous poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) (P(HEMA-co-GMA)) and magnetic glass microspheres were used for the isolation of bacterial DNA. P(HEMA-co-GMA) microspheres were prepared by the dispersion polymerization in toluene/2-methylpropan-1-ol mixture in the presence of magnetite nanoparticles obtained by coprecipitation of Fe(II) and Fe(III) salts with ammonium hydroxide. Carboxyl groups were then introduced by oxidation of the microspheres with potassium permanganate. The most extensive DNA recovery was achieved at PEG 6000 concentrations of 12% or 16% and 2 M NaCl. The method proposed was used for bacterial DNA isolation from different dairy products containing Bifidobacterium and Lactobacillus cells. The presence of target DNA and the quality of isolated DNA were checked by polymerase chain reaction (PCR) amplification with specific primers.

  7. Metabolite production and kinetics of branched-chain aldehyde oxidation in Staphylococcus xylosus

    DEFF Research Database (Denmark)

    Beck, Hans Christian; Hansen, A.M.; Lauritsen, F.R.

    2002-01-01

    The metabolite production of the gram positive bacterium Staphylococcus xylosus when cultivated in a defined medium containing 18 amino acids, 6 vitamins and 2 purines was characterised. Several compounds not previously reported as metabolites of this organism were identified including 2......,5-methylpyrazine, 2-phenylethylacetate, 2-methyltetrahydrothiophen-3-one, 3-(methylthio)-propanoic acid and 3-(methylthio)-propanal. The organoleptic metabolites derived from branched-chain amino acid catabolism; 2-methylpropanal from valine, 2-methylbutanal from isoleucine and 3-methylbutanal from leucine were...... detected at levels ranging from 0.4 to 2.0μM. The concentrations of the corresponding carboxy acids were 963, 858 and 1486μM respectively. We demonstrated that α-ketoisocaproic acid was biotransformed to 3-methylbutanal which immediately was oxidised into 3-methylbutanoic acid. Kinetic studies...

  8. Fluorinated Alkoxide-Based Magnesium-Ion Battery Electrolytes that Demonstrate Li-Ion-Battery-Like High Anodic Stability and Solution Conductivity.

    Science.gov (United States)

    Crowe, Adam J; Stringham, Kyle K; Bartlett, Bart M

    2016-09-01

    Based on DFT predictions, a series of highly soluble fluorinated alkoxide-based electrolytes were prepared, examined electrochemically, and reversibly cycled. The alcohols react with ethylmagnesium chloride to generate a fluoroalkoxy-magnesium chloride intermediate, which subsequently reacts with aluminum chloride to generate the electrolyte. Solutions starting from a 1,1,1,3,3,3-hexafluoro-2-methylpropan-2-ol precursor exhibit high anodic stability, 3.2 V vs Mg(2+/0), and a record 3.5 mS/cm solution conductivity. Excellent galvanostatic cycling and capacity retention (94%) is observed with more than 300 h of cycle time while employing the standard Chevrel phase-Mo6S8 cathode material.

  9. Preparation and Characterization of Lignin Graft Copolymer as a Filtrate Loss Control Agent for the Hydrocarbon Drilling Industry

    Directory of Open Access Journals (Sweden)

    Mohamad Nasir Mohamad Ibrahim

    2014-01-01

    Full Text Available Lignin graft copolymer (LGC was prepared using an addition polymerization technique that involved grafting a 2-acrylamido-2-methylpropane sulfonic acid (AMPS monomer onto soda lignin (SL. The optimal polymerization conditions were found to be as follows: soda lignin, 2.0 g; initiator, 3% (w/w potassium persulphate of SL; mass ratio of AMPS to SL, 1:2; reaction time, 7 h; and reaction temperature, 60 °C. The LGC was characterized using a Fourier transform infrared (FTIR spectroscopy, a thermogravimetric analyzer (TGA, and gel permeation chromatography (GPC. The filtrate loss controlling ability of the LGC was evaluated using the American Petroleum Institute Recommended Practice 13-B 1 standard procedures. The results showed that the LGC has remarkable rheological and filtration controlling properties at both room temperature and high aging temperatures (190 °C.

  10. Combinatory approach of methacrylated alginate and acid monomers for concrete applications.

    Science.gov (United States)

    Mignon, Arn; Devisscher, Dries; Graulus, Geert-Jan; Stubbe, Birgit; Martins, José; Dubruel, Peter; De Belie, Nele; Van Vlierberghe, Sandra

    2017-01-02

    Polysaccharides, and especially alginate, can be useful for self-healing of cracks in concrete. Instead of weak electrostatic bonds present within calcium alginate, covalent bonds, by methacrylation of the polysaccharides, will result in mechanically stronger superabsorbent polymers (SAPs). These methacrylated alginate chains as backbone are combined with two acrylic monomers in a varying molar fraction. These SAPs show a moisture uptake capacity up to 110% their own weight at a relative humidity of 95%, with a negligible hysteresis. The swelling capacity increased (up to 246 times its own weight) with a decreasing acrylic acid/2 acrylamido-2-methylpropane sulfonic acid ratio. The SAPs also showed a thermal stability up to 200°C. Interestingly, the SAP composed of alginate and acrylic acid exerted a very limited decrease in compressive strength (up to 7% with addition of 1wt% SAP) rendering this material interesting for the envisaged self-healing application. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Macrochain configuration, stucture of free volume and transport properties of poly(1-trimethylsilyl-1-propyne) and poly(1-trimethylgermyl-1-propyne)

    KAUST Repository

    Matson, Samira M.

    2012-08-01

    The relationship between poly(1-trimethylsilyl-1-propyne) (PTMSP) and poly(1-trimethylger- myl-1-propyne) (PTMGP) microstructure, gas permeability and structure of free volume is reported. n-Butane/methane mixed-gas permeation properties of PTMSP and PTMGP membranes with different cis-/trans-composition have been investigated. The n-butane/methane selectivities for mixed gas are by an order higher than the selectivities calculated from pure gas measurements (the mixed-gas n-butane/methane selectivities are 20-40 for PTMSP and 22-35 for PTMGP). Gas permeability and n-butane/methane selec- tivity essentially differ in polymers with different cis-/trans-composition. Positron annihilation lifetime spec- troscopy investigation of PTMSP and PTMGP with different microstructure has determined distinctions in total amount and structure of free volume, i.e. distribution of free volume elements. The correlation between total amount of free volume and gas transport parameters is established: PTMSP and PTMGP with bigger free volume exhibit higher n-butane permeability and mixed-gas n-butane/methane selectivity. Such behav- ior is discussed in relation to the submolecular structure of polymers with different microstructure and sorp- tion of n-butane in polymers with different free volume. © Pleiades Publishing, Ltd., 2012.

  12. A numerical analysis of the effects of a stratified pre-mixture on homogeneous charge compression ignition combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jamsran, Narankhuu; Lim, Ock Taeck [University of Ulsan, Ulsan (Korea, Republic of)

    2012-06-15

    We investigated the efficacy of fuel stratification in a pre-mixture of dimethyl ether (DME) and n-butane, which have different autoignition characteristics, for reducing the pressure rise rate (PRR) of homogeneous charge compression ignition engines. A new chemical reaction model was created by mixing DME and n-butane and compared with existing chemical reaction models to verify the effects observed. The maximum PRR depended on the mixture ratio. When DME was charged with stratification and n-butane was charged with homogeneity, the maximum PRR was the lowest among all the mixtures studied. Calculations were performed using CHEMKIN and modified using SENKIN software.

  13. 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

    Science.gov (United States)

    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.

  14. Synthesis of Branch Fluorinated Cationic Surfactant and Surface Properties

    Directory of Open Access Journals (Sweden)

    Hongke Wu

    2014-01-01

    Full Text Available A novel fluorinated quaternary ammonium salt cationic surfactant N,N,N-trimethyl-2-[[4-[[3,4,4,4-tetrafluoro-2-[1,2,2,2-tetrafluoro-1-(trifluoromethylethyl]-1,3-bis(tri-fluoromethyl-1-buten-1-yl]oxy]-benzoyl]amino]-iodide (FQAS was synthesized successfully, and its structure was characterized by FTIR, 1H-NMR, 19F-NMR, and MS. The surface activities of FQAS and the effect of temperature, electrolyte, and combination with hydrocarbon surfactant were investigated. The results showed that FQAS exhibited excellent surface activity and combination with hydrocarbon surfactant.

  15. XAFS Study of the Photo-Active Site of Mo/MCM-41

    Science.gov (United States)

    Miyamoto, Daisuke; Ichikuni, Nobuyuki; Shimazu, Shogo

    2007-02-01

    An Mo/MCM-41 catalyst was prepared and used for study of propene and 1-butene photo-metathesis reactions. XAFS analysis revealed that hydrogen reduction leads to a decreased role for the Mo=O site. The Mo-O site plays an important role for the olefin photo-metathesis reaction on the H2 reduced Mo/MCM-41. From EXAFS analysis, the active site of photo-metathesis reaction is the Mo=O part for oxidized Mo/MCM-41, whereas it is the Mo-O site for reduced Mo/MCM-41.

  16. TAME (tertiary-amyl-methyl ether) gasoline additive production process development; Desenvolvimento do processo de producao de TAME-aditivo para gasolina

    Energy Technology Data Exchange (ETDEWEB)

    Lovisi, Humberto [Petroflex Industria e Comercio S.A., Duqye de Caxias, RJ (Brazil); Piccoli, Ricardo [COPESUL, Companhia Petroquimica do Sul, Triunfo, RS (Brazil)

    1992-12-31

    PETROFLEX and COPESUL jointly developed a TAME production process. Tertiary-amyl-methyl ether (TAME) is obtained by the methoxylation of isoamylenes (2-methyl-1-butene and 2-methyl-2-butene) in a C{sub s} cut over a sulfonic acid resin. Process was developed on the basis of pilot plant and batch experiments. A simplified process flow-sheet and pilot plant data are presented. Isoamylenes conversions higher than 70% were achieved with low by-products formation. (author) 22 refs., 2 figs., 2 tabs.

  17. A New Synthesis Method and GABA Transporters Inhibitory Activities of Tiagabine and Its Analogues

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new synthetic method and GABA transporter inhibitory activities of Tiagabine and its analogues are described.The key intermediates 4-tosyl-1,1-diaryl/heteroaryl-1-butene 10a-10e were synthesized by Wittig reaction, and followed by N-alkylation with (R)-3-piperidinecarboxylate. The resultingN-diheterocyclylalkenylpiperidine-3-carboxylic acid ester 11a-11e were saponified and then acidified toget the target compounds 1a-1e. The preliminary bioassays show that compound 1a-1e exhibited excellent inhibition of [3H]-GABA uptake in vitro of culture cells.

  18. A New Synthesis of 4, 4-Diaryl/Diheteroaryl-3-butenyl Derivatives of Nipecotic Acids as GABA Transporter Inhibitors

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new method for the synthesis of 4, 4-diaryl/diheteroaryl-3-butenyl derivatives of nipecotic acid as GABA transporter inhibitors is described. The key intermediates 4-tosyl-1,1-diaryl/diheteroaryl-1-butene 10a-d were synthesized by Wittig reaction, and followed by alkylation with (R)-3-piperidinecarboxylate. The resulting N-cycloalkylated amino acid esters 11a-d were saponified and then acidified to get the target compounds 1a-d. The preliminary bioassays showed that 1a-d exhibited excellent inhibition of [3H]-GABA uptake in vitro of culture cells.

  19. Sulforaphane inhibits pancreatic cancer through disrupting Hsp90-p50Cdc37complex and direct interactions with amino acids residues of Hsp90

    NARCIS (Netherlands)

    Li, Yanyan; Karagöz, G. Elif; Seo, Young Ho; Zhang, Tao; Jiang, Yiqun; Yu, Yanke; Duarte, Afonso M.S.; Schwartz, Steven J.; Boelens, Rolf; Carroll, Kate; Rüdiger, Stefan G.D.; Sun, Duxin

    2012-01-01

    Sulforaphane [1-isothiocyanato-4-(methyl-sulfinyl) butane)], an isothiocyanate derived from cruciferous vegetables, has been shown to possess potent chemopreventive activity. We analyzed the effect of sulforaphane on the proliferation of pancreatic cancer cells. Sulforaphane inhibited pancreatic can

  20. Investigation on the exposure of hairdressers to chemical agents

    NARCIS (Netherlands)

    Wal, J.F. van der; Hoogeveen, A.W.; Moons, A.M.M.; Wouda, P.

    1997-01-01

    Concentrations of compounds released from hairdressing products such as ammonia, hydrogen peroxide, ethanol, propane, butane, volatile organic compounds, and dust particles were measured in hairdressing salons. When compared with general accepted standards for the work place (threshold limit values,

  1. Vapor liquid equilibrium constants through a non-equation of state approach: methane-free aliphatic binary systems

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, T.H.; Thodos, G.

    1975-06-01

    Northwestern University developed an alternate method to help predict vapor-liquid equilibrium constants without an equation of state by using the fundamental properties associated with the pure-state components and the critical pressure of the mixture. The method consists of developing correlations to help predict K-constants for other aliphatic binary mixtures not containing methane from vapor-liquid equilibrium measurements available in the literature for the 3 binaries of the system ethane-butane-heptane. This approach was tested for 7 other binaries (ethane/n-hexane, propane/i-butane, propane/i-butane, propane/n-pentane, propane/i-pentane, poprane/n-decane, and propylene/i-butane). The K-values obtained displayed good agreement with experimental measurements, especially in the vicinity of the critical point.

  2. Investigation on the exposure of hairdressers to chemical agents

    NARCIS (Netherlands)

    Wal, J.F. van der; Hoogeveen, A.W.; Moons, A.M.M.; Wouda, P.

    1997-01-01

    Concentrations of compounds released from hairdressing products such as ammonia, hydrogen peroxide, ethanol, propane, butane, volatile organic compounds, and dust particles were measured in hairdressing salons. When compared with general accepted standards for the work place (threshold limit values,

  3. Sulforaphane inhibits pancreatic cancer through disrupting Hsp90-p50Cdc37complex and direct interactions with amino acids residues of Hsp90

    NARCIS (Netherlands)

    Li, Yanyan; Karagöz, G. Elif; Seo, Young Ho; Zhang, Tao; Jiang, Yiqun; Yu, Yanke; Duarte, Afonso M.S.; Schwartz, Steven J.; Boelens, Rolf|info:eu-repo/dai/nl/070151407; Carroll, Kate; Rüdiger, Stefan G.D.|info:eu-repo/dai/nl/314076662; Sun, Duxin

    2012-01-01

    Sulforaphane [1-isothiocyanato-4-(methyl-sulfinyl) butane)], an isothiocyanate derived from cruciferous vegetables, has been shown to possess potent chemopreventive activity. We analyzed the effect of sulforaphane on the proliferation of pancreatic cancer cells. Sulforaphane inhibited pancreatic

  4. [Ventricular fibrillation following deodorant spray inhalation].

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-11-24

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Widely-tunable and sensitive optical sensor for multi-species detection in the mid-IR

    KAUST Repository

    Alquaity, Awad

    2017-10-05

    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. 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.

  9. A simplified chemistry module for atmospheric transport and dispersion models: Proof-of-concept using SCIPUFF

    Science.gov (United States)

    Burns, Douglas S.; Rottmann, Shawn D.; Plitz, Angela B. L.; Wiseman, Floyd L.; Moore, William; Chynwat, Veeradej

    2012-09-01

    An atmospheric chemistry module was developed to predict the fate of environmentally hazardous compounds discharged into the atmosphere. The computationally efficient model captures the diurnal variation within the environment and in the degradation rates of the released compounds, follows the formation of toxic degradation products, runs rapidly, and in principle can be integrated with any atmospheric transport and dispersion model. To accomplish this, a detailed atmospheric chemistry mechanism for a target toxic industrial compound (TIC) was reduced to a simple empirical effective degradation rate term (keff). Empirically derived decay functions for keff were developed as a function of important meteorological parameters such as solar flux, temperature, humidity, and cloud cover for various land uses and locations by statistically analyzing data generated from a detailed chemistry mechanism run over a wide range of (typical) atmospheric conditions. 1-Butene and two degradation products (propanal and nitrooxybutanone) were used as representative chemicals in the algorithm development for this proof-of-concept demonstration of the capability of the model. The quality of the developed model was evaluated via comparison with experimental chamber data and the results (decay rates) compared favorably for ethene, propene, and 1-butene (within a factor of two 75% or more of the time).

  10. Beta-H transfer from the metallacyclobutane: a key step in the deactivation and byproduct formation for the well-defined silica-supported rhenium alkylidene alkene metathesis catalyst.

    Science.gov (United States)

    Leduc, Anne-Marie; Salameh, Alain; Soulivong, Daravong; Chabanas, Mathieu; Basset, Jean-Marie; Copéret, Christophe; Solans-Monfort, Xavier; Clot, Eric; Eisenstein, Odile; Böhm, Volker P W; Röper, Michael

    2008-05-14

    The surface complex [([triple bond]SiO)Re([triple bond]CtBu)(=CHtBu)(CH2tBu)] (1) is a highly efficient propene metathesis catalyst with high initial activities and a good productivity. However, it undergoes a fast deactivation process with time on stream, which is first order in active sites and ethene. Noteworthy, 1-butene and pentenes, unexpected products in the metathesis of propene, are formed as primary products, in large amount relative to Re (>1 equiv/Re), showing that their formation is not associated with the formation of inactive species. DFT calculations on molecular model systems show that byproduct formation and deactivation start by a beta-H transfer trans to the weak sigma-donor ligand (siloxy) at the metallacyclobutane intermediate having a square-based pyramid geometry. This key step has an energy barrier slightly higher than that calculated for olefin metathesis. After beta-H transfer, the most accessible pathway is the insertion of ethene in the Re-H bond. The resulting pentacoordinated trisperhydrocarbyl complex rearranges via either (1) alpha-H abstraction yielding the unexpected 1-butene byproduct and the regeneration of the catalyst or (2) beta-H abstraction leading to degrafting. These deactivation and byproduct formation pathways are in full agreement with the experimental data.

  11. Intercomparison of Hantzsch and fiber-laser-induced-fluorescence formaldehyde measurements

    Science.gov (United States)

    Kaiser, J.; Li, X.; Tillmann, R.; Acir, I.; Holland, F.; Rohrer, F.; Wegener, R.; Keutsch, F. N.

    2014-06-01

    Two gas-phase formaldehyde (HCHO) measurement techniques, a modified commercial wet-chemical instrument based on Hantzsch fluorimetry and a custom-built instrument based on fiber laser-induced fluorescence (FILIF), were deployed at the atmospheric simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) to compare the instruments' performances under a range of conditions. Thermolysis of para-HCHO and ozonolysis of 1-butene were used as HCHO sources, allowing for calculations of theoretical HCHO mixing ratios. Calculated HCHO mixing ratios are compared to measurements, and the two measurements are also compared. Experiments were repeated under dry and humid conditions (RH 60%) to investigate the possibility of a water artifact in the FILIF measurements. The ozonolysis of 1-butene also allowed for the investigation of an ozone artifact seen in some Hantzsch measurements in previous intercomparisons. Results show that under all conditions the two techniques are well correlated (R2 ≥ 0.997), and linear regression statistics show measurements agree with within stated uncertainty (15% FILIF + 5% Hantzsch). No water or ozone artifacts are identified. While a slight curvature is observed in some Hantzsch vs. FILIF regressions, the potential for variable instrument sensitivity cannot be attributed to a single instrument at this time. Measurements at low concentrations highlight the need for a secondary method for testing the purity of air used in instrument zeroing and the need for further FILIF White cell outgassing experiments.

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

    Science.gov (United States)

    Jun, Daesu; Ishii, Kazuaki; Iida, Norimasa

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2007-03-15

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

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

    Science.gov (United States)

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

    2011-04-01

    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

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

    Science.gov (United States)

    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 O2 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

  17. Molecular Dynamics Study of a Dual-Cation Ionomer Electrolyte.

    Science.gov (United States)

    Chen, Xingyu; Chen, Fangfang; Jónsson, Erlendur; Forsyth, Maria

    2017-01-18

    The poly(N1222 )x Li1-x [AMPS] ionomer system (AMPS=2-acrylamido-2-methylpropane sulfonic acid) with dual cations has previously shown decoupled Li ion dynamics from polymer segmental motions, characterized by the glass-transition temperature, which can result in a conductive electrolyte material whilst retaining an appropriate modulus (i.e. stiffness) so that it can suppress dendrite formation, thereby improving safety when used in lithium-metal batteries. To understand this ion dynamics behavior, molecular dynamics techniques have been used in this work to simulate structure and dynamics in these materials. These simulations confirm that the Li ion transport is decoupled from the polymer particularly at intermediate N1222(+) concentrations. At 50 mol % N1222(+) concentration, the polymer backbone is more rigid than for higher N1222(+) concentrations, but with increasing temperature Li ion dynamics are more significant than polymer or quaternary ammonium cation motions. Herein we suggest an ion-hopping mechanism for Li(+) , arising from structural rearrangement of ionic clusters that could explain its decoupled behavior. Higher temperatures favor an aggregated ionic structure as well as enhancing these hopping motions. The simulations discussed here provide an atomic-level understanding of ion dynamics that could contribute to designing an improved ionomer with fast ion transport and mechanical robustness.

  18. On the atmospheric degradation of multifunctional organic compounds by NO3 and SO4- radicals in aqueous solution

    Science.gov (United States)

    Schöne, Luisa; Stieger, Bastian; Weller, Christian; Herrmann, Hartmut

    2014-05-01

    The atmospheric decomposition and transformation of a large number of organic compounds is initiated by radicals in the gas and aqueous phase. With increasing degree of oxidation and functionalization, organics become less volatile and more water soluble and partition into aqueous particles and cloud droplets where the oxidation by radicals continues. NO3 and SO4- radicals dominate the atmospheric aqueous phase besides OH radicals. Within this work, temperature dependent kinetic investigations were conducted by use of a laser flash photolysis laser long path absorption (LFPLLPA) setup. Second order rate constants for the reactions of 3-methoxy-1-propanol, diethylether, methylpropylether, 2-methyloxirane-2-carbaldehyde, 2,3-dihydroxy-2-methylpropanal, pyruvic, glyoxylic and glycolic acid as well as glyoxal, methylglyoxal and glycolaldehyde with NO3 and SO4- radicals were measured in a temperature range of 278 and 318 K applying pseudo-first order kinetics. The reactivity of the acids and their anions were investigated separately adjusting the pH to pH 1 or pH 8 for the acid or the anion form, respectively. From these measurements, activation parameters were derived. Measured k2nd range from 106 - 108 M1 s1. The kinetic and thermodynamic parameters as well as reaction mechanisms will be discussed within this contribution.

  19. Characterization of volatile aroma compounds in different brewing barley cultivars.

    Science.gov (United States)

    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.

  20. Zwitterionic Polymer P(AM-DMC-AMPS as a Low-Molecular-Weight Encapsulator in Deepwater Drilling Fluid

    Directory of Open Access Journals (Sweden)

    Xin Zhao

    2017-06-01

    Full Text Available In deepwater oil and gas drilling, the high-molecular-weight encapsulator aggravates the thickening of the drilling fluid at low temperatures. Therefore, it is hard to manage the downhole pressure, and drilling fluid loss occurs. In this paper, a zwitterionic polymer P(AM-DMC-AMPS which was the terpolymer of acrylamide, methacrylatoethyl trimethyl ammonium chloride, and 2-acrylamido-2-methylpropane sulfonic acid, was developed as a low-molecular-weight encapsulator. It was characterized by Fourier transform infrared spectrum analysis, nuclear magnetic resonance, and gel permeation chromatography. Moreover, the low-temperature rheology, shale inhibition and filtration properties of water-based drilling fluids (WBDFs containing different encapsulators were experimentally investigated and compared. The results showed that the molecular weight of P(AM-DMC-AMPS was about 260,000, much lower than that of the conventional encapsulators. In the deepwater drilling temperature range 4–75 °C, WBDF containing P(AM-DMC-AMPS had lower and more stable rheological property because of its short molecular chains. The high shale recovery rate and low swelling rate indicated its strong shale inhibition performance, owing to its adsorption on the clay surface and the wrapping effect through both hydrogen bonding and electrostatic interaction. It also improved the filtration property of WBDF, and was compatible with other WBDF components. This product is expected to simultaneously realize the good encapsulation performance and low-temperature rheological property for deepwater drilling fluid.

  1. Characterization of the key aroma compounds in an american bourbon whisky by quantitative measurements, aroma recombination, and omission studies.

    Science.gov (United States)

    Poisson, Luigi; Schieberle, Peter

    2008-07-23

    Thirty-one of the 45 odor-active compounds previously identified by us in an American Bourbon whisky were quantified by stable isotope dilution assays. Also for this purpose, new synthetic pathways were developed for the synthesis of the deuterium-labeled whisky lactone as well as for gamma-nona- and gamma-decalactone. To obtain the odor activity values (OAVs), the concentrations measured were divided by the odor thresholds of the odorants determined in water/ethanol (6:4 by vol.). Twenty-six aroma compounds showed OAVs >1, among which ethanol, ethyl (S)-2-methylbutanoate, 3-methylbutanal, 4-hydroxy-3-methoxybenzaldehyde, (E)-beta-damascenone, ethyl hexanoate, ethyl butanoate, ethyl octanoate, 2-methylpropanal, (3S,4S)- cis-whiskylactone, (E, E)-2,4-decadienal, 4-allyl-2-methoxyphenol, ethyl-3-methylbutanoate, and ethyl 2-methylpropanoate showed the highest values. The overall aroma of the Bourbon whisky could be mimicked by an aroma recombinate consisting of the 26 key odorants in their actual concentrations in whisky using water/ethanol (6:4 by vol.) as the matrix. Omission experiments corroborated the importance of, in particular, 4-hydroxy-3-methoxybenzaldehyde, (3S,4S)-cis-whiskylactone, ethanol, and the entire group of esters for the overall aroma of the Bourbon whisky.

  2. Intermolecular Hydrogen Transfer in Isobutane Hydrate

    Directory of Open Access Journals (Sweden)

    Takeshi Sugahara

    2012-05-01

    Full Text Available Electron spin resonance (ESR spectra of butyl radicals induced with γ-ray irradiation in the simple isobutane (2-methylpropane hydrate (prepared with deuterated water were investigated. Isothermal annealing results of the γ-ray-irradiated isobutane hydrate reveal that the isobutyl radical in a large cage withdraws a hydrogen atom from the isobutane molecule through shared hexagonal-faces of adjacent large cages. During this “hydrogen picking” process, the isobutyl radical is apparently transformed into a tert-butyl radical, while the sum of isobutyl and tert-butyl radicals remains constant. The apparent transformation from isobutyl to tert-butyl radicals is an irreversible first-order reaction and the activation energy was estimated to be 35 ± 3 kJ/mol, which was in agreement with the activation energy (39 ± 5 kJ/mol of hydrogen picking in the γ-ray-irradiated propane hydrate with deuterated water.

  3. Comparison of Aroma-Active Volatiles in Oolong Tea Infusions Using GC-Olfactometry, GC-FPD, and GC-MS.

    Science.gov (United States)

    Zhu, JianCai; Chen, Feng; Wang, LingYing; Niu, YunWei; Yu, Dan; Shu, Chang; Chen, HeXing; Wang, HongLin; Xiao, ZuoBing

    2015-09-02

    The aroma profile of oolong tea infusions (Dongdingwulong, DDWL; Tieguanyin, TGY; Dahongpao, DHP) were investigated in this study. Gas chromatography-olfactometry (GC-O) with the method of aroma intensity (AI) was employed to investigate the aroma-active compounds in tea infusions. The results presented forty-three, forty-five, and forty-eight aroma-active compounds in the TGY, DHP, and DDWL infusions, including six, seven, and five sulfur compounds, respectively. In addition, the concentration of volatile compounds in the tea infusions was further quantitated by solid phase microextraction-gas chromatography (SPME)-GC-MS and SPME-GC-flame photometric detection (FPD). Totally, seventy-six and thirteen volatile and sulfur compounds were detected in three types of tea infusions, respectively. Quantitative results showed that forty-seven aroma compounds were at concentrations higher than their corresponding odor thresholds. On the basis of the odor activity values (OAVs), 2-methylpropanal (OAV: 230-455), 3-methylbutanal (1-353), 2-methylbutanal (34-68), nerolidol (108-184), (E)-2-heptenal (148-294), hexanal (134-230), octanal (28-131), β-damascenone (29-59), indole (96-138), 6-methyl-5-hepten-2-one (34-67), (R)-(-)-linalool (63-87), and dimethyl sulfide (7-1320) presented relatively higher OAVs than those of other compounds, indicating the importance of these compounds in the overall aroma of tea infusions.

  4. A strong and tough interpenetrating network hydrogel with ultrahigh compression resistance.

    Science.gov (United States)

    Wang, Luyi; Shan, Guorong; Pan, Pengju

    2014-06-07

    A novel interpenetrating network (IPN) hydrogel with ultrahigh compressive strength and fracture strain has been prepared using the copolymer of 2-acrylamide-2-methylpropane sulfonic acid (AMPS) and acrylamide (AM) [P(AMPS-co-AM)] or N-isopropylacrylamide (NIPAM) [P(AMPS-co-NIPAM)] as the primary network and polyacrylamide (PAM) as the secondary network. The as-prepared IPN hydrogel of P(AMPS-co-AM)/PAM has a significantly high compressive strength (91.8 MPa), which is 4 times greater than that of the common PAMPS/PAM IPN hydrogel as well as the compressively strongest hydrogel reported in the literature. The P(AMPS-co-AM)/PAM IPN hydrogel is tough enough not to fracture even when the compressive strain reaches 98%. Synchrotron radiation small-angle X-ray scattering (SAXS) analysis has indicated that the presence of an AM comonomer changes the size of the physically cross-linked domains in the IPN hydrogel, which may partially account for its unique mechanical properties. This study has presented the compressively strongest hydrogel reported to date and also provided a novel and feasible method to prepare the highly strong and tough hydrogel.

  5. Removal of heavy metal ions from wastewater by a novel HEA/AMPS copolymer hydrogel: preparation, characterization, and mechanism.

    Science.gov (United States)

    Li, Zhengkui; Wang, Yueming; Wu, Ningmei; Chen, Qichun; Wu, Kai

    2013-03-01

    This study aims to synthesize 2-hydroxyethyl acrylate (HEA) and 2-acrylamido-2-methylpropane sulfonic (AMPS) acid-based hydrogels by gamma radiation and to investigate their swelling behavior and heavy metal ion adsorption capabilities. The copolymer hydrogels prepared were characterized via scanning electron microscopy, Fourier transformed infrared spectra, thermal gravimetric analysis, and X-ray photoelectron spectroscopy. The research showed that the copolymer hydrogel was beneficial for permeation due to its porous structure. In addition, the experimental group A-2-d [70 % water volume ratio and (n (AMPS)/n (HEA)) =1:1] was an optimal adsorbent. The optimal pH was 6.0 and the optimal temperature was 15 °C. Pb(2+), Cd(2+), Cu(2+), and Fe(3)+ achieved adsorption equilibriums within 24 h, whereas Cr(3+) reached equilibrium in 5 h. Pb(2)+, Cd(2+), Cr(3+), and Fe(3+) maximum load capacity was 1,000 mg L(-1), whereas the Cu(2+) maximum capacity was 500 mg L(-1). The priority order in the multicomponent adsorption was Cr(3+)>Fe(3+)>Cu(2+)>Cd(2+)>Pb(2+). The adsorption process of the HEA/AMPS copolymer hydrogel for the heavy metal ions was mainly due to chemisorption, and was only partly due to physisorption, according to the pseudo-second-order equation and Langmuir adsorption isotherm analyses. The HEA/AMPS copolymer hydrogel was confirmed to be an effective adsorbent for heavy metal ion adsorption.

  6. Development and characterization of a novel, antimicrobial, sterile hydrogel dressing for burn wounds: single-step production with gamma irradiation creates silver nanoparticles and radical polymerization.

    Science.gov (United States)

    Boonkaew, Benjawan; Barber, Philip M; Rengpipat, Sirirat; Supaphol, Pitt; Kempf, Margit; He, Jibao; John, Vijay T; Cuttle, Leila

    2014-10-01

    Patients with burn wounds are susceptible to wound infection and sepsis. This research introduces a novel burn wound dressing that contains silver nanoparticles (SNPs) to treat infection in a 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na(+) ) hydrogel. Silver nitrate was dissolved in AMPS-Na(+) solution and then exposed to gamma irradiation to form SNP-infused hydrogels. The gamma irradiation results in a cross-linked polymeric network of sterile hydrogel dressing and a reduction of silver ions to form SNPs infused in the hydrogel in a one-step process. About 80% of the total silver was released from the hydrogels after 72 h immersion in simulated body fluid solution; therefore, they could be used on wounds for up to 3 days. All the hydrogels were found to be nontoxic to normal human dermal fibroblast cells. The silver-loaded hydrogels had good inhibitory action against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. Results from a pilot study on a porcine burn model showed that the 5-mM silver hydrogel was efficient at preventing bacterial colonization of wounds, and the results were comparable to the commercially available silver dressings (Acticoat(TM) , PolyMem Silver(®) ). These results support its use as a potential burn wound dressing.

  7. Controlled delivery of valsartan by cross-linked polymeric matrices: Synthesis, in vitro and in vivo evaluation.

    Science.gov (United States)

    Sohail, Muhammad; Ahmad, Mahmood; Minhas, Muhammad Usman; Ali, Liaqat; Khalid, Ikrima; Rashid, Haroon

    2015-06-20

    The purpose of study was to develop chemically cross-linked chitosan-co-poly(AMPS) hydrogel based on low molecular weight chitosan for pH-responsive and controlled drug delivery of a model drug. Cross-linking was achieved chemically, by using free radical polymerization technique. Polymer (low molecular weight chitosan) was chemically cross-linked with monomer (2-acrylamido-2-methylpropane sulfonic acid) in aqueous medium. N, N'-Methylenebisacrylamide (MBA) was used as cross-linking agent. Sodium hydrogen sulfite (SHS) and ammonium peroxodisulphate (APS) were used as initiators in a chemical reaction. Hydrogels were characterized by FT-IR, SEM and DSC. Swelling studies and pH-sensitivity of hydrogels were studies at pH 1.2 and 7.4. Chitosan-co-poly(AMPS) hydrogels were administered to rabbits orally to evaluate its pharmacokinetic behavior. As a result of successful cross-linking of polymer and monomer, novel co-polymer has been developed, having suitable characteristics as desired for controlled release drug delivery system. Maximum swelling, drug loading and release have been observed at pH 7.4. In vivo results exhibited significant drug release and absorption at pH 7.4 in rabbits. It is concluded that highly swelling chitosan-AMPS based hydrogels were developed having pH independent swelling and pH dependent drug release properties. These hydrogels have great potential to be used for loading and controlled release of various therapeutic agents.

  8. Structural effects in photopolymerized sodium AMPS hydrogels crosslinked with poly(ethylene glycol) diacrylate for use as burn dressings.

    Science.gov (United States)

    Nalampang, Kanarat; Panjakha, Rachanida; Molloy, Robert; Tighe, Brian J

    2013-01-01

    Synthetic hydrogel polymers were prepared by free radical photopolymerization in aqueous solution of the sodium salt of 2-acrylamido-2-methylpropane sulfonic acid (Na-AMPS). Poly(ethylene glycol) diacrylate (PEGDA) and 4,4'-azo-bis(4-cyanopentanoic acid) were used as the crosslinker and UV-photoinitiator, respectively. The effects of varying the Na-AMPS monomer concentration within the range of 30-50% w/v and the crosslinker concentration within the range of 0.1-1.0% mol (relative to monomer) were studied in terms of their influence on water absorption properties. The hydrogel sheets exhibited extremely high swelling capacities in aqueous media which were dependent on monomer concentration, crosslink density, and the ionic strength and composition of the immersion medium. The effects of varying the number-average molecular weight of the PEGDA crosslinker from [Formula: see text] = 250 to 700 were also investigated. Interestingly, it was found that increasing the molecular weight and therefore the crosslink length at constant crosslink density decreased both the rate of water absorption and the equilibrium water content. Cytotoxicity testing by the direct contact method with mouse fibroblast L929 cells indicated that the synthesized hydrogels were nontoxic. On the basis of these results, it is considered that photopolymerized Na-AMPS hydrogels crosslinked with PEGDA show considerable potential for biomedical use as dressings for partial thickness burns. This paper describes some structural effects which are relevant to their design as biomaterials for this particular application.

  9. Cytotoxicity testing of silver-containing burn treatments using primary and immortal skin cells.

    Science.gov (United States)

    Boonkaew, Benjawan; Kempf, Margit; Kimble, Roy; Cuttle, Leila

    2014-12-01

    A novel burn wound hydrogel dressing has been previously developed which is composed of 2-acrylamido-2-methylpropane sulfonic acid sodium salt with silver nanoparticles (silver AMPS). This study compared the cytotoxicity of this dressing to the commercially available silver products; Acticoat™, PolyMem Silver(®) and Flamazine™ cream. Human keratinocytes (HaCaT and primary HEK) and normal human fibroblasts (NHF) were exposed to dressings incubated on Nunc™ polycarbonate inserts for 24, 48 and 72h. Four different cytotoxicity assays were performed including; Trypan Blue cell count, MTT, Celltiter-Blue™ and Toluidine Blue surface area assays. The results were expressed as relative cell viability compared to an untreated control. The cytotoxic effects of Acticoat™ and Flamazine™ cream were dependent on exposure time and cell type. After 24h exposure, Acticoat™ and Flamazine™ cream were toxic to all tested cell lines. Surprisingly, HaCaTs treated with Acticoat™ and Flamazine™ had an improved ability to survive at 48 and 72h while HEKs and NHFs had no improvement in survival with any treatment. The novel silver hydrogel and PolyMem Silver(®) showed low cytotoxicity to all tested cell lines at every time interval and these results support the possibility of using the novel silver hydrogel as a burn wound dressing. Researchers who rely on HaCaT cells as an accurate keratinocyte model should be aware that they can respond differently to primary skin cells.

  10. Rapid and Effective Removal of Cu2+ from Aqueous Solution Using Novel Chitosan and Laponite-Based Nanocomposite as Adsorbent

    Directory of Open Access Journals (Sweden)

    Jie Cao

    2016-12-01

    Full Text Available In this paper, a novel method for preparing nanoparticle-polymer hybrid adsorbent was established. Laponite was dispersed in distilled water to form Laponite nanoparticles. These nanoparticles were pre-adsorbed by 2-acrylamido-2-methylpropane-sulfonic acid (AMPS to improve their dispersion stability in chitosan solution. The nanoparticle-polymer hybrid adsorbent was prepared by copolymerization of chitosan, acrylamide, acrylic acid, AMPS, and Laponite nanoparticles. Four adsorbents were obtained and characterized by Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, and Brunauer-Emmett-Teller adsorption (BET. Additionally, the uptake capacities of Cu2+ using different samples were studied. Compared to the adsorbent without chitosan and Laponite components, the maximum uptake of the hybrid adsorbent increased from 0.58 to 1.28 mmol·g−1 and the adsorption equilibrium time of it decreased from more than 75 min to less than 35 min, which indicated that the addition of chitosan and Laponite could greatly increase the adsorption rate and capacity of polymer adsorbent. The effects of different experimental parameters—such as initial pH, temperature, and equilibrium Cu2+ concentration—on the adsorption capacities were studied. Desorption study indicated that this hybrid adsorbent was easy to be regenerated.

  11. Scale-up of the Reversible Addition-Fragmentation Chain Transfer (RAFT Polymerization Using Continuous Flow Processing

    Directory of Open Access Journals (Sweden)

    Nenad Micic

    2014-01-01

    Full Text Available A controlled radical polymerization process using the Reversible Addition-Fragmentation Chain Transfer (RAFT approach was scaled up by a factor of 100 from a small laboratory scale of 5 mL to a preparative scale of 500 mL, using batch and continuous flow processing. The batch polymerizations were carried out in a series of different glass vessels, using either magnetic or overhead stirring, and different modes of heating: Microwave irradiation or conductive heating in an oil bath. The continuous process was conducted in a prototype tubular flow reactor, consisting of 6 mm ID stainless steel tubing, fitted with static mixers. Both reactor types were tested for polymerizations of the acid functional monomers acrylic acid and 2-acrylamido-2-methylpropane-1-sulfonic acid in water at 80 °C with reaction times of 30 to 40 min. By monitoring the temperature during the exothermic polymerization process, it was observed that the type and size of reactor had a significant influence on the temperature profile of the reaction.

  12. Configuration control on the shape memory stiffness of molecularly imprinted polymer for specific uptake of creatinine

    Science.gov (United States)

    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.

  13. Determination of Residual Monomers in Polycarboxylate Superplasticizer Using High Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    GUO Liping; WANG Shaofeng; ZHANG Anfu; LEI Jiaheng; DU Xiaodi

    2011-01-01

    A procedure was developed for the determination of residual monomers in polycarboxylate superplasticizer (PCs) by reversed-phase high performance liquid chromatography (RP-HPLC). Four kinds of residual monomers were well separated and determined on a SinoChrom ODS-BP (C18) column with mobile phases composed of acetonitrile and phosphate buffer solution. The monomers were detected by UV detector at 205 nm and quantitatively analyzed with an external standard method. For those residual monomers, the linear response ranged from 4.0× 10-6 mol·L-1 to 2.0× 10-3 mol·L-1. The determination limit of acrylic acid, sodium methylallyl sulfonate and 2-Acrylamido-2-methylpropane sulfonic acid was 0.02× 10-5 mol·L-1, while that of methoxy-polyethylene glycol monoacrylate was 0.1 × 10-5 mol· L-1. The relative standard deviation (RSD) of high concentration samples was less than 1%, while that of the low concentration samples was between 1%-4%. The standard (additional) recovery ratio was 97.4% -104.2%.

  14. Application of ion mobility spectrometry for the detection of human urine.

    Science.gov (United States)

    Rudnicka, Joanna; Mochalski, Paweł; Agapiou, Agapios; Statheropoulos, Milt; Amann, Anton; Buszewski, Bogusław

    2010-11-01

    The aim of the present study was to evaluate the suitability of ion mobility spectrometry (IMS) for the detection of human urine as an indication of human presence during urban search and rescue operations in collapsed buildings. To this end, IMS with a radioactive ionization source and a multicapillary column was used to detect volatile organic compounds (VOCs) emitted from human urine. A study involving a group of 30 healthy volunteers resulted in the selection of seven volatile species, namely acetone, propanal, 3-methyl-2-butanone, 2-methylpropanal, 4-heptanone, 2-heptanone and octanal, which were detected in all samples. Additionally, a preliminary study on the permeation of urine volatiles through the materials surrounding the voids of collapsed buildings was performed. In this study, quartz sand was used as a representative imitating material. Four compounds, namely 3-methyl-2-butanone, octanal, acetone and 2-heptanone, were found to permeate through the sand layers during all experiments. Moreover, their permeation times were the shortest. Although IMS can be considered as a potential technique suitable for the detection, localization and monitoring of VOCs evolved from human urine, further investigation is necessary prior to selecting field chemical methods for the early location of trapped victims.

  15. Sulfonated macro-RAFT agents for the surfactant-free synthesis of cerium oxide-based hybrid latexes.

    Science.gov (United States)

    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.

  16. Quantitative analysis by GC-MS/MS of 18 aroma compounds related to oxidative off-flavor in wines.

    Science.gov (United States)

    Mayr, Christine M; Capone, Dimitra L; Pardon, Kevin H; Black, Cory A; Pomeroy, Damian; Francis, I Leigh

    2015-04-08

    A quantitation method for 18 aroma compounds reported to contribute to "oxidative" flavor in wines was developed. The method allows quantitation of the (E)-2-alkenals ((E)-2-hexenal, (E)-2-heptenal, (E)-2-octenal, and (E)-2-nonenal), various Strecker aldehydes (methional, 2-phenylacetaldehyde, 3-methylbutanal, and 2-methylpropanal), aldehydes (furfural, 5-methylfurfural, hexanal, and benzaldehyde), furans (sotolon, furaneol, and homofuraneol), as well as alcohols (methionol, eugenol, and maltol) in the same analysis. The aldehydes were determined after derivatization directly in the wine with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride; the formed oximes along with the underivatized aroma compounds were isolated by solid-phase extraction and analyzed by means of GC-MS/MS. The method was used to investigate the effect of different closures (synthetic closures, natural corks, and screw cap) on the formation of oxidation-related compounds in 14 year old white wine. Results showed a significant increase in the concentration of some of the monitored compounds in the wine, particularly methional, 2-phenylacetaldehyde, and 3-methylbutanal.

  17. Volatile compound profile of sous-vide cooked lamb loins at different temperature-time combinations.

    Science.gov (United States)

    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.

  18. Synthesis and application of hybrid polymer composites based on silver nanoparticles as corrosion protection for line pipe steel.

    Science.gov (United States)

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

    2014-05-16

    A facile method was developed to synthesize in high yield dispersed silver nanoparticles (AgNPs) with small particle sizes of less than 10 nm. Silver nitrate was reduced to silver nanoparticles by p-chloroaniline in the presence of polyoxyethylene maleate 4-nonyl-2-propylene-phenol (NMA) as a stabilizer. The produced AgNPs were used to prepare hybrid polymer based on N-isopropylacrylamide (NIPAm), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), N,N-methylenebisacrylamide (MBA) and potassium persulfate (KPS) using a semi-batch solution polymerization method. The prepared AgNPs and hybrid polymer were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM). The corrosion inhibition activity of the AgNPs and hybrid polymer towards steel corrosion in the presence of hydrochloric acid has been investigated by polarization and electrochemical impedance spectroscopy (EIS) methods. Polarization measurements indicate that the AgNPs and hybrid polymer 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.

  19. A solid-state dye-sensitized solar cell with a high voltage using indium hexacyanoferrate as a redox mediator

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Y.C.; Chen, L.C.; Ho, K.C. [National Taiwan Univ., Taipei, Taiwan (China). Dept. of Chemical Engineering

    2006-07-01

    In this study, the Prussian blue analogue indium hexacyanoferrate (InHCF) was used as the redox mediator to fabricate a high-voltage solid-state titanium oxide (TiO{sub 2}) dye-sensitized solar cell (DSSC). The aim of the study was to develop a solid-state TiO{sub 2} solar cell with a high voltage. TiO{sub 2} film was deposited onto a fluoride-doped tin oxide (FTO) conducting glass using a general sol-gel procedure. The solid-state cell was assembled with a KCI-saturated poly-2-acylamido-2-methylpropane sulfonic acid (AMPS) electrolyte (K-PAMPS). Cathodic and anodic peak potentials were average to obtain the formal redox potential of the couple in the K-PAMPS, which was estimated at 0.87 V vs. Ag/AgC1/saturated KCI. A memory effect was attributed to the poor contact between the InHCF mediator and the dye sensitizer. Contact problems and solid-state diffusion were identified as factors causing lower efficiency of 0.15 per cent. It was concluded that the imperfect dye/InHCF contact and the slow diffusion of K{sup +} in the InHCF thin film were responsible for the lower efficiency ratio. 5 refs., 3 figs.

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

    Science.gov (United States)

    Majumdar, Sanhita

    2016-07-01

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

  1. Isolation and Biological Evaluation of Two Bioactive Metabolites from Aspergillus gorakhpurensis

    Directory of Open Access Journals (Sweden)

    Venkateswarlu Yenamandra

    2009-06-01

    Full Text Available Fungi are known to produce a vast array of secondary metabolites that are gaining importance for their biotechnological applications. Screening of Aspergillus gorakhpurensis for the production of bioactive secondary metabolites results in the production of 4-(N-methyl-N-phenyl amino butan-2-one and itaconic acid. The structure of the known compounds was established by 1H-, 13C-NMR and Mass spectral data. Biological evaluation of the two compounds against test microorganisms showed strong inhibitory activity of 4-(N-methyl-N-phenyl amino butan-2-one towards bacteria and fungi. Only 4-( N -methyl-N- phenyl amino-butan-2-one showed a marked significant activity (LD 50 = 330.69 m g/mL in Spodoptera litura larvicidal bioassay.

  2. A new process for the valorisation of a bio-alcohol. The oxidehydration of 1-butanol into maleic anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Caldarelli, A.; Cavani, F.; Garone, O.; Pavarelli, G. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali; Bologna Univ. (Italy). CIRCC, Research Unit; Dubois, J.L. [ARKEMA, Colombes (France); Mitsova, I.; Simeonova, L. [JSC, Russe (Bulgaria). Orgachim

    2012-07-01

    This paper deals with a study on the gas-phase transformation of 1-butanol into maleic anhydride, using different types of catalysts. Indeed, catalytic acid properties are needed to dehydrate 1-butanol into 1-butene, whereas redox-type properties are required for the oxidation of the olefin into maleic anhydride. The two types of active sites can be combined in bifunctional systems, showing both acid and redox-type properties. We found that vanadyl pyrophosphate catalyzes the one-pot reaction, giving a maximum selectivity to maleic anhydride of 28%. In fact, various side reactions contributed to the formation of by-products, eg, 1-butanol (oxidative) dehydrogenation into butyraldehyde, formation of light carboxylic acids and carbon oxides, and condensation of unsaturated C{sub 4} intermediates (butenes and butadiene) with the formed maleic anhydride to yield heavier compounds. (orig.)

  3. Homo-polymerization of α-Olefins and Co-polymerization of Higher α-Olefins with Ethylene in the Presence of CpTiCl2(OC6H4X-p/MAO Catalysts (X = CH3, Cl

    Directory of Open Access Journals (Sweden)

    Z. Wieczorek

    2005-07-01

    Full Text Available Cyclopentadienyl-titanium complexes containing –OC6H4X ligands (X = Cl,CH3 activated with methylaluminoxane (MAO were used in the homo-polymerizationof ethylene, propylene, 1-butene, 1-pentene, 1-butene, and 1-hexene, and also in co-polymerization of ethylene with the α-olefins mentioned. The -X substituents exhibitdifferent electron donor-acceptor properties, which is described by Hammett’s factor (σ.The chlorine atom is electron acceptor, while the methyl group is electron donor. Thesecatalysts allow the preparation of polyethylene in a good yield. Propylene in the presenceof the catalysts mentioned dimerizes and oligomerizes to trimers and tetramers at 25oCunder normal pressure. If the propylene pressure was increased to 7 atmospheres,CpTiCl2(OC6H4CH3/MAO catalyst at 25oC gave mixtures with different contents ofpropylene dimers, trimers and tetramers. At 70oC we obtained only propylene trimer.Using the catalysts with a -OC6H4Cl ligand we obtained atactic polymers with Mw182,000 g/mol (at 25oC and 100,000 g/mol (at 70oC. The superior activity of theCpTiCl2(OC6H4Cl/MAO catalyst used in polymerization of propylene prompted us tocheck its activity in polymerization of higher α-olefins (1-butene, 1-pentene, 1-hexeneand in co-polymerization of these olefins with ethylene. However, when homo-polymerization was carried out in the presence of this catalyst no polymers wereobtained. Gas chromatography analysis revealed the presence of dimers. The activity ofthe CpTiCl2(OC6H4Cl/MAO catalyst in the co-polymerization of ethylene with higher α-olefins is limited by the length of the co-monomer carbon chain. Hence, the highest catalyst activities were observed in co-polymerization of ethylene with propylene (here a lower pressure of the reagents and shorter reaction time were applied to obtain catalytic activity similar to that for other co-monomers. For other co-monomers the activity of the catalyst

  4. Shock tube study of the fuel structure effects on the chemical kinetic mechanisms responsible for soot formation, part 2

    Science.gov (United States)

    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.

  5. Olefin metathesis reaction on a MoS/sub 2/ catalyst

    Energy Technology Data Exchange (ETDEWEB)

    1976-06-15

    Olefin metathesis reaction was found to take place on rather pure MoS/sub 2/ evacuated at 450/sup 0/C for several hours. Systematic studies of the isotopic scrambling in ethylene, propylene, 1-butene, and 2-butene on MoS/sub 2/ using microwave spectroscopy are reported. These studies were made using /sup 12/C- and /sup 13/C-labelled compounds and D-labelled compounds. Results indicated that the MoS/sub 2/ catalyst evacuated at 450/sup 0/C has two kinds of active sites, one is effective for the isomerization and the hydrogen isotopic mixing of olefins, and the other is effective for the hydrogenation reaction. This may be explained by assuming different degrees of coordinative unsaturation for the active sites. (BLM)

  6. Single Site Silica Supported Tetramethyl Niobium by the SOMC Strategy: Synthesis, Characterization and Structure-Activity Relationship in Ethylene Oligomerization Reaction

    KAUST Repository

    Hamieh, Ali Imad Ali

    2017-06-06

    Silica supported Tetramethyl niobium complex [(≡SiO)NbMe4] 2 has been isolated by surface alkylation of [(≡SiO-)NbCl3Me] 1 with dimethyl zinc in pentane. 1 can be easily synthesized by grafting of NbCl3Me2 on to the surface of partially dehydroxylated silica by the SOMC strategy. Precise structural analysis was carried out by the FTIR, advance solid state NMR, elemental analysis and mass balance techniques (gas quantification after treating 2 with degassed water) . Complex 1 was found to be active in the ethylene oligomerization to produce up to C30, whereas to our surprise complex 2 selectively dimerizes ethylene into 1-butene in the absence of a co-catalyst at the same conversion levels.

  7. Synthesis of Ni-SiO2/silicalite-1 core-shell micromembrane reactors and their reaction/diffusion performance

    KAUST Repository

    Khan, Easir A.

    2010-12-15

    Core-shell micromembrane reactors are a novel class of materials where a catalyst and a shape-selective membrane are synergistically housed in a single particle. In this work, we report the synthesis of micrometer -sized core-shell particles containing a catalyst core and a thin permselective zeolite shell and their application as a micromembrane reactor for the selective hydrogenation of the 1-hexene and 3,3-dimethyl-1-butene isomers. The bare catalyst, which is made from porous silica loaded with catalytically active nickel, showed no reactant selectivity between hexene isomers, but the core-shell particles showed high selectivities up to 300 for a 1-hexene conversion of 90%. © 2010 American Chemical Society.

  8. Reaction mechanism studies of unsaturated molecules using photofragment translational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Longfellow, C.A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley National Lab., CA (United States). Chemical Sciences Div.

    1996-05-01

    A number of molecules have been studied using the technique of photofragment translational spectroscopy. In Chapter One a brief introduction to the experimental technique is given. In Chapter Two the infrared multiphoton dissociation (IRMPD) of acetic acid is discussed. Carbon dioxide and methane were observed for the first time as products from dissociation under collisionless conditions. Chapter Three relates an IRMPD experiment of hexafluoropropene. The predominant channel produces CFCF{sub 3} or C{sub 2}F{sub 4} and CF{sub 2}, with the heavier species undergoing further dissociation to two CF{sub 2} fragments. In Chapter Four the ultraviolet (UV) dissociation of hexafluoropropene is investigated. Chapter Five explores the IRMPD of octafluoro-1-butene and octafluoro-2-butene.

  9. Energy Conversion and Combustion Sciences

    Science.gov (United States)

    2013-03-08

    History and Recent Progress 10 1 10 2 10 3 10 4 10 2 10 3 10 4 JetSURF 2.0 Ranzi mechanism comlete, ver 1201 methyl palmitate (CNRS) Gasoline (Raj et...al) 2-methyl alkanes (LLNL) Biodiesel (LLNL) before 2000 2000-2004 2005-2009 since 2010 iso-octane (LLNL) iso-octane (ENSIC-CNRS) n-butane (LLNL...methyl alkanes (LLNL) Biodiesel (LLNL) before 2000 2000-2004 2005-2009 since 2010 iso-octane (LLNL) iso-octane (ENSIC-CNRS) n-butane (LLNL) CH4

  10. Two-phase flows during a discharge of liquefied gases, initially at saturation. Effect of the nature of the fluid; Ecoulements diphasiques lors de la vidange de gaz liquefies initialement a saturation. Influence de la nature du fluide

    Energy Technology Data Exchange (ETDEWEB)

    Alix, P.

    1997-10-03

    In the case of a confinement loss (breakage of a connection piece) on a pressurized liquefied gas tank, a critical two-phase (liquid-vapour) flow is generated. This thesis is aimed at the validation of models describing these flows with various fluids (water, R 11, methanol, ethyl acetate, pure butane, commercial butane), using a pilot experimental plant. Results show that reduced upstream pressure is the main parameter, thus indicating that a model can be validated using minimal fluids. The homogenous models DEM and HRM appear to be more precise

  11. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    Science.gov (United States)

    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.

  12. Product ion distributions for the reactions of NO(+) with some physiologically significant aldehydes obtained using a SRI-TOF-MS instrument

    OpenAIRE

    Mochalski, P; Unterkofler, K.; Španěl, P; Smith, D; AMANN, A

    2014-01-01

    Product ion distributions for the reactions of NO(+) with 22 aldehydes involved in human physiology have been determined under the prevailing conditions of a selective reagent ionization time of flight mass spectrometry (SRI-TOF-MS) at an E/N in the flow/drift tube reactor of 130 Td. The chosen aldehydes were fourteen alkanals (the C2-C11 n-alkanals, 2-methyl propanal, 2-methyl butanal, 3-methyl butanal, and 2-ethyl hexanal), six alkenals (2-propenal, 2-methyl 2-propenal, 2-butenal, 3-methyl ...

  13. The North American natural gas liquids markets are chaotic

    OpenAIRE

    1999-01-01

    In this paper we test for deterministic chaos (i.e., nonlinear deterministic processes which look random) in seven Mont Belview, Texas hydrocarbon markets, using monthly data from 1985:1 to 1996:12--the markets are those of ethane, propane, normal butane, iso-butane, naptha, crude oil, and natural gas. In doing so, we use the Lyapunov exponent estimator of Nychka, Ellner, Gallant, and McCaffrey (1992). We conclude that there is evidence consistent with a chaotic nonlinear generation process i...

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

    KAUST Repository

    Li, Baiyan

    2016-11-04

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

  15. The elimination of water from a conformationally complex alcohol: A computational study of the gas phase dehydration of n-butanol

    Science.gov (United States)

    Moc, Jerzy; Simmie, John M.; Curran, Henry J.

    2009-06-01

    Relative stabilities of the 14 conformers of n-butanol were calculated at the CCSD(T)/cc-pVTZ//MP2/6-311G(d,p) level. The three most stable structures found, TGt, TGg and TGg' ( trans (T or t) and gauche (G or g) with respect to the CC-CC, CC-CO and CC-OH dihedral angles, respectively) lie within 0.14 kcal/mol, Δ H(0 K), with the TGt being favoured thermodynamically (the ZPVE corrections were found at the MP2 level). The rotational isomerizations to the other conformers were examined, in particular those involved in the elimination of water. The elimination of H 2O from n-butanol involving the formation of the corresponding carbene, 1-butene, methylcyclopropane and cyclobutane, 1,1-, 1,2-, 1,3- and 1,4-elimination, respectively, was systematically investigated. The 1,2-H 2O loss occurring from the TGg' conformer and involving a four-center transition state has been found to be thermodynamically and kinetically the most favoured route. This elimination which leads to the 1-butene olefin isomer is endothermic by 8.25 kcal/mol, Δ H(0 K), with an associated activation enthalpy at 0 K of 67.26 kcal/mol at the CCSD(T)/cc-pVTZ//MP2/6-311G(d,p) level (relative to the TGt conformer). The respective CBS-QB3 estimates are 7.84 and 67.88 kcal/mol.

  16. Estrogenic activity of styrene oligomers after metabolic activation by rat liver microsomes.

    Science.gov (United States)

    Kitamura, Shigeyuki; Ohmegi, Motoko; Sanoh, Seigo; Sugihara, Kazumi; Yoshihara, Shin'ichi; Fujimoto, Nariaki; Ohta, Shigeru

    2003-01-01

    In this study we examined estrogenic activity of styrene oligomers after metabolic activation by rat liver microsomes. Trans-1,2-diphenylcyclobutane (TCB), cis-1,2-diphenylcyclobutane (CCB), 1,3-diphenylpropane, 2,4-diphenyl-1-butene, 2,4,6-triphenyl-1-hexene, and 1-alpha-phenyl-4ss-(1 -phenylethyl)tetralin were negative in the yeast estrogen screening assay and estrogen reporter assay using estrogen-responsive human breast cancer cell line MCF-7. However, TCB exhibited estrogenic activity after incubation with liver microsomes of phenobarbital-treated rats in the presence of reduced nicotinamide adenine dinucleotide phosphate (NADPH). Minor activity was observed when liver microsomes of untreated or 3-methylcholanthrene-treated rats were used instead of those from phenobarbital-treated rats. CCB, 1,3-diphenylpropane, and 2,4-diphenyl-1-butene also exhibited estrogenic activity after metabolic activation by liver microsomes, but the activity was lower than that of TCB. 2,4,6-Triphenyl-1-hexene and 1-alpha-phenyl-4ss-(1 -phenylethyl)tetralin did not show estrogenic activity after such incubation. When TCB was incubated with liver microsomes of phenobarbital-treated rats in the presence of NADPH, three metabolites were detected by high-performance liquid chromatography (HPLC). One metabolite isolated by HPLC exhibited a significant estrogenic activity. The active metabolite was identified as trans-1-(4-hydroxyphenyl)-2-phenylcyclobutane by mass and nuclear magnetic resonance spectral analysis. These results suggest that the estrogenic activity of TCB was caused by the formation of the 4-hydroxylated metabolite. PMID:12611662

  17. Decarboxylative-coupling of allyl acetate catalyzed by group 10 organometallics, [(phen)M(CH3)]+.

    Science.gov (United States)

    Woolley, Matthew; Ariafard, Alireza; Khairallah, George N; Kwan, Kim Hong-Yin; Donnelly, Paul S; White, Jonathan M; Canty, Allan J; Yates, Brian F; O'Hair, Richard A J

    2014-12-19

    Gas-phase carbon-carbon bond forming reactions, catalyzed by group 10 metal acetate cations [(phen)M(O2CCH3)](+) (where M = Ni, Pd or Pt) formed via electrospray ionization of metal acetate complexes [(phen)M(O2CCH3)2], were examined using an ion trap mass spectrometer and density functional theory (DFT) calculations. In step 1 of the catalytic cycle, collision induced dissociation (CID) of [(phen)M(O2CCH3)](+) yields the organometallic complex, [(phen)M(CH3)](+), via decarboxylation. [(phen)M(CH3)](+) reacts with allyl acetate via three competing reactions, with reactivity orders (% reaction efficiencies) established via kinetic modeling. In step 2a, allylic alkylation occurs to give 1-butene and reform metal acetate, [(phen)M(O2CCH3)](+), with Ni (36%) > Pd (28%) > Pt (2%). Adduct formation, [(phen)M(C6H11O2)](+), occurs with Pt (24%) > Pd (21%) > Ni(11%). The major losses upon CID on the adduct, [(phen)M(C6H11O2)](+), are 1-butene for M = Ni and Pd and methane for Pt. Loss of methane only occurs for Pt (10%) to give [(phen)Pt(C5H7O2)](+). The sequences of steps 1 and 2a close a catalytic cycle for decarboxylative carbon-carbon bond coupling. DFT calculations suggest that carbon-carbon bond formation occurs via alkene insertion as the initial step for all three metals, without involving higher oxidation states for the metal centers.

  18. THE VIRIAL OF ANGLE-DEPENDENT POTENTIALS IN MOLECULAR-DYNAMICS SIMULATIONS

    NARCIS (Netherlands)

    BEKKER, H; AHLSTROM, P

    1994-01-01

    It is proved that the scalar virial of potentials that only depend on angles is zero. This is proved for nonperiodic boundary conditions as well as periodic boundary condition (PBC) systems. This theory is tested on an molecular dynamics simulation of butane with PBC.

  19. In situ vibrational spectroscopic investigation of C4 hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Zhi -Yang [Iowa State Univ., Ames, IA (United States)

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  20. 40 CFR 98.38 - Definitions.

    Science.gov (United States)

    2010-07-01

    ....103 67.74 Butane 0.101 65.15 Butylene 0.103 67.73 Naphtha ( 401 deg F) 0.139 76.22 Pentanes Plus 0.110 70.02 Petrochemical Feedstocks 0.129 70.97 Petroleum Coke 0.143 102.41 Special Naphtha 0.125 72.34...

  1. Assessing guest diffusivities in porous hosts from transient concentration profiles

    NARCIS (Netherlands)

    L. Heinke; D. Tzoulaki; C. Chmelik; F. Hibbe; J.M. van Baten; H. Lim; Y. Li; R. Krishna; J. Kärger

    2009-01-01

    Using the short-chain-length alkanes from ethane to n-butane as guest molecules, transient concentration profiles during uptake or release (via interference microscopy) and tracer exchange (via IR microimaging) in Zn(tbip), a particularly stable representative of a novel family of nanoporous materia

  2. Parametric Optimization of Regenerative Organic Rankine Cycle System for Diesel Engine Based on Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Hongjin Wang

    2015-09-01

    Full Text Available To efficiently recover the waste heat from a diesel engine exhaust, a regenerative organic Rankine cycle (RORC system was employed, and butane, R124, R416A, and R134a were used as the working fluids. The resulting diesel engine-RORC combined system was defined and the relevant evaluation indexes were proposed. First, the variation tendency of the exhaust energy rate under various diesel engine operating conditions was analyzed using experimental data. The thermodynamic model of the RORC system was established based on the first and second laws of thermodynamics, and the net power output and exergy destruction rate of the RORC system were selected as the objective functions. A particle swarm optimization (PSO algorithm was used to optimize the operating parameters of the RORC system, including evaporating pressure, intermediate pressure, and degree of superheat. The operating performances of the RORC system and diesel engine-RORC combined system were studied for the four selected working fluids under various operating conditions of the diesel engine. The results show that the operating performances of the RORC system and the combined system using butane are optimal on the basis of optimizing the operating parameters; when the engine speed is 2200 r/min and engine torque is 1215 N·m, the net power output of the RORC system using butane is 36.57 kW, and the power output increasing ratio (POIR of the combined system using butane is 11.56%.

  3. 40 CFR 60.503 - Test methods and procedures.

    Science.gov (United States)

    2010-07-01

    .../liter of gasoline loaded. Vesi=volume of air-vapor mixture exhausted at each interval “i”, scm. Cei...×106 for propane and 2.41×106 for butane, mg/scm. (4) The performance test shall be conducted...

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

    Science.gov (United States)

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

    2003-05-01

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

  5. Stoichiometric Experiments with Alkane Combustion: A Classroom Demonstration

    Science.gov (United States)

    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…

  6. Chain Length Effects of Linear Alkanes in Zeolite Ferrierite. 1. Sorption and 13C NMR Experiments

    NARCIS (Netherlands)

    Well, van Willy J.M.; Cottin, Xavier; Haan, vde Jan W.; Smit, Berend; Nivarthy, Gautam; Lercher, Johannes A.; Hooff, van Jan H.C.; Santen, van Rutger A.

    1998-01-01

    Temperature-programmed desorption, heat of adsorption, adsorption isotherm, and 13C NMR measurements are used to study the sorption properties of linear alkanes in ferrierite. Some remarkable chain length effects are found in these properties. While propane, n-butane, and n-pentane fill the ferrieri

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

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Z.Y.

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  8. Rhodium-Catalysed Asymmetric Hydroformylation of Unsaturated Nitriles

    NARCIS (Netherlands)

    Lambers-Verstappen, Mariëlle M.H.; Vries, Johannes G. de

    2003-01-01

    Asymmetric hydroformylation of crotononitrile (1) and allyl cyanide (2) was probed with the view to develop a synthesis for (R)-4-amino-2-methyl-butan-1-ol. Hydroformylation of 1 under a variety of conditions mainly led to hydrogenated product. Hydroformylation of 2 with

  9. On a novel coordination mode of phosphinine C5H5P.

    Science.gov (United States)

    Elschenbroich, Christoph; Six, Jörg; Harms, Klaus

    2006-08-28

    In an unprecedented coordination mode two phosphinines simultaneously bridge a Mn-Mn bond and the latter with two Mn(CO)3 fragments; the distortion of the resulting central heterobicyclo[1.1.0]butane unit follows from the Mn(18VE) requirement.

  10. Activity and selectivity control in reductive amination of butyraldehyde over noble metal catalysts.

    NARCIS (Netherlands)

    Bodis, E.; Lefferts, Leonardus; Muller, T.E.; Pestman, R.; Lercher, J.A.

    2005-01-01

    Approaches to control selectivity and activity in the catalytic reductive amination of butyraldehyde with ammonia over carbon supported noble metal catalysts (Ru, Rh, Pd, and Pt) were explored. Detailed analysis of the reaction network shows that the Schiff base N-[butylidene]butan-1-amine is the

  11. Branched chain aldehydes: production and breakdown pathways and relevance for flavour in foods

    NARCIS (Netherlands)

    Smit, B.A.; Engels, W.J.M.; Smit, G.

    2009-01-01

    Branched aldehydes, such as 2-methyl propanal and 2- and 3-methyl butanal, are important flavour compounds in many food products, both fermented and non-fermented (heat-treated) products. The production and degradation of these aldehydes from amino acids is described and reviewed extensively in lite

  12. Preliminary Assessment/Site Investigation: Tooele Army Depot, Utah. Volume 1. North Area and Facilities at Hill Air Force Base. Appendixes

    Science.gov (United States)

    1988-12-01

    PENTACOSANE C3AME PROPANOIC ACID , METHYL ESTER C30AKE TRIACONTANOIC ACID, METHYL ESTER C36 HEXATRIACONTANE C4 BUTANE C4KXlL CIS-4-HEXENI-OL C5A PENTANOIC ...PATPE PHOSPHORIC ACID, TRIPHENYL ESTER PA2HDE PROPANOIC ACID, 2-HYDROXYDECYL ESTER PA.2MBE PENTANOIC ACID, 2-METHYLBUTYL ESTER PB LEAD PBSTY LEAD

  13. A molecular simulation study of commensurate-incommensurate adsorption of n-alkanes in cobalt formate frameworks

    NARCIS (Netherlands)

    Krishna, R.; van Baten, J.M.

    2009-01-01

    The channels of the cobalt formate frameworks consist of one-dimensional channels that have a zig-zag configuration. Propane (C3) has a length that commensurates with the channel segment length; longer n-alkanes such as n-butane (nC4), n-pentane (nC5) and n-hexane (nC6) have conformations that

  14. Heterogeneously Catalysed Aldol Reactions in Supercritical Carbon Dioxide as Innovative and Non-Flammable Reaction Medium

    DEFF Research Database (Denmark)

    Musko, Nikolai; Grunwaldt, Jan-Dierk

    2011-01-01

    in this preliminary study under the entitled reaction conditions. Small and linear aldehydes, such as propanal, butanal, pentanal and hexanal, react more efficiently than the branched 3-methylbutanal, which is converted much slower. Whereas Amberlyst-15 showed the highest conversion based on the catalyst mass...

  15. chain length effects of linear alkanes in zeolite ferrierite.1. sorption and 13C NMR experiments

    NARCIS (Netherlands)

    van Well, Willy J.M.; Cottin, Xavier; vde Haan, Jan W.; Smit, Berend; Nivarthy, G.S.; Lercher, J.A.; van Hooff, Jan H.C.; van Santen, Rutger A.

    1998-01-01

    Temperature-programmed desorption, heat of adsorption, adsorption isotherm, and 13C NMR measurements are used to study the sorption properties of linear alkanes in ferrierite. Some remarkable chain length effects are found in these properties. While propane, n-butane, and n-pentane fill the

  16. Review Article

    African Journals Online (AJOL)

    Dr Ahmed

    zeolite based catalysts have been tested in this respect. This ... methyl t-butyl ether (MTBE), which has also found application as gasoline additive for raising ... mol mol-1 Hydrogen/hydrocarbon ratio, 20 bar total pressure and ... the catalysts. Eswaramoorthi et al., (2004) hydrothermally synthesized ..... of 2,2-dimethyl butane.

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

    Science.gov (United States)

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

    2014-03-01

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

  18. MOLECULARLY IMPRINTED POLYMER TECHNOLOGY: A ...

    African Journals Online (AJOL)

    dell

    Salbutamol (2-(hydroxymethyl)-4-[1-hydroxy-2-(tert-butylamino)ethyl]phenol) ... dimethylamino-3-methyl-1,2-diphenyl-butan-2-yl]propanoate) is an anti-cough agent. ... Efficacy of (S)-omeprazole over the racemic mixture is claimed. .... simultaneous exclusion of sulphur dioxide. ... thermal stability, which affords sterilization.

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

    Science.gov (United States)

    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...

  20. Fusarium solani pisi cutinase-catalyzed synthesis of polyamides

    NARCIS (Netherlands)

    Stavila, E.; Arsyi, R. Z.; Petrovic, D. M.; Loos, K.

    Polyamides, or nylon, are widely used in fiber and engineering plastic materials, due to their good mechanical and thermal properties. Synthesis of oligomers from nylon-4,10, nylon-6,10, and nylon-8,10 were performed via polycondensation of diamines (1,4-butane-diamine, 1,6-hexanediamine, and

  1. 10 CFR 205.12 - Addresses for filing documents with the DOE.

    Science.gov (United States)

    2010-01-01

    ... concerning price (see paragraph (a)(6) of this section), those designated as DOE or FEO forms (see paragraph...: Crude oil 10 Naphtha and gas oil 15 Propane, butane and natural gasoline 25 Other products 30 Bunker fuel 40 Residual fuel (nonutility) 50 Motor gasoline 60 Middle distillates 70 Aviation fuels...

  2. Hydrogen Bonding in Thermoplastic Polyurethane Elastomers: IR Thermal Analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The hydrogen bond percentage and its temperature dependence of the three TPU samples synthesized from polytetrahydrofuran, 4,4-diphenylmethane diisocyanate, N-methyl diethanol amine or 1,4-butane diol were studied by means of IR thermal analysis. The enthalpy and the entropy of the hydrogen bond dissociation were determined by the Vant Hoff plot.

  3. 75 FR 34017 - Protection of Stratospheric Ozone: Notice 25 for Significant New Alternatives Policy Program

    Science.gov (United States)

    2010-06-16

    ...-600 (Butane) (new and retrofit equipment) R-744 (Carbon dioxide, CO 2 ) (new equipment) R-1270... refrigerants to greenhouse gas emissions is limited given the venting prohibition under section 608(c)(2) of... refrigerants to greenhouse gas emissions is limited given the venting prohibition under section 608(c)(2)...

  4. Compositional Modeling for Optimum Design of Water-Alternating CO2-LPG EOR under Complicated Wettability Conditions

    Directory of Open Access Journals (Sweden)

    Jinhyung Cho

    2015-01-01

    Full Text Available The addition of LPG to the CO2 stream leads to minimum miscible pressure (MMP reduction that causes more oil swelling and interfacial tension reduction compared to CO2 EOR, resulting in improved oil recovery. Numerical study based on compositional simulation has been performed to examine the injectivity efficiency and transport behavior of water-alternating CO2-LPG EOR. Based on oil, CO2, and LPG prices, optimum LPG concentration and composition were designed for different wettability conditions. Results from this study indicate how injected LPG mole fraction and butane content in LPG affect lowering of interfacial tension. Interfacial tension reduction by supplement of LPG components leads to miscible condition causing more enhanced oil recovery. The maximum enhancement of oil recovery for oil-wet reservoir is 50% which is greater than 22% for water-wet reservoir. According to the result of net present value (NPV analysis at designated oil, CO2, propane, and butane prices, the optimal injected LPG mole fraction and composition exist for maximum NPV. At the case of maximum NPV for oil-wet reservoir, the LPG fraction is about 25% in which compositions of propane and butane are 37% and 63%, respectively. For water-wet reservoir, the LPG fraction is 20% and compositions of propane and butane are 0% and 100%.

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

    Science.gov (United States)

    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...

  6. The Application of Raman Spectroscopy for Analysis of Multicomponent Systems

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.; Stenby, Erling Halfdan

    1998-01-01

    gas and oils. Until now we have obtained Raman spectra on bottled gas (propane and butane) mixed with oxygen, condensate (from DONG A/S), many different oils, and natural gas (under normal conditions).Our goal is to obtain spectra of natural gas taken directly from the well. We have designed...

  7. Selective hydrogenation of 1,3-butadiene from crude C{sub 4} cracker stream with a solid catalyst with ionic liquid layer (SCILL). DSC and solubility study

    Energy Technology Data Exchange (ETDEWEB)

    Mangartz, T.; Korth, W.; Kern, C.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2013-11-01

    In petroleum as well as in fine chemical industry, selective catalytic hydrogenation is an important reaction. The selective hydrogenation of 1,3-butadiene (BD) to butene (trans-,1- and cis-butene) from the crude C4 steam cracker fraction represents one example, but under today's technical conditions undesired butane forms inevitably in relevant amounts. To increase the butene yield, the concept of Solid Catalyst with Ionic Liquid Layer (SCILL) was employed. The SCILL catalyst, in contrast to the uncoated catalyst, yielded a remarkably high selectivity to butenes (S{sub butenes} > 99 %) even at high residence times or at high hydrogen partial pressure. Nearly no butane (S{sub butane} {approx} 0 %) was analytically detected. We expected that due to different solubility, the poorer soluble compounds discharged from the ionic liquid and, thus, caused the shift in selectivity to a great extent. Temperature dependent solubility measurements in the used ionic liquid ([DMIM][DMP]) revealed that the order of increasing solubility is 1,3-butadiene > butenes > butane which matches the assumption. However, since differences in solubility cannot explain this SCILL effect satisfyingly, ionic liquids are expected to affect the surface of the catalyst (side-specific ligand-type effect). Investigations using spectroscopic methods (e.g. FTIR) confirmed this suggestion. (orig.)

  8. Role of LPG as an energy substitute in Algeria; Role des G.P.L. comme energie de substitution en Algerie

    Energy Technology Data Exchange (ETDEWEB)

    Boukadoum, Abdelhamid; Houghlaouene, Samir

    2010-09-15

    Algeria is a leader country in LPG industry. The availability of resources and the upstream production development efforts have oriented the large energy choices in terms of domestic market need satisfaction. LPG (propane and butane) plays a massive role in the change towards clean energy (case of LPG versus gas) and towards more practical energy (i.e. the case of bulk propane versus the packed butane, or versus natural gas). [French] L'Algerie est un pays leader dans l'industrie des GPL. La disponibilite des ressources et les efforts de developpement de la production en amont ont oriente les grands choix energetiques en matiere de satisfaction des besoins du marche domestique. En effet, les GPL (propane et butane) jouent un role majeur dans la substitution vers les sources d'energie propres (cas du GPL/C par rapport aux essences) et vers des energies plus commodes (par exemple le cas du propane vrac par rapport au butane conditionne, voire par rapport au gaz naturel).

  9. Combustion and Energy Transfer Experiments: A Laboratory Model for Linking Core Concepts across the Science Curriculum

    Science.gov (United States)

    Barreto, Jose C.; Dubetz, Terry A.; Schmidt, Diane L.; Isern, Sharon; Beatty, Thomas; Brown, David W.; Gillman, Edward; Alberte, Randall S.; Egiebor, Nosa O.

    2007-01-01

    Core concepts can be integrated throughout lower-division science and engineering courses by using a series of related, cross-referenced laboratory experiments. Starting with butane combustion in chemistry, the authors expanded the underlying core concepts of energy transfer into laboratories designed for biology, physics, and engineering. This…

  10. Method for producing diene hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Tsaylingol' d, A.L.; Abayev, G.N.; Mikhaylov, R.K.; Stepanov, G.A.; Troitskiy, A.P.

    1980-04-28

    A method is claimed for producing diene hydrocarbons by oxidational dehydration of paraffin or olefin hydrocarbons in a fluidized bed of a concentrate with circulation of the latter between the zones of the reaction of regeneration with the help of circulation stand pipes. To increase the efectiveness of the process, it is proposed to circulate the concentrate between the zones of reaction and regeneration, sequentially disposed in a common apparatus with a difference in the concentration of the concentrate in the circulation stand pipes disposed in the same apparatus and the zone of the reaction equal to 20-700 kg/m/sup 3/. For example, the process of oxidational dehydration of butane through the proposed system is conducted in an apparatus with a diameter of 1,000 mm, a circulation stand pipe diameter of 500 mm, a linear gas speed in the reaction zone of 0.6 m/s, and in the circulation stand pipe of 0.15 m/s. The concentration of the concentrate in the dehydration zone is 640 kg/m/sup 3/ and in the stand pipe, 970 kg/m/sup 3/. The volumetric ratio of the n-C/sub 4/H/sub 10/:air, air:vapor vapor in the form of a condensate is 1:7.2:4.5:5.5. The output of the butadiene is: in the passed butane, 32.9% and in the broken down butane, 52.5%. The butane conversion is 62.6%. The losses of the concentrate with the contact gas and with the regeneration gases is 1/3 as much for the supplied butane, than in a known method. The method makes it possible to reduce the air expenditure by 60%, to reduce the concentrate losses by 2-3 times and to simplify the industrial system.

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

    Science.gov (United States)

    Elliott, Scott; Blake, Donald R.; Rowland, F. Sherwood; Lu, Rong; Brown, Michael J.; Williams, Michael D.; Russell, Armistead G.; Bossert, James E.; Streit, Gerald E.; Santoyo, Marisa Ruiz; Guzman, Francisco; Porch, William M.; McNair, Laurie A.; Keyantash, John; Kao, Chih-Yue Jim; Turco, Richard P.; Eichinger, William E.

    1997-09-01

    The saturated hydrocarbons propane and the butane isomers are both indirect greenhouse gases and key species in liquefied petroleum gas (LPG). Leakage of LPG and its component alkanes/alkenes is now thought to explain a significant fraction of the volatile organic burden and oxidative potential in the basin which confines Mexico City. Propane and the butanes, however, are stable enough to escape from the basin. The gas Chromatographie measurements which have drawn attention to their sources within the urban area are used here to estimate rates of ventilation into the free troposphere. The calculations are centered on several well studied February/March pollution episodes. Carbon monoxide observations and emissions data are first exploited to provide a rough time constant for the removal of typical inert pollutant species from the valley. The timescale obtained is validated through an examination of meteorological simulations of three-dimensional flow. Heuristic arguments and transport modeling establish that propane and the butanes are distributed through the basin in a manner analogous to CO despite differing emissions functions. Ventilation rates and mass loadings yield outbound fluxes in a box model type computation. Estimated in this fashion, escape from the Valley of Mexico constitutes of the order of half of 1% of the northern hemispheric inputs for both propane and n-butane. Uncertainties in the calculations are detailed and include factors such as flow into the basin via surface winds and the size of the polluted regime. General quantification of the global propane and butane emissions from large cities will entail studies of this type in a variety of locales.

  12. Active groups for oxidative activation of C-H bond in C{sub 2}-C{sub 5} paraffins on V-P-O catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Zazhigalov, V.A. [AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Fizicheskoj Khimii

    1998-12-31

    For the first time in scientific literature, in our joint work with Dr. G. Ladwig in 1978 it was established phase portraite of the oxide vanadium-phosphorus system within wide range of P/V ratios from 0.5 to 3.2. Some later those data were confirmed. By investigation of the properties of individual vanadium-phosphorus phases it was also shown that the active component of such catalysts in n-butane oxidation was vanadyl pyrophosphate phase (VO){sub 2}Pr{sub 2}O{sub 7}. From then the conclusion has been evidenced by numerous publications and at present it has been out of doubt practically all over the world. It was hypothized that the unique properties of (VO){sub 2}P{sub 2}O{sub 7} in the reaction of n-butane oxidation could be explained by the presence of paired vanadyl groups and nearness of the distances between neighbouring vanadyl pairs and that between the first and fourth carbon atoms in n-butane molecule. The molecule activation occured at the latter atoms by proton abstraction. A comparison of the results on n-butane and butenes oxidation over vanadyl pyrophosphate allowed to conclude that the paraffin oxidation did not take place due to the molecule dehydrogenation process at the first stage of its conversion. Up to now, more than 100 papers related to paraffins oxidation over vanadyl pyrophosphate and the physico-chemical properties of the catalyst have been published. The process of n-butane oxidation is realized in practice. But still, the question about the nature of active sites of the catalyst and the reaction mechanism remains open and provokes further investigations. The present paper deals with our opinion about the problem and the experimental results supporting it. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, S. [Earth and Environmental Science Division, Geoanalysis Group, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Blake, D.R.; Sherwood Rowland, F. [Chemistry Department, University of California, Irvine (United States); Lu, R. [Atmospheric Sciences Department, University of California, Los Angeles (United States); Brown, M.J.; Williams, M.D. [Technology and Safety Assessment Division, Energy and Environmental Analysis Group, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Russell, A.G. [Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania (United States); Bossert, J.E. [Earth and Environmental Science Division, Geoanalysis Group, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Streit, G.E. [Technology and Safety Assessment Division, Energy and Environmental Analysis Group, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Santoyo, M.R.; Guzman, F. [Instituto Mexicano del Petroleo, Gerencia de Ciencias del Ambiente, (Mexico) D.F.; Porch, W.M. [Earth and Environmental Science Division, Geoanalysis Group, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); McNair, L.A. [Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania (United States); Keyantash, J. [Atmospheric Sciences Department, University of California, Los Angeles (United States); Kao, C.J. [Earth and Environmental Science Division, Geoanalysis Group, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Turco, R.P. [Atmospheric Sciences Department, University of California, Los Angeles (United States); Eichinger, W.E. [Earth and Environmental Science Division, Geoanalysis Group, Los Alamos National Laboratory, Los Alamos, New Mexico (United States)

    1997-09-01

    The saturated hydrocarbons propane and the butane isomers are both indirect greenhouse gases and key species in liquefied petroleum gas (LPG). Leakage of LPG and its component alkanes/alkenes is now thought to explain a significant fraction of the volatile organic burden and oxidative potential in the basin which confines Mexico City. Propane and the butanes, however, are stable enough to escape from the basin. The gas chromatographic measurements which have drawn attention to their sources within the urban area are used here to estimate rates of ventilation into the free troposphere. The calculations are centered on several well studied February/March pollution episodes. Carbon monoxide observations and emissions data are first exploited to provide a rough time constant for the removal of typical inert pollutant species from the valley. The timescale obtained is validated through an examination of meteorological simulations of three-dimensional flow. Heuristic arguments and transport modeling establish that propane and the butanes are distributed through the basin in a manner analogous to CO despite differing emissions functions. Ventilation rates and mass loadings yield outbound fluxes in a box model type computation. Estimated in this fashion, escape from the Valley of Mexico constitutes of the order of half of 1{percent} of the northern hemispheric inputs for both propane and n-butane. Uncertainties in the calculations are detailed and include factors such as flow into the basin via surface winds and the size of the polluted regime. General quantification of the global propane and butane emissions from large cities will entail studies of this type in a variety of locales.{copyright} 1997 American Geophysical Union

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

    Science.gov (United States)

    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.

  15. 一种复合型无磷缓蚀阻垢剂的研制%Research on a complex phosphate-free corrosion and scale inhibitor

    Institute of Scientific and Technical Information of China (English)

    曾德芳; 严欢

    2012-01-01

    A complex phosphate-free corrosion and scale inhibitors is made from 2 - acrylamido - 2 - methylpropane sulfonic acid (AMPS), inhibitor A, zinc salt , ascorbic acid. The formulations is se- lected from the static scale inhibition experiments and rotation coupon corrosion test. The results show when the quality of each component: 2 -acrylamido -2 -methylpropane sulfonic acid (AMPS) : BTA: zinc salts: inhibitor A = 5: 0. 3: 1.2:4 and when the dosage of the phosphate-free corrosion and scale inhibitor was 40 mg/L, the maximum inhibition and scale inhibition exceeded 92. 89% and 95.12% , respectively . Compared with the traditional corrosion and scale inhibitors , the corrosion inhibition ef- ficiency of this complex phosphate-free corrosion and scale inhibitors is almost the same, the inhibi- tion rate increased by 1.91%, and cost reduced by 16.67%. Since the recipe is Phosphate-free, it does not cause environmental eutrophication, so it has obvious environmental and economic benefits.%以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、缓蚀剂A、锌盐、抗坏血酸为原料进行复配,开发出一种复合型无磷缓蚀阻垢剂。通过静态阻垢实验、旋转挂片腐蚀实验、动电位电化学测试实验对配方进行筛选和测定。结果表明在各组分质量比为:2-丙烯酰胺基-2-甲基丙磺酸(AMPS):苯并三氮唑:锌盐:缓蚀剂A=5:0.3:1.2:4,复合型无磷缓蚀阻垢剂质量浓度为40mg/L时,缓蚀率达到92.89%,阻垢率达到95.12%。通过与传统含磷配方对比,该复合型无磷缓蚀阻垢剂与传统含磷配方缓蚀率相当,阻垢率提高1.91%,成本降低16.67%。由于该配方无磷,不会造成环境富营养化,具有明显环境与经济效益。

  16. Controlled release of moxifloxacin from intraocular lenses modified by Ar plasma-assisted grafting with AMPS or SBMA: An in vitro study.

    Science.gov (United States)

    Pimenta, A F R; Vieira, A P; Colaço, R; Saramago, B; Gil, M H; Coimbra, P; Alves, P; Bozukova, D; Correia, T R; Correia, I J; Guiomar, A J; Serro, A P

    2017-08-01

    Intraocular lenses (IOLs) present an alternative for extended, local drug delivery in the prevention of post-operative acute endophthalmitis. In the present work, we modified the surface of a hydrophilic acrylic material, used for manufacturing of IOLs, through plasma-assisted grafting copolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), with the aim of achieving a controlled and effective drug release. The material was loaded with moxifloxacin (MFX), a commonly used antibiotic for endophthalmitis prevention. The characterization of the modified material showed that relevant properties, like swelling capacity, wettability, refractive index and transmittance, were not affected by the surface modification. Concerning the drug release profiles, the most promising result was obtained when AMPS grafting was done in the presence of MFX. This modification led to a higher amount of drug being released for a longer period of time, which is a requirement for the prevention of endophthalmitis. The material was found to be non-cytotoxic for rabbit corneal endothelial cells. In a second step, prototype IOLs were modified with AMPS and loaded with MFX as previously and, after sterilization and storage (30days), they were tested under dynamic conditions, in a microfluidic cell with volume and renovation rate similar to the eye aqueous humour. MFX solutions collected in this assay were tested against Staphylococcus aureus and Staphylococcus epidermidis and the released antibiotic proved to be effective against both bacteria until the 12th day of release. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Amending the anisotropy barrier and luminescence behavior of heterometallic trinuclear linear [M(II) -Ln(III) -M(II) ] (Ln(III) =Gd, Tb, Dy; M(II) =Mg/Zn) complexes by change from divalent paramagnetic to diamagnetic metal ions.

    Science.gov (United States)

    Das, Sourav; Bejoymohandas, K S; Dey, Atanu; Biswas, Sourav; Reddy, M L P; Morales, Roser; Ruiz, Eliseo; Titos-Padilla, Silvia; Colacio, Enrique; Chandrasekhar, Vadapalli

    2015-04-20

    The sequential reaction of a multisite coordinating compartmental ligand [2-(2-hydroxy-3-(hydroxymethyl)-5-methylbenzylideneamino)-2-methylpropane-1,3-diol] (LH4 ) with appropriate lanthanide salts followed by the addition of [Mg(NO3 )2 ]⋅6 H2 O or [Zn(NO3 )2 ]⋅6 H2 O in a 4:1:2 stoichiometric ratio in the presence of triethylamine affords a series of isostructural heterometallic trinuclear complexes containing [Mg2 Ln](3+) (Ln=Dy, Gd, and Tb) and [Zn2 Ln](3+) (Ln=Dy, Gd, and Tb) cores. The formation of these complexes is demonstrated by X-ray crystallography as well as ESI-MS spectra. All complexes are isostructural possessing a linear trimetallic core with a central lanthanide ion. The comprehensive studies discussed involve the synthesis, structure, magnetism, and photophysical properties on this family of trinuclear [Mg2 Ln](3+) and [Zn2 Ln](3+) heterometallic complexes. [Mg2 Dy](3+) and [Zn2 Dy](3+) show slow relaxation of the magnetization below 12 K under zero applied direct current (dc) field, but without reaching a neat maximum, which is due to the overlapping with a faster quantum tunneling relaxation mediated through dipole-dipole and hyperfine interactions. Under a small applied dc field of 1000 Oe, the quantum tunneling is almost suppressed and temperature and frequency dependent peaks are observed, thus confirming the single-molecule magnet behavior of complexes [Mg2 Dy](3+) and [Zn2 Dy](3+) .

  18. Synthesis of an imprinted hybrid organic-inorganic polymeric sol-gel matrix toward the specific binding and isotherm kinetics investigation of creatinine.

    Science.gov (United States)

    Chang, Yong-Sheun; Ko, Ting-Hsien; Hsu, Ting-Jung; Syu, Mei-Jywan

    2009-03-15

    Hybrid organic-inorganic polymeric sol-gel materials imprinted with creatinine template molecules were synthesized for the specific binding of creatinine. Creatinine is a metabolite from creatine and is the final product from kidney metabolism. Therefore, creatinine can be an important index to estimate the function of the kidney. It was then chosen as the target molecule in this work. To achieve the specific binding toward creatinine, molecular imprinting was used to create a polymeric matrix for the regarding purpose. Sol-gel was further added to create a rigid network structure for the absorption of creatinine. An inorganic precursor, tetraethoxysilane (TEOS), was mixed with an organic functional monomer, 2-acrylamido-2-methylpropane-sulfonic acid (AMPS), and the creatinine template to form a hybrid organic-inorganic imprinted polymer. The chemical functionality was achieved as well as a confined matrix via the polymerization and the hydrolysis-condensation of the sol-gel. The imprinting effect from the hybrid materials against the corresponding nonimprinted was investigated. BET (Brunauer-Emmett-Teller) analysis was carried out for the imprinted and the nonimprinted materials. The specificity of the hybrid materials was further examined by capping the surface silanol groups with chloro-trimethylsilane (CTMS) and 1,1,1,3,3,3-hexamethyldisilazane (HMDS), respectively. The capping effect was compared and discussed from the binding results. Selectivity of the materials toward creatinine was obtained using mixture solutions in the presence of creatinine and its analogues. Reutilization and storage stability of the hybrid organic-inorganic imprinted material were also studied. Additionally, the affinity distribution of the hybrid imprinted materials derived from the allosteric model was also analyzed from the adsorption isotherm data.

  19. Dispersion of iron oxide particles in industrial waters. The influence of polymer structure, ionic charge, and molecular weight

    Energy Technology Data Exchange (ETDEWEB)

    Amjad, Z. [Goodrich (B.F.) Co., Brecksville, OH (United States)

    1999-01-01

    This paper deals with studies on the influence of polymeric and non-polymeric materials on the dispersion of iron oxide particles in aqueous system. The aim of the work was to evaluate the performance of a variety of additives as iron oxide dispersants. The polymers investigated include homopolymers of acrylamide, vinylpyrrolidone, actylic acid, maleic acid, 2-acrylamido-2-methylpropane sulfonic acid, and acrylic acid based copolymers containing a variety of functional groups. It has been found that the addition of low levels of copolymers to the iron oxide suspension has a marked effect in dispersing iron oxide particles. The dispersancy data of several polymers indicate that the performance of the polymer depends upon the functional group, molecular weight, composition, and the ionic charge of the polymer. The results on non-polymeric materials such as polyphosphates, phosphonates, and surfactants show that these additives, compared to copolymers are ineffective as iron oxide dispersants. (orig.) [Deutsch] In dieser Arbeit wird der Einfluss von polymeren und nichtpolymeren Stoffen auf die Dispergierung von Eisenoxidpartikeln in waessrigen Systemen untersucht. Ziel dieser Arbeit war es, die Wirkung verschiedener Additive als Eisenoxiddispergatoren zu bewerten. Die untersuchten Polymere waren homopolymeres Acrylamid, Vinylpyrrolidon, Acrylsaeure, Maleinsaeure, 2-Acrylamido-2-Methylpropansulfonsaeure und Copolymere auf Acrylsaeurebasis mit verschiedenen fuktionellen Gruppen. Die Zugabe von geringen Mengen Copolymeren zur Eisenoxidsuspension hat einen deutlichen Einfluss auf die Dispergierung dieser Partikel. Die Daten zum Dispergierverhalten einiger Polymere zeigen, dass die Wirkung eines Polymers von der fuktionellen Gruppe, dem Molgewicht, der Zusammensetzung und der Ionenladung des Polymers abhaengt. Ergebnisse, die mit nichtpolymeren Substanzen wie Polyphosphaten, Phosphonaten und Tensiden erhalten wurden, zeigen, dass sich diese Additive nicht so gut als

  20. Synthesis of Discodermolide Subunits by S(E)2' Addition of Nonracemic Allenylstannanes to Aldehydes.

    Science.gov (United States)

    Marshall, James A.; Lu, Zhi-Hui; Johns, Brian A.

    1998-02-01

    Three subunits, 15, 29, and 34, of the immunosuppressant discodermolide were prepared starting from (S)-3-[(tert-butyldimethylsilyl)oxy]-2-methylpropanal ((S)-1) and the enantioenriched allenylstannanes (P)-2a, (P)-2b, and (P)-31. The route to 15 involved BF(3)-promoted addition of stannane (P)-2a to aldehyde (S)-1 which afforded the syn,syn-homopropargylic alcohol adduct 3 in 97% yield. The derived p-methoxybenzylidene acetal 5 was treated with Red-Al to effect cleavage of the pivalate and reduction of the double bond leading to the (E)-allylic alcohol 6. Sharpless epoxidation and subsequent addition of Me(2)CuCNLi(2) yielded the syn,syn,syn,anti stereopentad, diol 8. Protection of the secondary alcohol and oxidation of the primary gave aldehyde 12, which was treated with the alpha-bromo allylsilane 13 and CrCl(2), followed by NaH to effect elimination to the diene 15. A similar sequence was employed to prepare aldehyde 29. In this case aldehyde (S)-1 was converted to the anti,syn-homopropargylic alcohol 20 by treatment with the allenyl indium reagent formed in situ from allenylstannane (P)-2b and InBr(3). Epoxy alcohol 24, prepared from alcohol 20 by the above-described sequence, was reduced with Red-Al to afford diol 25. Protection of the secondary alcohol and oxidation of the primary completed the synthesis of 29. The anti,syn-homopropargylic alcohol 32 was obtained through addition of the allenic indium reagent, from allenylstannane (P)-31, to aldehyde (S)-1. Protection of the derived diol 33 as the p-methoxybenzylidene acetal afforded the third subunit, acetylene 34. Addition of the lithio derivative of 34 to aldehyde 29 gave alcohol 35 with the carbinyl stereochemistry needed for C7 of discodermolide as the major product.

  1. Rate constants of the Br-initiated gas-phase oxidation of a series of alcohols, furans and benzenes at 300±2 K

    Science.gov (United States)

    Bierbach, A.; Barnes, I.; Becker, K. H.

    Using the relative kinetic technique, rate coefficients have been determined for the gas-phase reaction of Br atoms with a selection of organic compounds, including alcohols, furan derivatives and aromatic hydrocarbons, at 300±2 K in 1000 mbar of synthetic air. Rate coefficients have been obtained for the following compounds (in units of cm 3 molecule -1 s -1): methanol (≤5×10 -16); ethanol (9.2±1.8)×10 -15; propan-1-ol (8.3±1.6)×10 -15; propan-2-ol (4.6±0.9)×10 -14; 2-methylpropan-2-ol (≤5×10 -16); 3-bromobutan-2-ol (2.2±0.4)×10 -13; furan (1.6±0.3)×10 -15; 2-methylfuran (2.2±0.4)×10 -13; 2,5-dimethylfuran (1.9±0.4)×10 -12; furan-2-aldehyde (2.2±0.4)×10 -13; 5-methylfurfural (4.0±0.8)×10 -13; benzene (≤5×10 -16); toluene (1.3±0.2)×10 -14; o-xylene (8.9±1.8)×10 -14; m-xylene (6.6±1.3)×10 -14; p-xylene (9.0±1.8)×10 -14, and 1,2,3-trimethylbenzene (4.8±1.0)×10 -13. Apart from methanol, this study represents the first determination of the rate coefficients for these compounds.

  2. Effects of dicarbonyl trapping agents, antioxidants, and reducing agents on the formation of furan and other volatile components in canned-coffee model systems.

    Science.gov (United States)

    Zheng, Li Wei; Chung, Hyun; Kim, Young-Suk

    2015-09-01

    The formation of furan and certain volatiles related to furan formation mechanisms was studied using gas chromatography-mass spectrometry combined with solid-phase micro extraction after adding dicarbonyl trapping agents [epicatechin (EC), epigallocatechin gallate (EGCG), and catechin], water-soluble antioxidants (Trolox, caffeic acid, ferulic acid, and chlorogenic acid), fat-soluble antioxidants (α-tocopherol, BHT, and β-carotene), and reducing agents (glutathione and sodium sulfite) to canned-coffee model systems (CMS). The level of furan formation decreased significantly following the addition of EC (by 65.3%), EGCG (by 60.0%), and catechin (by 44.7%). In addition, the formation of Maillard reaction products, including furan derivatives (furfural and 5-methylfurfural), Strecker aldehyde (2-methylbutanal), pyrazines (2,6-dimethylpyrazine), and lipid oxidation products (including hexanal and 2-pentylfuran) was suppressed when any of the dicarbonyl trapping agents was added. Among the water-soluble antioxidants studied, chlorogenic acid most significantly decreased the furan level, by 67.0%, followed by ferulic acid (57.6%), Trolox (50.1%), and caffeic acid (48.2%) in the CMS. Chlorogenic acid also reduced the formation of furfural and lipid oxidation products. However, the addition of caffeic acid, ferulic acid, and chlorogenic acid decreased the generation of key coffee aroma components, such as Strecker aldehydes (2-methylpropanal and 2-methylbutanal), 5-methylfurfural, and pyrazines (2,6-dimethylpyrazine and 2-ethyl-5-methylpyrazine). Among the fat-soluble antioxidants, BHT and α-tocopherol decreased the furan level by 49.3% and 39.3%, respectively, while β-carotene increased the furan level by 34.8%. The addition of sodium sulfite and glutathione to CMS also led to considerable reductions in furan, of 64.1% and 44.9%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Hydrolysis and Photolysis of Herbicide Clomazone in Aqueous Solutions and Natural Water Under Abiotic Conditions

    Institute of Scientific and Technical Information of China (English)

    CAO Jia; DIAO Xiao-ping; HU Ji-ye

    2013-01-01

    The hydrolysis and photolysis of clomazone in aqueous solutions and natural water were assessed under natural and controlled conditions. Kinetics of hydrolysis and photolysis of clomazone were determined by HPLC-DAD. Photoproducts were identiifed by HPLC-MS. No noticeable hydrolysis occurred in aqueous buffer solutions ((25±2)°C, pH (4.5±0.1), pH (7.4±0.1), pH (9.0±0.1);(50±2)°C, pH (4.5±0.1), pH (7.4±0.1)) or in natural water up to 90 d. At pH (9.0±0.1) and (50±2)°C the half-life of clomazone was 50.2 d. Clomazone photodecomposition rate in aqueous solutions under UV radiation and natural sunlight followed ifrst-order kinetics. Degradation rates were faster under UV light (half-life of 51-59 min) compared to sunlight (half-life of 87-136 d). Under UV light, four major photoproducts were detected and tentatively identiifed according to HPLC-MS spectral information such as 2-chlorobenzamide, N-hydroxy-(2-benzyl)-2-methylpropan-amide, 2-[2-phenol]-4,4-dimethyl-3-isoxazolidinone and 2-[(4,6-dihydroxyl-2-chlorine phenol)]-4,4-dimethyl-3-isoxazolidinone. These results suggested that clomazone photodegradation proceeds via several reaction pathways:1) dehalogenation;2) substitution of chlorine group by hydroxyl;3) cleavage of the side chain. Photosensitizers, such as H2O2 and ribolfavin, could enhance photolysis of clomazone in natural sunlight. In summary, we found that photoreaction is an important dissipation pathway of clomazone in natural water systems.

  4. Bacterial degradation of tert-amyl alcohol proceeds via hemiterpene 2-methyl-3-buten-2-ol by employing the tertiary alcohol desaturase function of the Rieske nonheme mononuclear iron oxygenase MdpJ.

    Science.gov (United States)

    Schuster, Judith; Schäfer, Franziska; Hübler, Nora; Brandt, Anne; Rosell, Mònica; Härtig, Claus; Harms, Hauke; Müller, Roland H; Rohwerder, Thore

    2012-03-01

    Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as this molecule possesses several potential hydroxylation sites. In Aquincola tertiaricarbonis L108 and Methylibium petroleiphilum PM1, a likely candidate catalyst for hydroxylations is the putative tertiary alcohol monooxygenase MdpJ. However, by comparing metabolite accumulations in wild-type strains of L108 and PM1 and in two mdpJ knockout mutants of strain L108, we could clearly show that MdpJ is not hydroxylating TAA to diols but functions as a desaturase, resulting in the formation of the hemiterpene 2-methyl-3-buten-2-ol. The latter is further processed via the hemiterpenes prenol, prenal, and 3-methylcrotonic acid. Likewise, 3-methyl-3-pentanol is degraded via 3-methyl-1-penten-3-ol. Wild-type strain L108 and mdpJ knockout mutants formed isoamylene and isoprene from TAA and 2-methyl-3-buten-2-ol, respectively. It is likely that this dehydratase activity is catalyzed by a not-yet-characterized enzyme postulated for the isomerization of 2-methyl-3-buten-2-ol and prenol. The vitamin requirements of strain L108 growing on TAA and the occurrence of 3-methylcrotonic acid as a metabolite indicate that TAA and hemiterpene degradation are linked with the catabolic route of the amino acid leucine, including an involvement of the biotin-dependent 3-methylcrotonyl coenzyme A (3-methylcrotonyl-CoA) carboxylase LiuBD. Evolutionary aspects of favored desaturase versus hydroxylation pathways for TAA conversion and the possible role of MdpJ in the degradation of higher tertiary alcohols are discussed.

  5. Impacts d’un changement de politiques énergétiques sur les exploitations irriguées : éclairage sur la base d’un échantillon d’exploitations dans le Saiss (Maroc

    Directory of Open Access Journals (Sweden)

    Imane Rais

    2016-10-01

    Full Text Available Au Maroc, le gaz butane est fortement subventionné pour son usage domestique, et est devenu depuis une dizaine d’années une des sources principales d’énergie utilisées pour le pompage de l’eau souterraine dans les exploitations agricoles. Du fait de son coût élevé pour les finances publiques, il est envisagé un arrêt de cette subvention, couplé à une éventuelle subvention à l’investissement en énergie solaire. La présente étude analyse l’impact de scénarios d’évolutions des politiques énergétiques nationales sur des exploitations irrigantes. Ces évolutions possibles de type d’énergie utilisé sont analysées à la fois en termes de rentabilité et selon le point de vue de l’exploitant lui-même. Un ensemble de 18 exploitations, utilisant 4 différents types d’énergie (gasoil, butane, électrique, photovoltaïque, ont été enquêtées dans la plaine du Saiss. Trois scénarios ont été établis : 1 un arrêt de la subvention au butane ; 2 un arrêt de la subvention couplé à une subvention à l’investissement dans l’énergie solaire ; et 3 un arrêt de la subvention butane couplé à une subvention à l’investissement dans l’énergie électrique. Les résultats montrent que, en cas d’arrêt de la subvention sur le butane, la moitié des exploitants utilisant le butane lors de l’étude envisagent de revenir au gasoil. En cas de subvention de 50% des coûts d’installation de l’énergie photovoltaïque, trois quarts des agriculteurs utilisant le butane ou le gasoil changeraient de système. Seule la moitié des exploitations en butane ou gasoil serait intéressée par un passage à l’électrique, même dans le cas d’une forte subvention à l’investissement. La transition vers le photovoltaïque, préférée par les agriculteurs utilisant le butane ou le gasoil, ne sera pas cependant qu’une question de taux de subvention, du fait notamment d’un fort besoin d’appui technique pour

  6. Shock tube measurements of the tert-butanol + OH reaction rate and the tert-C4H8OH radical β-scission branching ratio using isotopic labeling.

    Science.gov (United States)

    Stranic, Ivo; Pang, Genny A; Hanson, Ronald K; Golden, David M; Bowman, Craig T

    2013-06-13

    The overall rate constant for the reaction tert-butanol + OH → products was determined experimentally behind reflected shock waves by using (18)O-substituted tert-butanol (tert-butan(18)ol) and tert-butyl hydroperoxide (TBHP) as a fast source of (16)OH. The data were acquired from 900 to 1200 K near 1.1 atm and are best fit by the Arrhenius expression 1.24 × 10(-10) exp(-2501/T [K]) cm(3) molecule(-1) s(-1). The products of the title reaction include the tert-C4H8OH radical that is known to have two major β-scission decomposition channels, one of which produces OH radicals. Experiments with the isotopically labeled tert-butan(18)ol also lead to an experimental determination of the branching ratio for the β-scission pathways of the tert-C4H8OH radical by comparing the measured pseudo-first-order decay rate of (16)OH in the presence of excess tert-butan(16)ol with the respective decay rate of (16)OH in the presence of excess tert-butan(18)ol. The two decay rates of (16)OH as a result of reactions with the two forms of tert-butanol differ by approximately a factor of 5 due to the absence of (16)OH-producing pathways in experiments with tert-butan(18)ol. This indicates that 80% of the (16)OH molecules that react with tert-butan(16)ol will reproduce another (16)OH molecule through β-scission of the resulting tert-C4H8(16)OH radical. (16)OH mole fraction time histories were measured using narrow-line-width laser absorption near 307 nm. Measurements were performed at the line center of the R22(5.5) transition in the A-X(0,0) band of (16)OH, a transition that does not overlap with any absorption features of (18)OH, hence yielding a measurement of (16)OH mole fraction that is insensitive to any production of (18)OH.

  7. Pressure dependence and branching ratios in the decomposition of 1-pentyl radicals: shock tube experiments and master equation modeling.

    Science.gov (United States)

    Awan, Iftikhar A; Burgess, Donald R; Manion, Jeffrey A

    2012-03-22

    The decomposition and intramolecular H-transfer isomerization reactions of the 1-pentyl radical have been studied at temperatures of 880 to 1055 K and pressures of 80 to 680 kPa using the single pulse shock tube technique and additionally investigated with quantum chemical methods. The 1-pentyl radical was generated by shock heating dilute mixtures of 1-iodopentane and the stable products of its decomposition have been observed by postshock gas chromatographic analysis. Ethene and propene are the main olefin products and account for >97% of the carbon balance from 1-pentyl. Also produced are very small amounts of (E)-2-pentene, (Z)-2-pentene, and 1-butene. The ethene/propene product ratio is pressure dependent and varies from about 3 to 5 over the range of temperatures and pressures studied. Formation of ethene and propene can be related to the concentrations of 1-pentyl and 2-pentyl radicals in the system and the relative rates of five-center intramolecular H-transfer reactions and β C-C bond scissions. The 3-pentyl radical, formed via a four-center intramolecular H transfer, leads to 1-butene and plays only a very minor role in the system. The observed (E/Z)-2-pentenes can arise from a small amount of beta C-H bond scission in the 2-pentyl radical. The current experimental and computational results are considered in conjunction with relevant literature data from lower temperatures to develop a consistent kinetics model that reproduces the observed branching ratios and pressure effects. The present experimental results provide the first available data on the pressure dependence of the olefin product branching ratio for alkyl radical decomposition at high temperatures and require a value of = (675 ± 100) cm(-1) for the average energy transferred in deactivating collisions in an argon bath gas when an exponential-down model is employed. High pressure rate expressions for the relevant H-transfer reactions and β bond scissions are derived and a Rice Ramsberger

  8. VOCs Speciation From Steam Boiler Stacks of Industries Located in Naucalpan

    Science.gov (United States)

    Mejia, G. M.; Tejeda, D. D.; Bremauntz, M. P.; Valdez, A.; Montufar, P. C.; Martinez, M. A.; Sierra, M. J.; Gonzalez, C. A.

    2007-05-01

    Results of VOCs speciation from industrial steam boiler stacks located in Naucalpan are presented and discussed. This municipality is located north of the Metropolitan Zone of the Valley of Mexico (MZVM). Speciation of VOCs is important to generate information about sources of pollution, to update emission inventories, to study the dynamics of pollutants in the atmosphere, and to estimate possible risks of population exposure. This information is valuable for decision making on air pollution control strategies. Samples from 35 steam boilers form industries burning Diesel, LPG, or CNG were taken using the US-EPA Method 18. Selected samples from the use of different fuels were analyzed using gas chromatography and flame ionization detection (GC-FID) according to US-EPA protocol TO-14. The VOCs analyzed included alkanes of 9 carbons or less, alkenes of 7 carbons or less and aromatics (families of benzene). The results show consistency on the VOCs detected on Diesel samples. The main compounds found were 1- Butene+iButylene, m/p-Xylene, Ethane, Propene, Propane, Acetylene, 2Me-1Butene, and Toluene. The average concentrations of these compounds were in the range of 130 to 385 ppbC. The results of LPG samples did not show a definite pattern of VOCs, although light components predominate and, in some samples, Toluene and Xylene. These last components were not expected for industries reporting the use of LPG, perhaps due to the use of a combination of fuels and mistakes in the reports of fuel used at the time of sampling. The analysis of CNG samples show predominance of light VOCs, in the range of 90 to 300 ppbC. As in the case of LPG, some aromatics showed high concentrations in some samples analyzed perhaps due to the use of different fuels in the boiler. The results of this study are the first results of VOCs speciation obtained form exhaust gases from stacks of Mexican industries. The data reported are valuable to analyze emission inventories of VOCs and to better

  9. Vibrational state distribution and relaxation of vinoxy radicals

    Science.gov (United States)

    Su, Hongmei; Bersohn, Richard

    2001-07-01

    The vinoxy radical ṡCH2CHO is a product of the reaction of O(3P) atoms with terminal alkenes and can also be made by photodissociation of an alkyl vinyl ether. In either case it is formed in a vibrationally excited state. The nascent radical displays a rich electronic spectrum to the red of its X→B band origin consisting of bands originating from vibrationally excited states. Some transitions, true "hot bands," terminate on the vibrationless B state; others, sequence bands, terminate on vibrationally excited B states. The spectra become unobservably weak at a certain energy. The difference between that energy and the energy of the band origin is roughly the maximum vibrational energy in the radical. This is 5600 cm-1 for the vinoxy produced by photodissociation of ethyl vinyl ether at 193 nm and 3200 cm-1 for the product of the reaction of O(3P) with ethylene, propene, 1-butene, and 1-pentene. There is a remarkable cooling of the vibrations as the hydrocarbon chain lengthens. The average vibrational energy of the vinoxy product of the reaction O(3P) with ethylene, propene, 1-butene, and 1-pentene is 2100, 1800, 1570, and 1180 cm-1, respectively. This cooling implies that the reaction complex lives long enough for internal vibrational relaxation to occur. The average vibrational energy in the reaction-produced vinoxy is small, which implies that there is considerable kinetic energy. The time dependence of the intensity of the hot bands measures the relaxation rates of different energies, some of which are the energies of a single vibrational state. The ground-state population increases monotonically to an asymptote. The population of most states grows with time and then decays. The growth is due to a cascading from upper states. The populations of the highest energy states decay monotonically; the still higher energy states are almost unpopulated. These results prove that the relaxation proceeds stepwise. The magnitude of the step, ˜200-300 cm-1, can be

  10. Distribution of MEG and methanol in well-defined hydrocarbon and water systems: Experimental measurement and modeling using the CPA EoS

    DEFF Research Database (Denmark)

    Riaz, Muhammad; Yussuf, Mustafe A.; Kontogeorgis, Georgios;

    2013-01-01

    and MEG) in various phases is modeled using CPA. The hydrocarbon phase consists of mixture-1 (methane, ethane, n-butane) or mixture-2 (methane, ethane, propane, n-butane, n-heptane, toluene and n-decane). CPA can satisfactorily predict the water content in the gas phase of the multicomponent systems...... + water. These data are satisfactorily correlated (binaries) and predicted (ternaries) using Cubic Plus Association (CPA) equation of state (EoS). CPA is also applied to binary LLE of aromatic hydrocarbon + water and VLE of methane + methanol. Finally the distribution of water and inhibitors (methanol...... containing mixture-1 over a range of temperatures and pressures. Similarly the methanol content in the gas phase of mixture-1 + water + methanol systems is predicted satisfactorily with accuracy within experimental uncertainty. For VLLE of mixture-2. +. water, mixture-2 + MEG + water and mixture-2 + methanol...

  11. Volatiles in a sausage surface model-influence of Penicillium nalgiovense, Pediococcus pentosaceus, ascorbate, nitrate and temperature

    DEFF Research Database (Denmark)

    Sunesen, Lars Oddershede; Trihaas, Jeorgos; Stahnke, Louise Heller

    2003-01-01

    Thirty-two agar sausage models were arranged in a 2((5-1)) fractional factorial design to analyse the effects of Penicillium nalgio-vense growth, Pediococcus pentosaceus starter, sodium ascorbate, sodium nitrate and temperature on 79 volatiles produced during incubation. The model focused...... on the outer 10 millimeters of sausages. Ascorbate addition showed clear antioxidative effects, and reduced the amount of more than half of all volatiles but increased concentrations of 2-methyl-propanal and 3-methyl-butanal. The effects of P. pentosaceus and Micrococcaceae were confounded, but together...... they had pronounced antioxidative effects, lowering the amount of straight chain aldehydes, 2-alkenals, furanes and ketones. P. pentosaceus and Micrococcaceae growth increased the leucine catabolites 3-methyl-butanal and 3-methyl-1-butanol. P. nalgiovense decreased the concentrations of 2-heptanone, 2...

  12. Monte Carlo simulation of a complex fluid confined to a pore with nanoscopically rough walls

    Science.gov (United States)

    Porcheron, Fabien; Schoen, Martin; Fuchs, Alain H.

    2002-04-01

    Understanding the properties of fluid films of nanometer scale thickness confined between two solid substrates is of fundamental interest as well as of practical importance for engineering applications such as lubrication, adhesion, and friction. We address here the question of the effect of the wall corrugation on the confined fluid structure. We report configurational bias grand canonical Monte Carlo simulations for model butane confined between planar and nonplanar walls. Furrowed walls have been used to model surface roughness effects on the nanometer length scale, while the confining walls remain smooth on the atomic scale. It is shown that the fluid confined between planar walls exhibits a damped oscillatory solvation pressure profile. A transition from an oscillatory to a nonoscillatory behavior is observed when the characteristic length of the furrow reaches the typical dimensions of a butane molecule. It is inferred from these simulations that disrupted oscillatory forces observed in the experiments may reflect the coupling between molecular and nanoscopic roughness length scales.

  13. A Novel Method for Preparation of Silicalite-1 Zeolite Membrane in Vapor Phase%一种气相合成Silicalite-1沸石膜的新方法

    Institute of Scientific and Technical Information of China (English)

    李军; 龙英才

    2001-01-01

    A silicalite-1 zeolite membrane was in situ crystallized from a layer of silica species prepared by a novel method of low temperature chemical vapor deposition (LTCVD) on a porous cordierite substrate. XRD patterns show that the membrane consists of MFI type zeolite crystals. The investigation with SEM indicats that the membrane is about 50 μm thick, and covered with well-intergrowth MFI zeolite crystals of about 10 μm in size. The EDX analysis confirms that the membrane is composed of silica in the absence of Al, indicating high silica MFI(Silicalite-1) zeolite grown on the support. The ratio of pure gas permeation is 296 for H2/iso-butane and 13.7 for n/iso-butane at room temperature respectively, confirming that the membrane synthesized on the support of cordierite is high quality without pinhole.

  14. A Quick Estimate of the Correlation Energy for Alkanes

    Institute of Scientific and Technical Information of China (English)

    黎书华; 李伟; 马晶

    2003-01-01

    Within the localized molecular orbital description, the intraand interorbital pair correlation energies calculated with the coupled cluster doubles (CCD) theory have been obtained for methane, ethane, propane, butane, isobutane, pentane,isopentane and neopentane using the 6-31G* basis set. The results showed the quantitative transferability of pair correlation energies and gross orbital correlation energies within this series of molecules. Based on the gross orbital correlation energies of five sample alkanes (butane, isobutane, pentane,isopentane and neopentane), we have derived a simple linear relationship to estimate the CCD correlation energy for an arbitrary large alkane. The correlation energy predicted by this simple relationship remarkably recovers more than 98.9% of the exact CCD correlation energy for a number of alkanes containing six to eight carbon atoms. The relative stability of less branched isomers can be correctly predicted.

  15. Carbon assimilation and extracellular antigens of some yeast-like fungi.

    Science.gov (United States)

    Middelhoven, W J; De Hoog, G S; Notermans, S

    1989-01-01

    Many yeast-like fungi assimilated n-hexadecane, butylamine and putrescine as sole carbon sources. Methanol was not assimilated. This points to a physiological similarity to endomycetous, hydrocarbon-utilizing yeasts. Stephanoascus ciferrii assimilated uric acid, adenine and allantoin as sole source of carbon and nitrogen. All strains of Geotrichum candidum and many other yeast-like fungi assimilated acetoin and butan-2,3-diol. Assimilation tests for adenine, uric acid, allantoin, acetoin and butan-2,3-diol were found to be suitable for taxonomic purposes. Extracellular antigens immunologically related to those produced by Geotrichum candidum were detected in the cell-free culture liquids of several yeast-like fungi. The extracellular antigen excreted by Stephanoascus ciferrii was species-specific.

  16. Conjugation of a 3-(1H-phenanthro[9,10-d]imidazol-2-yl)-1H-indole intercalator to a triplex oligonucleotide and to a three-way junction

    DEFF Research Database (Denmark)

    Fatthalla, Maha I.; Elkholy, Yehya M; Abbas, Nermeen S

    2012-01-01

    A new intercalating nucleic acid monomer M comprising a 4-(1-indole)-butane-1,2-diol moiety was synthesized via a classical alkylation reaction of indole-3-carboxaldehyde followed by a condensation reaction with phenanthrene-9,10-dione in the presence of ammonium acetate to form a phenanthroimida......A new intercalating nucleic acid monomer M comprising a 4-(1-indole)-butane-1,2-diol moiety was synthesized via a classical alkylation reaction of indole-3-carboxaldehyde followed by a condensation reaction with phenanthrene-9,10-dione in the presence of ammonium acetate to form...... a phenanthroimidazole moiety linked to the indole ring. Insertion of the new intercalator as a bulge into a Triplex Forming Oligonucleotide resulted in good thermal stability of the corresponding Hoogsteen-type triplexes. Molecular modeling supports the possible intercalating ability of M. Hybridisation properties...

  17. Volatile organic compound ratios as probes of halogen atom chemistry in the Arctic

    Directory of Open Access Journals (Sweden)

    P. B. Shepson

    2008-03-01

    Full Text Available Volatile organic compound concentration ratios can be used as indicators of halogen chemistry that occurs during ozone depletion events in the Arctic during spring. Here we use a combination of modeling and measurements of [acetone]/[propanal] as an indicator of bromine chemistry, and [isobutane]/[n-butane] and [methyl ethyl ketone]/[n-butane] are used to study the extent of chlorine chemistry during four ozone depletion events during the Polar Sunrise Experiment of 1995. Using a 0-D photochemistry model in which the input of halogen atoms is controlled and varied, the approximate ratio of [Br]/[Cl] can be estimated for each ozone depletion event. It is concluded that there must be an additional source of propanal (likely from the snowpack to correctly simulate the VOC chemistry of the Arctic, and further evidence that the ratio of Br atoms to Cl atoms can vary greatly during ozone depletion events is presented.

  18. Volatile organic compound ratios as probes of halogen atom chemistry in the Arctic

    Directory of Open Access Journals (Sweden)

    A. E. Cavender

    2007-08-01

    Full Text Available Volatile organic compound concentration ratios can be used as indicators of halogen chemistry that occurs during ozone depletion events in the Arctic during spring. Here we use a combination of modeling and measurements of [acetone]/[propanal] as an indicator of bromine chemistry, and [isobutane]/[n-butane] and [methyl ethyl ketone]/[n-butane] are used to study the extent of chlorine chemistry during four ozone depletion events during the Polar Sunrise Experiment of 1995. Using a 0-D photochemistry model in which the input of halogen atoms is controlled and varied, the approximate ratio of [Br]/[Cl] can be estimated for each ozone depletion event. It is concluded that there must be an additional source of propanal (likely from the snowpack to correctly simulate the VOC chemistry of the Arctic, and that the ratio of Br atoms to Cl atoms can vary greatly during ozone depletion events.

  19. Theoretical Studies on Critical Properties of Binary System with Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new expression of mixing rule is suggested according to the Mayson′s mixing rule in this paper, which adopts the Redlich-Kwong cubic equation of state and the modified Chueh-Prausnitz method to calculate the experiment critical points of six binary mixtures CO2+toluene, CO2+cyclohexane, CO2+n-butanal, CO2+i-butanal, CO2+methanol, CO2+ethanol. The coefficients of interaction parameter in the expression of mixing rule were optimized from experimental data. The calculated results of critical temperature and critical pressure meet the experiment data well. The maximum relative errors of temperature and pressure between the calculation results and experiment data are 1.493% and 5.2236% respectively, indicating that the proposed expression of mixing rule is reasonable. This may provide a fundamental method for studying and predicting the properties of supercritical fluids.

  20. Cytotoxic lignans from Larrea tridentata.

    Science.gov (United States)

    Lambert, Joshua D; Sang, Shengmin; Dougherty, Ann; Caldwell, Colby G; Meyers, Ross O; Dorr, Robert T; Timmermann, Barbara N

    2005-04-01

    Six lignans, including the cyclolignan 3,4'-dihydroxy-3',4'-dimethoxy-6,7'-cyclolignan, were isolated from the flowering tops of Larrea tridentata. Additionally the flavanone, (S)-4',5-dihydroxy-7-methoxyflavanone, was isolated for the first time from L. tridentata or any member of the family Zygophyllaceae. All of the compounds were assessed for their growth inhibitory activity against human breast cancer, human colon cancer and human melanoma cell lines. The lignans had IC50 values of 5-60 microM with the linear butane-type lignans being the most potent, and it was found that colon cancer cells were the least sensitive cell type tested. The relative potency of linear butane type lignans against human breast cancer appears to correlate positively with the number of O-methyl groups present on the molecule.

  1. 环戊烷水合物平衡数据%EQUILIBRIUM DATA OF CYCLOPENTANE HYDRATE

    Institute of Scientific and Technical Information of China (English)

    梁德青; 郭开华; 樊栓狮; 王如竹

    2001-01-01

    @@ In the oil and gas industry, it is important to determine hydrate phase boundary for avoiding hydrate formation. In general n-butane is regarded as the heaviest hydrocarbon hydrate. But for oil and gas condensate systems, it has been found that some hydrocarbons heavier than n-butane could enter the large cavity of structure-II hydrate due to their effective van der Waal's diameter. The hydrate formation characteristics of benzene[1], cyclohexane[2], and cyclopentane and neopentane in their binaries/tern-aries with methane or/and nitrogen have been reported[3]. Ripmeester et al[4] pointed out that cyclopentane could form gas hydrates without a help gas. However there are no further experimental data to support it.

  2. Antimoulting Activity of Eremanthus erythropappus (DC. MacLeisch

    Directory of Open Access Journals (Sweden)

    Danielle Barbosa

    2012-06-01

    Resumo. Os extratos e metabólitos secundários de plantas podem agir como agentes tóxicos e inibidores do da alimentação e do desenvolvimento em insetos. Neste estudo foi utilizado Oncopeltus fasciatus (Dallas (Hemiptera como modelo experimental a fim de avaliar as atividades do extrato etanólico bruto e frações obtidos das flores ou caules de Eremanthus erythropappus (DC. MacLeisch (Asteraceae, na mortalidade e sobre o desenvolvimento do inseto. A fração butanólica obtida do extrato etanólico mostrou toxidade sobre as ninfas de O. fasciatus, bem como atividade de inibição do crescimento. Os resultados sugerem que a fração butanólica de E. erythropappus possui substâncias ativas sobre a fisiologia, crescimento e desenvolvimento de insetos.

  3. Adding Value to Bioethanol through a Purification Process Revamp

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Mauricio Iglesias, Miguel; Huusom, Jakob Kjøbsted

    2017-01-01

    analyzed experimentally: Acetaldehyde, 1-propanal, 1-butanal, crotonaldehyde, benzaldehyde, ethyl acetate, methanol, 1-propanol, 1-butanol, 2-butanol, 2-methyl-l-propanol, 2-methyl-l-butanol, and 3-methyl-1-butanol. A simulation platform was established and evaluated with excellent agreement compared...... to the operational data. The beer composition (separation unit feed) and a complete stream summary for the separation unit is provided....

  4. Honey oil burns: a growing problem.

    Science.gov (United States)

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

    2015-01-01

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

  5. O teuto-brasileiro: a história de um conceito

    Directory of Open Access Journals (Sweden)

    André Fabiano Voigt

    2009-01-01

    Full Text Available The present article intends toanalyse, in general lines, the German-Brazilian not as the expression of a culturalidentity, but as a conceptual production,carried out from the decade of 1940,during the Second World War, sufferingfrom that time a series of dislocations andof interpretations, on a way to affirm theyare not a danger for the national unity, butan example of brazilian citizenship to befollowed.

  6. Peacemaking, Complex Emergencies, and Disaster Response: What Happens, How Do You Respond?

    Science.gov (United States)

    1999-02-01

    detail on any of these types of disasters, and we will spend 9. Examples include a butane gas explosion that leveled a Mexico surburb in 1984, the...Instability and assassination 1825 France recognizes Haitian independence 1862 ! United States recognizes Haitian ! independence 1911- 1915 Six...wwwnotes.reliefweb.int/websites/rwdomino.nsf/ VNaturalDisastersTheLatest [21] SJ. Guerra . Responses to Harm ’s-Way and Humanitarian Situa- tions by

  7. Database Translator (DATALATOR) for Integrated Exploitation

    Science.gov (United States)

    2010-10-31

    t»Soei\\ S Forrm\\ • butane*’ OOntoB»«\\ DhptayStofcf ^ J [ClASS BROWSER for Project: • Class Hierarchy MtM, THING B :SYSTEM-CLASS 1x1 ...have successfully funded early-stage companies, and (iii) industry experts with specialized knowledge of key vertical markets . The company will also... market . Situational applications are built on-the-fly to solve a specific business problem, which fits neatly with the agile development approach

  8. Jet Engine Exhaust Analysis by Subtractive Chromatography

    Science.gov (United States)

    1978-12-01

    and J. J. Brooks. Development of a portable miniature collection system for the exposure as- sessment within the microenvironment for carcinogens ...65 A-2. Recovery of acrylonitrile from standard sample generation system ...... ............. 66 B-I. Jet engine exhaust sampling and analysis...7 n-Butane 0.16 2.6 minutes 8 Propylene oxide 3.14 52 minutes 9 Acrylonitrile 9.35 2.6 hours 10 Phenanthrene 1.9 x 106 61 years 11 4-Bromodiphenyl

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

    Science.gov (United States)

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

    2013-04-02

    Transfer your hydrogen: Fast and general transfer hydrogenation of nitriles to form primary amines is possible with a homogeneous Ru/1,4-bis(diphenylphosphino)butane (DPPB) catalyst (see scheme). The use of 2-butanol as the hydrogen-transfer reagent is essential for the selective reduction of aromatic, heteroaromatic, and aliphatic nitriles with this system. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. A stronger perfume for LPG

    Energy Technology Data Exchange (ETDEWEB)

    Willcox, C.K.

    1996-11-01

    The odorisation of Liquefied Petroleum Gas (LPG) is undertaken to improve the safe use and transport of this popular fuel. Effective LPG odorisation should enable leaks to be detected by any person with a normal sense of smell before gas concentrations reach a hazardous level. The objective is identical to that for odorising natural gas. However, the physical characteristics of propane and butane present particular difficulties. These do not occur with natural gas, which has a dynamic, flowing, simple-phase system. (author)

  11. SYNTHESIS, CRYSTAL AND MOLECULAR-STRUCTURES, UV-VIS SPECTROSCOPY AND ELECTROCHEMICAL PROPERTIES OF 2 IRON(III) PHENOLATE COMPLEXES

    NARCIS (Netherlands)

    LUBBEN, M; MEETSMA, A; VANBOLHUIS, F; FERINGA, BL; HAGE, R

    1994-01-01

    The synthesis and molecular structures of two iron(III) phenolate complexes [(L(1))FeCl] (1) and [(L(2))(2)Fe][BPh(4)] (2) are described, where L(1)H(2) is 2,3-dimethyl-2,3-bis(3-tert-butylsalicylideneamino) butane and L(2)H is 2-(2-pyridyl)-1-salicylideneaminoethane. The complexes have been charact

  12. An investigation of the characteristics of Maxwell-Stefan diffusivities of binary mixtures in silica nanopores

    NARCIS (Netherlands)

    Krishna, R.; van Baten, J.M.

    2009-01-01

    Diffusion of pure components (hydrogen (H-2) argon (Ar), krypton (Kr), methane (C1), ethane (C2), propane (C3), n-butane (nC4), and n-hexane (nC6)) in silica nanopores with diameters of 1, 1.5, 2, 3, 4, 5.8, 7.6, and 10 nm were investigated using molecular dynamics (MD). The Maxwell-Stefan (M-S)

  13. Improvement of a New Gas Ionization Chamber

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to identify heavier elements, we have developed a new longitudinal field gas ionization chamber (IC)with an angle of 30° of plate (as shown in Fig.1). The IC is operated in flowing iso-butane gas at a pressure of 10kPa. After testing by using a 3- component α particle source and comparing with the old longitudinal field

  14. Combustion Characteristics of Sprays

    Science.gov (United States)

    1989-08-01

    regarded by implication or otherwise, or in any way licensing the holder or any other person or corporation, or conveying any rights or permission to...00 _’N 1. TI TLE inctuat Security CZaaafication5 Combustion Characteristics of Sprays 12. PERSONAL AUTHOR(S) Sohrab, Siavash H. 13& TYPE OF REPORT...to ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

  15. Olfactory Impact of Higher Alcohols on Red Wine Fruity Ester Aroma Expression in Model Solution.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2013-01-01

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

  17. EOR production technique tested on Codell

    Energy Technology Data Exchange (ETDEWEB)

    Stremel, K.

    1983-05-01

    A production method of natural gas that eliminated marketing problems and allowed maximum recovery was dicussed. The method involved the dehydration of the gas, stripping of the propane and butane products, and the compression and reinjection of the dry gas to the well. This maintenance of pressure will allow storage of the gas until marketing conditions improve. The production method is being tested at pilot wells in Colorado by Petromax Energy Corporation.

  18. Study of the production of polyesters for polyurethanes at pilot plant scale

    OpenAIRE

    Matos, Sandro Filipe dos Santos

    2010-01-01

    In the present work during an internship in ICTPOL (IST), we tried to develop a relationship between all the works done. Understanding variables that affect production of unsaturated polyester polyols based on dimer fatty acids Unidyme®14 andUnidyme®18 with ethylene glycol and 1,4-butane diol that were synthesized via the polycondensation reaction mechanism. We studied a fast way to determine molecular weight, which usually takes a lot of time and tha...

  19. Idroformilazione selettiva del 1,3-diisopropenilbenzene per la sintesi del Florhydral®

    OpenAIRE

    Marchetti, Mauro; Paganelli, Stefano; Sechi, Barbara

    2004-01-01

    Il Florhydral®, 3-(3'-isopropenilfenil)butanal, è una fragranza di sintesi commercializzata a partire dal m-diisopropenilbenzene I ed il passaggio chiave dello schema di sintesi è rappresentato dall'idroformilazione di questa di olefina catalizzata da complessi di rodio. L'oxosintesi, anche se altamente chemioselettiva, presenta però una selettività piuttosto bassa verso la desiderata monoaldeide II, precursore del Florhydral®, fornendo anche il prodotto dialdeidico III. Abbiamo pert...

  20. Heat pumps: which refrigerant will win?; Welche Kaeltemittel werden sich durchsetzen?

    Energy Technology Data Exchange (ETDEWEB)

    Genath, B.

    2004-07-01

    This article discusses the alternatives available to the refrigeration industry when new regulations concerning the use of hydrochlorofluorocarbons (HCFC) come into force. The alternatives include water, carbon dioxide, iso-butane and propene. Work being done in Europe and America is discussed and examples of installations using these alternative refrigerants are described. Global Warming and the persistence of the refrigerants in the atmosphere are discussed, as is their flammability. Further environmentally-relative characteristics of the various refrigerants are listed.

  1. Fatal fulminant hepatic failure in a 'solvent abuser'.

    OpenAIRE

    McIntyre, A S; Long, R G

    1992-01-01

    The case of a 17 year old abuser of butane aerosols who developed fulminant hepatic failure after taking a proprietary engine or carburetor cleaner is described. Fatalities as a result of liver failure due to volatile hydrocarbons or solvents have not previously been reported. The likely toxins included isopropyl alcohol, methyl amyl alcohol, butylated hydroxytoluene as well as petroleum products, and evidence for their toxicity is reviewed. The possibility of increased susceptibility to hepa...

  2. X-rays and Neutrons: Essential Tools for Nanoscience Research. Report of the National Nanotechnology Initiative Workshop, June 16-18, 2005, Washington, D.C.

    Science.gov (United States)

    2005-06-18

    morphologies. In the second example we have used SANS to probe the magnetoelectronic phase separation that occurs in doped perovskite cobaltites . This phase...in materials of limited dimensionality. Figure 2.8. A theoretical description of the adsorption of gold on magnesium oxide, with and without an F...structures: Left: Neutron diffraction profile of a monolayer butane film on magnesium oxide (MgO) nanocubes. (Copyright 2006 by the American Physical

  3. Smartphone Schlieren

    CERN Document Server

    Miller, Victor A

    2016-01-01

    We present a schlieren system comprised of 3D printed optical mounts, a sub-$10 mirror, and a smartphone camera. The system is intended to make schlieren imaging accessible to K-through-12 students, educators, as well as hobbyists. In the manuscript, we detail the design of the system, provide source files for continued iteration, and show some example schlieren images and videos of a butane lighter, a jet of compressed air, and an electric stove.

  4. Quinoxaline derivatives as corrosion inhibitors for mild steel in hydrochloric acid medium: Electrochemical and quantum chemical studies

    Science.gov (United States)

    Olasunkanmi, Lukman O.; Kabanda, Mwadham M.; Ebenso, Eno E.

    2016-02-01

    The corrosion inhibition potential of four quinoxaline derivatives namely, 1-[3-(4-methylphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Me-4-PQPB), 1-(3-(4-methoxyphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl)butan-1-one (Mt-4-PQPB), 1-[3-(3-methoxyphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Mt-3-PQPB) and 1-[3-(2H-1,3-benzodioxol-5-yl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Oxo-1,3-PQPB) was studied for mild steel corrosion in 1 M HCl solution using electrochemical, spectroscopic techniques and quantum chemical calculations. The results of both potentiodynamic polarization and electrochemical impedance spectroscopic studies revealed that the compounds are mixed-type inhibitors and the order of corrosion inhibition efficiency at 100 ppm is Me-4-PQPB>Mt-3-PQPB>Oxo-1,3-PQPB>Mt-4-PQPB. Fourier transform infrared (FTIR) and ultraviolet-visible (UV-vis) spectroscopic analyses confirmed the presence of chemical interactions between the inhibitors and mild steel surface. The adsorption of the inhibitor molecules on mild steel surface was found to be both physisorption and chemisorption but predominantly chemisorption. The experimental data obey Langmuir adsorption isotherm. Scanning electron microscopy studies revealed the formation of protective films of the inhibitors on mild steel surface. Quantum chemical parameters obtained from density functional theory (DFT) calculations support experimental results.

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

    Science.gov (United States)

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

    2003-05-21

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

  6. An Integrated Membrane Process for Butenes Production

    Directory of Open Access Journals (Sweden)

    Leonardo Melone

    2016-11-01

    Full Text Available Iso-butene is an important material for the production of chemicals and polymers. It can take part in various chemical reactions, such as hydrogenation, oxidation and other additions owing to the presence of a reactive double bond. It is usually obtained as a by-product of a petroleum refinery, by Fluidized Catalytic Cracking (FCC of naphtha or gas-oil. However, an interesting alternative to iso-butene production is n-butane dehydroisomerization, which allows the direct conversion of n-butane via dehydrogenation and successive isomerization. In this work, a simulation analysis of an integrated membrane system is proposed for the production and recovery of butenes. The dehydroisomerization of n-butane to iso-butene takes place in a membrane reactor where the hydrogen is removed from the reaction side with a Pd/Ag alloys membrane. Afterwards, the retentate and permeate post-processing is performed in membrane separation units for butenes concentration and recovery. Four different process schemes are developed. The performance of each membrane unit is analyzed by appropriately developed performance maps, to identify the operating conditions windows and the membrane permeation properties required to maximize the recovery of the iso-butene produced. An analysis of integrated systems showed a yield of butenes higher than the other reaction products with high butenes recovery in the gas separation section, with values of molar concentration between 75% and 80%.

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

    KAUST Repository

    Chrystie, Robin

    2015-05-29

    We report on a strategy to measure, in situ, the concentration of propene (C3H6) in combustion gases using laser absorption spectroscopy. Pyrolysis of n-butane was conducted in a shock tube, in which the resultant gases were probed using an extended cavity quantum-cascade laser. A differential absorption approach using online and offline wavelengths near λ = 10.9 μm enabled discrimination of propene, cancelling the effects of spectral interference from the simultaneous presence of intermediate hydrocarbon species during combustion. Such interference-free measurements were facilitated by exploiting the =C–H bending mode characteristic to alkenes (olefins). It was confirmed, for intermediate species present during pyrolysis of n-butane, that their absorption cross sections were the same magnitude for both online and offline wavelengths. Hence, this allowed time profiles of propene concentration to be measured during pyrolysis of n-butane in a shock tube. Time profiles of propene subsequent to a passing shock wave exhibit trends similar to that predicted by the well-established JetSurF 1.0 chemical kinetic mechanism, albeit lower by a factor of two. Such a laser diagnostic is a first step to experimentally determining propene in real time with sufficient time resolution, thus aiding the refinement and development of chemical kinetic models for combustion. © 2015 Springer-Verlag Berlin Heidelberg

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

    Science.gov (United States)

    Srinivasan, S.; Saghir, M. Z.

    2009-09-01

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

  9. Fluidization Characteristics of a Prototype Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    F. ABERUAGBA

    2005-01-01

    Full Text Available The fluidization characteristics of a prototype-fluidized bed laboratory reactor were understudied in order to investigate the suitable conditions at which the dehydrogenation reaction of butane could be carried out. To achieve this, a reactor with an effective volume of 1100ml was fabricated and coupled with temperature and pressure accessories.Zeolites were obtained from the market and clay obtained from different sources and pre-treated was used as catalyst. Airflow at high velocity between 3000-7000ml/hr was used as the fluidising medium to obtain the bed characteristics while butane gas was used to obtain the dehydrogenation kinetics.The temperature of the reactor system was varied between 353K and 413K while maintaining constant pressure of 1.5 105 N/m2 through a manifold gauge and a constant catalyst weight. Various methods such as pressure fluctuations, visual observations, and bed expansion were used to determine the transition velocity at which fluidization begins. It was observed that this depends on factors such as mean particle size, particle size distribution, and column diameter.The minimum fluidizing velocity obtained for zeolite was 0.0133m/s and 0.0102m/s for treated clay materials both for a particle size of 250μm. The conversion of butane over the catalysts showed an increase in both cases with a maximum at 0.9813 at 413K. This decreases as the reaction progresses.

  10. Identification of a Male-Produced Pheromone Component of the Citrus Longhorned Beetle, Anoplophora chinensis.

    Science.gov (United States)

    Hansen, Laura; Xu, Tian; Wickham, Jacob; Chen, Yi; Hao, Dejun; Hanks, Lawrence M; Millar, Jocelyn G; Teale, Stephen A

    2015-01-01

    The Asian wood-boring beetle Anoplophora chinensis (Forster) (Coleoptera: Cerambycidae) is an important pest of hardwood trees in its native range, and has serious potential to invade other areas of the world through worldwide commerce in woody plants and wood products. This species already has been intercepted in North America, and is the subject of ongoing eradication efforts in several countries in Europe. Attractants such as pheromones would be immediately useful as baits in traps for its detection. Because long-range pheromones are frequently conserved among closely related species of cerambycids, we evaluated two components of the volatile pheromone produced by males of the congener A. glabripennis (Motschulsky), 4-(n-heptyloxy)butan-1-ol and 4-(n-heptyloxy)butanal, as potential pheromones of A. chinensis. Both compounds subsequently were detected in headspace volatiles from male A. chinensis, but not in volatiles from females. Only 4-(n-heptyloxy)butanol elicited responses from beetle antennae in coupled gas chromatography-electroantennogram analyses, and this compound attracted adult A. chinensis of both sexes in field bioassays. These data suggest that 4-(n-heptyloxy)butan-1-ol is an important component of the male-produced attractant pheromone of A. chinensis, which should find immediate use in quarantine monitoring for this pest.

  11. Geochemical assessment of light gaseous hydrocarbons in near-surface soils of Kutch–Saurashtra: Implication for hydrocarbon prospects

    Indian Academy of Sciences (India)

    P Lakshmi Srinivasa Rao; T Madhavi; D Srinu; M S Kalpana; D J Patil; A M Dayal

    2013-02-01

    Light hydrocarbons in soil have been used as direct indicators in geochemical hydrocarbon exploration, which remains an unconventional path in the petroleum industry. The occurrence of adsorbed soil gases, methane and heavier homologues were recorded in the near-surface soil samples collected from Kutch–Saurashtra, India. Soil gas alkanes were interpreted to be derived from deep-seated hydrocarbon sources and have migrated to the surface through structural discontinuities. The source of hydrocarbons is assessed to be thermogenic and could have been primarily derived from humic organic matter with partial contribution from sapropelic matter. Gas chromatographic analyses of hydrocarbons desorbed from soil samples through acid extraction technique showed the presence of methane through -butane and the observed concentrations (in ppb) vary from: methane (C1) from 4–291, ethane (C2) from 0–84, propane (C3) from 0–37, i-butane (iC4) from 0–5 and -butane (nC4) from 0–4. Carbon isotopes measured for methane and ethane by GC-C-IRMS, range between −42.9‰ to −13.3‰ (Pee Dee Belemnite – PDB) and −21.2‰ to −12.4‰ (PDB), respectively. The increased occurrence of hydrocarbons in the areas near Anjar of Kutch and the area south to Rajkot of Saurashtra signifies the area potential for oil and gas.

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

    Science.gov (United States)

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

    2015-10-01

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

  13. Solubility and diffusivity study for light gases in heavy oil and its fractions

    Science.gov (United States)

    Ganapathi, Rajkumar

    Solvent-based recovery (VAPEX) is one of the most promising alternatives to thermal techniques to enhance heavy oil/bitumen recovery. Knowledge of the phase behavior and diffusion coefficients of gases in heavy oil is very important when designing recovery operations and facilities. In this work, a gravimetric microbalance was used to measure the solubility of carbon dioxide, ethane, propane and butane in a Lloydminster heavy oil and its fractions. Measurements were carried out on carbon dioxide and ethane at (290, 298 and 313) K over a pressure range from (200 to 2000) kPa. Similar measurements were performed on propane and butane below their vapor pressures. The Peng-Robinson equation of state was used to correlate the experimental results. The Solubility Parameter Theory was used to predict the solubility of CO2 and propane in heavy oil/bitumen over a wide range of pressures and temperatures. The associated Henry's Law constants for carbon dioxide, ethane and propane in heavy oil, its saturate fractions and aromatic fractions, were also determined from the absorption data. The gases had higher solubilities and the strongest interactions at lower temperatures in the heavy oil and its fractions. The diffusion coefficients of carbon dioxide, ethane and propane in heavy oil, its saturate and aromatic fractions were calculated using a simple diffusion model. The diffusion coefficient of carbon dioxide, ethane, propane and butane in heavy oil were calculated at different pressures. Estimated values were in agreement with published results and were found satisfactory.

  14. Synthesis of a new intercalating nucleic acid 6H-INDOLO[2,3-b] quinoxaline oligonucleotides to improve thermal stability of Hoogsteen-type triplexes.

    Science.gov (United States)

    Osman, Amany M A; Pedersen, Erik B; Bergman, Jan

    2013-01-01

    A new intercalating nucleic acid monomer X was obtained in high yield starting from alkylation of 4-iodophenol with (S)-(+)-2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethanol under Mitsunobu conditions followed by hydrolysis with 80% aqueous acetic acid to give a diol which was coupled under Sonogashira conditions with trimethylsilylacetylene (TMSA) to achieve the TMS protected (S)-4-(4-((trimethylsilyl)ethynyl)phenoxy)butane-1,2-diol. Tetrabutylammonium flouride was used to remove the silyl protecting group to obtain (S)-4-(4-ethynylphenoxy)butane-1,2-diol which was coupled under Sonogashira conditions with 2-(9-bromo-6H-indolo[2,3-b]quinoxalin-6-yl)-N,N-dimethylethanamine to achieve (S)-4-(4-((6-(2-(dimethylamino)ethyl)-6H-indolo[2,3-b]quinoxalin-9-yl)ethynyl)phenoxy)butane-1,2-diol. This compound was tritylated with 4,4'-dimethoxytrityl chloride followed by treatment with 2-cyanoethyltetraisopropylphosphordiamidite in the presence of N,N'-diisopropyl ammonium tetrazolide to afford the corresponding phosphoramidite. This phosphoramidite was used to insert the monomer X into an oligonucleotide which was used for thermal denaturation studies of a corresponding parallel triplex.

  15. Mass transfer and adsorption equilibrium study in MFI zeolites: application to the separation of mono and di-branched hydrocarbons in silicalite; Etude et modelisation de l'adsorption et du transfert de matiere dans les zeolithes de structure MFI. Application a la separation des hydrocarbures satures mono et di-branches

    Energy Technology Data Exchange (ETDEWEB)

    Jolimaitre, E.

    1999-11-30

    The aim of this study was to develop a model representing the breakthrough of hydrocarbon mixtures in fixed bed, and to estimate the parameters of this model. Equilibrium isotherms and effective diffusivities of 3-methyl-pentane, isopentane and 2,2-dimethyl-butane in silicalite were measured between 150 and 300 deg. C and for different concentrations, with a linear chromatography technique. Parameter estimation was made by mean of a linear model developed for this work, on which a parameter identifiability study was made. The method used for the parameter identifiability study can be applied to any linear fixed bed model. Experimental single component and mixtures breakthrough curves of 2-methyl-pentane, isopentane and 2,2-dimethyl-butane were then realized at 200 deg. C. Adsorption isotherms and self diffusivities were estimated from single-component curves, using a non linear model of the bed. The non-linear model was also developed and validated during this work. These parameters were injected into the non-linear model to simulate the experimental mixture breakthrough curves. Influence of the velocity variation in the bed and of the diffusion driving-force (Maxwell-Stefan or Fick theory) was studied. Most of the experimental breakthrough curves are correctly predicted by the model, expect for the isopentane-2,2-dimethyl-butane mixture, for which predicted breakthrough time is inferior to experimental values. (author)

  16. Mass transfer and adsorption equilibrium study in MFI zeolites: application to the separation of mono and di-branched hydrocarbons in silicalite; Etude et modelisation de l'adsorption et du transfert de matiere dans les zeolithes de structure MFI. Application a la separation des hydrocarbures satures mono et di-branches

    Energy Technology Data Exchange (ETDEWEB)

    Jolimaitre, E.

    1999-11-30

    The aim of this study was to develop a model representing the breakthrough of hydrocarbon mixtures in fixed bed, and to estimate the parameters of this model. Equilibrium isotherms and effective diffusivities of 3-methyl-pentane, isopentane and 2,2-dimethyl-butane in silicalite were measured between 150 and 300 deg. C and for different concentrations, with a linear chromatography technique. Parameter estimation was made by mean of a linear model developed for this work, on which a parameter identifiability study was made. The method used for the parameter identifiability study can be applied to any linear fixed bed model. Experimental single component and mixtures breakthrough curves of 2-methyl-pentane, isopentane and 2,2-dimethyl-butane were then realized at 200 deg. C. Adsorption isotherms and self diffusivities were estimated from single-component curves, using a non linear model of the bed. The non-linear model was also developed and validated during this work. These parameters were injected into the non-linear model to simulate the experimental mixture breakthrough curves. Influence of the velocity variation in the bed and of the diffusion driving-force (Maxwell-Stefan or Fick theory) was studied. Most of the experimental breakthrough curves are correctly predicted by the model, expect for the isopentane-2,2-dimethyl-butane mixture, for which predicted breakthrough time is inferior to experimental values. (author)

  17. Enhanced ethylene and ethane production with free-radical cracking catalysts.

    Science.gov (United States)

    Kolts, J H; Delzer, G A

    1986-05-09

    A series of free-radical catalysts have been discovered that increase the yield of highly valuable olefins from the cracking of low molecular weight paraffins. For example, catalytic cracking of n-butane, isobutane, and propane over manganese or iron supported on magnesium oxide (MgO) gave product distributions different from those given by thermal (free-radical) cracking or cracking over traditional acid catalysts. With n-butane and propane feeds, the products from catalytic cracking included large amounts of ethylene and ethane; with isobutane feed, propylene was the major product. Physical characterization of the MgO-supported catalyst showed the manganese to be in a 2+ oxidation state in the reduced catalyst and a 4+ oxidation state in the fully oxidized catalyst. Manganese was also shown to be uniformly distributed in the support material with very little enrichment at the surface. Matrix isolation of the gasphase radicals from n-butane feed showed that ethyl and methyl radicals were produced over the active catalysts. In the thermal process, only methyl radicals were produced. The mechanism of the catalytic reaction appears to be selective formation of primary carbanions at the catalyst surface followed by electron transfer and release of primary hydrocarbon radicals to the gas phase.

  18. One-pot synthesis of cyclic aldol tetramer and,β-unsaturated aldol from linear aldehydes using quaternary ammonium combined with sodium hydroxide as catalysts

    Institute of Scientific and Technical Information of China (English)

    许海峰; 钟宏; 王帅; 李方旭

    2015-01-01

    One-pot synthesis of cyclic aldol tetramer anda,β-unsaturated aldol from C3−C8 linear aldehydes using phase-transfer catalyst (PTC), quaternary ammonium, combined with sodium hydroxide as catalysts was investigated. Butanal was subjected for detail investigations to study the effect of parameters. It was found that the selectivity of cyclic aldol tetramer depends greatly on the operating conditions of the reaction, especially the PTC/butanal molar ratio. The average selectivity of 2-hydroxy-6-propyl-l, 3, 5-triethyl-3-cyclohexene-1-carboxaldehyde (HPTECHCA) was 54.41% using tetrabutylammonium chloride combined with 14% (mass fraction) NaOH as catalysts at 60 °C for 2 h with a PTC-to-butanal molar ratio of 0.09:1. Pentanal was more likely to generate cyclic aldol tetramer compared with other aldehydes under the optimum experimental conditions. Recovery of the PTC through water washing followed by adding enough sodium hydroxide from the washings was also demonstrated.

  19. Role of support nature (γ-Al2O3 and SiO2-Al2O3) on the performances of rhenium oxide catalysts in the metathesis of ethylene and 2-pentene

    Institute of Scientific and Technical Information of China (English)

    Weena Phongsawat; Benjamas Netiworaruksa; Kongkiat Suriye; Siraprapha Dokjampa; Piyasan Praserthdam; Joongjai Panpranot

    2012-01-01

    The metathesis of ethylene and 2-pentene was studied as an alternative route for propylene production over Re2O7/γ-Al2O3 and Re2O7/SiO2-Al2O3 catalysts.Both NH3 temperature-programmed desorption (NH3-TPD) and H2 temperature-programmed reduction (H2-TPR) results showed that Re2O7/SiO2-Al2O3 exhibited stronger acidity and weaker metal-support interaction than Re2O7/γ-Al2O3.At 35-60 ℃,isomerization free metathesis was observed only over Re2O7/γ-Al2O3,suggesting that the formation of metal-carbene metathesis active sites required only weak acidity.Our results suggest that on the Re2O7/SiO2-Al2O3,hydrido-rhenium species ([Re]-H) were formed in addition to the metathesis active sites,resulting in the isomerization of the initial 1-butene product into 2-butenes.A subsequent secondary metathesis reaction between these 2-butenes and the excess ethylene could explain the enhanced yields of propylene observed.The results demonstrate the potential for high yield of propylene from alternative feedstocks.

  20. Production of propylene from an unconventional metathesis of ethylene and 2-pentene over Re2O7/SiO2-Al2O3 catalysts

    Institute of Scientific and Technical Information of China (English)

    Weena Phongsawat; Benjamas Netivorruksa; Kongkiat Suriye; Siraprapha Dokjampa; Piyasan Praserthdam; Joongjai Panpranot

    2012-01-01

    An unconventional metathesis of ethylene and 2-pentene over Re2O7/SiO2-Al2O3 catalysts has been studied as an alternative route for the production of propylene.Complete conversion of 2-pentene and propylene yield as high as 88 wt% were obtained under mild reaction conditions at 35 ℃ and atmospheric pressure.Unlike the conventional metathesis of ethylene and 2-butenes in which isomerization is a competing side reaction,the isomerization of 1-butene product from the unconventional metathesis of ethylene and 2-pentene to 2-hutenes can further react with excess ethylene in the feed,resulting in additional increase in propylene yield.The secondary metathesis reaction was found to be favored under ethylene/2-pentene (E/2P) molar ratio ≥3 and gas hourly space velocity (GHSV) ≤ 1000 h-1 at the reaction temperature of 35 ℃.No catalyst deactivation was observed during the 455 min time-on-stream under the selected reaction conditions.