Sample records for butane

  1. 21 CFR 184.1165 - n-Butane and iso-butane. (United States)


    ... 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...

  2. Microbiology: Deep-sea secrets of butane metabolism (United States)

    Ragsdale, Stephen W.


    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

  3. 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


    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.

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

    Directory of Open Access Journals (Sweden)

    He-ping Li


    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.

  5. Exploring Butane Hash Oil Use: A Research Note. (United States)

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


    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.

  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


    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)



    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. Elimination of butanal from odorous air by a labscale biofilter

    NARCIS (Netherlands)

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


    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

  9. A critical analysis on the rotation barriers in butane. (United States)

    Mo, Yirong


    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.

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

    Energy Technology Data Exchange (ETDEWEB)



    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.)

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

    Energy Technology Data Exchange (ETDEWEB)



    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.)

  12. 2,3-Bis[(3-methylbiphenyl-4-ylimino]butane

    Directory of Open Access Journals (Sweden)

    Jingjing Chen


    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.


    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...

  14. Catalytic reactive distillation process development for 1,1 diethoxy butane production from renewable sources. (United States)

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


    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.

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

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

    Directory of Open Access Journals (Sweden)

    Yating Zhang


    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.

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

    Directory of Open Access Journals (Sweden)

    K. F. Mustafa


    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.

  18. 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.

  19. Monte Carlo simulation of n-butane in water. Conformational evidence for the hydrophobic effecta) (United States)

    Jorgensen, William L.


    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.

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

    NARCIS (Netherlands)

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


    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

  1. Thermal diffusion and partial molar enthalpy variations of n-butane in silicalite-1. (United States)

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


    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.

  2. 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)


    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.

  3. Biooxidation of n-butane to 1-butanol by engineered P450 monooxygenase under increased pressure. (United States)

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


    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.

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


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


    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.

  5. Draft Genome Sequence of Propane- and Butane-Oxidizing Actinobacterium Rhodococcus ruber IEGM 231. (United States)

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


    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.


    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...

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

    NARCIS (Netherlands)

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


    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

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

    KAUST Repository

    Szeto, Kaï Chung


    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.

  9. 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.


    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

  10. Trichloroethylene aerobic cometabolism by suspended and immobilized butane-growing microbial consortia: a kinetic study. (United States)

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


    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.

  11. 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))


    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.

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

    Directory of Open Access Journals (Sweden)

    J. P. Bender


    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.

  13. 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


    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.)

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

    KAUST Repository

    Veloo, Peter S.


    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.

  15. 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


    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.

  16. Ring-strain-enabled reaction discovery: new heterocycles from bicyclo[1.1.0]butanes. (United States)

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


    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

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

    Directory of Open Access Journals (Sweden)



    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.

  18. Crystal structure of 1-(piperidin-1-yl)butane-1,3-dione. (United States)

    Schwierz, Markus; Görls, Helmar; Imhof, Wolfgang


    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.

  19. 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)


    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.

  20. 6-Methyl-1,3,5-triazine-2,4-diamine butane-1,4-diol monosolvate

    Directory of Open Access Journals (Sweden)

    Rajni M. Bhardwaj


    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.

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

    Indian Academy of Sciences (India)



    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.

  2. 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)


    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.

  3. 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


    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).

  4. 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


    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.

  5. 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.


    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...

  6. 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.


    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

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

    Bücker, D.; Wagner, W.


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

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

    KAUST Repository

    Xiong, Yuan


    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.

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

    Directory of Open Access Journals (Sweden)

    P. M. Ndiaye


    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.

  10. 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


    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.

  11. 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.


    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...

  12. Synthesis and evaluation of inhaled [11C]butane and intravenously injected [11C]acetone as potential radiotracers for studying inhalant abuse. (United States)

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


    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.

  13. 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


    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.

  14. 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: [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: [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)


    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.

  15. Implications of sterically constrained n-butane oxidation reactions on the reaction mechanism and selectivity to 1-butanol (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    Juan M. Salazar


    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.

  17. Recreational inhalation of butane and propane in adolescents: Two forensic cases of accidental death. (United States)

    Sironi, Luca; Amadasi, Alberto; Zoja, Riccardo


    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.

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

    Directory of Open Access Journals (Sweden)

    S.M. Gheno


    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.

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

    KAUST Repository

    Pasha, Farhan Ahmad


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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).

  1. 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)


    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

  2. 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


    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℃.

  3. 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. (United States)

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


    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.

  4. 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


    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.

  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


    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. 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)


    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)

  7. Direct Dehydrogenation of n-Butane Over Pt/Sn/Zn-K/Al2O3 Catalyst: Effect of Hydrogen in the Feed. (United States)

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


    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.

  8. A novel predictive model for formation enthalpies of Si and Ge hydrides with propane- and butane-like structures. (United States)

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


    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

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

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


    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.

  10. Use of butane-isobutane refrigerant spray in the management of a mucocoele in a visually impaired child. (United States)

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


    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.

  11. L'engelure causée par le butane commercial au cours d’un accident industriel (United States)

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


    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

  12. 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. (United States)

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


    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.

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

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


    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)

  14. 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


    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.

  15. 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)


    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.

  16. 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


    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.

  17. 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


    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.

  18. 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


    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.

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

    KAUST Repository

    Choi, Byungchul


    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. 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


    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.

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


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

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

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

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

  6. 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


    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.

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

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


    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.

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

    KAUST Repository

    Badra, Jihad


    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.

  9. The Power of Biocatalysis: A One‐Pot Total Synthesis of Rhamnolipids from Butane as the Sole Carbon and Energy Source (United States)

    Gehring, Christian; Wessel, Mirja; Schaffer, Steffen


    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

  10. (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:


    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.

  11. (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:


    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.

  12. 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


    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.

  13. 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


    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.

  14. 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


    [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.

  15. Temperature measurement of axi- symmetric butane diffusion flame under the influence of upward decreasing gradient magnetic field using digital holographic interferometry (United States)

    Kumar, Varun; Kumar, Manoj; Shakher, Chandra


    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.

  16. 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


    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.

  17. 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)


    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.

  18. 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


    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.

  19. 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


    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.

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

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

    KAUST Repository

    Chakraborty, Anutosh


    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.

  2. Comparison of two-body and three-body decomposition of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene (United States)

    Chin, Chih-Hao; Lee, Shih-Huang


    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.

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

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


    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.

  4. 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


    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.

  5. 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)


    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)

  6. Effect of modification methods on the surface properties and n-butane isomerization performance of La/Ni-promoted SO42-/ZrO2-Al2O3 (United States)

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


    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.

  7. 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


    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.

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

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


    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.

  9. 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. (United States)

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


    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.

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

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


    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.

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

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


    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.

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

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


    Kinetic parameters were evaluated for inhibition of native and reactivation of tabun-inhibited human erythrocyte acetylcholinesterase (AChE, EC and human plasma butyrylcholinesterase (BChE, EC 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.

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


    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.

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

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


    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.

  15. 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


    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.

  16. Development of a pre-concentration system and auto-analyzer for dissolved methane, ethane, propane, and butane concentration measurements with a GC-FID (United States)

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


    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

  17. 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


    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.

  18. 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


    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.

  19. 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 (United States)

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


    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.

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


    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.

  1. 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)


    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.

  2. 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:


    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.

  3. 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


    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.

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


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


    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...

  5. 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


    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.

  6. 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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  7. 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). (United States)

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


    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.

  8. 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.


    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

  9. 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). (United States)

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


    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.

  10. 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


    [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

  11. 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. (United States)

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


    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.

  12. 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.


    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.

  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


    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. 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


    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.

  15. (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)


    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.

  16. 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


    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.

  17. 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. (United States)

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


    [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.

  18. 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


    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。

  19. 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


    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.

  20. 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


    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.

  1. 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)



    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.)

  2. 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)



    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.)

  3. Simulated consumer exposure to dimethyl ether and propane/butane in hairsprays. (United States)

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


    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.

  4. 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.


    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.

  5. Performance of Commercially Available Flame Arrestors for Butane/Air and Gasoline/Air Mixtures (United States)


    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

  6. 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.;


    . 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...

  7. 2,2′-{1,1′-[Butane-1,4-diylbis(oxynitrilo]diethylidyne}di-1-naphthol

    Directory of Open Access Journals (Sweden)

    Wen-Kui Dong


    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.

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


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

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

    Schwierz, Markus; Görls, Helmar; Imhof, Wolfgang


    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].

  10. Durable antibacterial and cross-linking cotton with colloidal silver nanoparticles and butane tetracarboxylic acid without yellowing. (United States)

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


    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.

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

    KAUST Repository

    Petrenko, V.O.


    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.

  12. 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


    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.

  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



  14. 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


    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.

  15. 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


    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.

  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.


    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...

  17. 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


    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.

  18. 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.;


    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...

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

    Gainsford, Graeme J; Hinkley, Simon


    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.

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

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


    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.

  1. 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


    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.

  2. 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: [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana)


    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.

  3. 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



  4. 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


    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.

  5. 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. (United States)

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


    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.

  6. 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


    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%.

  7. 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.


    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

  8. 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;


    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...

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

    DEFF Research Database (Denmark)

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


    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...

  10. Planar gas chromatography column on aluminum plate with multi-walled carbon nanotubes as stationary phase (United States)

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


    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.

  11. 2,4-Bis(diphenyl­phosphan­yl)-1,1,2,3,3,4-hexa­phenyl-1,3-diphospha-2,4-dibora­cyclo­butane tetra­hydro­furan sesqui­solvate (United States)

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


    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

  12. 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


    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.

  13. 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.


    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.

  14. 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)


    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.

  15. Two simple amine hydrochlorides from the soft coral Lobophytum strictum

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Naik, C.G.; Das, B.; Kamat, S.Y.

    Two simple amine hydrochlorides, viz., 1-amino-1, 1-dimethyl-3-oxo-butane hydrochloride (1) (Diacetonamine) and 2, 2, 6, 6-tetramethylpiperidone hydrochloride (2) have been isolated from the fraction of the methanolic extract of the soft coral...

  16. 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.


    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,

  17. 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


    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

  18. Substance use -- inhalants (United States)

    ... spray paint. Gases, such as butane (lighter fluid), computer cleaning spray, freon , helium, nitrous oxide (laughing gas), ... need (crave) them to get through daily life. Addiction can lead to tolerance. Tolerance means that more ...

  19. [Ventricular fibrillation following deodorant spray inhalation]. (United States)

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


    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.

  20. From an equilibrium based MOF adsorbent to a kinetic selective carbon molecular sieve for paraffin/iso-paraffin separation. (United States)

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


    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.

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

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


    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.

  2. Central Appalachian basin natural gas database: distribution, composition, and origin of natural gases (United States)

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


    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.

  3. In situ studies of fuel oxidation in solid oxide fuel cells. (United States)

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


    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.

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

  5. Isolation and Biological Evaluation of Two Bioactive Metabolites from Aspergillus gorakhpurensis

    Directory of Open Access Journals (Sweden)

    Venkateswarlu Yenamandra


    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.

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

    Majumdar, Sanhita


    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.

  7. Product ion distributions for the reactions of NO(+) with some physiologically significant aldehydes obtained using a SRI-TOF-MS instrument


    Mochalski, P; Unterkofler, K.; Španěl, P; Smith, D; AMANN, A


    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 ...

  8. Regioselective alkane hydroxylation with a mutant AlkB enzyme (United States)

    Koch, Daniel J.; Arnold, Frances H.


    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.

  9. 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.


    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

  10. Energy Conversion and Combustion Sciences (United States)


    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 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

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

    KAUST Repository

    Li, Baiyan


    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.

  12. The North American natural gas liquids markets are chaotic



    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...


    NARCIS (Netherlands)



    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.

  14. 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


    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).

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

  16. 75 FR 34017 - Protection of Stratospheric Ozone: Notice 25 for Significant New Alternatives Policy Program (United States)


    ...-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)...

  17. Hydrogen Bonding in Thermoplastic Polyurethane Elastomers: IR Thermal Analysis

    Institute of Scientific and Technical Information of China (English)


    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.

  18. Branched chain aldehydes: production and breakdown pathways and relevance for flavour in foods

    NARCIS (Netherlands)

    Smit, B.A.; Engels, W.J.M.; Smit, G.


    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

  19. Seasonal behavior of non-methane hydrocarbons in the firn air at Summit, Greenland (United States)

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


    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.

  20. High-pressure measuring cell for Raman spectroscopic studies of natural gas

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.; Stenby, Erling Halfdan


    to detect hydrogen sulfide at concentrations of 1-3 mg H2S/Nm(3). An attempt to make a quantitative analysis of natural gas by the so-called "ratio method" is presented. In addition to this, the relative normalized differential Raman scattering cross sections for ethane and i-butane molecules at 8.0 MPa...

  1. Stoichiometric Experiments with Alkane Combustion: A Classroom Demonstration (United States)

    Zhilin, Denis M.


    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…

  2. 40 CFR 60.503 - Test methods and procedures. (United States)


    .../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...

  3. 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.


    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

  4. 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.


    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.

  5. 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. (United States)

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


    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.

  6. MEMS-based fuel cells with integrated catalytic fuel processor and method thereof (United States)

    Jankowski, Alan F.; Morse, Jeffrey D.; Upadhye, Ravindra S.; Havstad, Mark A.


    Described herein is a means to incorporate catalytic materials into the fuel flow field structures of MEMS-based fuel cells, which enable catalytic reforming of a hydrocarbon based fuel, such as methane, methanol, or butane. Methods of fabrication are also disclosed.

  7. 10 CFR 205.12 - Addresses for filing documents with the DOE. (United States)


    ... 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...

  8. 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)


    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.

  9. 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


    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

  10. On a novel coordination mode of phosphinine C5H5P. (United States)

    Elschenbroich, Christoph; Six, Jörg; Harms, Klaus


    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.

  11. Parametric Optimization of Regenerative Organic Rankine Cycle System for Diesel Engine Based on Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Hongjin Wang


    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%.

  12. Combustion and Energy Transfer Experiments: A Laboratory Model for Linking Core Concepts across the Science Curriculum (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.


    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…

  13. 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


    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.)

  14. 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


    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.)

  15. Ventilation of liquefied petroleum gas components from the Valley of Mexico (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.


    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.

  16. 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)


    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

  17. Physics of the multi-functionality of lanthanum ferrite ceramics (United States)

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


    In the present work, we have illustrated the physics of the multifunctional characteristics of nano-crystalline LaFeO3 powder prepared using auto-combustion synthesis. The synthesized powders were phase pure and crystallized into centro-symmetric Pnma space group. The temperature dependence of dielectric constant of pure LaFeO3 exhibits dielectric maxima similar to that observed in ferroelectric ceramics with non-centrosymmetric point group. The dielectric relaxation of LaFeO3 correlates well with small polaron conduction. The occurrence of polarization hysteresis in LaFeO3 (with centro-symmetric Pnma space group) is thought to be spin current induced type. The canting of the Fe3+ spins induce weak ferromagnetism in nano-crystalline LaFeO3. Room temperature saturation magnetization of pure LaFeO3 is reported to be 3.0 emu/g. Due to the presence of both ferromagnetic as well as polarization ordering, LaFeO3 behaves like a single phase multiferroic ceramics. The magneto-electric coupling in this system has been demonstrated through the magneto-dielectric measurements which yield about 0.8% dielectric tuning (at 10 kHz) with the application of 2 T magnetic field. As a typical application of the synthesized nano-crystalline LaFeO3 powder, we have studied its butane sensing characteristics. The efficient butane sensing characteristics have been correlated to their catalytic activity towards oxidation of butane. Through X-ray photoelectron spectroscopy analyses, we detect the surface adsorbed oxygen species on LaFeO3 surface. Surface adsorbed oxygen species play major role in their low temperature butane sensing. Finally, we have hypothesized that the desorbed H2O and O2 (originate from surface adsorbed hydroxyl and oxygen) initiate the catalytic oxidative dehydrogenation of n-butane resulting in weakening of the electrostatics of the gas molecules.

  18. 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


    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

  19. Shock tube measurements of the tert-butanol + OH reaction rate and the tert-C4H8OH radical β-scission branching ratio using isotopic labeling. (United States)

    Stranic, Ivo; Pang, Genny A; Hanson, Ronald K; Golden, David M; Bowman, Craig T


    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.

  20. 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


    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.

  1. Carbon assimilation and extracellular antigens of some yeast-like fungi. (United States)

    Middelhoven, W J; De Hoog, G S; Notermans, S


    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.

  2. Volatile organic compound ratios as probes of halogen atom chemistry in the Arctic

    Directory of Open Access Journals (Sweden)

    P. B. Shepson


    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.

  3. Volatile organic compound ratios as probes of halogen atom chemistry in the Arctic

    Directory of Open Access Journals (Sweden)

    A. E. Cavender


    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.

  4. 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


    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.

  5. Monte Carlo simulation of a complex fluid confined to a pore with nanoscopically rough walls (United States)

    Porcheron, Fabien; Schoen, Martin; Fuchs, Alain H.


    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.

  6. 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


    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.

  7. Antimoulting Activity of Eremanthus erythropappus (DC. MacLeisch

    Directory of Open Access Journals (Sweden)

    Danielle Barbosa


    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.

  8. Theoretical Studies on Critical Properties of Binary System with Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)


    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.

  9. 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;


    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...

  10. Response surface optimization and identification of isothiocyanates produced from broccoli sprouts. (United States)

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


    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.

  11. Cytotoxic lignans from Larrea tridentata. (United States)

    Lambert, Joshua D; Sang, Shengmin; Dougherty, Ann; Caldwell, Colby G; Meyers, Ross O; Dorr, Robert T; Timmermann, Barbara N


    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.


    Institute of Scientific and Technical Information of China (English)

    梁德青; 郭开华; 樊栓狮; 王如竹


    @@ 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.

  13. Smartphone Schlieren

    CERN Document Server

    Miller, Victor A


    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.


    NARCIS (Netherlands)



    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

  15. O teuto-brasileiro: a história de um conceito

    Directory of Open Access Journals (Sweden)

    André Fabiano Voigt


    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.

  16. A stronger perfume for LPG

    Energy Technology Data Exchange (ETDEWEB)

    Willcox, C.K.


    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)

  17. Study of the production of polyesters for polyurethanes at pilot plant scale


    Matos, Sandro Filipe dos Santos


    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...

  18. Improvement of a New Gas Ionization Chamber

    Institute of Scientific and Technical Information of China (English)


    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

  19. Database Translator (DATALATOR) for Integrated Exploitation (United States)


    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

  20. Heat pumps: which refrigerant will win?; Welche Kaeltemittel werden sich durchsetzen?

    Energy Technology Data Exchange (ETDEWEB)

    Genath, B.


    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'.


    McIntyre, A S; Long, R G


    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. EOR production technique tested on Codell

    Energy Technology Data Exchange (ETDEWEB)

    Stremel, K.


    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.

  3. Olfactory Impact of Higher Alcohols on Red Wine Fruity Ester Aroma Expression in Model Solution. (United States)

    Cameleyre, Margaux; Lytra, Georgia; Tempere, Sophie; Barbe, Jean-Christophe


    This study focused on the impact of five higher alcohols on the perception of fruity aroma in red wines. Various aromatic reconstitutions were prepared, consisting of 13 ethyl esters and acetates and 5 higher alcohols, all at the average concentrations found in red wine. These aromatic reconstitutions were prepared in several matrices. Sensory analysis revealed the interesting behavior of certain compounds among the five higher alcohols following their individual addition or omission. The "olfactory threshold" of the fruity pool was evaluated in several matrices: dilute alcohol solution, dilute alcohol solution containing 3-methylbutan-1-ol or butan-1-ol individually, and dilute alcohol solution containing the mixture of five higher alcohols, blended together at various concentrations. The presence of 3-methylbutan-1-ol or butan-1-ol alone led to a significant decrease in the "olfactory threshold" of the fruity reconstitution, whereas the mixture of alcohols raised the olfactory threshold. Sensory profiles highlighted changes in the perception of fruity nuances in the presence of the mixture of higher alcohols, with specific perceptive interactions, including a relevant masking effect on fresh- and jammy-fruit notes of the fruity mixture in both dilute alcohol solution and dearomatized red wine matrices. When either 3-methylbutan-1-ol or butan-1-ol was added to the fruity reconstitution in dilute alcohol solution, an enhancement of butyric notes was reported with 3-methylbutan-1-ol and fresh- and jammy-fruit with butan-1-ol. This study, the first to focus on the impact of higher alcohols on fruity aromatic expression, revealed that these compounds participate, both quantitatively and qualitatively, in masking fruity aroma perception in a model fruity wine mixture.

  4. Combustion Characteristics of Sprays (United States)


    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 ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

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

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


    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.

  6. Jet Engine Exhaust Analysis by Subtractive Chromatography (United States)


    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

  7. Technologies for Hemostasis and Stabilization of the Acute Traumatic Wound (United States)


    swine survival studies. Alginates are naturally occurring polysaccharides that are derived primarily from seaweed. They are composed of linked β-D...high storage pressures and prior to delivery, the Tween/butane/formulation blend may form an emulsion, which is particularly amenable for foam...take several months because the DoD will have to rubber stamp whatever the local IACUC approves. Swine 192, p. 1 of 2 Figure 1, swine 192

  8. Honey oil burns: a growing problem. (United States)

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


    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.

  9. X-rays and Neutrons: Essential Tools for Nanoscience Research. Report of the National Nanotechnology Initiative Workshop, June 16-18, 2005, Washington, D.C. (United States)


    morphologies. In the second example we have used SANS to probe the magnetoelectronic phase separation that occurs in doped perovskite cobaltites . This 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

  10. Quinoxaline derivatives as corrosion inhibitors for mild steel in hydrochloric acid medium: Electrochemical and quantum chemical studies (United States)

    Olasunkanmi, Lukman O.; Kabanda, Mwadham M.; Ebenso, Eno E.


    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.

  11. 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


    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.

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

    KAUST Repository

    Chrystie, Robin


    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

  13. 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.


    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)

  14. Enhanced ethylene and ethane production with free-radical cracking catalysts. (United States)

    Kolts, J H; Delzer, G A


    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.

  15. Synthesis of a new intercalating nucleic acid 6H-INDOLO[2,3-b] quinoxaline oligonucleotides to improve thermal stability of Hoogsteen-type triplexes. (United States)

    Osman, Amany M A; Pedersen, Erik B; Bergman, Jan


    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.

  16. Identification of a Male-Produced Pheromone Component of the Citrus Longhorned Beetle, Anoplophora chinensis. (United States)

    Hansen, Laura; Xu, Tian; Wickham, Jacob; Chen, Yi; Hao, Dejun; Hanks, Lawrence M; Millar, Jocelyn G; Teale, Stephen A


    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.

  17. 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


    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.

  18. Solubility and diffusivity study for light gases in heavy oil and its fractions (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.

  19. Fluidization Characteristics of a Prototype Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)



    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.

  20. An Integrated Membrane Process for Butenes Production

    Directory of Open Access Journals (Sweden)

    Leonardo Melone


    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%.

  1. Analysis of volatiles in meat from Iberian pigs and lean pigs after refrigeration and cooking by using SPME-GC-MS. (United States)

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


    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.

  2. Hybrid simulations: combining atomistic and coarse-grained force fields using virtual sites. (United States)

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


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

  3. Vehicular fuel composition and atmospheric emissions in South China: Hong Kong, Macau, Guangzhou, and Zhuhai

    Directory of Open Access Journals (Sweden)

    W. Y. Tsai


    Full Text Available Vehicular emission is an important source of air pollutants in urban cities in the Pearl River Delta (PRD region of South China. In order to study the impact of vehicular fuel on air quality, several commonly used fuel samples were collected in four main cities in the PRD region – Hong Kong, Guangzhou, Macau and Zhuhai, and analyzed for their volatile organic compounds (VOCs composition. Source profiles of the vehicular fuels used in these cities were constructed and are believed to be the first reported for the PRD region. The C8–C10 hydrocarbons were the main constituents of diesel. Different from diesel, gasoline used in the PRD region was mainly comprised of lighter C4–C7 hydrocarbons, with toluene and i-pentane being the two most abundant species. The benzene content in the Guangzhou and Zhuhai gasoline samples were higher than that in Hong Kong and Macau and exceeded the maximum benzene levels for Mainland China unleaded gasoline. Liquefied Petroleum Gas (LPG samples were collected only in Hong Kong and were comprised mainly of n-butane, propane and i-butane. Traffic samples indicated that evaporative loss and vehicular combustion were the primary contributors to elevated VOC levels in roadside atmospheres. Significant i-pentane and toluene concentrations were observed in roadside atmospheres in all four cities. Ratio of i-pentane in gasoline samples to that in roadside samples were calculated and this showed that the degree of evaporative loss was higher in Guangzhou and Zhuhai than that in Hong Kong and Macau. We suggest the difference is due to the better maintenance and more new cars in Hong Kong and Macau. From tunnel samples collected in Hong Kong in two different years, we found that the relative amount of propane, i-butane, and n-butane increased between 2001 to 2003, consistent with the 40% increase in LPG fueled vehicles. Propane to butanes ratios were calculated for LPG and

  4. Vehicular fuel composition and atmospheric emissions in South China: Hong Kong, Macau, Guangzhou, and Zhuhai

    Directory of Open Access Journals (Sweden)

    W. Y. Tsai


    Full Text Available Vehicular emission is an important source of air pollutants in urban cities in the Pearl River Delta (PRD region of South China. In order to study the impact of evaporative loss of vehicular fuel on air quality, several commonly used fuel samples were collected in four main cities in the PRD region – Hong Kong, Guangzhou, Macau and Zhuhai, and analyzed for their volatile organic compounds (VOCs composition. Source profiles of vapors of the vehicular fuels used in these cities were constructed and are believed to be the first reported for the PRD region. The C8-C10 hydrocarbons were the main constituents of diesel. Different from diesel, gasoline used in the PRD region was mainly comprised of lighter C4-C7 hydrocarbons, with toluene and i-pentane being the two most abundant species. The toluene content in the Hong Kong and Macau gasoline samples were higher than that in Guangzhou and Zhuhai, while the reverse was true for the benzene content. The benzene levels in Guangzhou and Zhuhai exceeded the maximum allowable benzene levels for Mainland China unleaded gasoline. Liquefied Petroleum Gas (LPG samples were collected only in Hong Kong and were comprised mainly of n-butane, propane and i-butane. Traffic samples indicated that evaporative loss and vehicular combustion were the primary contributors to elevated VOC levels in roadside atmospheres. Significant i-pentane and toluene concentrations were observed in roadside atmospheres in all four cities. Ratio of i-pentane in gasoline vapors to that in roadside samples were calculated and this showed that the degree of evaporative loss were higher in Guangzhou and Zhuhai than that in Hong Kong and Macau. We suggest the difference is due to the better maintenance and more new cars in Hong Kong and Macau. From tunnel samples collected in Hong Kong in two different years, we found that the relative amount of propane, i-butane, and n-butane increased between 2001 to 2003, consistent with the 40% increase

  5. Vehicular fuel composition and atmospheric emissions in South China: Hong Kong, Macau, Guangzhou, and Zhuhai (United States)

    Tsai, W. Y.; Chan, L. Y.; Blake, D. R.; Chu, K. W.


    Vehicular emission is an important source of air pollutants in urban cities in the Pearl River Delta (PRD) region of South China. In order to study the impact of evaporative loss of vehicular fuel on air quality, several commonly used fuel samples were collected in four main cities in the PRD region - Hong Kong, Guangzhou, Macau and Zhuhai, and analyzed for their volatile organic compounds (VOCs) composition. Source profiles of vapors of the vehicular fuels used in these cities were constructed and are believed to be the first reported for the PRD region. The C8-C10 hydrocarbons were the main constituents of diesel. Different from diesel, gasoline used in the PRD region was mainly comprised of lighter C4-C7 hydrocarbons, with toluene and i-pentane being the two most abundant species. The toluene content in the Hong Kong and Macau gasoline samples were higher than that in Guangzhou and Zhuhai, while the reverse was true for the benzene content. The benzene levels in Guangzhou and Zhuhai exceeded the maximum allowable benzene levels for Mainland China unleaded gasoline. Liquefied Petroleum Gas (LPG) samples were collected only in Hong Kong and were comprised mainly of n-butane, propane and i-butane. Traffic samples indicated that evaporative loss and vehicular combustion were the primary contributors to elevated VOC levels in roadside atmospheres. Significant i-pentane and toluene concentrations were observed in roadside atmospheres in all four cities. Ratio of i-pentane in gasoline vapors to that in roadside samples were calculated and this showed that the degree of evaporative loss were higher in Guangzhou and Zhuhai than that in Hong Kong and Macau. We suggest the difference is due to the better maintenance and more new cars in Hong Kong and Macau. From tunnel samples collected in Hong Kong in two different years, we found that the relative amount of propane, i-butane, and n-butane increased between 2001 to 2003, consistent with the 40% increase in LPG fueled

  6. Non-methane hydrocarbons over the Eastern Mediterranean during summer, measured from northwest Cyprus (United States)

    Sauvage, Carina; Derstroff, Bettina; Bourtsoukidis, Efstratios; Keßel, Stephan; Thorenz, Ute; Baker, Angela; Williams, Jonathan; Lelieveld, Jos


    In summer 2014 the CYprus Photochemistry EXperiment (CYPHEX) field campaign took place at an elevated (600m) measurement site in the north western part of Cyprus close (10 km) to the coast (35,96N, 32,4E) in order to investigate the photochemistry and air mass transport of the eastern Mediterranean. Non-methane hydrocarbons were measured with a commercial GC-FID (AMA instruments GmbH, Ulm, Germany) with a final dataset consisting of two weeks of continuous, hourly measurements for 10 NMHC. NMHCs are a class of volatile organic compounds (VOC) which are emitted by both anthropogenic and natural sources. Their predominant sink in the atmosphere is photochemically driven oxidation by OH radicals. Their atmospheric lifetimes, which range from a few days for more reactive compounds such as pentanes and butanes and up to a month for less reactive ones like ethane, make it possible to deduce photochemical histories and transport regimes from NMHC observations. Furthermore, in the presence of NOx they are important precursors for tropospheric ozone. Backward trajectories show that the airmasses reaching the measurement site had been influenced periodically by emissions from western continental Europe (France, Spain) that crossed the Mediterranean Sea and from eastern continental Europe (Greece and Turkey) more recently influenced by industrial emissions. Varying patterns in NMHC data delineates these two regimes very well, with aged western European air masses being characterized by low level ethane and with toluene and benzene being higher and more variable in plumes from eastern Europe. Additionally, atypical n-butane and i-butane ratios suggest a deviation from the expected predominant oxidation by OH, possibly indicating reaction with chlorine radicals (Cl). The dataset has been evaluated with respect to NMHC sources and oxidative history using different methods of approach.

  7. Ten-year chemical signatures associated with long-range transport observed in the free troposphere over the central North Atlantic

    Directory of Open Access Journals (Sweden)

    B. Zhang


    Full Text Available Ten-year observations of trace gases at Pico Mountain Observatory (PMO, a free troposphere site in the central North Atlantic, were classified by transport patterns using the Lagrangian particle dispersion model, FLEXPART. The classification enabled identifying trace gas mixing ratios associated with background air and long- range transport of continental emissions, which were defined as chemical signatures. Comparison between the chemical signatures revealed the impacts of natural and anthropogenic sources, as well as chemical and physical processes during long transport, on air composition in the remote North Atlantic. Transport of North American anthropogenic emissions (NA-Anthro and summertime wildfire plumes (Fire significantly enhanced CO and O3 at PMO. Summertime CO enhancements caused by NA-Anthro were found to have been decreasing by a rate of 0.67 ± 0.60 ppbv/year in the ten-year period, due possibly to reduction of emissions in North America. Downward mixing from the upper troposphere and stratosphere due to the persistent Azores-Bermuda anticyclone causes enhanced O3 and nitrogen oxides. The 'd' [O3]/'d' [CO] value was used to investigate O3 sources and chemistry in different transport patterns. The transport pattern affected by Fire had the lowest 'd' [O3]/'d' [CO], which was likely due to intense CO production and depressed O3 production in wildfire plumes. Slightly enhanced O3 and 'd' [O3]/'d' [CO] were found in the background air, suggesting that weak downward mixing from the upper troposphere is common at PMO. Enhancements of both butane isomers were found during upslope flow periods, indicating contributions from local sources. The consistent ratio of butane isomers associated with the background air and NA-anthro implies no clear difference in the oxidation rates of the butane isomers during long transport. Based on observed relationships between non-methane hydrocarbons, the averaged photochemical age of the air masses at

  8. Unravelling the impact of hydrocarbon structure on the fumarate addition mechanism--a gas-phase ab initio study. (United States)

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


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

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  10. Relative contribution of oxygenated hydrocarbons to the total biogenic VOC emissions of selected mid-European agricultural and natural plant species (United States)

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

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

  11. Study of Methanol Conversion over Fe-Zn-Zr Catalyst

    Institute of Scientific and Technical Information of China (English)

    Xiaoming Ni; Yisheng Tan; Yizhuo Han


    The methanol conversion over Fe-Zn-Zr catalyst was studied at 0.1 MPa and 280-360℃.The experimental results indicate that the main products of methanol conversion are methane and butane,and that other hydrocarbons are scarcely produced.All results show that propylene is most probably the olefin formed first in methanol conversion rather than ethene over Fe-Zn-Zr catalyst.Methane is formed from methoxy group,and C4 is possibly yielded on the surface from propylene through binding with a methoxy group.

  12. New macrocyclic compounds using organotin complexes as intermediates: synthesis and characterization

    Directory of Open Access Journals (Sweden)

    Harminder Kaur


    Full Text Available Background & Aim:A new series of macrocyclic compounds 1-4 have been synthesized using tin as templates.Method:Tin templates are formed by refluxing the solution of dibutyltin (IV oxide with orthophenylenediamine (L1H,4-chlorocatechol (L2H, butane dithiol (L3H and 3-carboxypropyldisulphide (L4H. Results:The reaction is visualizedby cleavage X-Sn-X (X= oxygen/ nitrogen/ sulphur atom bond of tin template when treated withadipoyldichloride. Conclusion:The compounds 1-4 are characterized with the aid of elemental analyses, IR and NMR(1H, 13C studies which confirmed their proposed framework.

  13. Monte Carlo simulation of several biologically relevant molecules and zwitterions in water (United States)

    Patuwo, Michael Y.; Bettens, Ryan P. A.


    In this work, we study the hydration free energies of butane, zwitterionic alanine, valine, serine, threonine, and asparagine, and two neuraminidase inhibitors by means of Monte Carlo (MC) simulation. The solute molecule, represented in the form of distributed multipoles and modified 6-12 potential, was varied from a non-interacting 'ghost' molecule to its full potential functions in TIP4P water. Intermediate systems with soft-core solute-solvent interaction potentials are simulated separately and then subjected to Bennett's Acceptance ratio (BAR) for the free energy calculation. Hydration shells surrounding the solute particles were used to assess the quality of potential functions.

  14. Electricity Generation and the Present Challenges in the Nigerian Power Sector

    Energy Technology Data Exchange (ETDEWEB)

    Sambo, Abubakar Sani; Garba, Bashiru; Zarma, Ismaila Haliru; Gaji, Muhammed Musa


    Adequate power supply is an unavoidable prerequisite to any nation's development, and electricity generation, transmission and distribution are capital-intensive requiring huge resources for both funds and capacity. In Nigeria where funds are available and has an estimated of 176 trillion cubic feet of proven natural gas reserves, giving the country one of the top ten natural gas endowments in Africa. Natural gas is a natural occurring gaseous mixture of hydrocarbons gases found in underground reservoirs. It consists mainly of methane (70% - 95%). With small percentage of ethane, butane and other heavier hydrocarbons with some impurities such as water vapour, etc.

  15. Micro solid oxide fuel cell on the chip. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M.; Hotz, N.; Bieri, N.; Poulikakos, D.


    The aim of this project is the numerical and experimental investigation of hydrocarbon-to-syngas reforming in micro reformers for incorporation into an entire micro fuel cell system. Numerical simulations are used to achieve deeper understanding of several determining aspects in such a micro reformer. These insights are used to optimize the reforming performance by proper choice of operational and geometrical parameters of a reformer. These numerical results are continued by comprehensive experimental studies. In the first chapter, the effect of wall conduction of a tubular methane micro reformer is investigated numerically. Methane is used as the representative hydrocarbon because its detailed surface reaction mechanism is known. It is found that the axial wall conduction can strongly influence the performance of the microreactor and should not be neglected without a careful a priori investigation of its impact. In the second chapter, the effect of the catalyst amount and reactor geometry on the reforming process was investigated. It was found that the hydrogen selectivity changes significantly with varying catalyst loading. Thus, the reaction path leading to higher hydrogen production becomes more important by increasing the catalyst surface site density on the active surface. Another unexpected result is the presence of optimum channel geometry and optimum catalyst amount. In the third chapter of this project, the capability of flame-made Rh/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} nanoparticles catalyzing the reforming of butane to H{sub 2}- and CO-rich syngas was investigated experimentally in a packed bed reactor. The main goal of this study was the efficient reforming of butane at temperatures between 500 and 600 {sup o}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 proved to be a very promising material for butane-to-syngas reforming with complete butane conversion and a hydrogen yield of 77

  16. Laser-Initiated Free Radical Chain Reactions: Synthesis Of Hydroperoxides (United States)

    Bray, R. G.; Chou, M. S.


    We have investigated the advantages of using laser-initiation for the synthesis of cumenehydroperoxide and t-butylhydroperoxide. Laser-initiation significantly improves the oxidation rates of cumene in the liquid phase and iso-butane in the vapor phase (using HBr promoters) with moderate photoefficiencies (418 and 490 respectively). The primary effect of laser-initiation is to reduce the induction period of the reaction. For the oxidation of cumene the beneficial effect of laser initiation is strongly dependent on laser wavelength, alternately enhancing (at 351 nm) or inhibiting (at 249 nm) the oxidation rate. For isobutane oxidation, laser-initiation also minimizes the HBr depletion rate relative to oxidation rate.

  17. 4,6-Dichloro-2-((E-{4-[(E-3,5-dichloro-2-hydroxybenzylideneamino]butylimino}methylphenol

    Directory of Open Access Journals (Sweden)

    Hadi Kargar


    Full Text Available The asymmetric unit of the title compound, C18H16Cl4N2O2, comprises half of a potentially tetradentate Schiff base ligand. It is located about a twofold rotation axis that bisects the central C—C bond of the butane-1,4-diamine group. There are two intramolecular O—H...N hydrogen bonds making S(6 ring motifs. In the crystal, molecules are linked by pairs of weak C—H...Cl interactions, forming inversion dimers, which are further connected by C—H...O hydrogen bonds into two-dimensional frameworks that lie parallel to (001.

  18. Volatile Profiles of Emissions from Different Activities Analyzed Using Canister Samplers and Gas Chromatography-Mass Spectrometry (GC/MS) Analysis: A Case Study (United States)

    Orecchio, Santino; Fiore, Michele; Barreca, Salvatore; Vara, Gabriele


    The objective of present study was to identify volatile organic compounds (VOCs) emitted from several sources (fuels, traffic, landfills, coffee roasting, a street-food laboratory, building work, indoor use of incense and candles, a dental laboratory, etc.) located in Palermo (Italy) by using canister autosamplers and gas chromatography-mass spectrometry (GC-MS) technique. In this study, 181 VOCs were monitored. In the atmosphere of Palermo city, propane, butane, isopentane, methyl pentane, hexane, benzene, toluene, meta- and para-xylene, 1,2,4 trimethyl benzene, 1,3,5 trimethyl benzene, ethylbenzene, 4 ethyl toluene and heptane were identified and quantified in all sampling sites. PMID:28212294

  19. Flavonóides O-glicosilados de Croton campestris St. Hill. (Euphorbiaceae)


    Santos,Paula M.L. dos; Schripsema, Jan; Kuster, Ricardo M


    Do extrato butanólico de Croton campestris St. Hill. (Euphorbiaceae) foram isolados quatro flavonóides, todos O-glicosídeos da quercetina. Estas substâncias foram identificadas como 3-O-b-D-apiofuranosil-(1®2)-galactopiranosil quercetina (1), 3-O-b-D-galactopiranosil quercetina (hiperina) (2), 3-O-a-L-arabinopiranosil quercetina (guaijaverina) (3) e 3-O-a-L-ramnopiranosil quercetina (quercitrina) (4).O presente trabalho relata a presença destas substâncias pela primeira vez para esta espécie ...

  20. Perfluorocarbons and their use in Cooling Systems for Semiconductor Particle Detectors

    CERN Document Server

    Vacek, V; Ilie, S; Lindsay, S


    We report on the development of evaporative fluorocarbon cooling for the semiconductor pixel and micro-strip sensors of inner tracking detector of the ATLAS experiment at the future CERN Large Hadron Collider (LHC). We proceeded with studies using perfluoro-n-propane (3M-"PFG 5030"; C3F8), perfluoro-n-butane (3M-"PFG 5040"; C4F10), trifluoro-iodo-methane (CF3I) and custom C3F8/C4F10 mixtures. Certain thermo-physical properties had to be verified for these fluids.

  1. Thermal non-oxidative aromatization of light alkanes catalyzed by gallium nitride. (United States)

    Li, Lu; Mu, Xiaoyue; Liu, Wenbo; Kong, Xianghua; Fan, Shizhao; Mi, Zetian; Li, Chao-Jun


    The thermal catalytic activity of GaN in non-oxidative alkane dehydroaromatization has been discovered for the first time. The origin of the catalytic activity was studied experimentally and theoretically. Commercially available GaN powders with a wurtzite crystal structure showed superior stability and reactivity for converting light alkanes, including methane, propane, n-butane, n-hexane and cyclohexane into benzene at an elevated temperature with high selectivity. The catalyst is highly robust and can be used repeatedly without noticeable deactivation.

  2. High-resolution mid-IR spectrometer based on frequency upconversion

    DEFF Research Database (Denmark)

    Hu, Qi; Dam, Jeppe Seidelin; Pedersen, Christian


    allowing for direct detection with a silicon-based CCD camera. This approach allows for low noise detection even without cooling of the detector. A setup is realized for the 3xA0;x3BC;m regime with a spectral resolution of 0.2xA0;nm using lithium niobate as the nonlinear material and mixing with a single......-frequency 1064xA0;nm laser. We investigate water vapor emission lines from a butane burner and compare the measured results to model data. The presented method we suggest to be used for real-time monitoring of specific gas lines and reference signals....

  3. Modification of the performance of WO{sub 3}-ZrO{sub 2} catalysts by metal addition in hydrocarbon reactions

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Gerardo Carlos; Manuale, Debora Laura; Benitez, Viviana Monica; Vera, Carlos Roman; Yori, Juan Carlos, E-mail: [Instituto de Investigaciones en Catalisis y Petroquimica, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Cientifica y Tecnicas, Santiago del Estero Santa Fe (Argentina)


    A study of the different hydrocarbon reactions over Ni doped WO{sub 3}-ZrO{sub 2} catalysts was performed. Ni was found as NiO at low Ni concentration while at high Ni concentrations a small fraction was present as a metal. For both cases, Ni strongly modified total acidity and concentration of strong acid sites. In the cyclohexane dehydrogenation reaction, Ni addition promotes both benzene and methyl cyclopentane production. The hydroconversion activity (n-butane and n-octane) increases with the augment of total acidity produced by Ni. The selectivity to reaction products is modified according to the acid strength distribution changes produced by Ni addition. (author)

  4. Structure of molecules and internal rotation

    CERN Document Server

    Mizushima, San-Ichiro


    Structure of Molecules and Internal Rotation reviews early studies on dihalogenoethanes. This book is organized into two parts encompassing 8 chapters that evaluate the Raman effect in ethane derivatives, the energy difference between rotational isomers, and the infrared absorption of ethane derivatives. Some of the topics covered in the book are the potential barrier to internal rotation; nature of the hindering potential; entropy difference between the rotational isomers; internal rotation in butane, pentane, and hexane; and internal rotation in long chain n-paraffins. Other chapters deal wi

  5. Regioselective alkane hydroxylation with a mutant CYP153A6 enzyme (United States)

    Koch, Daniel J.; Arnold, Frances H.


    Cytochrome P450 CYP153A6 from Myobacterium sp. strain HXN1500 was engineered using in-vivo directed evolution to hydroxylate small-chain alkanes regioselectively. Mutant CYP153A6-BMO1 selectively hydroxylates butane and pentane at the terminal carbon to form 1-butanol and 1-pentanol, respectively, at rates greater than wild-type CYP153A6 enzymes. This biocatalyst is highly active for small-chain alkane substrates and the regioselectivity is retained in whole-cell biotransformations.

  6. Cosmic ray tests of a 4.6 m-long test drift chamber for JLC

    CERN Document Server

    Kurihara, Y; Sudo, S; Abe, T; Fujii, K; Ishihara, N; Khalatyan, N; Matsui, T; Nitoh, O; Ohama, T; Okuno, H; Sugiyama, A; Takahashi, K; Watanabe, T; Yoshida, T


    Performance of a 4.6 m-long drift chamber filled with a CO sub 2 iso-butane (90:10) mixture was studied using cosmic-ray data, in the course of detector R and D for JLC. After correcting the data for wire displacements due to gravitational and electrostatic forces, a spatial resolution of 100 mu m per wire was achieved over the full length of the chamber. The relation between wire efficiency and oxygen remnant in the chamber gas is also discussed.

  7. Experimental study of THGEM detector with mini-rim

    CERN Document Server

    Zhang, Ai-Wu; Xie, Yu-Guang; Liu, Hong-Bang; An, Zheng-Hua; Wang, Zhi-Gang; Cai, Xiao; Sun, Xi-Lei; Shi, Feng; Fang, Jian; Xue, Zhen; Lu, Qi-Wen; Sun, Li-Jun; Ge, Yong-Shuai; Liu, Ying-Biao; Hu, Tao; Zhou, Li; Lu, Jun-Guang


    The gas gain and energy resolution of single and double THGEM detectors (5{\\times}5cm2 effective area) with mini-rims (rim is less than 10{\\mu}m) were studied. The maximum gain can reach 5{\\times}103 and 2{\\times}105 for single and double THGEM respectively, while the energy resolution of 5.9 keV X-ray varied from 18% to 28% for both single and double THGEM detectors of different hole sizes and thicknesses.All the experiments were investigated in mixture of noble gases(argon,neon) and small content of other gases(iso-butane,methane) at atmospheric pressure.

  8. 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


    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...

  9. Dehidroisomerización de n-butano sobre catalizadores bifuncionales tipo Al-MCM-41 y Ga-MCM-41 impregnados con Pt o Ga

    Directory of Open Access Journals (Sweden)

    Dino Brisigotti


    Full Text Available A series of bi-functional catalysts was prepared by using Al-MCM-41 and Ga-MCM-41 with Si/Me ratios of 15 and 50 impregnated with 0,5 Wt% of Pt or Ga. The n-butane dehydroisomerization was studied at 773 K. Catalysts based on Pt/Al-MCM-41 were less selective (more hydrogenolyzing than those based on Ga-MCM-41. For the latter, Ga species segregated to extra-framework positions might exercise a kind of geometric effect on the Pt clusters inhibiting hydrogenolysis. The catalyst Ga/Al-MCM-41 showed the closest approach to the ideal dehydroisomerization catalyst.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dali [Los Alamos National Laboratory; Orler, Bruce [Los Alamos National Laboratory; Tornga, Stephanie [Los Alamos National Laboratory; Welch, Cindy [Los Alamos National Laboratory


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

  11. Computational Study of Low-Temperature Catalytic C-C Bond Activation of Alkanes for Portable Power (United States)


    the RhCl3 system. Our initial computations regarding this system showed that • RhII chloride salts are stable in a mixture of RhI and RhIII, so that...inhibiting the reaction. We found that Fluorinated phosphines are sufficiently π-accepting to satisfy this role. In our next step, we wanted to determine...flames” Proc. Comb. Inst. 2005, 30, 439–446 4. A. Onopchenko, J.G.D. Schulz “Oxidation of butane with cobalt salts and oxygen via electron

  12. Towards cancer cell-specific phototoxic organometallic rhenium(I) complexes


    Leonidova, Anna; Pierroz, Vanessa; Rubbiani, Riccardo; Heier, Jakob; Ferrari, Stefano; Gasser, Gilles


    Over the recent years, several Re(i) organometallic compounds have been shown to be toxic to various cancer cell lines. However, these compounds lacked sufficient selectivity towards cancer tissues to be used as novel chemotherapeutic agents. In this study, we probe the potential of two known N,N-bis(quinolinoyl) Re(i) tricarbonyl complex derivatives, namely Re(i) tricarbonyl [N,N-bis(quinolin-2-ylmethyl)amino]-4-butane-1-amine () and Re(i) tricarbonyl [N,N-bis(quinolin-2-ylmethyl)amino]-5-va...

  13. Synthesis and characterization of fluorinated copolyetherimides with -CH2-C6F13 side chains based on the ULTEM structure


    Kaba, Meriyam; Romero, Ricardo Escarcena; Essamri, Azzouz; Mas, Andre


    International audience; Step polymn. of bisphenol A diphthalic anhydride (BAPA) with various mixts. from m-phenylene diamine (m-PDA) and 2-(perfluorohexylmethyl)butan-1,4-diamine (TFD) led to hydrophobic copolyetherimides bearing RF = CH2C6F13 side chains that were characterized by NMR, element anal., DSC, TGA and surface energy anal. By increasing the TFD unit %, the glass transition temp. (Tg) decreases according to the Fox equation from 217° (m-PDA 100% and TFD 0% like in ULTEM 1000) to 11...

  14. Selective oxidation of isobutane on V–Mo–O mixed oxide catalysts

    Directory of Open Access Journals (Sweden)



    Full Text Available Four V–Mo–O mixed metal oxides were prepared, characterized and tested for the selective oxidation of isobutane in the temperature range 350–550 °C, at atmospheric pressure. Isobutane was mainly oxidized to iso-butene and carbon oxides. The systems with low vanadium contents showed low activities but high isobutene selectivities, while the systems with high vanadium contents showed high activities with high carbon oxides selectivities. The effects of temperature, contact time and the molar ratio iso-butane to oxygen on the conversion of isobutane and the selectivity of the oxidation were studied.

  15. Nanorheology of Liquid Alkanes

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S.A., Cochran, H.D., Cummings, P.T. [Tennessee Univ., Knoxville, TN (United States). Dept. of Chemical Engineering], [Oak Ridge National Lab., TN (United States)


    We report molecular dynamics simulations of liquid alkanes, squalane and tetracosane, confined between moving walls to which butane chains are tethered, effectively screening the details of the wall. As in an experiment, heat is removed by thermostatting the tethered molecules. Results obtained at high strain rates, typical of practical applications, suggest little or no difference between the bulk rheology and confined flow, and the occurrence of a high degree of slip at the wall-fluid interface at the conditions studied. At relatively low velocities and high densities, tetracosane shows the formation of fully-extended chains at certain wall spacings.

  16. Sulfated binary and trinary oxide solid superacids

    Institute of Scientific and Technical Information of China (English)

    缪长喜; 华伟明; 陈建民; 高滋


    A series of sulfated binary and trinary oxide solid superacids were prepared, and their catalytic activities for n-butane isomerization at low temperature were measured. The incorporation of different metal oxides into ZrO2 may produce a positive or negative effect on the acid strength and catalytic activity of the solid superacids. Sulfated oxides of Cr-Zr, Fe-Cr-Zr and Fe-V-Zr are 2 - 3 times more active than the reported sulfated Fe-Mn-Zr oxide. The enhancement in the superacidity and catalytic activity of these new solid superacids has been discussed on account of the results of various characteriation techniques.

  17. HFO1234ze(E) And HFC134a Flow Boiling Inside a 4mm Horizontal Smooth Tube


    Longo, Giovanni A.; Mancin, Simone; Righetti, Giulia; Zilio, Claudio


    Nowadays, the substitution of HFC134a with low GWP refrigerants is one of the most important challenge for refrigeration and air conditioning. The possible substitutes include natural refrigerants, such as HC600 (Butane) and HC600a (Isobutane), and also synthetic refrigerants, such as HFO1234yf and HFO1234ze(E). The HC refrigerants exhibit very low GWP, 3 and 4 HC600a and HC600 respectively, good thermodynamic and transport properties, and pressure and volumetric performance very similar to H...

  18. Synthesis and biological properties of novel triazole-thiol and thiadiazole derivatives of the 1,2,4-Triazole-3(5)-one class. (United States)

    Düğdü, Esra; Unver, Yasemin; Unlüer, Dilek; Sancak, Kemal


    2,2'-(4,4'(Butane-1,4-diyl/hexane-1,6-diyl)bis(3-methyl-5-oxo-4,5-dihydro-1,2,4- triazole-4,1-diyl)) diacetohydrazides 3a,b were obtained via the formation of diethyl 2,2'-(4,4'(butane-1,4-diyl/hexane-1,6-diyl)bis(3-methyl-5-oxo-4,5-dihydro-1,2,4-triazole-4,1- diyl))diacetates 2a,b, obtained starting from di-[3(methyl-2-yl-methyl)-4,5-dihydro-1H-[1,2,4]-triazole-5-one-4yl]-n-alkanes 1a,b in two steps. The synthesis of the compounds 7a,b-9a,b incorporating the 1,3,4-thiadiazole, and 10a,b-11a,b with a 1,2,4-triazole-thiol nucleus as the second heterocycle, was performed by the acidic or basic treatment of compounds 4a,b-6a,b which were obtained from the reaction of 3a,b with several isothiocyanates. Newly synthesized compounds were screened for antimicrobial activities and their antioxidant properties by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method. Compounds 4a,b, 5a,b, and 6a,b were found to possess good antioxidant properties. Almost all compounds have significant antimicrobial activities.

  19. View of the LP gas supply/demand in Asia and a survey of the Middle East trend; Asia no LP gas jukyu tenbo to Chuto doko chosa

    Energy Technology Data Exchange (ETDEWEB)



    A study was made on the LP gas supply/demand in Asia including an outlook for 2000. Eleven countries in Asia including NIES countries, ASEAN countries, China and India have been continuing their rapid growth of economy and have rapidly been increasing their energy consumption. There, LP gas spreads as a home use fuel, and countries excluding some LP gas producing countries depend considerably upon the import from the Middle East. The LP gas consumption quantity is steadily increasing in China and India having huge population, etc., and dependence of LP gas is increasing upon LP gas producing countries of the Middle East. Nevertheless, in the Middle East, the domestic consumption of LP gas, mostly butane, is increasing. Namely, butane is used as raw material of MTBE, and LP gas as that of petroleum chemicals. The Middle East has a lot of plant projects of a sizable size in the future, which predicts that LP gas export from LP gas producing countries of the Middle East is decreasing. 2 refs., 62 figs., 57 tabs.

  20. Nanostructured composite TiO{sub 2}/carbon catalysts of high activity for dehydration of n-butanol

    Energy Technology Data Exchange (ETDEWEB)

    Cyganiuk, Aleksandra [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland); Klimkiewicz, Roman [Institute of Low Temperature and Structure Research PAN, 50-422 Wroclaw (Poland); Bumajdad, Ali [Faculty of Science, Kuwait University, PO Box 5969 Safat, Kuwait 13060 (Kuwait); Ilnicka, Anna [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland); Lukaszewicz, Jerzy P., E-mail: [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland)


    Highlights: • New biotechnological method for fabrication of composite catalysts. • In situ synthesis of nanosized TiO{sub 2} clusters in the carbon matrix. • High dispersion of TiO{sub 2} in carbon matrix. • High catalytic activity achieved for very low active phase content. • Efficient dehydration of n-butanol to butane-1. - Abstract: A novel method of wood impregnation with titanium ions is presented. Titanium(IV) ions were complexed to peroxo/hydroxo complexes which were obtained by treating a TiCl{sub 4} water solution with H{sub 2}O{sub 2}. The solution of chelated titanium ions was used for the impregnation of living stems of Salix viminalis wood. Saturated stems were carbonized at 600–800 °C, yielding a microporous carbon matrix, in which nanoparticles of TiO{sub 2} were uniformly distributed. A series of composite TiO{sub 2}–carbon catalysts was manufactured and tested in the process of n-butanol conversion to butane-1. The composite catalysts exhibited very high selectivity (ca. 80%) and yield (ca. 30%) despite a low content of titanium (ca. 0.5% atomic). The research proved that the proposed functionalization led to high dispersion of the catalytic phase (TiO{sub 2}), which played a crucial role in the catalyst performance. High dispersion of TiO{sub 2} was achieved due to a natural transport of complexed titanium ions in living plant stems.

  1. Total-factor energy efficiency of regions in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Honma, Satoshi [Faculty of Economics, Kyushu Sangyo University, 2-3-1 Matsukadai, Higashi-ku, Fukuoka 813-8503 (Japan); Hu, Jin-Li [Institute of Business and Management, National Chiao Tung University (China)


    This study computes the regional total-factor energy efficiency (TFEE) in Japan by employing the data envelopment analysis (DEA). A dataset of 47 prefectures in Japan for the period 1993-2003 is constructed. There are 14 inputs, including three production factors (labor employment, private, and public capital stocks) and 11 energy sources (electric power for commercial and industrial use, electric power for residential use, gasoline, kerosene, heavy oil, light oil, city gas, butane gas, propane gas, coal, and coke). GDP is the sole output. Following Fukao and Yue [2000. Regional factor inputs and convergence in Japan - how much can we apply closed economy neoclassical growth models? Economic Review 51, 136-151 (in Japanese)], data on private and public capital stocks are extended. All the nominal variables are transformed into real variables, taking into consideration the 1995 price level. For kerosene, gas oil, heavy oil, butane gas, coal, and coke, there are a few prefectures with TFEEs less than 0.7. The five most inefficient prefectures are Niigata, Wakayama, Hyogo, Chiba, and Yamaguchi. Inland regions and most regions along the Sea of Japan are efficient in energy use. Most of the inefficient prefectures that are developing mainly upon energy-intensive industries are located along the Pacific Belt Zone. A U-shaped relation similar to the environmental Kuznets curve (EKC) is discovered between energy efficiency and per capita income for the regions in Japan. (author)

  2. Selective Oxidation of Light Hydrocarbons Using Lattice Oxygen Instead of Molecular Oxygen

    Institute of Scientific and Technical Information of China (English)

    沈师孔; 李然家; 周吉萍; 余长春


    In this paper, selective oxidation of n-butane to maleic anhydride (MA) and partial oxidation of methane to synthesis gas with lattice oxygen instead of molecular oxygen are investigated. For the oxidation of butane to MA in the absence of molecular oxygen, the Ce-Fe promoted VPO catalyst has more available lattice oxygen and provides higher conversion and selectivity than that of the unpromoted one. It is supposed that the introduction of Ce-Fe complex oxides improves redox performance of VPO catalyst and increases the activity of lattice oxygen.For partial oxidation of methane to synthesis gas over LaFeO3 and Lao.8Sro.gFeO3 oxides, the reaction with flow switched between 11% O2-Ar and 11% CH4-He at 900℃ was carried out. The results show that methane can be oxidized to CO and H2 with selectivity over 93% by the lattice oxygen of the catalyst in an appropriate reaction condition, while the lost lattice oxygen can be supplemented by air re-oxidation. It is viable for the lattice oxygen of the LaFeO3 and La0.8Sr0.2FeO3 catalyst instead of molecular oxygen to react with methane to synthesis gas in the redox mode.

  3. Isolation and Structure Elucidation of Uncommon Secondary Metabolites from Cistus salviifolius L.

    Directory of Open Access Journals (Sweden)

    Perihan Gürbüz


    Full Text Available To our knowledge this is the first report on the isolation of a flavonoid glycoside: quercetin 3-O-α-arabinopyranoside (5, two phenylbutanon glycosides: 4-(4'-O-[6''-O-galloyl-β-galactopyranosyl]-3'-hydroxyphenyl-butan-2-on (8, 4-(3'-O-β-glucopyranosyl-4'-hydroxyphenyl-butan-2-on (9, one phloroglucinol glycoside: 1-O-β-glucopyranosyl-3,5-dimethoxybenzene (10 and a steroid glycoside: sitosterol-3-O-(6''-O-butanoyl-β-galactopyranoside (14 from the Cistus species (Cistaceae. Additional to these compounds three flavonol aglycones: kaempferol (1, quercetin (2, myricetin (3; three flavonoid glycosides; kaempferol 3-O-β-(6''-O-trans-p-coumaroyl-glucopyranoside (4, quercetin 3-O-β-galactopyranoside (6, myricetin 3-O-β-galactopyranoside (7; one phloroglucinol glycoside: 1-O-β-glucopyranosyl-3,5-dimethoxybenzene (11; one steroid aglycone: β-sitosterol (12; one steroid glycoside: Sitosterol-3-O- β-glucopyranoside (13 were isolated from the aerial parts of the Cistus salviifolius L.. Their structures were identified using spectral methods (UV, IR, 1D- and 2D-NMR, and ESI-MS.

  4. The synthesis and spectroscopic study of stable free radicals related to piperidine-n-oxyl, including a stable bi-radical; Syntheses et etudes spectroscopiques de radicaux libres piperidiniques et d'un biradical stable, du type nitroxyde

    Energy Technology Data Exchange (ETDEWEB)

    Briere, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires, Laboratoire de chimie organique physique


    A new synthesis of di-tert-butyl nitroxide using the reaction between tert-butyl magnesium chloride and nitro-tert-butane is presented in the first section. Synthesis and investigation of stable free piperidine-N-oxyl radicals are described in the second section. All these nitroxides have been characterised by their I. R., U. V. and E. P. R. absorption spectra. The final section contains a description of the synthesis of a stable bi-radical of the nitroxide type by condensation of 2,2, 6, 6-tetramethyl-piperid-4-one-l-oxyl with hydrazine. (author) [French] La premiere partie expose une nouvelle methode de synthase du di-t-butyl nitroxyde, par action d'halogenures de t-butyl magnesium sur le nitro-t-butane (Rdt maximum 45 pour cert, purete 86 pour cent). Une etude de radicaux. libres stables pipericliniques est faite dans une seconde partie. Ces composes sont obtenus par oxydation de derives de la triacetonamine. Les caracteristiques spectroscopiques ultra-violette, infra-rouge, et paramagnetique electronique de ces radicaux sont donnees. La grande inertie chimique du groupement nitroxyde a permis la syn-these d'un biradical stable par formation d'azine d'une cetone radicalaire, ce qui fait 1'objet de la troisieme partie. (auteur)


    Institute of Scientific and Technical Information of China (English)

    Shahid Mahboob; Bilal Hussain; Zahid Iqbal; Abdul Shakoor Chaudhry


    Analysis of fish meat using gas chromatography is described. Flavor is the sensation arising from the interplay of the signals of sensing smell, taste and irritating stimuli from food stuff. For human, flavor and nutrition are inseparable. In fish, trace amount of volatile organic compounds (VOCs) are the major compounds to affect consumer's preference, which are produced during storage and spoilage. In the present study, volatile compounds were extracted by Likens-Nickerson con-current distillation apparatus from wild and farmed Cirrhina mrigala and Cyprinus carpio. The quantitative and qualitative estimation of volatiles was made by gas chromatography. Wild and farmed fish of different fish sizes were compared for these compounds (appearing in the form of peaks), which were identified from their retention time by comparing with the stand-ards. Fifteen major VOCs were found in these species which included hexadecane, 3-octanol, hexanal, decane, 3-hexene-1-ol, 2-undecanone, 2-heptanone, butanal, 2-nonanone, 1-heptanal, furaldehyde, 3-methyl-1-butanal, trans-3-hexene-1-ol, octanal and decanal. These compounds varied qualitatively and quantitatively in both wild and farmed fish of different fish sizes.

  6. Implementing and Comparison between Two Algorithms to Make a Decision in a Wireless Sensors Network

    Directory of Open Access Journals (Sweden)

    Fouad Essahlaoui


    Full Text Available The clinical presentation of acute CO poisoning and hydrocarbon gas (Butane CAS 106-97-8 varies depending on terrain, humidity, temperature, duration of exposure and the concentration of gas toxic: From then consciousness disorders (100 ppm or 15% rapidly limiting miners to ambient air and under oxygen until sudden coma (300 ppm or 45% required hospitalization monitoring unit, if not the result in few minutes it’s death in the poisoning site [1]. Leakage of the filling butane gas in the plant and very close to the latter position at the Faculty and under gas detection project. Has met a set of sensors to warn of possible leak, which can affect students, teachers and staff of the institution. Therefore, this document describes the implementation of two methods: the first is Average filter and the second as Cusum algorithm, to make a warning decision swished a signal given by the wireless sensors [9] [14-15]. Which installed in the inner side of Faculty of Science and Technology in Errachidia.

  7. Phase behaviour in water/hydrocarbon mixtures involved in gas production systems; etude des equilibres des systemes: eau-hydrocarbures-gaz acides dans le cadre de la production de gaz

    Energy Technology Data Exchange (ETDEWEB)

    Chapoy, A.


    Inside wells, natural gases frequently coexist with water. The gases are in equilibrium with the sub-adjacent aquifer. Many problems are associated with the presence of water during the production, transport and processing of natural gases. Accurate knowledge of the thermodynamic properties of the water/hydrocarbon and water-inhibitor/hydrocarbon equilibria near the hydrate forming conditions, at sub-sea pipeline conditions and during the transport is crucial for the petroleum industry. An apparatus based on a static/analytic method combined with a dilutor apparatus to calibrate on the gas chromatograph (GC) detectors with water was used to measure the water content of binary systems (i.e.: water - methane, ethane - water, nitrogen - water...) as well of a synthetic hydrocarbon gas mixture (i.e.: 94% methane, 4% ethane and 2% n-butane) with and without inhibitor. This same apparatus was also used generate data of methane, ethane, propane, n-butane and nitrogen solubility in water and also the solubilities of a synthetic mixture in water. In-house software has been developed in order to fit and model the experimental data. (author)

  8. New Steroidal Erythrityl Triesters from the Heat Processed Roots of Panax ginseng

    Directory of Open Access Journals (Sweden)

    Ill-Min Chung


    Full Text Available Two new compounds stigmasta-3α-ol-3α-(2′R,3′S-butane-1′,2′,3′,4′-tetraolyl-2′,3′-dioctadec-9″/9‴-enoyl-4′-octadec-9″″,12″″-dienoate (1 and stigmasta-5-en-3β-ol-3β-(2′R,3′S-butane-1′,2′,3′,4′-tetraolyl-2′,3′-dioctadec-9″/9‴-enoyl-4′-octadec-9″″,12″″-dienoate (2 along with β-sitosterol-β-D-glucoside were isolated and identified from the heat processed roots of Panax ginseng. The structures of the new compounds were elucidated by 1D and 2D NMR (COSY, HSQC, and HMBC spectroscopic techniques aided by FAB-MS, ESI FT/MS, and IR spectra.

  9. Analysis of volatile organic compounds liberated and metabolised by human umbilical vein endothelial cells (HUVEC) in vitro. (United States)

    Mochalski, Paweł; Theurl, Markus; Sponring, Andreas; Unterkofler, Karl; Kirchmair, Rudolf; Amann, Anton


    Gas chromatography with mass spectrometric detection combined with head-space needle trap extraction as the pre-concentration technique was applied to identify and quantify volatile organic compounds released or metabolised by human umbilical vein endothelial cells. Amongst the consumed species there were eight aldehydes (2-methyl 2-propenal, 2-methyl propanal, 2-methyl butanal, 3-methyl butanal, n-hexanal, benzaldehyde, n-octanal and n-nonanal) and n-butyl acetate. Further eight compounds (ethyl acetate, ethyl propanoate, ethyl butyrate, 3-heptanone, 2-octanone, 2-nonanone, 2-methyl-5-(methylthio)-furan and toluene) were found to be emitted by the cells under study. Possible metabolic pathways leading to the uptake and release of these compounds by HUVEC are proposed and discussed. The uptake of aldehydes by endothelial cells questions the reliability of species from this chemical class as breath or blood markers of disease processes in human organism. The analysis of volatiles released or emitted by cell lines is shown to have a potential for the identification and assessment of enzymes activities and expression.

  10. Free Energy-Based Coarse-Grained Force Field for Binary Mixtures of Hydrocarbons, Nitrogen, Oxygen, and Carbon Dioxide. (United States)

    Cao, Fenglei; Deetz, Joshua D; Sun, Huai


    The free energy based Lennard-Jones 12-6 (FE-12-6) coarse-grained (CG) force field developed for alkanes1 has been extended to model small molecules of light hydrocarbons (methane, ethane, propane, butane, and isobutane), nitrogen, oxygen, and carbon dioxide. The adjustable parameters of the FE-12-6 potential are determined by fitting against experimental vapor-liquid equilibrium (VLE) curves and heat of vaporization (HOV) data for pure substance liquids. Simulations using the optimized FE-12-6 parameters correctly reproduced experimental measures of the VLE, HOV, density, vapor pressure, compressibility, critical point, and surface tension for pure substances over a wide range of thermodynamic states. The force field parameters optimized for pure substances were tested on methane/butane, nitrogen/decane, and carbon dioxide/decane binary mixtures to predict their vapor-liquid equilibrium phase diagrams. It is found that for nonpolar molecules represented by different sized beads, a common scaling factor (0.08) that reduces the strength of the interaction potential between unlike beads, generated using Lorentz-Berthelot (LB) combination rules, is required to predict vapor-liquid phase equilibria accurately.

  11. Elucidation of the aroma compositions of Zhenjiang aromatic vinegar using comprehensive two dimensional gas chromatography coupled to time-of-flight mass spectrometry and gas chromatography-olfactometry. (United States)

    Zhou, Zhilei; Liu, Shuangping; Kong, Xiangwei; Ji, Zhongwei; Han, Xiao; Wu, Jianfeng; Mao, Jian


    In this work, a method to characterize the aroma compounds of Zhenjiang aromatic vinegar (ZAV) was developed using comprehensive two dimensional gas chromatography (GC×GC) coupled with time-of-flight mass spectrometry (TOFMS) and gas chromatography olfactometry (GC-O). The column combination was optimized and good separation was achieved. Structured chromatograms of furans and pyrazines were obtained and discussed. A total of 360 compounds were tentatively identified based on mass spectrum match factors, structured chromatogram and linear retention indices comparison. The most abundant class in number was ketones. A large number of esters, furans and derivatives, aldehydes and alcohols were also detected. The odor-active components were identified by comparison of the reported odor of the identified compounds with the odor of corresponding GC-O region. The odorants of methanethiol, 2-methyl-propanal, 2-methyl-butanal/3-methyl-butanal, octanal, 1-octen-3-one, dimethyl trisulfide, trimethyl-pyrazine, acetic acid, 3-(methylthio)-propanal, furfural, benzeneacetaldehyde, 3-methyl-butanoic acid/2-methyl-butanoic acid and phenethyl acetate were suspected to be the most potent. About half of them were identified as significant aroma constituents in ZAV for the first time. Their contribution to specific sensory attribute of ZAJ was also studied. The results indicated that the presented method is suitable for characterization of ZAV aroma constituents. This study also enriches our knowledge on the components and aroma of ZAV.

  12. Effect of cysteine and cystine addition on sensory profile and potent odorants of extruded potato snacks. (United States)

    Majcher, Małgorzata A; Jeleń, Henryk H


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

  13. Characterization of flavor of whey protein hydrolysates. (United States)

    Leksrisompong, Pattarin P; Miracle, R Evan; Drake, Maryanne


    Twenty-two whey protein hydrolysates (WPH) obtained from 8 major global manufacturers were characterized by instrumental analysis and descriptive sensory analysis. Proximate analysis, size exclusion chromatography, and two different degrees of hydrolysis (DH) analytical methods were also conducted. WPH were evaluated by a trained descriptive sensory panel, and volatile compounds were extracted by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Eleven representative WPH were selected, and 15 aroma active compounds were quantified by GC-MS via the generation of external standard curves. Potato/brothy, malty, and animal flavors and bitter taste were key distinguishing sensory attributes of WPH. Correlations between bitter taste intensity, degree of hydrolysis (using both methods), and concentration of different molecular weight peptides were documented, with high DH samples having high bitter taste intensity and a high concentration of low molecular weight peptides and vice versa. The four aroma-active compounds out of 40 detected by GC-O present at the highest concentration and with consistently high odor activity values in WPH were Strecker derived products, dimethyl sulfide (DMS), 3-methyl butanal, 2-methyl butanal, and methional. Orthonasal thresholds of WPH were lower (p applications.

  14. Volatile substance misuse: an updated review of toxicity and treatment. (United States)

    Ford, Jonathan B; Sutter, Mark E; Owen, Kelly P; Albertson, Timothy E


    Educational campaigns and legislative actions may have led to an overall decrease in the prevalence of volatile substance misuse (VSM) in many countries; however, it is still a common practice throughout the world. Studies currently suggest that girls are misusing volatile substances more than before and at a prevalence rate equal to or exceeding that of boys in several countries. Products that may be misused are ubiquitous and relatively easy to acquire. The most commonly misused substances in recent studies are fuels such as butane or petrol and compressed gas dusters and deodorants that may contain fluorocarbons and/or butane. Detection of VSM is challenging, therefore physicians must maintain a high level of suspicion based on history and clinical presentation. Clues to misuse are often subtle and may include the patient's proximity to a volatile substance or paraphernalia when found intoxicated, dermal burns, blisters, pigments, or rashes, and chemical odors. The primary targets of toxicity are the brain and the heart. The leading cause of death from VSM is from ventricular dysrhythmias. Treatment of toxicity begins with support of airway, breathing, and circulation. Exogenous catecholamines should be avoided if possible due to the theoretical "sensitized" and irritable myocardium. In the case of ventricular dysrhythmias, direct current defibrillation and/or beta-adrenergic receptor antagonism should be used. New evidence demonstrates the addictive potential of VSM yet effective therapy remains uncertain. Further research is needed in developing methods for preventing, detecting, and treating the harmful effects of VSM.

  15. 主产地泽泻药材顶空萃取挥发性成分的GC-MS分析

    Institute of Scientific and Technical Information of China (English)

    李兰; 吴启南


    目的 对福建、江西、四川产泽泻药材的挥发性成分进行研究.方法 顶空萃取泽泻药材中的挥发性成分,利用气相色谱一质谱联用技术对其进行分析.结果 经毛细管气相色谱分离、质谱分析工作站NIST标准图库检索,参照有关文献,确认了17种共有成分.含量较高的有:δ-elemene(δ-榄香烯),3-mthyl-butanal(三甲基正丁醛),2-methyl-butanal(二甲基正丁醛),hxanoie aeid,ethyl ester(己酸己酯),β-elemene(β-榄香烯),beta-caryophyUene(β-石竹烯),2一pentyl-furan(二戊基呋喃),α-caryophyllene(蛇麻烯),elixene,caryophynene oxide(氧化石竹烯)等.化合物类型主要为倍半萜类.结论 利用GC-MS法分析鏊定泽泻挥发性成分,具有快速、稳定、重现性好的特点,可用于泽泻药材挥发性成分的分析.

  16. Study on the Application of the Combination of TMD Simulation and Umbrella Sampling in PMF Calculation for Molecular Conformational Transitions

    Directory of Open Access Journals (Sweden)

    Qing Wang


    Full Text Available Free energy calculations of the potential of mean force (PMF based on the combination of targeted molecular dynamics (TMD simulations and umbrella samplings as a function of physical coordinates have been applied to explore the detailed pathways and the corresponding free energy profiles for the conformational transition processes of the butane molecule and the 35-residue villin headpiece subdomain (HP35. The accurate PMF profiles for describing the dihedral rotation of butane under both coordinates of dihedral rotation and root mean square deviation (RMSD variation were obtained based on the different umbrella samplings from the same TMD simulations. The initial structures for the umbrella samplings can be conveniently selected from the TMD trajectories. For the application of this computational method in the unfolding process of the HP35 protein, the PMF calculation along with the coordinate of the radius of gyration (Rg presents the gradual increase of free energies by about 1 kcal/mol with the energy fluctuations. The feature of conformational transition for the unfolding process of the HP35 protein shows that the spherical structure extends and the middle α-helix unfolds firstly, followed by the unfolding of other α-helices. The computational method for the PMF calculations based on the combination of TMD simulations and umbrella samplings provided a valuable strategy in investigating detailed conformational transition pathways for other allosteric processes.

  17. Anti-allergic agents from natural sources (4): anti-allergic activity of new phloroglucinol derivatives from Mallotus philippensis (Euphorbiaceae). (United States)

    Daikonya, Akihiro; Katsuki, Shigeki; Wu, Jin-Bin; Kitanaka, Susumu


    Two new phloroglucinol derivatives, mallotophilippen A (1). and B (2). were isolated from the fruits of Mallotus philippensis. These compounds were identified, using chemical and spectral data, as 1-[5,7-dihydroxy-2,2-dimethyl-6-(2,4,6-trihydroxy-3-isobutyryl-5-methyl-benzyl)-2H-chromen-8-yl]-2-methyl-butan-1-one and 1-[6-(3-Acetyl-2,4,6-trihydroxy-5-methyl-benzyl)-5,7-dihydroxy-2,2-dimethyl-2H-chromen-8-yl]-2-methyl-butan-1-one, respectively. They inhibited nitric oxide (NO) production and inducible NO synthase (iNOS) gene expression by a murine macrophage-like cell line (RAW 264.7), which was activated by lipopolysaccharide (LPS) and recombinant mouse interferon-gamma (IFN-gamma). Furthermore, they inhibited histamine release from rat peritoneal mast cells induced by Compound 48/80. These results suggest that the novel phloroglucinol derivatives have anti-inflammatory effects.

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

    Energy Technology Data Exchange (ETDEWEB)

    Werkema, Evan; Yahia, Ahmed; Maron, Laurent; Eisenstein, Odile; Andersen, Richard


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

  19. Honeydew volatile emission acts as a kairomonal message for the Asian lady beetle Harmonia axyridis (Coleoptera:Coccinellidae)

    Institute of Scientific and Technical Information of China (English)

    Pascal D. Leroy; Eric Haubruge; Stéphanie Heuskin; Ahmed Sabri; Fran(c)ois J. Verheggen; Julien Farmakidis; Georges Lognay; Philippe Thonart; Jean-Paul Wathelet; Yves Brostaux


    The Asian lady beetle Harmonia axyridis Pallas is considered as an invasive species in most territories where it has been introduced.Because aphid honeydew acts as an attractant for many aphid predators and parasitoids,the objectives of this work were to collect and identify the volatile compounds released from the aphid excretory product to evaluate how these semiochemicals could affect the H.axyridis foraging behavior.Twelve volatile chemicals were identified from the Megoura viciae Buckton honeydew including four alcohols,three ketones,three aldehydes,a pyrazine and a monoterpene.The volatiles 3-methyl-1-butanol and 3-methyl-butanal were highlighted as the two most abundant semiochemicals released from the M.viciae honeydew.Vicia faba L.plants treated with crude honeydew attracted more than 80% of the tested individuals with 40% of attracted beetles located on the plant.Four volatile compounds (3-hydroxy-2-butanone,3-methyl-butanal,3-methyl-1-butanol and limonene) were also highlighted to attract more than 75% of the coccinellids toward the odor source and to locate about 35% of them on the plants.Limonene was the most efficient attractant since 89% of the H.axyridis responded to this odor.The use of the identified semiochemicals as well as the composition of an artificial honeydew could certainly be helpful to control the dispersal of the Asian lady beetle H.axyridis.

  20. Isobutane ignition delay time measurements at high pressure and detailed chemical kinetic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Healy, D.; Curran, H.J. [Combustion Chemistry Centre, School of Chemistry, NUI Galway (Ireland); Donato, N.S.; Aul, C.J.; Petersen, E.L. [Department of Mechanical Engineering, Texas A and M University, College Station, TX (United States); Zinner, C.M. [Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL (United States); Bourque, G. [Rolls-Royce Canada Limited, 9500 Cote de Liesse, Lachine, Quebec (Canada)


    Rapid compression machine and shock-tube ignition experiments were performed for real fuel/air isobutane mixtures at equivalence ratios of 0.3, 0.5, 1, and 2. The wide range of experimental conditions included temperatures from 590 to 1567 K at pressures of approximately 1, 10, 20, and 30 atm. These data represent the most comprehensive set of experiments currently available for isobutane oxidation and further accentuate the complementary attributes of the two techniques toward high-pressure oxidation experiments over a wide range of temperatures. The experimental results were used to validate a detailed chemical kinetic model composed of 1328 reactions involving 230 species. This mechanism has been successfully used to simulate previously published ignition delay times as well. A thorough sensitivity analysis was performed to gain further insight to the chemical processes occurring at various conditions. Additionally, useful ignition delay time correlations were developed for temperatures greater than 1025 K. Comparisons are also made with available isobutane data from the literature, as well as with 100% n-butane and 50-50% n-butane-isobutane mixtures in air that were presented by the authors in recent studies. In general, the kinetic model shows excellent agreement with the data over the wide range of conditions of the present study. (author)

  1. Drug vaping applied to cannabis: Is “Cannavaping” a therapeutic alternative to marijuana? (United States)

    Varlet, Vincent; Concha-Lozano, Nicolas; Berthet, Aurélie; Plateel, Grégory; Favrat, Bernard; De Cesare, Mariangela; Lauer, Estelle; Augsburger, Marc; Thomas, Aurélien; Giroud, Christian


    Therapeutic cannabis administration is increasingly used in Western countries due to its positive role in several pathologies. Dronabinol or tetrahydrocannabinol (THC) pills, ethanolic cannabis tinctures, oromucosal sprays or table vaporizing devices are available but other cannabinoids forms can be used. Inspired by the illegal practice of dabbing of butane hashish oil (BHO), cannabinoids from cannabis were extracted with butane gas, and the resulting concentrate (BHO) was atomized with specific vaporizing devices. The efficiency of “cannavaping,” defined as the “vaping” of liquid refills for e-cigarettes enriched with cannabinoids, including BHO, was studied as an alternative route of administration for therapeutic cannabinoids. The results showed that illegal cannavaping would be subjected to marginal development due to the poor solubility of BHO in commercial liquid refills (especially those with high glycerin content). This prevents the manufacture of liquid refills with high BHO concentrations adopted by most recreational users of cannabis to feel the psychoactive effects more rapidly and extensively. Conversely, “therapeutic cannavaping” could be an efficient route for cannabinoids administration because less concentrated cannabinoids-enriched liquid refills are required. However, the electronic device marketed for therapeutic cannavaping should be carefully designed to minimize potential overheating and contaminant generation. PMID:27228348

  2. Drug vaping applied to cannabis: Is "Cannavaping" a therapeutic alternative to marijuana? (United States)

    Varlet, Vincent; Concha-Lozano, Nicolas; Berthet, Aurélie; Plateel, Grégory; Favrat, Bernard; De Cesare, Mariangela; Lauer, Estelle; Augsburger, Marc; Thomas, Aurélien; Giroud, Christian


    Therapeutic cannabis administration is increasingly used in Western countries due to its positive role in several pathologies. Dronabinol or tetrahydrocannabinol (THC) pills, ethanolic cannabis tinctures, oromucosal sprays or table vaporizing devices are available but other cannabinoids forms can be used. Inspired by the illegal practice of dabbing of butane hashish oil (BHO), cannabinoids from cannabis were extracted with butane gas, and the resulting concentrate (BHO) was atomized with specific vaporizing devices. The efficiency of "cannavaping," defined as the "vaping" of liquid refills for e-cigarettes enriched with cannabinoids, including BHO, was studied as an alternative route of administration for therapeutic cannabinoids. The results showed that illegal cannavaping would be subjected to marginal development due to the poor solubility of BHO in commercial liquid refills (especially those with high glycerin content). This prevents the manufacture of liquid refills with high BHO concentrations adopted by most recreational users of cannabis to feel the psychoactive effects more rapidly and extensively. Conversely, "therapeutic cannavaping" could be an efficient route for cannabinoids administration because less concentrated cannabinoids-enriched liquid refills are required. However, the electronic device marketed for therapeutic cannavaping should be carefully designed to minimize potential overheating and contaminant generation.

  3. Sensors for online determination of CNG gas quality; Sensorer foer onlinebestaemnning av fordonsgaskvalitet

    Energy Technology Data Exchange (ETDEWEB)

    Stenlaaaas, Ola; Roedjegaard, Henrik


    Swedish automotive gas has until now been a very uniform, high quality automotive fuel. Elsewhere in Europe the quality of automotive gas varies significantly. Gas from different sources with different flammability require engine settings adjusted to the chosen gas' unique composition. The prospects for a vehicle-mounted sensor based on infrared technology for gas quality measurement has been studied and solutions are presented with questions that must be answered in a possible future work. The proposed vehicle mounted sensor is based on two channels, one of which measures the partial pressure of methane and the other measures the partial pressure of heavier hydrocarbons in 'equivalents of butane'. Ethane produces a signal of about 0.6 equivalents of butane and propane about 0.8 equivalents. The sensor can be accommodated in a cube with 5 cm side and should be equipped with nipple connections to the existing system. The sensor is expected to work throughout their entire lifetime without manual calibration, through continuous automatic calibration, so-called ABC (Automatic Baseline Compensation). The sensor will have to meet tough quality and environmental standards in which primarily contact ring, vibration and prevention of leakage are identified as extra difficult. Working temperatures and the electrical conditions of power supply and communication interface is considered less challenging. In one million volumes, the cost per sensor could be 200 to 300 SEK.

  4. 抗莱克多巴胺多克隆抗体的制备%Preparation for Ractopamine Polyclonal Antibodies

    Institute of Scientific and Technical Information of China (English)

    张红琳; 陈昌云; 周红霞; 于小莲; 杨剑波; 石国庆


    为了制备抗莱克多巴胺多克隆抗体,试验通过连接剂butane-1,4-diol diglyciydyl ether把莱克多巴胺和载体蛋白BSA和0VA偶联成免疫抗原和包被抗原,免疫新西兰大白兔,饱和硫铵沉淀方法纯化抗体,间接ELISA法检测抗血清效价.结果通过免疫兔获得了抗莱克多巴胺的多克隆抗体.经ELISA测定,其效价为1:12800.%The RCT (Ractopamine) was coupled with BSA and OVA to produce immunogen and envelope antigen by using coupling agent butane-l, 4-diol diglyciydyl ether, respectively. The polyclonal antibodies was obtained by immuning New Zealand rabbits with BSA-RCT and purified by saturated ammonium sulfate precipitation. The indirect ELISA method was used to detect its antiserum titer. The results showed that the polyclonal antibodies against RCT had been obtained from immunized rabbits and the titer of the polyclonal antiserum was 1:12 800.

  5. Advanced structural analysis of nanoporous materials by thermal response measurements. (United States)

    Oschatz, Martin; Leistner, Matthias; Nickel, Winfried; Kaskel, Stefan


    Thermal response measurements based on optical adsorption calorimetry are presented as a versatile tool for the time-saving and profound characterization of the pore structure of porous carbon-based materials. This technique measures the time-resolved temperature change of an adsorbent during adsorption of a test gas. Six carbide and carbon materials with well-defined nanopore architecture including micro- and/or mesopores are characterized by thermal response measurements based on n-butane and carbon dioxide as the test gases. With this tool, the pore systems of the model materials can be clearly distinguished and accurately analyzed. The obtained calorimetric data are correlated with the adsorption/desorption isotherms of the materials. The pore structures can be estimated from a single experiment due to different adsorption enthalpies/temperature increases in micro- and mesopores. Adsorption/desorption cycling of n-butane at 298 K/1 bar with increasing desorption time allows to determine the pore structure of the materials in more detail due to different equilibration times. Adsorption of the organic test gas at selected relative pressures reveals specific contributions of particular pore systems to the increase of the temperature of the samples and different adsorption mechanisms. The use of carbon dioxide as the test gas at 298 K/1 bar provides detailed insights into the ultramicropore structure of the materials because under these conditions the adsorption of this test gas is very sensitive to the presence of pores smaller than 0.7 nm.

  6. Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Rodolfo Sosa, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Humberto Bravo, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico)], E-mail:; Violeta Mugica, A. [Universidad Autonoma Metropolitana, Azcapotzalco, D.F. (Mexico); Pablo Sanchez, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Emma Bueno, L. [Centro Nacional de Investigacion y Capacitacion Ambiental, Instituto Nacional de Ecologia (Mexico); Krupa, Sagar [Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (United States)


    Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City.

  7. Ultrahigh and High Resolution Structures and Mutational Analysis of Monomeric Streptococcus pyogenes SpeB Reveal a Functional Role for the Glycine-rich C-terminal Loop

    Energy Technology Data Exchange (ETDEWEB)

    González-Páez, Gonzalo E.; Wolan, Dennis W. (Scripps)


    Cysteine protease SpeB is secreted from Streptococcus pyogenes and has been studied as a potential virulence factor since its identification almost 70 years ago. Here, we report the crystal structures of apo mature SpeB to 1.06 {angstrom} resolution as well as complexes with the general cysteine protease inhibitor trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and a novel substrate mimetic peptide inhibitor. These structures uncover conformational changes associated with maturation of SpeB from the inactive zymogen to its active form and identify the residues required for substrate binding. With the use of a newly developed fluorogenic tripeptide substrate to measure SpeB activity, we determined IC{sub 50} values for trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and our new peptide inhibitor and the effects of mutations within the C-terminal active site loop. The structures and mutational analysis suggest that the conformational movements of the glycine-rich C-terminal loop are important for the recognition and recruitment of biological substrates and release of hydrolyzed products.

  8. Advanced liquefaction using coal swelling and catalyst dispersion techniques. Quarterly technical progress report, July--September 1992

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, C.W. [Auburn Univ., AL (United States); Gutterman, C. [Foster Wheeler Development Corp., Livingston, NJ (United States); Chander, S. [Pennsylvania State Univ., University Park, PA (United States)


    The experimental study of coal swelling ratios have been determined with a wide variety of solvents. Only marginal levels of coal swelling were observed for the hydrocarbon solvents, but high levels were found with solvents having heteroatom functionality. Blends were superior to pure solvents. The activity of various catalyst precursors for pyrene hydrogenation and coal conversion was measured. Higher coal conversions were observed for the S0{sub 2}-treated coal than the raw coal, regardless of catalyst type. Coal conversions were highest for Molyvan-L, molybdenum naphthenate, and nickel octoate, respectively. Bottoms processing consists of a combination of the ASCOT process coupling solvent deasphalting with delayed coking. Initial results indicate that a blend of butane and pentane used near the critical temperature of butane is the best solvent blend for producing a yield/temperature relationship of proper sensitivity and yet retaining an asphalt phase of reasonable viscosity. The literature concerning coal swelling, both alone and in combination with coal liquefaction, and the use of dispersed or unsupported catalysts in coal liquefaction has been updated.

  9. Structure of Titan's evaporites (United States)

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


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

  10. Highly porous polytriazole ion exchange membranes cast from solutions in non-toxic cosolvents

    KAUST Repository

    Chisca, Stefan


    The development of highly functionalized porous materials for protein separation is important for biotech processes. We report the preparation of highly porous polytriazole with sulfonic acid functionalization. The resulting ion exchange membranes are selective for protein adsorption. The starting material was a hydroxyl-functionalized polytriazole, which is an advantageous platform for further modification. The polymer was dissolved in a mixture of 1-ethyl-3-methylimidazolium acetate ([C2mim]OAc) and dimethyl carbonate (DMC), which can be both considered green solvents. The polymer solubilization was only possible due to an interesting effect of cosolvency, which is discussed, based in phase diagrams. Membranes were prepared by solution casting, followed by immersion in a non-solvent bath. We then grafted sulfone groups on the membranes, by reacting the hydroxyl groups with 1,3-propane sultone and 1,4-butane sultone. Lysozyme adsorption was successfully evaluated. Membranes modified with 1,4-butane sultone adsorbed more protein than those with 1,3-propane sultone.

  11. Transverse approach between real world concentrations of SO2, NO2, BTEX,aldehyde emissions and corrosion in the Grand Mare tunnel

    Institute of Scientific and Technical Information of China (English)

    I. Ameur-Bouddabbous; J. Kasperek; A. Barbier; F. Harel; B. Hannoyer


    With regard to automotive traffic,a tunnel-type semi enclosed atmosphere is characterized by a higher concentration of gaseous pollutants than on urban traffic roads and highlights the gaseous effluent species having an impact on material degradation.Therefore,a transverse approach between air quality and its consequences upon the longevity of materials is necessary,implying better knowledge of tunnel atmosphere and a better understanding of material degradation inside a tunnel for operating administration.Gaseous pollutant measurements carried out in a road tunnel in Rouen (Normandy) give the real world traffic concentrations of experimental exposure conditions.The sampling campaigns,achieved in summer and winter include SO2,NO2,BTEX and aldehyde analyses.Effluent profiles in the upward and downward tubes have been established.The current work shows that SO2,NO2,formaldehyde,acetaldehyde,propanal and butanal must be considered in the degradation process of materials in a stuffy environment.As regards NO2,its concentration depends on the modification of the automotive fleet.The total aldehyde concentrations indicate no particular trend between the two bores.Formaldehyde,acetaldehyde,propanal,butanal and acrolein species are the most abundant species emitted by vehicles and represent 90% to 95% of the total aldehyde emissions.

  12. Structure of Titan's evaporites

    CERN Document Server

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


    Numerous geological features that could be evaporitic in origin have been identified on the surface of Titan. Although they seem to be water-ice poor, their main properties -chemical composition, thickness, stratification- are essentially unknown. In this paper, which follows on a previous one focusing on the surface composition (Cordier et al., 2013), we provide some answers to these questions derived from a new model. This model, based on the up-to-date thermodynamic theory known as "PC-SAFT", has been validated with available laboratory measurements and specifically developed for our purpose. 1-D models confirm the possibility of an acetylene and/or butane enriched central layer of evaporitic deposit. The estimated thickness of this acetylene-butane layer could explain the strong RADAR brightness of the evaporites. The 2-D computations indicate an accumulation of poorly soluble species at the deposit's margin. Among these species, HCN or aerosols similar to tholins could play a dominant role. Our model pre...

  13. VOC signatures from North American oil and gas sources (Invited) (United States)

    Simpson, I. J.; Marrero, J.; Blake, N. J.; Barletta, B.; Hartt, G.; Meinardi, S.; Schroeder, J.; Apel, E. C.; Hornbrook, R. S.; Blake, D. R.


    Between 2008 and 2013 UC Irvine has used its whole air sampling (WAS) technique to investigate VOC source signatures from a range of oil and gas sources in North America, including five separate field campaigns at the Alberta oil sands (1 airborne, 4 ground-based); the 2010 Deepwater Horizon oil spill (airborne and ship-based); the 2012 airborne Deep Convective Clouds and Chemistry Project (DC3) mission over oil and gas wells in Colorado, Texas and Oklahoma; and the 2013 ground-based Barnett Shale Campaign in Texas. Each campaign has characterized more than 80 individual C1-C10 VOCs including alkanes, alkenes and aromatics. For example, oil sands are an extra-heavy, unconventional crude oil that is blended with diluent in order to flow, and upgraded into synthetic crude oil. The VOC signature at the oil sands mining and upgrading facilities is alkane-rich, and the fuel gas associated with these operations has an i-butane/n-butane ratio similar to that of liquefied petroleum gas (LPG). In addition to light alkanes, enhanced levels of benzene were observed over US oil and natural gas wells during DC3, likely because of its use in hydrofracking fluid. A series of VOC emission ratios from North American petrochemical sources will be presented and compared, including oil sands, conventional oil and hydrofracking operations.

  14. An experimental study of different hydrocarbon components in natural gas and their impact on engine performance in a HCCI engine

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, Kristoffer


    Natural gas is a well suited fuel for HCCI (Homogenous Charge Compression Ignition) operation. Commercial natural gas consists of many different hydrocarbons where the lighter hydrocarbons, methane, ethane propane and butane are the most common and methane having the highest percentage. The composition of natural gas varies widely all over the world. It is well known that the higher hydrocarbons have a great impact on the ignition characteristics. As a spontaneous auto-ignition process initiates HCCI, this type of engine is very sensitive of the fuels ignition characteristics. To investigate the influence of the higher hydrocarbons an extensive test series was carried out. The impact of different concentrations of ethane, propane, iso- and n-butane were tested. Using different equivalence ratios, concentrations of the hydrocarbons, levels of EGR and levels of boost pressure the tests were carried out. Data collected during the testing were emission, mass flow, indicated mean effective pressure, inlet temperature and engine speed. From these data, specific emissions and efficiencies could be calculated. As a test a value of released heat per cycle was also evaluated, and used to check the mass flow. The results show that the ignition characteristics of the charge is very sensitive to fuel composition. A strong connection between the required inlet air temperature and the fuel composition was detected. With an increasing amount of heavier components in the gas, this temperature was decreased. This is connected to the octane number of the components. Much of the engine performance can be related to this change of temperature. Emissions and power output (imep) showed the highest dependency of the concentration of component gas. Butanes had the highest impact on the inlet temperature, followed by propane and ethane. With the use of 20% EGR the inlet temperature had to be raised. The impact of the component gases was the same as with no EGR. The combustion efficiency

  15. Seismic wave attenuation and velocity dispersion in UAE carbonates (United States)

    Ogunsami, Abdulwaheed Remi

    Interpreting the seismic property of fluids in hydrocarbon reservoirs at low frequency scale has been a cherished goal of petroleum geophysics research for decades. Lately, there has been tremendous interest in understanding attenuation as a result of fluid flow in porous media. Although interesting, the emerging experimental and theoretical information still remain ambiguous and are practically not utilized for reasons not too obscure. Attenuation is frequency dependent and hard to measure in the laboratory at low frequency. This thesis describes and reports the results of an experimental study of low frequency attenuation and velocity dispersion on a selected carbonate reservoir samples in the United Arab Emirates (UAE). For the low frequency measurements, stress-strain method was used to measure the moduli from which the velocity is derived. Attenuation was measured as the phase difference between the applied stress and the strain. For the ultrasonic component, the pulse propagation method was employed. To study the fluid effect especially at reservoir in situ conditions, the measurements were made dry and saturated with liquid butane and brine at differential pressures of up to 5000 psi with pore pressure held constant at 500 psi. Similarly to what has been documented in the literatures for sandstone, attenuation of the bulk compressibility mode dominates the losses in these dry and somewhat partially saturated carbonate samples with butane and brine. Overall, the observed attenuation cannot be simply said to be frequency dependent within this low seismic band. While attenuation seems to be practically constant in the low frequency band for sample 3H, such conclusion cannot be made for sample 7H. For the velocities, significant dispersion is observed and Gassmann generally fails to match the measured velocities. Only the squirt model fairly fits the velocities, but not at all pressures. Although the observed dispersion is larger than Biot's prediction, the fact

  16. Shock tube measurements of the rate constants for seven large alkanes+OH

    KAUST Repository

    Badra, Jihad


    Reaction rate constants for seven large alkanes + hydroxyl (OH) radicals were measured behind reflected shock waves using OH laser absorption. The alkanes, n-hexane, 2-methyl-pentane, 3-methyl-pentane, 2,2-dimethyl-butane, 2,3-dimethyl-butane, 2-methyl-heptane, and 4-methyl-heptane, were selected to investigate the rates of site-specific H-abstraction by OH at secondary and tertiary carbons. Hydroxyl radicals were monitored using narrow-line-width ring-dye laser absorption of the R1(5) transition of the OH spectrum near 306.7 nm. The high sensitivity of the diagnostic enabled the use of low reactant concentrations and pseudo-first-order kinetics. Rate constants were measured at temperatures ranging from 880 K to 1440 K and pressures near 1.5 atm. High-temperature measurements of the rate constants for OH + n-hexane and OH + 2,2-dimethyl-butane are in agreement with earlier studies, and the rate constants of the five other alkanes with OH, we believe, are the first direct measurements at combustion temperatures. Using these measurements and the site-specific H-abstraction measurements of Sivaramakrishnan and Michael (2009) [1,2], general expressions for three secondary and two tertiary abstraction rates were determined as follows (the subscripts indicate the number of carbon atoms bonded to the next-nearest-neighbor carbon): S20=1.58×10-11exp(-1550K/T)cm3molecule-1s-1(887-1327K)S30=2.37×10-11exp(-1850K/T)cm3molecule-1s-1(887-1327K)S21=4.5×10-12exp(-793.7K/T)cm3molecule-1s-1(833-1440K)T100=2.85×10-11exp(-1138.3K/T)cm3molecule-1s-1(878-1375K)T101=7.16×10-12exp(-993K/T)cm3molecule-1s-1(883-1362K) © 2014 The Combustion Institute.

  17. Analysis of the Properties of Working Substances for the Organic Rankine Cycle based Database “REFPROP”

    Directory of Open Access Journals (Sweden)

    Galashov Nikolay


    Full Text Available The object of the study are substances that are used as a working fluid in systems operating on the basis of an organic Rankine cycle. The purpose of research is to find substances with the best thermodynamic, thermal and environmental properties. Research conducted on the basis of the analysis of thermodynamic and thermal properties of substances from the base “REFPROP” and with the help of numerical simulation of combined-cycle plant utilization triple cycle, where the lower cycle is an organic Rankine cycle. Base “REFPROP” describes and allows to calculate the thermodynamic and thermophysical parameters of most of the main substances used in production processes. On the basis of scientific publications on the use of working fluids in an organic Rankine cycle analysis were selected ozone-friendly low-boiling substances: ammonia, butane, pentane and Freon: R134a, R152a, R236fa and R245fa. For these substances have been identified and tabulated molecular weight, temperature of the triple point, boiling point, at atmospheric pressure, the parameters of the critical point, the value of the derivative of the temperature on the entropy of the saturated vapor line and the potential ozone depletion and global warming. It was also identified and tabulated thermodynamic and thermophysical parameters of the steam and liquid substances in a state of saturation at a temperature of 15 °C. This temperature is adopted as the minimum temperature of heat removal in the Rankine cycle when working on the water. Studies have shown that the best thermodynamic, thermal and environmental properties of the considered substances are pentane, butane and R245fa. For a more thorough analysis based on a gas turbine plant NK-36ST it has developed a mathematical model of combined cycle gas turbine (CCGT triple cycle, where the lower cycle is an organic Rankine cycle, and is used as the air cooler condenser. Air condenser allows stating material at a temperature

  18. Vertical profiles of ozone, VOCs and meteorological parameters in within and outside of Mexico City during the MILAGRO field Campaign (United States)

    Marquez, C.; Greenberg, J.; Bueno, E.; Bernabe, R.; Aguilar, J.; Blanco, S.; Wöhrnschimmel, H.; Guenther, A.; Cardenas, B.; Turnipseed, A.


    High ozone levels with maxima over 250 ppb have been an air quality problem in Mexico City for more than a decade. This ozone is produced in the daytime by photochemical reactions, initiated by its precursors, nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of solar ultraviolet radiation. The objective of this work is to contribute to the understanding of the evolution of these air pollutants at different heights of the boundary layer by means of vertical profile measurements. Ozone, VOCs and meteorological vertical profiles were determined in Northern Mexico City (T0 site) using a tethered balloon for 10 days during the MILAGRO field Campaign 2006, between 4 AM and 4 PM. Measurements were done up to 1000 meter above ground (ozone and meteorological parameters) and up to 200 m above ground for VOCs. VOCs samples were collected during 4 minutes in canisters and analyzed with GC-FID to identify 13 species (ethane, propane, propylene, butane, acetylene, pentane, hexane, heptane, benzene, octane, toluene, nonane and o-xylene). For 4 of the days, VOC integrated samples were also taken using personal pumps and absorbent cartridges at height between 200 and 1000 m. Sample cartridges were analyzed by GC-MS for volatile organic compounds (n-butane, i-pentane, n- pentane, benzene, toluene, ethyl-benzene, o-xylene, m&p-xylene, 1,2,4-tri-methyl-benzene and C3-benzenes). Ozone vertical profiles, frequently presented high concentrations above 400 m in the early morning. During the daytime, more homogeneous profiles indicate an increased vertical mixing. VOCs profiles show similar concentrations for all heights at dawn. In the morning, highest concentrations were determined at a height of about 100 meter, whereas at noon and in the afternoon concentrations decreased with height. Comparing VOC concentrations during the course of a day, highest values are measured in the morning. The highest VOC concentrations were propane, butane, and toluene. For some

  19. Analysis of the Properties of Working Substances for the Organic Rankine Cycle based Database "REFPROP" (United States)

    Galashov, Nikolay; Tsibulskiy, Svyatoslav; Serova, Tatiana


    The object of the study are substances that are used as a working fluid in systems operating on the basis of an organic Rankine cycle. The purpose of research is to find substances with the best thermodynamic, thermal and environmental properties. Research conducted on the basis of the analysis of thermodynamic and thermal properties of substances from the base "REFPROP" and with the help of numerical simulation of combined-cycle plant utilization triple cycle, where the lower cycle is an organic Rankine cycle. Base "REFPROP" describes and allows to calculate the thermodynamic and thermophysical parameters of most of the main substances used in production processes. On the basis of scientific publications on the use of working fluids in an organic Rankine cycle analysis were selected ozone-friendly low-boiling substances: ammonia, butane, pentane and Freon: R134a, R152a, R236fa and R245fa. For these substances have been identified and tabulated molecular weight, temperature of the triple point, boiling point, at atmospheric pressure, the parameters of the critical point, the value of the derivative of the temperature on the entropy of the saturated vapor line and the potential ozone depletion and global warming. It was also identified and tabulated thermodynamic and thermophysical parameters of the steam and liquid substances in a state of saturation at a temperature of 15 °C. This temperature is adopted as the minimum temperature of heat removal in the Rankine cycle when working on the water. Studies have shown that the best thermodynamic, thermal and environmental properties of the considered substances are pentane, butane and R245fa. For a more thorough analysis based on a gas turbine plant NK-36ST it has developed a mathematical model of combined cycle gas turbine (CCGT) triple cycle, where the lower cycle is an organic Rankine cycle, and is used as the air cooler condenser. Air condenser allows stating material at a temperature below 0 °C. Calculation of the

  20. Elaboration et caractérisation de gels hybrides à base d'aluminium (United States)

    Touati, F.; Gharbi, N.; Zarrouk, H.


    De nouveaux gels hybrides "organique—inorganique" à base d'aluminium sont élaborés par voie sol—gel. Le précurseur moléculaire utilisé est le butylate secondaire d'aluminium Al(OBu S) 3 dissous dans CCl 4, modifié par le propane-1,2-diol, le butane-1, x-diol ( x = 2, 3), et le pentane-1,2-diol. Nous avons étudié l'influence des principaux facteurs (nature du solvant, nature et quantité du diol) sur l'obtention des gels monolithiques et transparents. Toutes les préparations sont réalisées sans ajout d'eau. L'étude par RMN MAS 27Al, RMN CP MAS 13C, et par spectroscopie IR montre qu'une réaction d'échange a lieu entre les groupements OBus de l'alcoxyde d'aluminium et les diols utilisés. Les gels obtenussont monolithiques et transparents, les atomes d'aluminium y sont liés entre eux par des ponts organiques selon la formule —Al—O—R —O—Al— où R est une chaîne hydrocarbonée provenant du diol. This paper presents an original method for elaboration of gels with mixed organic—inorganic networks of the general formula —Al—O—R—O—Al—, with R being a hydrocarbon chain. Starting materials used are aluminum tri-sec-butoxide Al(O-sec-C 4H 9) 3, propane-1,2-diol, butane-1,2-diol, butane-1,3-diol, and pentane-1,2-diol. The reactions were carried out with either CCl 4 or cyclohexane as solvent. The exchange reaction between the diols and Al(O-sec-C 4H 9) 3 occurs with the elimination of sec-butanol molecules. Gels are obtained without the addition of water. The monolithic and transparent gels obtained are characterized by IR and as well as 13C and 27Al RMN techniques.

  1. Descomposicion termica del diperoxido de pinacolona (3,6-diterbutil-3,6-dimetil-1,2,4,5-tetraoxaciclohexano en solución de 2-metoxietanol

    Directory of Open Access Journals (Sweden)

    Eyler Gladys N.


    Full Text Available The thermal decomposition reaction of pinacolone diperoxide (DPP; 0.02 mol kg-1 in 2-methoxyethanol solution studied in the temperature range of 110.0-150.0 °C, follows a first-order kinetic law up to at least 50% DPP conversion. The organic products observed were pinacolone, methane and tert-butane. A stepwise mechanism of decomposition was proposed where the first step is the homolytic unimolecular rupture of the O-O bond. The activation enthalpy and activation entropy for DPP in 2-methoxyethanol were calculated (deltaH# = 43.8 ± 1.0 kcal mol-1 and deltaS# = 31.9 ± 2.6 cal mol-1K-1 and compared with those obtained in other solvents to evaluate the solvent effect.

  2. Fuels for homogenous, self-igniting combustion processes; Brennstoffe fuer homogene selbstgezuendete Verbrennungsprozesse - Jahresbericht 2007

    Energy Technology Data Exchange (ETDEWEB)

    Escher, A.; Boulouchos, K.


    This annual report for the Swiss Federal Office of Energy (SFOE), reports on work done in 2007 at the Swiss Federal Institute of Technology ETH in Zurich, Switzerland, on fuels for homogenous, self-igniting combustion processes. A single-stroke engine was used to test the combustion of n-heptane, n-butane and their combinations. The flexibility of the test-bed is discussed and the combustion characteristics observed are described. Also, the results obtained are presented and discussed. Multi-zone simulation and factors influencing the combustion are examined. Ignition and combustion of synthetic, diesel-like fuels are discussed. Co-operation with the project started in 2007 by the Society for Research on Combustion Engines which involves other universities and several industrial companies is noted.

  3. Gas Sorption, Diffusion and Permeation in a Polymer of Intrinsic Microporosity (PIM-7)

    KAUST Repository

    Alaslai, Nasser Y.


    of He, H2, N2, O2, CH4, CO2, C2H6, C3H8 and n-C4H10 were measured at 35 oC and 2 atm feed pressure using a home-made constant-volume/variable pressure pure-gas permeation system. Hydrocarbon-induced plasticization of PIM-7 was confirmed by measuring the permeability coefficients of C3H8 and n-C4H10 as function of pressure at 35 oC. Diffusion coefficients were calculated from the permeability and solubility data at 2 atm for all penetrants tested and as function of pressure for C3H8 and n-C4H10; the values for C3 and C4 increased significantly with pressure because of plasticization. Physical aging was studied by measuring the permeability coefficients of a number of gases in fresh and aged films. Mixed-gas permeation tests were performed for a feed mixture of 2 vol% n-butane and 98 vol% methane. Based on BET surface area measurements using N2 as a probe molecule, PIM-7 is a microporous polymer (S = 690 m2/g) and it was expected to exhibit selectivity for n-butane over methane, as previously observed for other microporous polymers, such as PIM-1 and PTMSP. Surprisingly, PIM-7 is more permeable to methane than n-butane and exhibits a mixed-gas methane/n-butane selectivity of up to 2.3. This result indicates that the micropore size in PIM-7 is smaller than that in other PIMs materials. Consequently, PIM-7 is not a suitable candidate membrane material for separation of higher hydrocarbons from methane.

  4. Trends in bond dissociation energies of alcohols and aldehydes computed with multireference averaged coupled-pair functional theory. (United States)

    Oyeyemi, Victor B; Keith, John A; Carter, Emily A


    As part of our ongoing investigation of the combustion chemistry of oxygenated molecules using multireference correlated wave function methods, we report bond dissociation energies (BDEs) in C1-C4 alcohols (from methanol to the four isomers of butanol) and C1-C4 aldehydes (from methanal to butanal). The BDEs are calculated with a multireference averaged coupled-pair functional-based scheme. We compare these multireference BDEs with those derived from experiment and single-reference methods. Trends in BDEs for the alcohols and aldehydes are rationalized by considering geometry relaxations of dissociated radical fragments, resonance stabilization, and hyperconjugation. Lastly, we discuss the conjectured association between bond strengths and rates of hydrogen abstraction by hydroxyl radicals. In general, abstraction reaction rates are higher at sites where the C-H bond energies are lower (and vice versa). However, comparison with available rate data shows this inverse relationship between bond strengths and abstraction rates does not hold at all temperatures.

  5. Interaction between active ruthenium complex [RuCl3(dppb)(VPy)] and phospholipid Langmuir monolayers: Effects on membrane electrical properties (United States)

    Sandrino, B.; Wrobel, E. C.; Nobre, T. M.; Caseli, L.; Lazaro, S. R.; Júnior, A. C.; Garcia, J. R.; Oliveira, O. N.; Wohnrath, K.


    We report on the interaction between mer-[RuCl3(dppb)(VPy)] (dppb = 1,4-bis(diphenylphosphine)butane and VPy = 4-vinylpyridine) (RuVPy) and dipalmitoyl phosphatidyl serine (DPPS), in Langmuir and Langmuir-Blodgett (LB) films. Interaction of RuVPy with DPPS, which predominates in cancer cell membranes, should be weaker than for other phospholipids since RuVPy is less toxic to cancer cells than to healthy cells. Incorporation of RuVPy induced smaller changes in electrochemical properties of LB films of DPPS than for other phospholipids, but the same did not apply to surface pressure isotherms. This calls for caution in establishing correlations between effects from a single property and phenomena on cell membranes.

  6. Excess molar enthalpies and heat capacities of dimethyl sulfoxide + seven normal alkanols at 303.15 K and atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Rubini, Katia [Dipartimento di Chimica ' G. Ciamician' , Universita Studi, via Selmi 2, I-40126 Bologna (Italy); Francesconi, Romolo [Dipartimento di Chimica ' G. Ciamician' , Universita Studi, via Selmi 2, I-40126 Bologna (Italy); Bigi, Adriana [Dipartimento di Chimica ' G. Ciamician' , Universita Studi, via Selmi 2, I-40126 Bologna (Italy); Comelli, Fabio [Istituto per la Sintesi Organica e la Fotoreattivita (ISOF)-CNR, via Gobetti 101, I-40129 Bologna (Italy)]. E-mail:


    Excess molar enthalpies and heat capacities of binary mixtures containing dimethyl sulfoxide (DMSO) + seven normal alkanols, namely methanol, ethanol, propan-1-ol, butan-1-ol, hexan-1-ol, octan-1-ol, and decan-1-ol, have been determined at 303.15 K and atmospheric pressure. With the exception of the DMSO-methanol system, which shows negative values, all mixtures show positive values of excess molar enthalpies over the whole range of mole fraction, increasing as the number of carbon atoms increases. Heat capacities of pure components have been determined in the range 288.15 < T (K) < 325.15. Molar heat capacities of the mixtures are always positive and decrease as the number of carbon atoms decreases. The results were fitted to the Redlich-Kister polynomial equation. Molecular interactions in the mixtures are interpreted on the basis of the results obtained.

  7. Permeation Characteristics of Light Hydrocarbons Through Poly(amide-6-β-ethylene oxide) Multilayer Composite Membranes

    Institute of Scientific and Technical Information of China (English)

    REN Xiaoling; REN Jizhong; LI Hui; DENG Maicun


    In this paper,poly(amide-6-β-ethylene oxide) (PEBA1657) copolymer was used to prepare multilayer polyetherimide (PEI)/polydimethylsiloxane (PDMS)/PEBA1657/PDMS composite membranes by dip-coating method.Permeation behaviors of ethylene,ethane,propylene,propane,n-butane,methane and nitrogen through the multilayer composite membranes were investigated over a range of operating temperature and pressure.The permeances of light hydrocarbons through PEI/PDMS/PEBA1657/PDMS composite membranes increase with their increasing condensability,and the olefins are more permeable than their corresponding paraffins.For light hydrocarbons,the gas permeances increase significantly as temperature increasing.When the transmembrane pressure difference increases,the gas permeance increases moderately due to plasticization effect,while their apparent activation energies for permeation decrease.

  8. Characterization of Mixed xWO3(1-xY2O3 Nanoparticle Thick Film for Gas Sensing Application

    Directory of Open Access Journals (Sweden)

    M. H. Shahrokh Abadi


    Full Text Available Microstructural, topology, inner morphology, and gas-sensitivity of mixed xWO3(1-xY2O3 nanoparticles (x = 1, 0.95, 0.9, 0.85, 0.8 thick-film semiconductor gas sensors were studied. The surface topography and inner morphological properties of the mixed powder and sensing film were characterized with X-ray diffraction (XRD, atomic force microscopy (AFM, transmission electron microscopy (TEM, and scanning electron microscopy (SEM. Also, gas sensitivity properties of the printed films were evaluated in the presence of methane (CH4 and butane (C4H10 at up to 500 °C operating temperature of the sensor. The results show that the doping agent can modify some structural properties and gas sensitivity of the mixed powder.

  9. Synthesis of Luminescent Copper(Ⅰ)β-Diketone Complex by a New Preparation Method%一种新方法合成荧光β-二酮铜(Ⅰ)配合物

    Institute of Scientific and Technical Information of China (English)

    郭利兵; 朱靖; 蒋凯; 张传建


    At room temperature, the reducing reaction between the bis(diphenylphosphino)butane (dppb) ligand and the compound [Cu(tfac)2] (tfac=2-thenoyltrifluoroacetone) gave luminescent copper(Ⅰ) complex [Cu(dppb)(tfac)]2. They have been characterized by physicochemical and spectroscopic methods. Crystal structure of the title complex shows that 2-thenoyltrifluoroacetone behaves as chelating ligand and dppb coordinates as bridging bidentate ligand to Cu(Ⅰ) atoms in the newly prepared copper(Ⅰ) complex. The crystal is monoclinic, space group P21/n, with cell parameters a = 1.031 0(2) nm, b = 1.873 0(4) nm, c= 1.763 0(4) nm, β = 95.10(3)°, Z = 4, V = 3.391 0(12)nm3, R = 0.0603, wR = 0.1434. CCDC: 228393.

  10. Synthesis of a new intercalating nucleic acid 6H-INDOLO[2,3-b] quinoxaline oligonucleotides to improve thermal stability of Hoogsteen-type triplexes

    DEFF Research Database (Denmark)

    Osman, Amany M A; Pedersen, Erik Bjerregaard; Bergman, Jan


    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 c...... 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....

  11. Studies of properties of complex carbon-silica adsorbents used in sorption-desorption processes (solid-phase extraction)

    Energy Technology Data Exchange (ETDEWEB)

    Rudzinski, W. [Maria Curie-Sklodowska Univ., Lublin (Poland). Faculty of Chemistry; Gierak, A. [Maria Curie-Sklodowska Univ., Lublin (Poland). Faculty of Chemistry; Leboda, R. [Maria Curie-Sklodowska Univ., Lublin (Poland). Faculty of Chemistry; Dabrowski, A. [Maria Curie-Sklodowska Univ., Lublin (Poland). Faculty of Chemistry


    Adsorption properties of carbon and carbon-silica adsorbents, prepared by n-octanol and glucose pyrolysis and catalytic decomposition of n-butane, have been studied regarding their applicability for the extraction and concentration of phenol, its nitro- and chloro-derivatives and trihalomethanes [THM] from aqueous solutions in the concentration range of 2 to 20 mg/l. The adsorbents investigated have been subjected to various physico-chemical processes (hydrothermal treatment, oxidation, silanization) in order to improve their efficiency. The adsorption isotherms measured correspond well to the Freundlich equation. A good correlation have been observed between the values of the Freundlich constant k and the adsorbent efficiency. The investigation has been carried out using the ``off line`` method, and recovery rates for the compounds studied as high as 40-100% have been obtained. (orig.)

  12. Novel psychoactive substance intoxication resulting in attempted murder. (United States)

    Stevenson, Richard; Tuddenham, Laurence


    A man in his twenties who had no previous history of violence, snorted large quantities of two substances he identified as 3-methoxyphencyclidine (3-MeO-PCP), and methylenedioxypyrovalerone (MDPV); both are recognised as novel psychoactive substances, or commonly described in the media as "legal highs". He also inhaled butane gas. He experienced vivid hallucinations and developed bizarre ideas. During this state of mind he stabbed his father multiple times and was arrested and charged with attempted murder. He had a previous history of drug induced psychosis and although he had some slight residual symptoms before he consumed the substances, these were not considered relevant to his criminal liability at the time of the offence. The hallucinations caused by the use of these substances took six weeks to completely recede. He was convicted of attempted murder and sentenced to four years in prison.

  13. A Gas Chromatographic Analysis of Light Hydrocarbons on a Column Packed with Modified Silica Gel

    Institute of Scientific and Technical Information of China (English)


    A one-meter long column packed with silica gel is used to separate light hydrocarbons. The silica gel has been modified with several kinds of gas chromatography stationary phases. Among these, PEG 2000 shows fairly good effect when using 80-100 meshes silica gel for the separation of mixture of methane, ethane, ethylene, acetylene, propane, propylene and n-, i-butane. The different behavior of silica gel between batch to batch is also found. When silica gel is coated with a small amount of Al2O3 prepared with sol-gel method, better resolution has been observed on a 2-meter column compared with the non-modified silica gel.

  14. Preparation, characterisation, engine performance and emission characteristics of coconut oil based hybrid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pranil J.; Singh, Anirudh [Division of Physics, School of Engineering and Physics, Faculty of Science, Technology and Environment, University of the South Pacific, 325 Fletcher Road, Suva (Fiji); Khurma, Jagjit [Division of Chemistry, School of Biological, Chemical and Environmental Sciences, Faculty of Science, Technology and Environment, University of the South Pacific, Suva (Fiji)


    In this study, hybrid fuels consisting of coconut oil, aqueous ethanol and a surfactant (butan-1-ol) were prepared and tested as a fuel in a direct injection diesel engine. After determining fuel properties such as the density, viscosity and gross calorific values of these fuels, they were used to run a diesel engine. The engine performance and exhaust emissions were investigated and compared with that of diesel. The experimental results show that the efficiency of the hybrid fuels is comparable to that of diesel. As the viscosity of the hybrid fuels decreased and approached that of diesel, the efficiency increased progressively towards that of diesel. The exhaust emissions were lower than those for diesel, except carbon monoxide emissions, which increased. Hence, it is concluded that these hybrid fuels can be used successfully as an alternative fuel in diesel engines without any modifications. Their completely renewable nature ensures that they are environmentally friendly with regard to their emissions characteristics. (author)

  15. Synthesis and mesomorphic behaviour of lithocholic acid derivatives

    Indian Academy of Sciences (India)

    V A E Shaikh; N N Maldar; S V Lonikar


    A series of liquid crystalline derivatives of lithocholic acid were prepared using simple chemical reactions involving the terminal functional group—hydroxyl at C-3 and/or carboxyl at C-24. Thus methyl -3-(3-carboxy propionyl) lithocholate (I), 3-(3-carboxy propionyl) lithocholic acid (II), 3-acetyl lithocholic acid (III), 3-propionyl lithocholic acid (IV), 3-benzoyl lithocholic acid (V), 3-(4-nitrobenzoyl) lithocholic acid (VI), 3-cinnamoyl lithocholic acid (VII), methyl-3-(4-nitrobenzoyl) lithocholate (VIII) and 1,4-bis [cholan-24-methoxy carbonyl-3-oxycarbonyl] butane (IX) were prepared in good yields and characterized by IR, NMR and polarizing optical microscopy. Compounds (I) and (IX) exhibited monotropic behaviour while the others were enantiotropic. Some of the compounds also showed a high tendency of super cooling. Compounds (V), (VI) and (IX) formed cholesteric phase while the remaining compounds displayed smectic phase.

  16. Thailandepsin A

    Directory of Open Access Journals (Sweden)

    Cheng Wang


    Full Text Available Thailandepsin A [systematic name: (E-(1S,5S,6R,9S,20R-6-[(2S-butan-2-yl]-5-hydroxy-20-[2-(methylsulfanylethyl]-2-oxa-11,12-dithia-7,19,22-triazabicyclo[7.7.6]docosa-15-ene-3,8,18,21-tetraone], C23H37N3O6S3, is a newly reported [Wang et al. (2011. J. Nat. Prod. doi:10.1021/np200324x] bicyclic depsipeptide that has potent histone deacetylase inhibitory activity and broad-spectrum antiproliferative activity. The absolute configuration of thailandepsin A has been determined from the anomalous dispersion and the stereochemistry of all chiral C atoms. Intramolecular N—H...O and N—H...S hydrogen bonds occur. Intermolecular N—H...O and O—H...O hydrogen bonds are observed in the crystal structure.

  17. Supercritical fluid extraction of plant flavors and fragrances. (United States)

    Capuzzo, Andrea; Maffei, Massimo E; Occhipinti, Andrea


    Supercritical fluid extraction (SFE) of plant material with solvents like CO₂, propane, butane, or ethylene is a topic of growing interest. SFE allows the processing of plant material at low temperatures, hence limiting thermal degradation, and avoids the use of toxic solvents. Although today SFE is mainly used for decaffeination of coffee and tea as well as production of hop extracts on a large scale, there is also a growing interest in this extraction method for other industrial applications operating at different scales. In this review we update the literature data on SFE technology, with particular reference to flavors and fragrance, by comparing traditional extraction techniques of some industrial medicinal and aromatic crops with SFE. Moreover, we describe the biological activity of SFE extracts by describing their insecticidal, acaricidal, antimycotic, antimicrobial, cytotoxic and antioxidant properties. Finally, we discuss the process modelling, mass-transfer mechanisms, kinetics parameters and thermodynamic by giving an overview of SFE potential in the flavors and fragrances arena.

  18. Energy consumptions per sector; Les consommations d'energie par secteur

    Energy Technology Data Exchange (ETDEWEB)



    This document presents the energy consumption data of France per energy type and sector of use in the form of tables and graphics for the last decade and sometimes before: 1 - residential and tertiary sector: energy consumption per energy source, energy consumption per use (coal, heavy and domestic fuels, natural gas, LPG (butane, propane), electricity), comparison of the share of each energy source between 1973 and 2003, 20 years of space heating data in main dwellings (1982-2002), district heating networks from 1987 to 1997; 2 - transportation sector: fuel consumption of individual cars in France (1990-2003, 1990-2002, 1990-2001, 1987-1999), some indicators about the energy consumption in transports in France (2000-2001); 3 - industry sector: consumption of fuel substitutes in the cement industry in 2001, importance and limitations. (J.S.)

  19. Sudden death due to inhalant abuse in youth: Case report

    Directory of Open Access Journals (Sweden)

    Ramazan Akcan


    Full Text Available Intentional inhalation or abuse of volatile substances is a common public health problem all over the world. As these substances generate euphoria frequency of use among adolescents and young adults is increasing steadily. In cases using inhalants to achieve a euphoric state -without knowing possible consequences- sudden death may occurdue to acute cardio-pulmonary dysfunction.Here we present a case of sudden death of a nineteen-year-old female due to inhalation of volatile from butane containing lighter gas tube, with the findings of autopsy and death scene investigation.In the context of this case; it was aimed to draw attention to the risk of sudden death and steady increase of frequencyof volatile substance abuse among adolescents and young adults due to various psycho-social factors.

  20. Efficient control of odors and VOC emissions via activated carbon technology. (United States)

    Mohamed, Farhana; Kim, James; Huang, Ruey; Nu, Huong Ton; Lorenzo, Vlad


    This research study was undertaken to enhance the efficiency and economy of carbon scrubbers in controlling odors and volatile organic compounds (VOCs) at the wastewater collection and treatment facilities of the Bureau of Sanitation, City of Los Angeles. The butane activity and hydrogen sulfide breakthrough capacity of activated carbon were assessed. Air streams were measured for odorous gases and VOCs and removal efficiency (RE) determined. Carbon towers showed average to excellent removal of odorous compounds, VOCs, and siloxanes; whereas, wet scrubbers demonstrated good removal of odorous compounds but low to negative removal of VOCs. It was observed that the relative humidity and empty bed contact time are one of the most important operating parameters of carbon towers impacting the pollutant RE. Regular monitoring of activated carbon and VOCs has resulted in useful information on carbon change-out frequency, packing recommendations, and means to improve performance of carbon towers.

  1. Session 6: High Throughput Screening of VOC Removal Catalysts in Scanning Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Yaccato, K.; Hagemeyer, A.; Lefort, L.; Turner, H.; Volpe, A.; Weinberg, H. [Symyx Technologies Inc., Santa Clara, CA (United States)


    Volatile organic compounds (VOCs) are considered an important group of air pollutants. We have targeted more efficient VOC removal catalysts with high activity for total combustion at low temperature, negligible organics slip, high selectivity to CO{sub 2} without production of intermediate CO, oxygenates or cracking products. Butane was used as the model feed for VOC in Symyx' high-throughput Scanning Mass Spectrometer. The screening protocol encompassed bulk (unsupported) mixed metal oxides calcined in air at 400 C. Transition metals M{sub 1} known to have some oxidation activity M{sub 1}=Ti, V, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Cu and Ag, were combined with each other into binaries as well as doped with M{sub 2} = K, Cs, Mg, Sr, Sc, Y, Ce, Sm, Zr, Nb, Ta, Zn, Cd, B, Al, In, Sn, Pb, P, Sb, Bi and Te, using 5- point compositional gradients (5 different compositions per binary). Five M/Z values were monitored, namely 44, 68, 70, 72 and 98. CO{sub 2} at M/Z equal to 44 is the dominant product, and only traces of oxygenates are formed. Co, Cr, Ni, Mn, Cu are identified as the most active metals. Subsequently, CoCrM{sub 3} and CrZnM{sub 3} ternaries were synthesized and screened with M{sub 3} selected from M{sub 3} Li, K, Cs, Mg, Sr, Y, Mo, Ru, Rh, Pd, Pt, Ag, Zn, Al, Ga, In, Sn, Pb, P, Sb and Bi, (M{sub 3} {<=} 10%, 15 different compositions/ternaries; 3 copies: (a) unsupported, calcined at 400 C, (b) unsupported, calcined at 600 C, (c) Al{sub 2}O{sub 3}, calcined at 400 C). CoCr ternaries from Symyx' library archive were also screened. High CO{sub 2} production for the CoCr/400 C systems was observed. Catalyst compositions were then optimized in focus libraries. An example for a CoCrTi/CoVSi bis-ternary focus library will be discussed in detail. VPO catalysts were used as 'standards' to establish the correlation between primary and tertiary screening. High CO{sub 2} signals were also observed for Co-rich CoCr and CoCrTi systems. The best Co

  2. Characterization of arsenic (V) and arsenic (III) in water samples using ammonium molybdate and estimation by graphite furnace atomic absorption spectroscopy. (United States)

    Sounderajan, Suvarna; Udas, A C; Venkataramani, B


    Arsenic (V) is known to form heteropolyacid with ammonium molybdate in acidic aqueous solutions, which can be quantitatively extracted into certain organic solvents. In the present work, 12-molybdoarsenic acid extracted in butan-1-ol is used for quantification of As (V). Total arsenic is estimated by converting arsenic (III) to arsenic (V) by digesting samples with concentrated nitric acid before extraction. Concentration of As (III) in the sample solutions could be calculated by the difference in total arsenic and arsenic (V). The characterization of arsenic was carried out by GFAAS using Pd as modifier. Optimization of the experimental conditions and instrumental parameters was investigated in detail. Recoveries of (90-110%) were obtained in the spiked samples. The detection limit was 0.2 microg l(-1). The proposed method was successfully applied for the determination of trace amount of arsenic (III) and arsenic (V) in process water samples.

  3. Electrocatalytic Production of C3-C4 Compounds by Conversion of CO2 on a Chloride-Induced Bi-Phasic Cu2O-Cu Catalyst. (United States)

    Lee, Seunghwa; Kim, Dahee; Lee, Jaeyoung


    Electrocatalytic conversion of carbon dioxide (CO2) has recently received considerable attention as one of the most feasible CO2 utilization techniques. In particular, copper and copper-derived catalysts have exhibited the ability to produce a number of organic molecules from CO2. Herein, we report a chloride (Cl)-induced bi-phasic cuprous oxide (Cu2O) and metallic copper (Cu) electrode (Cu2OCl) as an efficient catalyst for the formation of high-carbon organic molecules by CO2 conversion, and identify the origin of electroselectivity toward the formation of high-carbon organic compounds. The Cu2OCl electrocatalyst results in the preferential formation of multi-carbon fuels, including n-propanol and n-butane C3-C4 compounds. We propose that the remarkable electrocatalytic conversion behavior is due to the favorable affinity between the reaction intermediates and the catalytic surface.

  4. Measurements and receptor modeling of volatile organic compounds in south-eastern Mexico City, 2000–2007

    Directory of Open Access Journals (Sweden)

    V. Gutiérrez


    Full Text Available Ambient samples of volatile organic compounds (VOCs were measured between 2000 and 2007 in south-eastern Mexico City, quantifying 13 species (ethane, propane, propylene, butane, acetylene, pentane, hexane, heptane, benzene, octane, toluene, nonane, o-xylene. These time series were analyzed for long-term trends, using linear regression models. A main finding was that the concentrations for several of the quantified VOC species were decreasing during this period. A receptor model was applied to identify possible VOC sources, as well as temporal patterns in their respective activities. Domestic use of liquefied petroleum gas and vehicle exhaust are suggested to be the principal emission sources, contributing together between 70% and 80% to total VOC. Both diurnal and seasonal patterns, as well as a weekend effect were recognized in the modelled source activities. Furthermore, vehicle exhaust emissions showed a decreasing trend over time, with a reduction of about 8% per year.

  5. Development of Effective Aerobic Cometabolic Systems for the In Situ Transformation of Problematic Chlorinated Solvent Mixtures (United States)


    Testing Duration Chemicals Injected Average Concentration Process Studied 9/28-10/7/02 (0 to 8 days) H2O2 10 mg/L H2O2 decompostion to oxygen...and disinfection 10/7-10/21/02 (9 to 23 days) 1H2O2 2Oxygen 1,1,1-TCA Bromide 10 mg/L 30 mg/L 115 µg/L 140 mg/L 1,1,1-TCA transport and...4 mg/L 100 mg/L Bioaugmentation, biostimulation, and biotransformation 11/17-12/5/02 (48-71 days) Oxygen H2O2 1,1,1-TCA Butane 30 mg/L

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

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


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

  7. Buprenorphine. (United States)

    Mazurek, Jaroslaw; Hoffmann, Marcel; Fernandez Casares, Anna; Cox, Phillip D; Minardi, Mathew D


    In the crystal structure of a semi-synthetic opioid drug buprenorphine, C29H41NO4 {systematic name: (2S)-2-[(5R,6R,7R,14S)-9α-cyclo-propyl-methyl-3-hy-droxy-6-meth-oxy-4,5-ep-oxy-6,14-ethano-morphinan-7-yl]-3,3-di-methyl-butan-2-ol}, the cyclo-propyl-methyl group is disordered over two sites with an occupancy factor of 0.611 (3) for the major component. One of the hy-droxy groups is involved in intra-molecular O-H⋯O hydrogen bond. The other hy-droxy group acts as a proton donor in an inter-molecular O-H⋯O inter-action that connects mol-ecules into a zigzag chain along the b axis.

  8. Chile exploits LNG

    Energy Technology Data Exchange (ETDEWEB)


    Simultaneously with its exploitation of offshore hydrocarbon reservoirs Chile is developing the production and selling of LNG. Chile produces a large quantity of associated gas from its reservoirs at Megallanes and processes it at the Manantiales, Cullen and Posesion plants recovering propane, butane and natural gas liguids. The stripped gas is reinjected for pressure maintenance operations. With the completion of the LNG program full use of the gas will be achieved. It will totally meet the needs of combustible liquids for the central and northern parts of the country, a volume of 2200 million cu m/yr. For its treatment natural gas is sent through gas pipelines to the LNG plant at Cabo Negro. By means of a cooling process, the gas is cooled to -160 C where it becomes a liquid and its volume is reduced by a factor of 600. It is then stored in tanks at atmospheric pressure.

  9. High Temperature PEM Fuel Cells - Degradation and Durability

    DEFF Research Database (Denmark)

    Araya, Samuel Simon

    A harmonious mix of renewable and alternative energy sources, including fuel cells is necessary to mitigate problems associated with the current fossil fuel based energy system, like air pollution, Greenhouse Gas (GHG) emissions, and economic dependence on oil, and therefore on unstable areas...... of the globe. Fuel cells can harness the excess energy from other renewable sources, such as the big players in the renewable energy market, Photovoltaic (PV) panels and wind turbines, which inherently suffer from intermittency problems. The excess energy can be used to produce hydrogen from water or can...... be stored in liquid alcohols such as methanol, which can be sources of hydrogen for fuel cell applications. In addition, fuel cells unlike other technologies can use a variety of other fuels that can provide a source of hydrogen, such as biogas, methane, butane, etc. More fuel flexibility combined...

  10. Investigation of C3-C10 aldehydes in the exhaled breath of healthy subjects using selected ion flow tube-mass spectrometry (SIFT-MS). (United States)

    Huang, Juzheng; Kumar, Sacheen; Hanna, George B


    Aldehydes have attracted great scientific and clinical interest as potential disease biomarkers. We have investigated selected ion flow tube-mass spectrometry (SIFT-MS) in detecting and quantifying C3 to C10 saturated aldehydes (propanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal and decanal) from the exhaled breath of 26 healthy human volunteers. To assess the reliability of the Nalophan® bag sampling method employed, the water level in the breath sample was measured up to 4 h after collection and showed no significant degradation. Propanal was found to be the most abundant aldehyde in the exhaled breath of healthy volunteers. For the C4-C10 aldehydes, their median concentrations were all less than 3 ppbv, demonstrating only trace quantities are present in the exhaled breath of the 26 healthy volunteers.

  11. Mass Spectrometry Study of OH-initiated Photooxidation of Toluene

    Institute of Scientific and Technical Information of China (English)

    Ming-qiang Huang; Wei-iun Zhang; Zhen-ya Wang; Li Fang; Rui-hong Kong; Xiao-bin Shan; Fu-yi Liu; Liu-si Sheng


    The composition of products formed from photooxidation of the aromatic hydrocarbon toluene was investigated.The OH-initiated photooxidation experiments were conducted by irradiating toluene/CH3ONO/NO/air mixtures in a smog chamber,the gaseous products were detected under the supersonic beam conditions by utilizing vacuum ultraviolet photoionization mass spectrometer using synchrotron radiation in real-time.And an aerosol time-of-flight mass spectrometer was used to provide on-line measurements of the individual secondary organic aerosol particle resulting from irradiating toluene.The experimental results demonstrated that there were some differences between the gaseous products and that of particle-phase,the products of glyoxal,2-hydroxyl-3-oxo-butanal,nitrotoluene,and methyl-nitrophenol only existed in the particle-phase.However,furane,methylglyoxal,2-methylfurane,benzaldehyde,cresol,and benzoic acid were the predominant photooxidation products in both the gas phase and particle phase.

  12. Aroma compound analysis of Eruca sativa (Brassicaceae) SPME headspace leaf samples using GC, GC-MS, and olfactometry. (United States)

    Jirovetz, Leopold; Smith, David; Buchbauer, Gerhard


    The aroma compounds of rocket salad (Eruca sativa) SPME headspace samples of fresh leaves were analyzed using GC, GC-MS, and olfactometry. More than 50 constituents of the Eruca headspace could be identified to be essential volatiles, responsible for the characteristic intense green; herbal; nutty and almond-like; Brassicaceae-like (direction of cabbage, broccoli, and mustard); and horseradish-like aroma of these salad leaves. As aroma impact compounds, especially isothiocyanates, and derivatives of butane, hexane, octane, and nonane were identified. 4-Methylthiobutyl isothiocyanate (14.2%), cis-3-hexen-1-ol (11.0%), cis-3-hexenyl butanoate (10.8%), 5-methylthiopentyl isothiocyanate (9.3%), cis-3-hexenyl 2-methylbutanoate (5.4%), and 5-methylthiopentanenitrile (5.0%) were found in concentrations higher than 5.0% (calculated as % peak area of GC analysis using a nonpolar column).

  13. Effect of positron-atom interactions on the annihilation gamma spectra of molecules

    CERN Document Server

    Green, D G; Wang, F; Gribakin, G F; Surko, C M


    Calculations of gamma spectra for positron annihilation on a selection of molecules, including methane and its fluoro-substitutes, ethane, propane, butane and benzene are presented. The annihilation gamma spectra characterise the momentum distribution of the electron-positron pair at the instant of annihilation. The contribution to the gamma spectra from individual molecular orbitals is obtained from electron momentum densities calculated using modern computational quantum chemistry density functional theory tools. The calculation, in its simplest form, effectively treats the low-energy (thermalised, room-temperature) positron as a plane wave and gives annihilation gamma spectra that are about 40% broader than experiment, although the main chemical trends are reproduced. We show that this effective "narrowing" of the experimental spectra is due to the action of the molecular potential on the positron, chiefly, due to the positron repulsion from the nuclei. It leads to a suppression of the contribution of smal...

  14. Catalytic functionalization of methane and light alkanes in supercritical carbon dioxide. (United States)

    Fuentes, M Ángeles; Olmos, Andrea; Muñoz, Bianca K; Jacob, Kane; González-Núñez, M Elena; Mello, Rossella; Asensio, Gregorio; Caballero, Ana; Etienne, Michel; Pérez, Pedro J


    The development of catalytic methods for the effective functionalization of methane yet remains a challenge. The best system known to date is the so-called Catalytica Process based on the use of platinum catalysts to convert methane into methyl bisulfate with a TOF rate of 10(-3) s. In this contribution, we report a series of silver complexes containing perfluorinated tris(indazolyl)borate ligands that catalyze the functionalization of methane into ethyl propionate upon reaction with ethyl diazoacetate (EDA) by using supercritical carbon dioxide (scCO2) as the reaction medium. The employment of this reaction medium has also allowed the functionalization of ethane, propane, butane, and isobutane.

  15. Feasibility of the preparation of silica monoliths for gas chromatography: fast separation of light hydrocarbons. (United States)

    Azzouz, Imadeddine; Essoussi, Anouar; Fleury, Joachim; Haudebourg, Raphael; Thiebaut, Didier; Vial, Jerome


    The preparation conditions of silica monoliths for gas chromatography were investigated. Silica-based monolithic capillary columns based on sol-gel process were tested in the course of high-speed gas chromatographic separations of light hydrocarbons mixture (C1-C4). The impact of modifying the amount of porogen and/or catalyst on the monolith properties were studied. At the best precursor/catalyst/porogen ratio evaluated, a column efficiency of about 6500 theoretical plates per meter was reached with a very good resolution (4.3) for very light compounds (C1-C2). The test mixture was baseline separated on a 70cm column. To our knowledge for the first time a silica-based monolithic capillary column was able to separate light hydrocarbons from methane to n-butane at room temperature with a back pressure in the range of gas chromatography facilities (under 4.1bar).

  16. Polyvinylpolypyrrolidone Supported Brønsted Acidic Catalyst for Esterification

    Directory of Open Access Journals (Sweden)

    Song Wang


    Full Text Available A polyvinylpolypyrrolidone (PVPP supported Brønsted acidic catalyst ([PVPP-BS]HSO4 was prepared by coupling SO3H-functionalized polyvinylpolypyrrolidone with H2SO4 in this work. After the characterization through FT-IR, FESEM, TG, BET, and elemental analysis, it was found that 1,4-butane sultone (BS and sulfuric acid reacted with PVPP and were immobilized on PVPP surface. The prepared [PVPP-BS]HSO4 catalyst shows high catalytic activity for a series of esterification reactions and could be separated from the reacted mixture easily. Moreover, this catalyst could be recycled and reused for six times without significant loss of catalytic performance.

  17. Formation of positive ions in hydrocarbon containing dielectric barrier discharge plasmas (United States)

    Mihaila, Ilarion; Pohoata, Valentin; Jijie, Roxana; Nastuta, Andrei Vasile; Rusu, Ioana Alexandra; Topala, Ionut


    Low temperature atmospheric pressure plasma devices are suitable experimental solutions to generate transitory molecular environments with various applications. In this study we present experimental results regarding the plasma chemistry of dielectric barrier discharges (DBD) in helium - hydrogen (0.1%) - hydrocarbons (1.2%) mixtures. Four types of hydrocarbon gases were studied: methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10). Discharge diagnosis and monitoring was assured by electrical measurements and optical emission spectroscopy. Molecular beam mass spectrometry is engaged to sample positive ions populations from two different plasma sources. Dissociation and generation of higher-chain and cyclic (aromatic) hydrocarbons were discussed as a function of feed gas and discharge geometry. We found a strong influence of these parameters on both molecular mass distribution and recombination processes in the plasma volume.

  18. In vitro reactivation potency of acetylcholinesterase reactivators--K074 and K075--to reactivate tabun-inhibited human brain cholinesterases. (United States)

    Kuca, Kamil; Cabal, Jiri; Jun, Daniel; Musilek, Kamil


    In this work, two oximes for the treatment of tabun-inhibited acetylcholinesterase (AChE; EC, K074 (1,4-bis(4-hydroxyiminomethylpyridinium)butane dibromide) and K075 ((E)-1,4-bis(4-hydroxyiminomethylpyridinium)but-2-en dibromide), were tested in vitro as reactivators of AChE. Comparison was made with currently used AChE reactivators (pralidoxime, HI-6, methoxime and obidoxime). Human brain homogenate was taken as an appropriate source of the cholinesterases. As resulted, oxime K074 appears to be the most potent reactivator of tabun-inhibited AChE, with reactivation potency comparable to that of obidoxime. A second AChE reactivator, K075, does not attain as great a reactivation potency as K074, although its maximal reactivation (17%) was achieved at relevant concentrations for humans.

  19. Minutes of the tenth meeting of the centers for the analysis of thermal/mechanical energy conversion concepts

    Energy Technology Data Exchange (ETDEWEB)

    DiPippo, R.


    The agenda, list of participants, and minutes of the meeting are presented. Included in the appendices are figures, data, outlines, etc. from the following presentations: 500 kW Direct-Contact Heat Exchanger Pilot Plant; LBL/EPRI Heat Exchanger Field Test, Critical Temperature and Pressure Comparisons for n-Butane/n-Pentane Mixtures; Second Law Techniques in the Correlation of Cost-Optimized Binary Power Plants; Outline of Chapter on Geothermal Well Logging; Outline and Highlights from Geothermal Drilling and Completion Technology Development Program Annual Progress: October 1979-September 1980; Geothermal Well Stimulation; World Update on Installed Geothermal Power Plants; Baca No. 1 Demonstration Flask Plant: Technical and Cost Data; Heber Binary Project; 45 mw Demonstration Plant; Raft River 5 mw Geothermal Dual-Boiling-Cycle Plant; Materials Considerations in the Design of Geothermal Power Plants; Raft River Brine Treatment for Tower Make-up; and Site Photographs of Raft River Valley.

  20. Effect of vorticity flip-over on the premixed flame structure: First experimental observation of type I inflection flames

    CERN Document Server

    El-Rabii, Hazem


    Premixed flames propagating in horizontal tubes are observed to take on shape convex towards the fresh mixture, which is commonly explained as a buoyancy effect. A recent rigorous analysis has shown, on the contrary, that this process is driven by the balance of vorticity generated by a curved flame front with the baroclinic vorticity, and predicted existence of a regime in which the leading edge of the flame front is concave. We report first experimental realization of this regime. Our experiments on ethane and n-butane mixtures with air show that flames with an inflection point on the front are regularly produced in lean mixtures, provided that a sufficiently weak ignition is used. The observed flame shape perfectly agrees with the theoretically predicted.

  1. Conditional solvation of isoleucine in model extended and helical peptides: context dependence of hydrophobic hydration and the failure of the group-transfer model

    CERN Document Server

    Tomar, Dheeraj; Pettitt, B M; Asthagiri, D


    The hydration thermodynamics of the GXG tripeptide relative to the reference GGG defines the \\textit{conditional} hydration contribution of X. This quantity or the hydration thermodynamics of a small molecule analog of the side-chain or some combination of such estimates, have anchored the interpretation of many of the seminal experiments on protein stability and folding and in the genesis of the current views on dominant interactions stabilizing proteins. We show that such procedures to model protein hydration have significant limitations. We study the conditional hydration thermodynamics of the isoleucine side-chain in an extended pentapeptide and in helical deca-peptides, using as appropriate an extended penta-glycine or appropriate helical deca-peptides as reference. Hydration of butane in the gauche conformation provides a small molecule reference for the side-chain. We use the quasichemical theory to parse the hydration thermodynamics into chemical, packing, and long-range interaction contributions. The...

  2. Fabrication and Characterisation of Oil-Free Large Bakelite Resistive Plate Chamber

    CERN Document Server

    Ganai, Rajesh; Agarwal, Kshitij; Ahammed, Zubayer; Choudhury, Subikash; Chattopadhyay, Subhasis


    A large (240 cm $\\times$ 120 cm $\\times$ 0.2 cm) oil-free bakelite Resistive Plate Chamber (RPC) has been developed at VECC-Kolkata using locally available P-301 OLTC grade bakelite paper laminates. The chamber has been operated in streamer mode using Argon, Freon(R134a) and Iso-butane in a ratio of 34:57:9 by volume. The electrodes and glue samples were characterised by measuring their electrical parameters like bulk resistivity and surface resistivity. The performance of the chamber was studied by measuring the efficiency, time resolution and uniformity in detection of cosmic muons. The chamber showed an efficiency $>$95$\\%$ and time resolution ($\\sigma$) of $\\sim$0.83 ns. Details of the material characterisation, fabrication procedure and performance studies have been discussed.

  3. Light alkane conversion processes - Suprabiotic catalyst systems for selective oxidation of light alkane gases to fuel oxygenates

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.


    The objective of the work presented in this paper is to develop new, efficient catalysts for the selective transformation of the light alkanes in natural gas to alcohols for use as liquid transportation fuels, fuel precursors and chemical products. There currently exists no DIRECT one-step catalytic air-oxidation process to convert these substrates to alcohols. Such a one-step route would represent superior useful technology for the utilization of natural gas and similar refinery-derived light hydrocarbon streams. Processes for converting natural gas or its components (methane, ethane, propane, and the butanes) to alcohols for use as motor fuels, fuel additives or fuel precursors will not only add a valuable alternative to crude oil but will produce a clean-burning, high octane alternative to conventional gasoline.

  4. Light alkane conversion processes - Suprabiotic catalyst systems for selective oxidation of light alkane gases to fuel oxygenates.

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.


    The objective of the work presented in this paper is to develop new, efficient catalysts for the selective transformation of the light alkanes in natural gas to alcohols for use as liquid transportation fuels, fuel precursors and chemical products. There currently exists no DIRECT one-step catalytic air-oxidation process to convert these substrates to alcohols. Such a one-step route would represent superior useful technology for the utilization of natural gas and similar refinery-derived light hydrocarbon streams. Processes for converting natural gas or its components (methane, ethane, propane, and the butanes) to alcohols for use as motor fuels, fuel additives or fuel precursors will not only add a valuable alternative to crude oil but will produce a clean-burning, high octane alternative to conventional gasoline.

  5. Experimental and theoretical studies on a novel helical architecture driven by hydrogen and halogen bonding interactions

    Indian Academy of Sciences (India)



    A novel two-dimensional (2D), layered, helical supramolecular architecture constructed via cooperative hydrogen bond and halogen bonds was synthesized and characterized: [(BMBA)₂(TPB)]n (1) [BMBA= 3-bromo-2-methylbenzoic acid, TPB = 1,2,3,4-tetra-(4-pyridyl)-butane]. Density functional theory (DFT) calculations were carried out to investigate the nature of intermolecular interactions between BMBA and TPB. The cooperation between hydrogen bond and halogen bond in building up the open organic architecture was demonstrated elaborately. Complex 1 exhibits strong photoluminescence and high thermal stability. The nature of electronic transitions in the photoluminescent process was investigated by means of time-dependent DFT (TDDFT) calculations and molecular orbital analyses, revealing that the luminescent property of the helical supramolecular architecture of 1 was ligand-based. Periodic DFT calculations show that 1 is an electrical insulator with a band gap of 3.29 eV.

  6. Catalytic ring opening of decalin. Biofunctional versus hydrogenolytic pathways

    Energy Technology Data Exchange (ETDEWEB)

    Weitkamp, J.; Rabl, S.; Haas, A.; Santi, D. [Stuttgart Univ. (Germany). Inst. of Chemical Technology; Ferrari, M.; Calemma, V. [Eni R and M Div., San Donato Milanese (Italy)


    Ir/silica, Pt/La-X and Rh/H-Beta were prepared and tested in the hydroconversion of cisdecalin at different temperatures. The catalytic tests were carried out under hydrogen in a high-pressure flow-type apparatus at 5.2 MPa. On the three catalysts open-chain decane yields up to 20 % were achieved, which is much higher than the yields reported so far in the literature. Pt/La-X and Rh/H-Beta behave as bifunctional catalysts with a high tendency for skeletal isomerization. On these catalysts the so-called paring reaction via carbenium ions occurs, leading to iso-butane and methylcyclopentane as main hydrocracked products. On Ir/SiO{sub 2}, carbon-carbon bond cleavage occurs through hydrogenolysis on the noble metal without prior isomerization. As a consequence the product spectrum is less complex than on the bifunctional catalysts which makes the system particularly amenable to mechanistic studies. (orig.)

  7. Adsorption and hydrogenation of simple alkenes at Pt-group metal electrodes studied by DEMS: influence of the crystal orientation (United States)

    Müller, Ulrich; Schmiemann, Udo; Dülberg, Andreas; Baltruschat, Helmut


    The adsorption of ethene and cyclohexene on mono-and polycrystalline Pt and on polycrystalline Pd electrodes was studied using differential electrochemical mass spectrometry (DEMS). Both molecules are partially hydrated to an oxygen containing species upon adsorption on Pt. In the case of ethene, this species dissociated to methane and adsorbed CO at negative potentials. Another part of the adsorbed ethene can be cathodically desorbed as ethane and butane. The ratio of the various species formed strongly depends on crystal orientation and adsorption potential. Contrary to heterogenous gas phase hydrogenation (and also contrary to some earlier reports on electrochemical hydrogenation), the rate of the Faradaic hydrogenation reaction is also strongly dependent on the crystallographic orientation, being faster on Pt(110) or roughened surfaces. During hydrogenation, H/D exchange occurs to an appreciable degree, suggesting the participation of adsorbed intermediates.

  8. Chemical reduction of complex kinetic models of combustion; Reduction chimique des modeles cinetiques complexes de combustion

    Energy Technology Data Exchange (ETDEWEB)

    Fournet, R.; Glaude, P.A.; Warth, V.; Battin-Leclerc, F.; Scacchi, G.; Come, G.M. [Institut National Polytechnique de Lorraine, Ecole Nationale Superieure des Industries Chimiques, CNRS UMR 7630, INPL ENSIC, Dept. de Chimie Physique des Reacteurs, 54 - Nancy (France)


    This paper presents an automatized method allowing to notably reduce the size of the primary mechanism of alkane combustion. The free radicals having the same raw formulation and the same functional groups are presented in a global way as a unique species. In this way, the number of radicals can be divided by a factor of 16 in the case of n-heptane combustion. The kinetic parameters linked with the global mechanism are obtained from a weighted average of the kinetic constants of the detailed mechanism, and this without any adjustment.The simulations performed for the combustion mechanisms of the n-heptane and of a mixture of n-heptane and 2,2,3 trimethyl butane are presented in order to show the validity of the proposed method. (J.S.)

  9. Performance investigation of a waste heat driven pressurized adsorption refrigeration cycle (United States)

    Habib, K.


    This article presents performance investigation of a waste heat driven two bed pressurised adsorption refrigeration system. In this study, highly porous activated carbon (AC) of type Maxsorb III has been selected as adsorbent while n-butane, R-134a, R410a, R507a and carbon dioxide (CO2) are chosen as refrigerants. All the five refrigerants work at above atmospheric pressure. Among the five pairs studied, the best pairs will be identified which will be used to provide sufficient cooling capacity for a driving heat source temperature above 60°C. Results indicate that for a driving source temperature above 60°C, AC-R410a pair provides highest cooling capacity while AC-CO2 pairs works better when the heat source temperature falls below 60°C.

  10. Novel sensing approach for LPG leakage detection: Part I: Operating Mechanism and Preliminary Results

    KAUST Repository

    Mukhopadhyay, Subhas


    Gas sensing technology has been among the topical research work for quite some time. This paper showcases the research done on the detection mechanism of leakage of domestic cooking gas at ambient conditions. MEMS-based interdigital sensors were fabricated on oxidized single crystal silicon surfaces by maskless photolithography technique. The electrochemical impedance analysis of these sensors was done to detect liquefied petroleum gas (LPG) with and without coated particles of tin oxide (SnO2) in form of thin layer.A thin-film of SnO2 was spin-coated on the sensing surface of the interdigital sensor to induce selectivity to LPG that consists of a 60/40 mixture of propane and butane respectively. The paper reports a novel strategy for gas detection under ambient temperature and humidity conditions. The response time of the coated sensor was encouraging and own a promising potential to the development of a complete efficient gas sensing system.

  11. A mounded spherical storage tank at Papeete; Une sphere sous talus a Papeete

    Energy Technology Data Exchange (ETDEWEB)



    Because demand for liquid petroleum gas (LPG) in French Polynesia is burgeoning, deliveries of the product are on the rise, in particular from New Zealand. In consideration of this, Gaz de Tahiti has had a mounded 1.800 m{sup 3} spherical propane storage tank built by the Tissot group. The new tank joins the ranks of the standard 2.500 m{sup 3} spherical butane tank that Gaz de Tahiti already has at its Papeete site. The slope consists of earth-filled gabions, which are at least one metre thick at any point of the steel structure. The project is proof once again that Gaz de Tahiti has no reason to envy European companies when it comes to technology and development. (authors)

  12. A high-throughput method for the quantification of proanthocyanidins in forage crops and its application in assessing variation in condensed tannin content in breeding programmes for Lotus corniculatus and Lotus uliginosus. (United States)

    Marshall, Athole; Bryant, David; Latypova, Galina; Hauck, Barbara; Olyott, Phil; Morris, Phillip; Robbins, Mark


    Lotus corniculatus and Lotus uliginosus are agronomically important forage crops used in ruminant livestock production. The condensed tannin (CT) content, dry matter (DM) production, and persistence of these species are key characteristics of interest for future exploitation of these crops. Here we present field data on 19 varieties of L. corniculatus, 2 varieties of L. uliginosus and, additionally, a glasshouse experiment using 6 varieties of L. corniculatus and 2 varieties of L. uliginosus. Current methods for the quantification of condensed tannins in crop species are slow and labor intensive and are generally based upon polymer hydrolysis following the extraction of chlorophyll in a liquid phase. Presented here is a high-throughput protocol for condensed tannin quantification suitable for microtiter plates based upon the precipitation of condensed tannin polymers in complex with bovine serum albumin (BSA) with subsequent hydrolysis of precipates using butan 1-ol/ hydrochloric acid.

  13. SOFT ROBOTICS. A 3D-printed, functionally graded soft robot powered by combustion. (United States)

    Bartlett, Nicholas W; Tolley, Michael T; Overvelde, Johannes T B; Weaver, James C; Mosadegh, Bobak; Bertoldi, Katia; Whitesides, George M; Wood, Robert J


    Roboticists have begun to design biologically inspired robots with soft or partially soft bodies, which have the potential to be more robust and adaptable, and safer for human interaction, than traditional rigid robots. However, key challenges in the design and manufacture of soft robots include the complex fabrication processes and the interfacing of soft and rigid components. We used multimaterial three-dimensional (3D) printing to manufacture a combustion-powered robot whose body transitions from a rigid core to a soft exterior. This stiffness gradient, spanning three orders of magnitude in modulus, enables reliable interfacing between rigid driving components (controller, battery, etc.) and the primarily soft body, and also enhances performance. Powered by the combustion of butane and oxygen, this robot is able to perform untethered jumping.

  14. Energy from forests in the countries of the Congo Basin; L'energie forestiere dans les pays du bassin du Congo

    Energy Technology Data Exchange (ETDEWEB)

    Boundzanga, G.C. [Centre National d' Inventaire et d' Amenagement des Ressources Forestieres et Fauniques du Zaire (Zaire); Loumeto, J. [Brazzaville Univ., Brazzaville (Congo, The Democratic Republic of the). Faculty of Science


    Deforestation and overexploitation of timber in the forests of the Congo Basin in Central Africa has resulted in environmental damage. This article listed the consumption of wood energy for Cameroon, the Central African Republic, Gabon, Republic of the Congo, Democratic Republic of the Congo, and Equatorial Guinea and emphasized the need to create a process to enable better management of forest resources by assigning more transparent concessions and establishing standards for the regeneration of the forest. Wood energy continues to be used in urban centres despite advances being made to promote the use of butane gas. As such, the ecological damage is visible in densely populated areas despite the fact that vast amounts of land would be well suited for tree plantations. 2 refs., 1 tab., 2 figs.

  15. Synthesis and Characterization of Poly BAMO Suitable for Binder Application%BAMO聚合物的合成与表征

    Institute of Scientific and Technical Information of China (English)

    M.V.Maheshkumar; M.J.Joseph; K.Sreekumar; H-G.Ang


    A new synthetic methodology has been developed for the synthesis of poly BAMO and poly BAMO-co-THF with controlled molecular weight and narrow molecular weight distribution. The synthesis of BCMO,the precursor of the BAMO monomer was accomplished using the reaction of Vilsmeir reagent with pentaerythritol. The BAMO monomer could be synthesized with an over all yield of 60% and polymerized using BF3·Et2O as the initiator and 1,4-butane diol as the co-initiator. Computational evaluation of the energy releasing properties of the poly BAMO derivatives was performed using Gaussian algorithm. The theoretically calculated values agreed very well with the experimentally determined ones.

  16. Calorimetric Determination of Enthalpy of Formation of Natural Gas Hydrates%天然气水合物生成焓的实验研究

    Institute of Scientific and Technical Information of China (English)


    This paper reports the measurements of enthalpies of natural gas hydrates in typical natural gas mixturecontaining methane, ethane, propane and iso-butane at pressure in the vicinity of 2000 kPa (300 psi) and 6900 kPa(1000psi). The measurements were made in a multi-cell differential scanning calorimeter using modified highpressure cells. The enthalpy of water and the enthalpy of dissociation of the gas hydrate were determined fromthe calorimeter response during slow temperature scanning at constant pressure. The amount of gas released fromthe dissociation of hydrate was determined from the pumped volume of the high pressure pump. The occupationratio (mole ratio) of the water to gas and the enthalpy of hydrate formation are subject to uncertainty of 1.5%.The results show that the enthalpy of hydrate formation and the occupation ratio are essentially independent of pressure.

  17. Calorimetric Determination of Enthalpy of Formation of Natural Gas Hydrates

    Institute of Scientific and Technical Information of China (English)

    高军; KennethN.Marsh


    This paper reports the measurements of enthalpies of natural gas hydrates in typical natural gas mixture containing methane, ethane, propane and iso-butane at pressure in the vicinity of 2000 kPa (300 psi) and 6900 kPa(1000psi). The measurements were made in a multi-cell differential scanning calorimeter using modified high pressure cells. The enthalpy of water and the enthalpy of dissociation of the gas hydrate were determined from the calorimeter response during slow temperature scanning at constant pressure. The amount of gas released from the dissociation of hydrate was determined from the pumped volume of the high pressure pump. The occupation ratio (mole ratio) of the water to gas and the enthalpy of hydrate formation are subject to uncertainty of 1.5%.The results show that the enthalpy of hydrate formation and the occupation ratio are essentially independent of pressure.

  18. Silicon Based Solid Oxide Fuel Cell Chip for Portable Consumer Electronics -- Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Alan Ludwiszewski


    LSI’s fuel cell uses efficient Solid Oxide Fuel Cell (“SOFC”) technology, is manufactured using Micro Electrical Mechanical System (“MEMS”) fabrication methods, and runs on high energy fuels, such as butane and ethanol. The company’s Fuel Cell on a Chip™ technology enables a form-factor battery replacement for portable electronic devices that has the potential to provide an order-of-magnitude run-time improvement over current batteries. Further, the technology is clean and environmentally-friendly. This Department of Energy funded project focused on accelerating the commercialization and market introduction of this technology through improvements in fuel cell chip power output, lifetime, and manufacturability.

  19. New series of aromatic/ five-membered heteroaromatic butanesulfonyl hydrazones as potent biological agents: Synthesis, physicochemical and electronic properties (United States)

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


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

  20. 合成角鲨烯的新方法%New Synthesis Method for Squalene

    Institute of Scientific and Technical Information of China (English)

    曾庆宇; 张剑平; 李小军; 王旭明; 石炼刚


    对角鲨烯的合成方法作出重要改进,新的合成路线包括以1,4-二氯丁烷为起始原料,经Arbuzov反应、wittig-horner反应合成角鲨烯。反应选择性好,副产物少,工艺较简单,操作方便。%The new synthesis method for Squalene was discussed. Using 1,4-dichloro-butane as the starting material, via Arbuzov reaction, Witting-horner reaction, Squalene was obtained. The new method has advantages such as high reaction selectivity, less by-product, simple process and easy control.

  1. Performance Analysis of Supercritical Binary Geothermal Power Plants

    Directory of Open Access Journals (Sweden)

    Ahmet Dagdas


    Full Text Available It is possible to generate electricity by utilizing medium-temperature geothermal sources in various closed cycles. These geothermal power plants are very important and valuable as they utilize the sources which have low exergy. In recent years, medium-temperature sources that are around 150°C are used widely for electricity generation. In this study, performance of a supercritical binary power plant, that uses such a geothermal source, is analyzed to find the optimum turbine inlet pressure that maximizes power generation. In this power plant different working fluids are analyzed to find the appropriate fluid that maximizes power generation and efficiency. The observed working fluids are R134a, isobutane, R404a, n-Butane, and R152a. The performance of the plant is calculated with these fluids separately and it is found that the best fluid for performance is R152a for pure fluid and R404a for mixture fluid.

  2. Isomorphic Viscosity Equation of State for Binary Fluid Mixtures. (United States)

    Behnejad, Hassan; Cheshmpak, Hashem; Jamali, Asma


    The thermodynamic behavior of the simple binary mixtures in the vicinity of critical line has a universal character and can be mapped from pure components using the isomorphism hypothesis. Consequently, based upon the principle of isomorphism, critical phenomena and similarity between P-ρ-T and T-η-(viscosity)-P relationships, the viscosity model has been developed adopting two cubic, Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR), equations of state (EsoS) for predicting the viscosity of the binary mixtures. This procedure has been applied to the methane-butane mixture and predicted its viscosity data. Reasonable agreement with the experimental data has been observed. In conclusion, we have shown that the isomorphism principle in conjunction with the mapped viscosity EoS suggests a reliable model for calculating the viscosity of mixture of hydrocarbons over a wide pressure range up to 35 MPa within the stated experimental errors.

  3. Synthesis and Characterization of Sulfonated Graphene Oxide Nanofiller for Polymer Electrolyte Membrane (United States)

    Ch'ng, Y. Y.; Loh, K. S.; Daud, W. R. W.; Mohamad, A. B.


    In this study, sulfonated graphene oxide (SGO) nanocomposite were produced as potential nanofiller to improve the properties of polymer electrolyte membrane (PEM) for fuel cell applications. The GO is produced by modified Hummers's method and the as-synthesized GO was used to prepare SGO with three distinctive precursors, namely 3- mercaptomethoxysilane (MPTMS), sulfanilic acid (SA) and butane sultone (BS). The SGO samples were characterized with several physical characterization techniques (XRD, FTIR, SEM-EDX and XPS) to provide the insights into the morphology; the state of homogenization; the crystallography and the functional groups. The experimental result indicated that the sulfonic acid group has been successfully incorporated with GO and can be used as filler in PEM.

  4. Carbon mediated catalysis:A review on oxidative dehydrogenation

    Institute of Scientific and Technical Information of China (English)

    De Chen; Anders Holmen; Zhijun Sui; Xinggui Zhou


    Carbon mediated catalysis has gained an increasing attention in both areas of nanocatalysis and nanomaterials. The progress in carbon nanomaterials provides many new opportunities to manip-ulate the types and properties of active sites of catalysts through manipulating structures, function-alities and properties of carbon surfaces. The present review focuses on progresses in carbon medi-ated oxidative dehydrogenation reactions of ethylbenzene, propane, and butane. The state-of-the-art of the developments of carbon mediated catalysis is discussed in terms of fundamental studies on adsorption of oxygen and hydrocarbons, reaction mechanism as well as effects of carbon nano-material structures and surface functional groups on the catalytic performance. We highlight the importance and challenges in tuning of the electron density of carbon and oxygen on carbon surfac-es for improving selectivity in oxidative dehydrogenation reactions.

  5. Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference. (United States)

    Kim, Youngmok; Lee, Kwang-Geun; Kim, Mina K


    Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164 mg/L), in comparison to later harvested green teas (11,961 mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

  6. A new approach to the non-oxidative conversion of gaseous alkanes in a barrier discharge and features of the reaction mechanism (United States)

    Kudryashov, S.; Ryabov, A.; Shchyogoleva, G.


    A new approach to the non-oxidative conversion of C1-C4 alkanes into gaseous and liquid products in a barrier discharge is proposed. It consists in inhibiting the formation of deposits on the reactor electrode surfaces due to the addition of distilled water into the flow of hydrocarbon gases. The energy consumption on hydrocarbon conversion decreases from methane to n-butane from ~46 to 35 eV molecule-1. The main gaseous products of the conversion of light alkanes are hydrogen and C2-C4 hydrocarbons. The liquid reaction products contain C5+ alkanes with a predominantly isomeric structure. The results of modeling the kinetics of chemical reactions show that an increase in the molecular weight of the reaction products is mainly due to processes involving CH2 radical and the recombination of alkyl radicals.

  7. Beowawe Bottoming Binary Unit - Final Technical Report for EE0002856

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Dale Edward


    This binary plant is the first high-output refrigeration based waste heat recovery cycle in the industry. Its working fluid is environmentally friendly and as such, the permits that would be required with a butane based cycle are not necessary. The unit is modularized, meaning that the unit’s individual skids were assembled in another location and were shipped via truck to the plant site. This project proves the technical feasibility of using low temperature brine The development of the unit led to the realization of low temperature, high output, and environmentally friendly heat recovery systems through domestic research and engineering. The project generates additional renewable energy for Nevada, resulting in cleaner air and reduced carbon dioxide emissions. Royalty and tax payments to governmental agencies will increase, resulting in reduced financial pressure on local entities. The major components of the unit were sourced from American companies, resulting in increased economic activity throughout the country.

  8. A set of molecular models based on quantum mechanical ab initio calculations and thermodynamic data

    CERN Document Server

    Eckl, Bernhard; Hasse, Hans


    A parameterization strategy for molecular models on the basis of force fields is proposed, which allows a rapid development of models for small molecules by using results from quantum mechanical (QM) ab initio calculations and thermodynamic data. The geometry of the molecular models is specified according to the atom positions determined by QM energy minimization. The electrostatic interactions are modeled by reducing the electron density distribution to point dipoles and point quadrupoles located in the center of mass of the molecules. Dispersive and repulsive interactions are described by Lennard-Jones sites, for which the parameters are iteratively optimized to experimental vapor-liquid equilibrium (VLE) data, i.e. vapor pressure, saturated liquid density, and enthalpy of vaporization of the considered substance. The proposed modeling strategy was applied to a sample set of ten molecules from different substance classes. New molecular models are presented for iso-butane, cyclohexane, formaldehyde, dimethyl...

  9. A novel triterpenoid carbon skeleton in immature sulphur-rich sediments

    Energy Technology Data Exchange (ETDEWEB)

    Schouten, S.; Sinninghe Damste, J.S.; De Leeuw, J.W. [Netherlands Inst. for Sea Research (NIOZ), Texel (Netherlands)


    A novel S compound, 1,4-bis(2{sup {prime}}, 5{sup {prime}}, 5{sup {prime}}, 8a{sup {prime}}-tetramethylhexahydrothiochroman)-butane has been detected in several immature S-rich sediments, of which the desulphurized counterpart was unambiguously identified by synthesis of an authentic standard and coinjection experiments. This C skeleton of the S compound, 1, 10-bis(2{sup {prime}}, 2{sup {prime}}, 6{sup {prime}}-trimethylcyclohexyl)-3,8-dimethyldodecane(I), has not been reported yet in any sediment or organism. We suggest that it may be biosynthesized through an enzymatic cyclization reaction of squalene (II), which shows similarities with the biosynthesis of {Beta}, {Beta}-carotene (III) from lycopene (IV). 24 refs., 4 figs.

  10. Adsorption de polluants gazeux sur des filtres de charbon actif. Modélisation des échanges couples de matière et de chaleur


    Fiani, Emmanuel


    286 pages; No english abstract; Dans le cadre de la dépollution automobile, l'élimination de vapeurs d'essence et celle de molécules odorantes constituent les deux applications étudiées. L'étude thermodynamique et cinétique de la fixation de gaz représentatifs est effectuée sur des charbons actifs. 1. Sulfure d'hydrogène et n-butane sont choisis pour représenter les molécules odorantes. Différents charbons actif tissés sont considérés : Seul L'adsorbant imprégné par KOH présente des performan...


    CERN Document Server

    Niinikoski, T O


    The conceptual design of an evaporative two-phase flow cooling system for the ATLAS SCT detector is described, using perfluorinated propane (C3F8) as a coolant. Comparison with perfluorinated butane (C4F10) is made, although the detailed design is presented only for C3F8. The two-phase pressure drop and heat transfer coefficient are calculated in order to determine the dimensions of the cooling pipes and module contacts for the Barrel SCT. The region in which the flow is homogeneous is determined. The cooling cycle, pipework, compressor, heat exchangers and other main elements of the system are calculated in order to be able to discuss the system control, safety and reliability. Evaporative cooling appears to be substantially better than the binary ice system from the point of view of safety, reliability, detector thickness, heat transfer coefficient, cost and simplicity.

  12. Potent acetylcholinesterase inhibitory compounds from Myristica fragrans. (United States)

    Cuong, To Dao; Hung, Tran Manh; Han, Hyoung Yun; Roh, Hang Sik; Seok, Ji-Hyeon; Lee, Jong Kwon; Jeong, Ja Young; Choi, Jae Sue; Kim, Jeong Ah; Min, Byung Sun


    The anti-cholinesterase activity was evaluated of the ethyl acetate fraction of the methanol extract of Myristica fragrans Houtt (Myristicaceae) seeds and of compounds isolated from it by various chromatographic techniques. The chemical structures of the compounds were determined from spectroscopic analyses (NMR data). Thirteen compounds (1-13) were isolated and identified. Compound 8 { [(7S)-8'-(4'-hydroxy-3'-methoxyphenyl)-7-hydroxypropyl]benzene-2,4-diol) showed the most effective activity with an IC50 value of 35.1 microM, followed by compounds 2 [(8R,8'S)-7'-(3',4'-methylenedioxyphenyl)-8,8'-dimethyl-7-(3,4-dihydroxyphenyl)-butane] and 11 (malabaricone C) with IC50 values of 42.1 and 44.0 pM, respectively. This is the first report of significant anticholinesterase properties of M. fragrans seeds. The findings demonstrate that M. fragrans could be used beneficially in the treatment of Alzheimer's disease.

  13. Volatile compounds of dry-cured Iberian ham as affected by the length of the curing process. (United States)

    Ruiz, J; Ventanas, J; Cava, R; Andrés, A; García, C


    Volatile compounds from 10 dry-cured Iberian hams ripened for two different processing times, a prolonged traditional one (600 days) and a shortened process (420 days), were analysed by purge and trap coupled to gas chromatography-mass spectroscopy. Eighty-three compounds were identified which agreed with the major classes found in other ham types. The amount of methyl branched alkanes was much higher than in other dry-cured ham types, probably due to the feeding regime. The percentages of 2- and 3-methylbutanal were higher (p<0.0001 and p<0.0003, respectively) in the longer aged hams, whereas the amounts of some compounds from lipid oxidation decreased from 420 to 600 days aging. In agreement with these observations, 600-day hams had higher scores for those odour and flavour traits usually considered to be positive attributes and lower scores for rancidity. A positive and significant correlation between 2-methyl butanal and cured flavour was found.


    Directory of Open Access Journals (Sweden)

    Jozef KRAJŇÁK


    Full Text Available In our department has long been devoted specifically flexible pneumatic shaft couplings. These couplings are filled with a gaseous medium air. Examination, we found that the type of gas, its properties such as gas density, compressibility factor, molecular weight and viscosity alter dynamic properties pneumatic coupling. The main objective of this article is to determine how various gaseous media influences damping coefficient b. The article compares three different gases, air, helium and propane-butane. These gases have different properties and it can change damping coefficient b. The measurements are performed in the laboratories of our department in Košice. We used flexible one-bellow pneumatic coupling 4-1/70-T-C and two-bellows pneumatic coupling 4-2/70-T-C. Pressure gaseous medium was varied in the range of 100 to 600kPa.

  15. Catalytic cracking of the C5+ fraction of natural gasoline using HZSM-5 zeolite; Craqueamento catalitico de uma fracao de C5+ do GN utilizando a zeolita HZSM-5

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Marcelo J.B.; Silva, Antonio O.S. [Rio Grande do Norte Univ., Natal, RN (Brazil). Dept. de Engenharia Quimica]. E-mail:; Fernandes Junior, Valter J.; Araujo, Antonio S. [Rio Grande do Norte Univ., Natal, RN (Brazil). Dept. de Quimica


    In this work was realized a study of the catalytic cracking of the C5+ fraction from Polo of Guamare (RN) over acid the HZSM-5 zeolite. The ZSM-5 zeolite was synthesized by hydrothermal crystallization with subsequent, filtering, washing and calcination to obtain the sodium form (NaZSM-5). To obtain the acidic form (HZSM-5), the NaZSM-5 zeolite was submitted to ion exchange with ammonium chloride solution. The obtained material was characterized by x ray diffraction, infrared spectroscopy, atomic absorption spectrophotometry and acidity via TG/DTG. The catalytic cracking reactions of the C5+ feedstock were performed in a fixed bed continuous flow reactor and the reaction products were analyzed in a gas chromatography coupled in a mass spectrometer (GC/MS). The obtained result shown the formation of high aggregate value hydrocarbons as: LPG (propane and butane) and industrial gas (ethane and ethene). (author)

  16. An UV Vis spectroscopic study on carbenium ions formed on HY FAU zeolite upon the adsorption of various hydrocarbons (United States)

    Kiricsi, I.; Pálinkó, I.; Kollár, T.


    It was shown that adsorbed hydrogen-rich carbonaceous residues could be formed on zeolites, but, when the temperature was not too high, they were typical only for unsaturated hydrocarbons. The overlayer then mainly contained alkenyl carbenium ions of various length. They were detected on the zeolite surface by UV-Vis spectroscopy. In the formation of these ions both Brønsted and Lewis acid centres played significant role. The unsaturated carbenium ions provided additional Lewis acid sites participating in hydride ion abstraction. The formation of alkenyl carbenium ions started at temperature as low as 298 K for butadiene. When n-butane, a saturated hydrocarbon, was the model, adsorbed hydrogen-rich carbonaceous residues were not found even at adsorption temperature as high as 473 K.

  17. Entamoeba histolytica HM1:IMSS: hemoglobin-degrading neutral cysteine proteases. (United States)

    Serrano-Luna, J J; Negrete, E; Reyes, M; de la Garza, M


    Entamoeba histolytica HMI:IMSS trophozoites were able to utilize human hemoglobin but not hemin as a sole iron source to grow in vitro. Proteases from crude extracts of E. histolytica degraded human, porcine, and bovine hemoglobins at pH 7.0. These proteolytic activities were found by electrophoresis in SDS-polyacrylamide gels copolymerized with hemoglobin, with apparent molecular weights of 116, 82, and 21 kDa, the 82-kDa protein being the most active protease against this substrate. The proteases were classified in the cysteine group since the activities were inhibited by l-trans-epoxysuccinylleucylamido(4-guanidino)butane, p-hydroxymercuribenzoate, iodoacetate, and N-ethylmaleimide and activated with dithiothreitol. Other pathogenic strains of E. histolytica showed the same pattern of hemoglobinases. These hemoglobin-degrading proteases could be playing an important role in iron acquisition by E. histolytica.

  18. On the chemical composition of Titan's dry lakebed evaporites

    CERN Document Server

    Cordier, Daniel; Ferreira, Abel


    Titan, the main satellite of Saturn, has an active cycle of methane in its troposphere. Among other evidence for a mechanism of evaporation at work on the ground, dry lakebeds have been discovered. Recent Cassini infrared observations of these empty lakes have revealed a surface composition poor in water ice compared to that of the surrounding terrains --- suggesting the existence of organic evaporites deposits. The chemical composition of these possible evaporites is unknown. In this paper, we study evaporite composition using a model that treats both organic solids dissolution and solvent evaporation. Our results suggest the possibility of large abundances of butane and acetylene in the lake evaporites. However, due to uncertainties of the employed theory, these determinations have to be confirmed by laboratory experiments.

  19. Computer monitors natural-gas-liquids line

    Energy Technology Data Exchange (ETDEWEB)

    Muldoon, J.F.; Wilson, W.O.


    A new computer-based system continuously monitors composition, flow, and specific gravity of natural-gas liquids flowing in a pipeline. Compositional analysis is performed automatically, under computer control, by a process gas chromatograph. The chromatograph is tailored for hydrocarbon analysis and will separate these compounds into individual components: nitrogen, carbon dioxide, methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, 1-hexane, 2-hexane, 3-hexane, 4-hexane, and heptanes-and-heavier. At the completion of the analysis, the compositional totals, barrels, and pounds, are updated based on flow and average specific gravity. Reports generated include a compositional report, a subtotal ticket report, and a ticket report. The new system, designated Pro-PACE-100, has been successfully installed in several pipeline applications, including one for Mid-America Pipeline Co. in New Mexico.

  20. Studies on the key odorants formed by roasting of wild mango seeds (Irvingia gabonensis). (United States)

    Tairu, A O; Hofmann, T; Schieberle, P


    Application of the aroma extract dilution analysis on a concentrate of volatiles obtained by solvent extraction and high vacuum distillation from roasted seeds (180 degrees C; 15 min) of wild mango (Irvingia gabonensis) revealed 32 odor-active compounds with flavor dilution (FD) factors ranging from 8 (low odor activity) to 2048 (high odor activity). The identification experiments based on the use of reference odorants revealed methional (cooked potato-like) followed by 2-acetyl-1-pyrroline (roasty, popcorn-like), butan-2,3-dione, pentan-2,3-dione, 2-ethyl-3,5-dimethylpyrazine, and 2,3-diethyl-5-methylpyrazine as the key aroma compounds among the 27 odorants identified. All odorants are reported for the first time as components of roasted wild mango seeds.

  1. Electric energy generation using biomass gasification; Generacion de energia electrica a partir de la gasificacion de biomassa

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, J.; Arauzo, J.; Gonzalo, Alberto; Sanchez, Jose Luis [Universidad de Zaragoza, Aragon (Spain). Inst. de Investigacion. Grupo de Procesos Termoquimicos; Rocha, J.D. [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico (NIPE); Mesa Perez, J.M. [Bioware Tecnologia, Campinas, SP (Brazil)


    Gasification experiments have been carried out with a atmospheric pressure down draft gasifier of a capacity of 250 kg/h of biomass. Biomass used have been almond shells and olive cut. Results obtained show a similar behaviour in gas composition with two biomass. A small fraction of the generated gas from the gasifier has been fed to a small generator of 4 kV A. The gas has been previously cleaned and dried by means of a scrubber and a condenser, to remove tar products. The generator has been operated with a great stability without any modification, and energy generated with gas from gasification are relatively close to the values obtained with conventional fuels such as gasoline or commercial butane. (author)

  2. (η5-Pentamethylcyclopentadienyl(η6-4-phenylbutan-2-oneruthenium(II tetraphenylborate

    Directory of Open Access Journals (Sweden)

    Bradley T. Loughrey


    Full Text Available The title compound, [Ru(C10H15(C10H12O][B(C6H54], crystallizes as discrete (η5-pentamethylcyclopentadienylRu(η6-4-phenylbutan-2-one]+ cations and [BPh4]− anions. In the cation, the non-H atoms of the butan-2-one group are approximately planar (r.m.s. deviation = 0.056 Å and lie nearly perpendicular to the plane of the phenyl ring with a dihedral angle between the two planes of 69.3 (1°. No significant C—H...O interactions are observed between the methyl and phenyl H atoms and the carbonyl O atom.

  3. Bioenvironmental Engineer’s Guide to TVA-1000B Toxic Vapor Analyzer (United States)


    Ethene 10.52 1,1-Dibromoethane 10.19 Diethyl amine 8.01 Ethyl acetate 10.11 1,1-Dichloroethane 11.12 Diethyl ether 9.53 Ethyl alcohol 10.48 1,1...chloroethane) 10.98 1,2-Dichloroethane 11.12 Dihydropyran 8.34 Ethyl disulfide 8.27 1,2-Dichloropropane 10.87 Diiodomethane 9.34 Ethyl ether 9.51 1,3...butane 10.06 Dimethyl amine 8.24 Ethyl isothiocyanate 9.14 2,2-Dimethyl propane 10.35 Dimethyl ether 10.00 Ethyl mercaptan 9.29 2,3-Dichloropropene

  4. Pollution characteristic of VOCs of ambient air in winter and spring in Shijiazhuang City

    Directory of Open Access Journals (Sweden)

    Qing CHANG


    Full Text Available In order to further explore the pollution characteristics of volatile organic compounds in ambient air in winter and spring in Shijiazhuang City, the pollution characteristics of 62 volatile organic compounds (VOCs, monthly and quarterly variation, the correlation between VOCs and PM2.5, and the main sources of VOCs are investigated by using EPA TO-15 method. It shows that 40 organic compounds of the 64 VOCs have been quantitatively determined in winter and spring in the city, which are mainly acetone, benzene, carbon tetrachloride, dichloromethane, toluene, ethyl acetate, etc.. In the no-quantitatively determined components, higher ethanol, butyl acetate, butane etc. are detected. The VOCs concentration has positive correlation with the PM2.5 concentration during haze days.

  5. From waste molecules to consumer products : upgrader and refinery off-gases processing on the rise in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Bentein, J.


    Only two companies process off-gases from bitumen upgraders in Alberta: Williams Energy Canada and Aux Sable Canada LP. Their projects, one at the Suncor plant north of Fort McMurray and the other at the Scotford complex near Edmonton, are designed to convert the streams into value-added petrochemical and fuel feedstock. In 2002, Williams built a cryogenic liquids extraction unit at the Suncor plant and a fractioning and distribution facility near Redwater, Alberta, which processes off-gases into liquid propane, propylene, condensates, butane, and butylenes. An expansion to the Redwater processing plant will allow for the upgrading of butane and butylene components as well as octane. Williams wants to build extraction units at two upgraders near Fort McMurray and is working with the Alberta Government to attract a petrochemical plant to Alberta that can process propylene, which must be exported at present. Aux Sable will process off-gases to produce hydrogen, ethane, and a propane-plus mix. Processing off-gases substantially reduces carbon dioxide and sulfur dioxide emissions from upgraders. Off-gas has the potential to be a new feedstock supply for the petrochemical industry in Alberta. The volumes processed by Williams are olephenic, whereas the volumes processed by Aux Sable are paraffinic, but both companies take molecules that would otherwise become atmospheric carbon dioxide and turn them into plastic for consumer goods. The off-gas projects are being driven by market forces without government incentives. Low natural gas prices have made it economical for upgraders to use more gas and sell off-gases for value-added use. 1 fig.

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

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


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

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

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


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

  8. Variability analyses, site characterization, and regional [OH] estimates using trace gas measurements from the NOAA Global Greenhouse Gas Reference Network

    Directory of Open Access Journals (Sweden)

    Jan Pollmann


    Full Text Available Abstract Trace gas measurements from whole air samples collected weekly into glass flasks at background monitoring sites within the NOAA Global Greenhouse Gas Reference Network program (with most of the sites also being World Meteorological Organization (WMO Global Atmospheric Watch (GAW stations were used to investigate the variability-lifetime relationship for site characterization and to estimate regional and seasonal OH concentrations. Chemical species considered include the atmospheric trace gases CO, H2, and CH4, as well as the non-methane hydrocarbons (NMHC ethane (C2H6, propane (C3H8, i-butane (i-C4H10, and n-butane (n-C4H10. The correlation between atmospheric variability and lifetime was applied on a global scale spanning 42 sites with observations covering a period of 5 years. More than 50,000 individual flask measurement results were included in this analysis, making this the most extensive study of the variability-lifetime relationship to date. Regression variables calculated from the variability-lifetime relationship were used to assess the “remoteness” of sampling sites and to estimate the effect of local pollution on the measured distribution of atmospheric trace gases. It was found that this relationship yields reasonable results for description of the site remoteness and local pollution influences. Comparisons of seasonal calculated OH concentrations ([OH] from the variability-lifetime relationships with six direct station measurements yielded variable agreement, with deviations ranging from ∼20% to a factor of ∼2–3 for locations where [OH] monitoring results had been reported. [OH] calculated from the variability-lifetime relationships was also compared to outputs from a global atmospheric model. Resutls were highly variable, with approximately half of the sites yielding agreement to within a factor of 2–3, while others showed deviations of up to an order of magnitude, especially during winter.

  9. Experimental Study of MHD-Assisted Mixing and Combustion Under Low Pressure Conditions (United States)

    Gao, Ling; Zhang, Bailing; Li, Yiwen; Fan, Hao; Duan, Chengduo; Wang, Yutian


    In order to reveal the mechanism of MHD-assisted mixing, and analyse the major parameters which influence the effect of MHD-assisted mixing, experiments of MHD-assisted mixing are carried out with a non-premixed butane-air combustion system. The evolvement of the discharge section and the effect of MHD-assisted mixing on combustion are investigated by changing the magnetic flux density and airflow velocity. The results show that the discharge area not only bends but also rotates around the centered wire electrode, which are mainly caused by the Lorentz force. Moreover, the highest curvature occurs near the centered wire electrode. The discharge localizes near the surface of the wire electrode and annular electrode when there is no ponderomotive force. However, if the ponderomotive force is applied, the discharge happens between these two electrodes and it gradually shrinks with time. The discharge area cannot localize near the annular electrode, which is due to the increase of energy loss in the airflow. When the airflow velocity exceeds a certain value, the discharge section becomes unstable because the injected energy cannot maintain the discharge. The rotation motion of the discharge section could enlarge the contact surface between butane and air, and is therefore beneficial for mixing and combustion. Magnetic flux density and airflow velocity are critical parameters for MHD-assisted mixing. supported by National Natural Science Foundation of China (No. 11372352) and the Mechanism Research on Near Electrode Thermal-Electromagnetic-Flow of High Temperature Supersonic MHD Generation (No. 51306207), and Natural Science Foundation of Shaanxi Province of China (No. 2015JM5184)

  10. Development and validation of a liquid chromatographic method for the stability study of a pharmaceutical formulation containing voriconazole using cellulose tris(4-chloro-3-methylphenylcarbamate) as chiral selector and polar organic mobile phases. (United States)

    Servais, Anne-Catherine; Moldovan, Radu; Farcas, Elena; Crommen, Jacques; Roland, Isabelle; Fillet, Marianne


    The ophthalmic solution of voriconazole, i.e. (2R,3S)-2-(2,4-difluorophenyl)-3-(5-fluoropyrimidin-4-yl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol, made from an injection formulation which also contains sulfobutylether-β-cyclodextrin sodium salt as an excipient (Vfend), is used for the treatment of fungal keratitis. A liquid chromatographic (LC) method using polar organic mobile phase and cellulose tris(4-chloro-3-methylphenylcarbamate) coated on silica as chiral stationary phase was successfully developed to evaluate the chiral stability of the ophthalmic solution. The percentage of methanol (MeOH) in the mobile phase containing acetonitrile (ACN) as the main solvent significantly influenced the retention and resolution of voriconazole and its enantiomer ((2S,3R)-2-(2,4-difluorophenyl)-3-(5-fluoropyrimidin-4-yl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol). The optimized mobile phase consisted of ACN/MeOH/diethylamine/trifluoroacetic acid (80/20/0.1/0.1; v/v/v/v). The method was found to be selective not only regarding the enantiomer of voriconazole but also regarding the specified impurities described in the monograph from the European Pharmacopoeia. The LC method was then fully validated applying the strategy based on total measurement error and accuracy profiles. Under the selected conditions, the determination of 0.1% of voriconazole enantiomer could be performed. Finally, a stability study of the ophthalmic solution was conducted using the validated LC method.

  11. The structure-directing effect of n-propylamine in the crystallization of open-framework aluminophosphates

    Institute of Scientific and Technical Information of China (English)

    LU HuiYing; YAN Yan; TONG XiaoQiang; YAN WenFu; YU JiHong; XU RuRen


    Using n-propylamine as a template,deioned water and secondary-butanol(butan-2-ol)as solvents,a three-dimensional(3D)open-framework aluminophosphate[C3NH10]·[HAl3P3O13](1)and a two-dimensional layered aluminophosphate[C3NH10]3·[Al3P4O16](2)were crystallized from the initial mixtures with compositions of Al2O3:2.4 P2O5:5.0 n-propylamine:100 H2O/butan-2-ol,respectively.They are characterized by X-ray powder diffraction(XRD),thermogravimetric(TG),and elemental(CHN)analyses and structurally determined by single-crystal X-ray diffraction analysis.Compound 1 crystallizes in the monoclinic space group P21/c with a=0.85831(13)nm,b=1.7677(3)nm,c=1.04353(12)nm,=123.887(9)°,and V=1.3143(3)nm3.Compound 2 crystallizes in the monoclinic space group P21/c with a=1.1313(2)nm,b=1.4874(3)nm,c=1.8020(6)nm,=125.07(2)°,and V=2.4817(11)nm3.The results show that the properties of solvent have a significant influence on the structure-directing effect of n-propylamine in the crystallization of the open-framework aluminophosphates.

  12. Arctic springtime observations of volatile organic compounds during the OASIS-2009 campaign (United States)

    Hornbrook, Rebecca S.; Hills, Alan J.; Riemer, Daniel D.; Abdelhamid, Aroob; Flocke, Frank M.; Hall, Samuel R.; Huey, L. Gregory; Knapp, David J.; Liao, Jin; Mauldin, Roy L.; Montzka, Denise D.; Orlando, John J.; Shepson, Paul B.; Sive, Barkley; Staebler, Ralf M.; Tanner, David. J.; Thompson, Chelsea R.; Turnipseed, Andrew; Ullmann, Kirk; Weinheimer, Andrew J.; Apel, Eric C.


    Gas-phase volatile organic compounds (VOCs) were measured at three vertical levels between 0.6 m and 5.4 m in the Arctic boundary layer in Barrow, Alaska, for the Ocean-Atmosphere-Sea Ice-Snowpack (OASIS)-2009 field campaign during March-April 2009. C4-C8 nonmethane hydrocarbons (NMHCs) and oxygenated VOCs (OVOCs), including alcohols, aldehydes, and ketones, were quantified multiple times per hour, day and night, during the campaign using in situ fast gas chromatography-mass spectrometry. Three canister samples were also collected daily and subsequently analyzed for C2-C5 NMHCs. The NMHCs and aldehydes demonstrated an overall decrease in mixing ratios during the experiment, whereas acetone and 2-butanone showed increases. Calculations of time-integrated concentrations of Br atoms, ∫[Br]dt, yielded values as high as (1.34 ± 0.27) × 1014 cm-3 s during the longest observed ozone depletion event (ODE) of the campaign and were correlated with the steady state Br calculated at the site during this time. Both chlorine and bromine chemistry contributed to the large perturbations on the production and losses of VOCs. Notably, acetaldehyde, propanal, and butanal mixing ratios dropped below the detection limit of the instrument (3 parts per trillion by volume (pptv) for acetaldehyde and propanal, 2 pptv for butanal) during several ODEs due to Br chemistry. Chemical flux calculations of OVOC production and loss are consistent with localized high Cl-atom concentrations either regionally or within a very shallow surface layer, while the deeper Arctic boundary layer provides a continuous source of precursor alkanes to maintain the OVOC mixing ratios.

  13. The impact of liquefied petroleum gas usage on air quality in Mexico City (United States)

    Gasca, J.; Ortiz, E.; Castillo, H.; Jaimes, J. L.; González, U.

    Liquefied petroleum gas (LPG) is the main fuel used in the residential sector of the Metropolitan Zone in the Valley of Mexico (MZVM). LPG represents 16% of the total fuel consumption in the MZVM and its demand increased 14% from 1986 to 1999. Propane and butanes, the main compounds of LPG, constituted 29% of all non-methane hydrocarbons found in the air of Mexico City. Some researchers have reported that LPG losses are a significant cause of high ozone concentration in MZVM. Three analyses are carried out in this work to estimate LPG's share of responsibility for MZVM pollution problems. First, the correlation between LPG consumption and three ozone pollution indicators was calculated for the period of 1986-1999. The non-significant correlation of these indicators with LPG consumption in a monthly basis suggests that LPG associated emissions are not the foremost cause of ozone formation. Second, a simulation model is applied to three LPG related emission control strategies to estimate the reduction in the maximum ozone concentration. The most noticeable effect was obtained when both hydrocarbon (HC) and oxides of nitrogen (NO x) emissions associated with LPG use were totally reduced. The other two strategies, that only reduce HC emissions, had a minimum effect on the ozone concentration. Third, organic compounds consumption in air samples captured and irradiated in outdoor smog chambers is used to determine the chemical loss rate of LPG associated species and aromatics in the MZVM. The smog chamber results showed that 70% of propane and n-butane remain at the end of a 1-day irradiation, therefore they remain in the MZVM atmosphere for several days being the reason for the high concentration of these compounds. LPG associated compounds only account for 18% of ozone formed but aromatics contribute 35% to ozone in smog chamber.

  14. The impact of liquefied petroleum gas usage on air quality in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Gasca, J.; Ortiz, E.; Castillo, H.; Jaimes, J.L.; Gonzalez, U. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas, Mexico City (Mexico)


    Liquefied petroleum gas (LPG) is the main fuel used in the residential sector of the Metropolitan Zone in the Valley of Mexico (MZVM). LPG represents 16% of the total fuel consumption in the MZVM and its demand increased 14% from 1986 to 1999. Propane and butanes, the main compounds of LPG, constituted 29% of all non-methane hydrocarbons found in the air of Mexico City. Some researchers have reported that LPG losses are a significant cause of high ozone concentration in MZVM. Three analyses are carried out in this work to estimate LPG's share of responsibility for MZVM pollution problems. First, the correlation between LPG consumption and three ozone pollution indicators was calculated for the period of 1986-1999. The non-significant correlation of these indicators with LPG consumption on a monthly basis suggests that LPG associated emissions are not the foremost cause of ozone formation. Second, a simulation model is applied to three LPG related emission control strategies to estimate the reduction in the maximum ozone concentration. The most noticeable effect was obtained when both hydrocarbon (HC) and oxides of nitrogen (NO{sub x}) emissions associated with LPG use were totally reduced. The other two strategies, that only reduce HC emissions, had a minimum effect on the ozone concentration. Third, organic compounds consumption in air samples captured and irradiated in outdoor smog chambers is used to determine the chemical loss rate of LPG associated species and aromatics in the MZVM. The smog chamber results showed that 70% of propane and n-butane remain at the end of a 1-day irradiation, therefore they remain in the MZVM atmosphere for several days being the reason for the high concentration of these compounds. LPG associated compounds only account for 18% of ozone formed but aromatics contribute 35% to ozone in smog chamber. (Author)

  15. Climatic factors directly impact the volatile organic compound fingerprint in green Arabica coffee bean as well as coffee beverage quality. (United States)

    Bertrand, B; Boulanger, R; Dussert, S; Ribeyre, F; Berthiot, L; Descroix, F; Joët, T


    Coffee grown at high elevations fetches a better price than that grown in lowland regions. This study was aimed at determining whether climatic conditions during bean development affected sensory perception of the coffee beverage and combinations of volatile compounds in green coffee. Green coffee samples from 16 plots representative of the broad range of climatic variations in Réunion Island were compared by sensory analysis. Volatiles were extracted by solid phase micro-extraction and the volatile compounds were analysed by GC-MS. The results revealed that, among the climatic factors, the mean air temperature during seed development greatly influenced the sensory profile. Positive quality attributes such as acidity, fruity character and flavour quality were correlated and typical of coffees produced at cool climates. Two volatile compounds (ethanal and acetone) were identified as indicators of these cool temperatures. Among detected volatiles, most of the alcohols, aldehydes, hydrocarbons and ketones appeared to be positively linked to elevated temperatures and high solar radiation, while the sensory profiles displayed major defects (i.e. green, earthy flavour). Two alcohols (butan-1,3-diol and butan-2,3-diol) were closely correlated with a reduction in aromatic quality, acidity and an increase in earthy and green flavours. We assumed that high temperatures induce accumulation of these compounds in green coffee, and would be detected as off-flavours, even after roasting. Climate change, which generally involves a substantial increase in average temperatures in mountainous tropical regions, could be expected to have a negative impact on coffee quality.

  16. Universal Indicators for Oil and Gas Prospecting Based on Bacterial Communities Shaped by Light-Hydrocarbon Microseepage in China. (United States)

    Deng, Chunping; Yu, Xuejian; Yang, Jinshui; Li, Baozhen; Sun, Weilin; Yuan, Hongli


    Light hydrocarbons accumulated in subsurface soil by long-term microseepage could favor the anomalous growth of indigenous hydrocarbon-oxidizing microorganisms, which could be crucial indicators of underlying petroleum reservoirs. Here, Illumina MiSeq sequencing of the 16S rRNA gene was conducted to determine the bacterial community structures in soil samples collected from three typical oil and gas fields at different locations in China. Incubation with n-butane at the laboratory scale was performed to confirm the presence of "universal microbes" in light-hydrocarbon microseepage ecosystems. The results indicated significantly higher bacterial diversity in next-to-well samples compared with background samples at two of the three sites, which were notably different to oil-contaminated environments. Variation partitioning analysis showed that the bacterial community structures above the oil and gas fields at the scale of the present study were shaped mainly by environmental parameters, and geographic location was able to explain only 7.05% of the variation independently. The linear discriminant analysis effect size method revealed that the oil and gas fields significantly favored the growth of Mycobacterium, Flavobacterium, and Pseudomonas, as well as other related bacteria. The relative abundance of Mycobacterium and Pseudomonas increased notably after n-butane cultivation, which highlighted their potential as biomarkers of underlying oil deposits. This work contributes to a broader perspective on the bacterial community structures shaped by long-term light-hydrocarbon microseepage and proposes relatively universal indicators, providing an additional resource for the improvement of microbial prospecting of oil and gas.

  17. Diverse sulfate-reducing bacteria of the Desulfosarcina/Desulfococcus clade are the key alkane degraders at marine seeps. (United States)

    Kleindienst, Sara; Herbst, Florian-Alexander; Stagars, Marion; von Netzer, Frederick; von Bergen, Martin; Seifert, Jana; Peplies, Jörg; Amann, Rudolf; Musat, Florin; Lueders, Tillmann; Knittel, Katrin


    Biogeochemical and microbiological data indicate that the anaerobic oxidation of non-methane hydrocarbons by sulfate-reducing bacteria (SRB) has an important role in carbon and sulfur cycling at marine seeps. Yet, little is known about the bacterial hydrocarbon degraders active in situ. Here, we provide the link between previous biogeochemical measurements and the cultivation of degraders by direct identification of SRB responsible for butane and dodecane degradation in complex on-site microbiota. Two contrasting seep sediments from Mediterranean Amon mud volcano and Guaymas Basin (Gulf of California) were incubated with (13)C-labeled butane or dodecane under sulfate-reducing conditions and analyzed via complementary stable isotope probing (SIP) techniques. Using DNA- and rRNA-SIP, we identified four specialized clades of alkane oxidizers within Desulfobacteraceae to be distinctively active in oxidation of short- and long-chain alkanes. All clades belong to the Desulfosarcina/Desulfococcus (DSS) clade, substantiating the crucial role of these bacteria in anaerobic hydrocarbon degradation at marine seeps. The identification of key enzymes of anaerobic alkane degradation, subsequent β-oxidation and the reverse Wood-Ljungdahl pathway for complete substrate oxidation by protein-SIP further corroborated the importance of the DSS clade and indicated that biochemical pathways, analog to those discovered in the laboratory, are of great relevance for natural settings. The high diversity within identified subclades together with their capability to initiate alkane degradation and growth within days to weeks after substrate amendment suggest an overlooked potential of marine benthic microbiota to react to natural changes in seepage, as well as to massive hydrocarbon input, for example, as encountered during anthropogenic oil spills.

  18. Catalytic Combustion Characteristics of H2/n-CaH10/Air Mixtures in Swiss-Roll Combustor%H2/n-C4H10/Air预混气在Swiss—roll燃烧器中的催化燃烧特性

    Institute of Scientific and Technical Information of China (English)

    杨帆; 钟北京


    In micro catalytic combustion, due to the competitive adsorption between fuel and oxygen molecular on the catalyst surface, the lower combustion limits are at the fuel rich condition. To enhance the utilization of fuel and enlarge the flammable range, hydrogen was added into the n-butane/air mixtures. Then catalytic combustion characteristics of H2/n-C4H10/air mixtures in Swiss-roll combustor were studied. Experimental results indicate that the addition of hydrogen and enlarge the flammable range of n-butane and the lower limits is fuel lean. Thus the utilization of fuel is high. The steady state combustion experiments show that the highest temperature of combustor is at fuel rich.%在微尺度催化燃烧中,由于燃料和氧气对于催化剂表面活性位的竞争,导致了可燃下限为富燃的情况。为了提高燃料利用率,拓宽可燃范围,本文在正丁烷/空气的混合气中加入一定量的氢气,在Swiss—roll燃烧器内研究了氯气/正丁烷/空气预混气的燃烧特性。结果表明,氢气能够有效拓宽正丁烷的可燃范围,可燃下限能够低于1,以贫燃的条件实现高燃料利用率。对于稳定燃烧温度的实验结果表明,燃烧器最高温度出现在富燃料一侧。

  19. Development of an attached-growth process for the on-site bioremediation of an aquifer polluted by chlorinated solvents. (United States)

    Frascari, Dario; Bucchi, Giacomo; Doria, Francesco; Rosato, Antonella; Tavanaie, Nasrin; Salviulo, Raffaele; Ciavarelli, Roberta; Pinelli, Davide; Fraraccio, Serena; Zanaroli, Giulio; Fava, Fabio


    A procedure for the design of an aerobic cometabolic process for the on-site degradation of chlorinated solvents in a packed bed reactor was developed using groundwater from an aquifer contaminated by trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA). The work led to the selection of butane among five tested growth substrates, and to the development and characterization from the site's indigenous biomass of a suspended-cell consortium capable to degrade TCE (first order constant: 96 L gprotein(-1) day(-1) at 30 °C and 4.3 L gprotein(-1) day(-1) at 15 °C) with a 90 % mineralization of the organic chlorine. The consortium immobilization had strong effects on the butane and TCE degradation rates. The microbial community structure was slightly changed by a temperature shift from 30 to 15 °C, but remarkably affected by biomass adhesion. Given the higher TCE normalized degradation rate (0.59 day(-1) at 15 °C) and attached biomass concentration (0.13 gprotein Lbioreactor(-1) at 15 °C) attained, the porous ceramic carrier Biomax was selected as the best option for the packed bed reactor process. The low TeCA degradation rate exhibited by the developed consortium suggested the inclusion of a chemical pre-treatment based on the TeCA to TCE conversion via β-elimination, a very fast reaction at alkaline pH. To the best of the authors' knowledge, this represents the first attempt to develop a procedure for the development of a packed bed reactor process for the aerobic cometabolism of chlorinated solvents.

  20. Purification and biological evaluation of the metabolites produced by Streptomyces sp. TK-VL_333. (United States)

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


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

  1. Characterization of volatile organic compounds at a roadside environment in Hong Kong: An investigation of influences after air pollution control strategies (United States)

    Huang, Yu; Ling, Zhen Hao; Lee, Shun Cheng; Ho, Steven Sai Hang; Cao, Jun Ji; Blake, Donald R.; Cheng, Yan; Lai, Sen Chao; Ho, Kin Fai; Gao, Yuan; Cui, Long; Louie, Peter K. K.


    Vehicular emission is one of the important anthropogenic pollution sources for volatile organic compounds (VOCs). Four characterization campaigns were conducted at a representative urban roadside environment in Hong Kong between May 2011 and February 2012. Carbon monoxide (CO) and VOCs including methane (CH4), non-methane hydrocarbons (NMHCs), halocarbons, and alkyl nitrates were quantified. Both mixing ratios and compositions of the target VOCs show ignorable seasonal variations. Except CO, liquefied petroleum gas (LPG) tracers of propane, i-butane and n-butane are the three most abundant VOCs, which increased significantly as compared with the data measured at the same location in 2003. Meanwhile, the mixing ratios of diesel- and gasoline tracers such as ethyne, alkenes, aromatics, halogenated, and nitrated hydrocarbons decreased by at least of 37%. The application of advanced multivariate receptor modeling technique of positive matrix factorization (PMF) evidenced that the LPG fuel consumption is the largest pollution source, accounting for 60 ± 5% of the total quantified VOCs at the roadside location. The sum of ozone formation potential (OFP) for the target VOCs was 300.9 μg-O3 m-3, which was 47% lower than the value of 567.3 μg-O3 m-3 measured in 2003. The utilization of LPG as fuel in public transport (i.e., taxis and mini-buses) contributed 51% of the sum of OFP, significantly higher than the contributions from gasoline- (16%) and diesel-fueled (12%) engine emissions. Our results demonstrated the effectiveness of the switch from diesel to LPG-fueled engine for taxis and mini-buses implemented by the Hong Kong Special Administrative Region (HKSAR) Government between the recent ten years, in additional to the execution of substitution to LPG-fueled engine and restrictions of the vehicular emissions in compliance with the updated European emission standards.

  2. Pretreatment with pyridinium oximes improves antidotal therapy against tabun poisoning. (United States)

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


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

  3. Analysis of volatile compounds of Ilex paraguariensis A. St. - Hil. and its main adulterating species Ilex theizans Mart. ex Reissek and Ilex dumosa Reissek Análise de compostos voláteis de Ilex paraguariensis A. St. - Hil. e suas principais espécies adulterantes Ilex theizans Mart. ex Reissek e Ilex dumosa Reissek

    Directory of Open Access Journals (Sweden)

    Rogério Marcos Dallago


    Full Text Available The adulteration of the product Ilex paraguariensis with other Ilex species is a mAjor problem for maté tea producers. In this work, three species of Ilex were evaluated for their volatile composition by headspace solid phase microextraction coupled to gas chromatography and mass spectrum detector (HS-SPME/GC-MS. The adulterating species I. dumnosa and I. theizans Mart. ex Reissek presented a different profile of volatile organic compounds when compared to I. paraguariensis. Aldehydes methyl-butanal, pentanal, hexanal, heptanal and nonanal were detected only in the adulterating species. This result suggests that such compounds are potential chemical markers for identification of adulteration and quality analysis of products based on Ilex paraguariensis.A adulteração do produto Ilex paraguariensis com outras espécies de Ilex é um dos principais problemas dos produtores de erva-mate. Neste trabalho, três espécies de Ilex foram avaliadas quanto à sua composição volátil por microextração em fase sólida acoplada à cromatografia gasosa e detector de espectro de massas (HS-SPME/GC-MS. As espécies adulterantes I. dumnosa e I. theizans Mart. ex Reissek apresentaram um perfil diferente de compostos orgânicos voláteis, quando comparadas com a I. paraguariensis. Os aldeídos metil-butanal, pentanal, hexanal, heptanal e nonanal foram detectados apenas nas espécies adulterantes. Esse resultado sugere que esses compostos químicos são marcadores potenciais para a identificação de adulteração e análise da qualidade dos produtos à base de Ilex paraguariensis.

  4. Effect of strain rate on sooting limits in counterflow diffusion flames of gaseous hydrocarbon fuels: Sooting temperature index and sooting sensitivity index

    KAUST Repository

    Wang, Yu


    The effect of the strain rate on the sooting limits in counterflow diffusion flames was investigated in various gaseous hydrocarbon fuels by varying the nitrogen dilution in the fuel and oxidizer streams. The sooting limit was defined as the critical fuel and oxygen mole fraction at which soot started to appear in the elastic light scattering signal. The sooting region for normal alkane fuels at a specified strain rate, in terms of the fuel and oxygen mole fraction, expanded as the number of carbon atoms increased. The alkene fuels (ethylene, propene) tested had a higher propensity for sooting as compared with alkane fuels with the same carbon numbers (ethane, propane). Branched iso-butane had a higher propensity for sooting than did n-butane. An increase in the strain rate reduced the tendency for sooting in all the fuels tested. The sensitivity of the sooting limit to the strain rate was more pronounced for less sooting fuels. When plotted in terms of calculated flame temperature, the critical oxygen mole fraction exhibited an Arrhenius form under sooting limit conditions, which can be utilized to significantly reduce the effort required to determine sooting limits at different strain rates. We found that the limiting temperatures of soot formation flames are viable sooting metrics for quantitatively rating the sooting tendency of various fuels, based on comparisons with threshold soot index and normalized smoke point data. We also introduce a sooting temperature index and a sooting sensitivity index, two quantitative measures to describe sooting propensity and its dependence on strain rate. © 2013 The Combustion Institute.

  5. Characterization of non-methane hydrocarbons in Asian summer monsoon outflow observed by the CARIBIC aircraft

    Directory of Open Access Journals (Sweden)

    A. K. Baker


    Full Text Available Between April and December 2008 the CARIBIC commercial aircraft conducted monthly measurement flights between Frankfurt, Germany and Chennai, India. These flights covered the period of the Asian summer monsoon (June–September, during which enhancements in a number of atmospheric species were observed in monsoon outflow. In addition to in situ measurements of trace gases and aerosols, whole air samples were collected during the flights, and these were subsequently analyzed for a suite of trace gases that included the non-methane hydrocarbons. Non-methane hydrocarbons are relatively short-lived compounds and the large enhancements in their mixing ratios in the upper troposphere over Southwest Asia between June and September, sometimes more than double their spring and fall means, provides qualitative evidence for the influence of convectively uplifted boundary layer air. The particularly large enhancements of the combustion tracers benzene and ethyne, along with the similarity of their ratios to carbon monoxide and emission ratios from the burning of household biofuels, indicate a strong influence of biofuel burning to NMHC emissions in this region. Conversely, the ratios of ethane and propane to carbon monoxide, along with the ratio between i-butane and n-butane, indicate a significant source of these compounds from the use of LPG and natural gas, and comparison to previous campaigns suggests that this source could be increasing. Photochemical aging patterns of NMHCs showed that the CARIBIC samples were collected in two distinctly different regions of the monsoon circulation: a southern region where air masses had been recently influenced by low level contact and a northern region, where air parcels had spent substantial time in transit in the upper troposphere before being probed. Estimates of age using ratios of individual NMHCs have ranges of 3–6 d in the south and 9–12 d in the north.

  6. Synthesis, structure, lattice energy and enthalpy of 2D hybrid perovskite [NH3(CH2)4NH3]CoCl4, compared to [NH3(CH2)nNH3]CoCl4, n=3-9 (United States)

    Abdel-Aal, Seham K.; Abdel-Rahman, Ahmed S.


    A new organic-inorganic 2D hybrid perovskite [NH3(CH2)4NH3]CoCl4,1,4butane diammonium tetra-chlorocobaltate, has been synthesized. Blue prismatic single crystals were grown from ethanolic solution in 1:1 stoichiometric ratio (organic/inorganic) by gradual cooling to room temperature after heating at 70 °C for 1 h. The hybrid crystallizes in a triclinic phase with the centrosymetric space group P 1 bar . Its unit cell parameters are a=7.2869 (2) Å, b=8.1506 (2) Å, c=10.4127 (3) Å, α=77.2950 (12)°, β=80.0588 (11)°, γ=82.8373 (12)° and Z=2. The final R factor is 0.064. The structure consists of organic dications [NH3(CH2)4NH3]2+ which act as spacer between layers of inorganic dianions [CoCl4]2- in which CoII ions are coordinated by four Cl atoms in an isolated tetrahedral structure. The organic and inorganic layers form infinite 2D sheets which are parallel to the ac plane, stacking alternatively along the b-axis, and are connected via N-H…. Cl hydrogen bonds. The lamellar structure of the 1,4 butane diammonium tetrachlorocobaltate hybrid is typically considered as naturally self-assembled multiple quantum wells (MQW). The calculated lattice potential energy Upot (kJ/mol) and lattice enthalpy ΔHL (kJ/mol) are inversely proportional to the molecular volume Vm (nm3) of perovskite hybrid of the formula [NH3(CH2)nNH3]CoCl4, n=3-9.

  7. Arabidopsis AtSerpin1, Crystal Structure and in Vivo Interaction with Its Target Protease RESPONSIVE TO DESICCATION-21 (RD21)

    Energy Technology Data Exchange (ETDEWEB)

    Lampl, Nardy; Budai-Hadrian, Ofra; Davydov, Olga; Joss, Tom V.; Harrop, Stephen J.; Curmi, Paul M.G.; Roberts, Thomas H.; Fluhr, Robert (WIS-I); (Macquarie); (New South)


    In animals, protease inhibitors of the serpin family are associated with many physiological processes, including blood coagulation and innate immunity. Serpins feature a reactive center loop (RCL), which displays a protease target sequence as a bait. RCL cleavage results in an irreversible, covalent serpin-protease complex. AtSerpin1 is an Arabidopsis protease inhibitor that is expressed ubiquitously throughout the plant. The x-ray crystal structure of recombinant AtSerpin1 in its native stressed conformation was determined at 2.2 {angstrom}. The electrostatic surface potential below the RCL was found to be highly positive, whereas the breach region critical for RCL insertion is an unusually open structure. AtSerpin1 accumulates in plants as a full-length and a cleaved form. Fractionation of seedling extracts by nonreducing SDS-PAGE revealed the presence of an additional slower migrating complex that was absent when leaves were treated with the specific cysteine protease inhibitor l-trans-epoxysuccinyl-l-leucylamido (4-guanidino)butane. Significantly, RESPONSIVE TO DESICCATION-21 (RD21) was the major protease labeled with the l-trans-epoxysuccinyl-l-leucylamido (4-guanidino)butane derivative DCG-04 in wild type extracts but not in extracts of mutant plants constitutively overexpressing AtSerpin1, indicating competition. Fractionation by nonreducing SDS-PAGE followed by immunoblotting with RD21-specific antibody revealed that the protease accumulated both as a free enzyme and in a complex with AtSerpin1. Importantly, both RD21 and AtSerpin1 knock-out mutants lacked the serpin-protease complex. The results establish that the major Arabidopsis plant serpin interacts with RD21. This is the first report of the structure and in vivo interaction of a plant serpin with its target protease.

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

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


    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 The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual

  9. Anthropogenic non-methane volatile hydrocarbons at Mt. Cimone (2165 m a.s.l., Italy): Impact of sources and transport on atmospheric composition (United States)

    Lo Vullo, Eleonora; Furlani, Francesco; Arduini, Jgor; Giostra, Umberto; Graziosi, Francesco; Cristofanelli, Paolo; Williams, Martin L.; Maione, Michela


    To advance our understanding of the factors that affect pollution in mountainous areas, long-term, high frequency measurements of thirteen Non Methane Volatile Organic Compounds (NMVOCs) have been carried out at the atmospheric observatory on the top of Mt. Cimone (2165 m a.s.l.), whose location is ideal for sampling both aged air masses representing the regional background and polluted air masses coming from nearby sources of anthropogenic pollution. An analysis of the NMVOC time series available at Mt. Cimone during 2010-2014 was used to examine the influence of transport processes on NMVOC atmospheric composition and to derive information on the emission sources. We performed a multifactor principal component analysis whose results allowed us to identify the source categories emitting the NMVOCs measured at Mt. Cimone as well as to assess transport ranges in winter and summer. Aged air masses, due to long-range transport and related to vehicular traffic exhaust emissions accounted for 78% of the NMVOC variability in winter and 62% in summer, whereas evaporative emissions, likely to be associated with fresh emissions from nearby sources, accounted for 12% of the NMVOC variability and 24% in winter and summer, respectively. Such results have been confirmed by a further analysis in which the NMVOC variability as a function of their atmospheric lifetimes has been evaluated. The ratios of alkane isomers potentially provides a metric to investigate seasonal changes in NMVOCs composition and in the emission fields of butanes and pentanes, suggesting that during the summer the butanes are originating mainly from the European domain and that for pentanes non-anthropogenic sources may be contributing to the measured concentrations.

  10. Effect of different stripping media on 1,2-dichloro ethane stripping desorption process%汽提介质对二氯乙烷汽提脱除效果的影响研究

    Institute of Scientific and Technical Information of China (English)

    曲云; 李勇


    1,2-Dichloro ethane stripping desorption process of homogeneous phase cationic polymerization system in C5 hydrogenation petroleum resin unit was simulated with Aspen Plus. The effects of stripping media such as 180℃ superheated steam, nitrogen, ethane, n-butane, iso-butane and C4 mixture, on the stripping desorption process were simulated in this paper. The results show that when nitrogen is used as the stripping media,the residual amount of 1,2-dichloro ethane is 5 ppm. The recovery of 1,2-dichloro ethane is 94. 12% and no equipment corrosion is caused. So it can be concluded that nitrogen is a favorable media for 1,2-dichloro ethane desorption.%对碳五加氢石油树脂均相阳离子聚合体系二氯乙烷的脱除工艺进行了模拟.按照设计工艺流程,分别以180℃过热蒸汽、N2、乙烷、正丁烷、异丁烷及混合碳四为汽提介质,模拟了汽提介质对二氯乙烷残余量、汽提塔尺寸及二氯乙烷损耗量的影响,并分析了以上几种介质可能导致的设备腐蚀问题.结果表明,以N2作汽提介质时,二氯乙烷残余质量分数为0.0005%,回收率为94.12%,且不会产生腐蚀,是一种用于脱除二氯乙烷的良好汽提介质.

  11. The formation of diethyl ether via the reaction of iodoethane with atomic oxygen on the Ag(110) surface (United States)

    Jones, G. Scott; Barteau, Mark A.; Vohs, John M.


    The reactions of iodoethane (ICH 2CH 3) on clean and oxygen-covered Ag(110) surfaces were investigated using temperature-programmed desorption (TPD) and high-resolution electron energy-loss spectroscopy (HREELS). Iodoethane adsorbs dissociatively at 150 K to produce surface ethyl groups on both clean and oxygen-covered Ag(110) surfaces. The ethyl species couple to form butane on both surfaces, with the desorption peak maximum located between 218 and 238 K, depending on the ethyl coverage. In addition to butane, a number of oxidation products including diethyl ether, ethanol, acetaldehyde, surface acetate, ethylene, carbon dioxide and water were formed on the oxygen-dosed Ag(110) surface. Diethyl ether was the major oxygenate produced at all ethyl:oxygen ratios, and the peak temperature for ether evolution varied from 220 to 266 K depending on the relative coverages of these reactants. The total combustion products, CO 2 and H 2O, were primarily formed at low ethyl coverages in the presence of excess oxygen. The formation of ethylene near 240 K probably involves an oxygen-assisted dehydrogenation pathway since ethylene is not formed from ethyl groups on the clean surface. Acetaldehyde and ethanol evolve coincidentally with a peak centered at 270-280 K, and are attributed to the reactions of surface ethoxide species. The surface acetate which decomposes near 620 K is formed from subsequent reactions of acetaldehyde with oxygen atoms. The addition of ethyl to oxygen to form surface ethoxides was verified by HREELS results. The yields of all products exhibited a strong dependence on the relative coverages of ethyl and oxygen.

  12. X-Ray Absorption Studies of Vanadium-Containing Metal Oxide Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Hohn, Keith, L.


    Metal oxide nanocrystals offer significant potential for use as catalysts or catalyst supports due to their high surface areas and unique chemical properties that result from the high number of exposed corners and edges. However, little is known about the catalytic activity of these materials, especially as oxidation catalysts. This research focused on the preparation, characterization and use of vanadium-containing nanocrystals as selective oxidation catalysts. Three vanadium-containing nanocrystals were prepared using a modified sol-gel procedure: V/MgO, V/SiO2, and vanadium phosphate (VPO). These represent active oxidation catalysts for a number of industrially relevant reactions. The catalysts were characterized by x-ray diffraction and Raman, UV-VIS, infrared and x-ray absorption spectroscopies with the goal of determining the primary structural and chemical differences between nanocrystals and microcrystals. The catalytic activity of these catalysts was also studied in oxidative dehydrogenation of butane and methanol oxidation to formaldehyde. V/MgO nanocrystals were investigated for activity in oxidative dehydrogenation of butane and compared to conventional V/MgO catalysts. Characterization of V/MgO catalysts using Raman spectroscopy and x-ray absorption spectroscopy showed that both types of catalysts contained magnesium orthovanadate at vanadium loadings below 15 weight%, but above that loading, magnesium pyrovanadate may have been present. In general, MgO nanocrystals had roughly half the crystal size and double the surface area of the conventional MgO. In oxidative dehydrogenation of butane, nanocrystalline V/MgO gave higher selectivity to butene than conventional V/MgO at the same conversion. This difference was attributed to differences in vanadium domain size resulting from the higher surface areas of the nanocrystalline support, since characterization suggested that similar vanadium phases were present on both types of catalysts. Experiments in

  13. 亚临界流体萃取胡麻籽低温压榨饼中油脂%Subcritical fluid extraction of oil from cold press linseed cake

    Institute of Scientific and Technical Information of China (English)

    万楚筠; 黄凤洪; 张明; 李文林; 黄庆德


    linseed, a solvent extraction has to be used. However, solvent extraction with petroleum distillates, such as hexane, is not allowed, due to its high temperature process. In order to obtain high quality linseed oil from cold press linseed cake, subcritical butane is used to extract linseed oil and then the quality of the oil and meal obtained is studied, compared with n-hexane extraction. The affection of factors, which includes extraction temperature, time and ratio of solvent to material effecting on oil yield, is investigated, and the extraction parameters are optimized by D-optimum response surface methodology. The model equation for predicting the optimum response values is established by Design Expert software. The adequacy of the model equation for predicting the optimum response values was effectively verified by the validation. The experiment result indicates that affection of ratio of solvent to material and extraction time on oil yield are more significant than extraction temperature. The interaction between extraction temperature and ratio of solvent to material has a significant affection on oil yield. The optimum operation parameters of subcritical butane extraction are:extraction temperature 26℃,ratio of solvent to material 8.4 mL/g, and extraction time 40 min. In this optimal condition, the oil yield is 96.50%and is similar to the 96.82%predicted as maximum oil yield by the mathematical model under the condition of temperature 25.77℃and ratio of solvent to material 8.36 mL/g with extraction time 40 min. The subcritical butane extraction of linseed oil from cold press linseed cake has a nice color and better acid and peroxide value compared to n-hexane extraction. The phospholipid content of oil extracted with subcritical butane is 0.67 mg/g, which is about 1/10 of the n-hexane extraction, and the vitamin E content are 43.78 mg/100 g, which is a little larger than the n-hexane extraction process. The linseed meal obtained from cold press linseed cake

  14. Estimated MP2 and CCSD(T) interaction energies of n-alkane dimers at the basis set limit: Comparison of the methods of Helgaker et al. and Feller (United States)

    Tsuzuki, Seiji; Honda, Kazumasa; Uchimaru, Tadafumi; Mikami, Masuhiro


    The MP2 (the second-order Møller-Plesset calculation) and CCSD(T) (coupled cluster calculation with single and double substitutions with noniterative triple excitations) interaction energies of all-trans n-alkane dimers were calculated using Dunning's [J. Chem. Phys. 90, 1007 (1989)] correlation consistent basis sets. The estimated MP2 interaction energies of methane, ethane, and propane dimers at the basis set limit [EMP2(limit)] by the method of Helgaker et al. [J. Chem. Phys. 106, 9639 (1997)] from the MP2/aug-cc-pVXZ (X =D and T) level interaction energies are very close to those estimated from the MP2/aug-cc-pVXZ (X =T and Q) level interaction energies. The estimated EMP2(limit) values of n-butane to n-heptane dimers from the MP2/cc-pVXZ (X =D and T) level interaction energies are very close to those from the MP2/aug-cc-pVXZ (X =D and T) ones. The EMP2(limit) values estimated by Feller's [J. Chem. Phys. 96, 6104 (1992)] method from the MP2/cc-pVXZ (X =D, T, and Q) level interaction energies are close to those estimated by the method of Helgaker et al. from the MP2/cc-pVXZ (X =T and Q) ones. The estimated EMP2(limit) values by the method of Helgaker et al. using the aug-cc-pVXZ (X =D and T) are close to these values. The estimated EMP2(limit) of the methane, ethane, propane, n-butane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane dimers by the method of Helgaker et al. are -0.48, -1.35, -2.08, -2.97, -3.92, -4.91, -5.96, -6.68, -7.75, and -8.75kcal /mol, respectively. Effects of electron correlation beyond MP2 are not large. The estimated CCSD(T) interaction energies of the methane, ethane, propane, and n-butane dimers at the basis set limit by the method of Helgaker et al. (-0.41, -1.22, -1.87, and -2.74kcal/mol, respectively) from the CCSD(T )/cc-pVXZ (X =D and T) level interaction energies are close to the EMP2(limit) obtained using the same basis sets. The estimated EMP2(limit) values of the ten dimers were fitted to the form m0+m1X (X

  15. Research on Volatile Organic Compounds in the Mexico City Metropolitan Area (MCMA) in two campaigns collected in the Winter-2011 and Spring-2012 (United States)

    Magaña, M.; González-Vargas, S.; Blanco, S.; Watanabe, T.; Maeda, T.; Cardenas, B.


    Because of the importance of information on the concentration and speciation of Volatile Organic Compounds (VOC) in the atmosphere for the development of regulatory programs or emission control, is necessary to determine the type and the concentrations of reactive and toxic VOC in atmospheric air. The aim of this study is to determine the speciation and quantification of VOC in the atmospheric air of the Mexico City Metropolitan Area (MCMA), from samples obtained in November-December 2011 (cold-dry) and March-April (warm-dry). This study presents the results of characterization of VOC in ambient air in the MCMA conducted during 2011-2012. Sampling of VOC was done in two sampling campaigns: from November 17th to December 11th, 2011, and March 1st to April 6th, 2012 through collection of ambient air each six days in six liters stainless steel SUMMA canisters of 24 hours integrated samples, in three sites (Merced: commercial area with vehicular sources, Pedregal: residential area with vehicular sources and San Agustin: industrial sources with heavy traffic), in the MCMA. The analysis of samples was carried out with two chromatographic systems: 1) method equivalent to the EPA's Method TO-14, and 2) GC/MSD coupled to a preconcentrator ENTECH, for the analysis of the compounds listed in EPA method TO15. It was investigated the concentration of 111 volatile organic compounds, (ozone precursors and toxic compounds). It was found that concentrations of 23 species, constitute 80% of the total VOC concentration tested: ethane, propane, isobutane, n-butane, n-pentane, n-hexane, isopentane, methylcyclopentane, ethylene, propylene, acetylene, benzene, toluene, ethylbenzene, m/p-xylene, o-xylene, 1,2,4-trimethylbenzene, ethyl and isopropyl alcohols, acetone, 2-butanone, MTBE and ethyl acetate. Both in 2011 and 2012, the highest concentrations measured in the three sites were for compounds associated with the combustion of LPG gas: propane, n-butane. The highest concentrations of

  16. 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. (United States)

    Simmie, John M; Curran, Henry J


    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

  17. C4烃在FAU、BEA、LTL型分子筛中吸附的蒙特卡罗研究%Monte Carlo Investigation into C4 Hydrocarbon Adsorption in FAU,BEA and LTL Zeolites

    Institute of Scientific and Technical Information of China (English)

    翟冬; 赵亮; 潘惠芳; 赵震; 段爱军; 高金森; 陈玉


    应用蒙特卡罗(MC)模拟方法研究了1,3-丁二烯、1-丁烯、正丁烷三种C4烃在FAU、BEA、LTL三种分子筛中的吸附行为.模拟分别得到了298 K时这些C4烃的纯组分在分子筛中的吸附等温线、吸附质分布和吸附热-结果表明,在饱和吸附状态下这些C4烃在FAU分子筛中的吸附量最大,在BEA分子筛中的吸附量居中,在LTL分子筛中的吸附量最少.对于同一种分子筛来说,正丁烷在其中的等量吸附热最大,1-丁烯居中,1,3-丁二烯最小.对于同一种C4烃来说,它在LTL分子筛中的吸附热与在BEA分子筛中的吸附热相近,并且高于在FAU分子筛中的吸附热.还模拟了543 K、2.0 MPa时这些C4烃的三元混合组分在分子筛中的吸附,发现正丁烷的吸附量占的比例最大,1-丁烯居中,1,3-丁二烯最少.%The adsorption of 1,3-butadiene, 1-butylene, and n-butane in FAU, BEA, and LTL zeolites was investigated by Monte Carlo (MC) simulations. The adsorption isotherms, distribution of adsorbates, and isosteric heat of the C4 hydrocarbons in the zeolites at 298 K were obtained by simulation. The results show that the amount of C4 hydrocarbon saturated adsorption in FAU was the highest, in BEA it was the second highest, and in LTL it was the lowest. For the same zeolite, the isosteric heat of n-butane was the largest, 1-butylene the second largest, and 1,3-butadiene was the lowest. For the same C4 hydrocarbon,the isosteric heat in LTL was almost the same as that in BEA. The isosteric heat in FAU was the lowest.The adsorption of C4 hydrocarbon mixtures onto the zeolites at 543 K, 2.0 MPa was also simulated. In these mixtures the amount of n-butane adsorption was the highest, 1-butylene the second highest, and 1,3-butadiene the lowest.


    Institute of Scientific and Technical Information of China (English)

    山红红; 李春义; 赵辉; 杨朝合; 张建芳


    Online pulsereaction chromatography and MS transient response technique were used to investigate the cracking de sulfurization of thiophene over a USY zeolite The products of thiophene cracki ng contain hydrocarbons (propylene, butane, and butene, etc) and sulfides (H 2S,2methylthiophene, 3 methylthiophene, dimethylthiophene, trimethy lthiophene and benzothiophene)During the reaction, cracking and hydrogen tr ansfer are two important elementary steps Thermodynamically, the former favors higher temperature while the latter does lower The contradiction leads to abo ut 400℃ to be the optimal temperature for thiophene conversion Based on the experimental results, the desulfurization mechanism of thiophene over the USY z eolite is proposed sufurization of thiophene over a USY zeolite The products of thiophene cracki ng contain hydrocarbons (propylene, butane, and butene, etc) and sulfides (H 2S,2methylthiophene, 3methylthiophene, dimethylthiophene, trimethy lthiophene and benzothiophene) During the reaction, cracking and hydrogen tr ansfer are two important elementary steps Thermodynamically, the former favors higher temperature while the latter does lower The contradiction leads to abo ut 400?℃ to be the optimal temperature for thiophene conversion Based on the experimental results, the desulfurization mechanism of thiophene over the USY z eolite is proposed%采用在线脉冲反应色谱和质谱瞬变响应技术,对噻吩在USY沸石上的裂化脱硫反应行为进行了研究.结果表明,噻吩在USY沸石上发生反应,除生成烃和H2S外,还可以生烷基噻吩和苯并噻吩等硫化物;但噻吩的裂化脱硫是主要反应.噻吩在USY沸石上裂化脱硫反应中,裂化和氢转移是两个重要的反应步骤.热力学上高温有利于前者而低温有利于后者,这对矛盾使得400?℃左右最有利于噻吩的裂化脱硫.本文在实验结果的基础上,提出了

  19. Ligand and substrate effects in gas-phase reactions of NiX(+)/RH couples (X=F, Cl, Br, I; R=CH3, C2H5, nC3H7, nC4H9). (United States)

    Schlangen, Maria; Schröder, Detlef; Schwarz, Helmut


    The reactions of small saturated hydrocarbons by gaseous nickel cations NiX+ (X=F, Cl, Br, I) are investigated by means of electrospray ionization mass spectrometry. The halide cations are obtained from solutions of the corresponding Ni(II) salts in water or methanol as solvents. NiF+ is the only Ni(II) halide complex that brings about thermal activation of methane. The branching ratios of the observed reactions with C2H6, C3H8, and nC4H10 are shifted systematically by changing the nature of both the ligand X and the substrate RH. In the elimination of HX (X=F, Cl, Br, I), the formal oxidation state of the metal ion appears to be conserved, and the importance of this reaction channel decreases in going from NiF+ to NiI+. A reversed trend is observed in the losses of small closed-shell neutral molecules, that is, H2, CH4 and C2H6, which dominate the gas-phase ion chemistry of NiI+/RH couples. Additionally, inner-sphere electron-transfer reactions take place for a few systems, that is, the delivery of hydride or methanide ions from the hydrocarbon to NiX+ in the course of which the hydrocarbon is converted to a carbenium ion and the cationic metal complex gives rise to a neutral RNiX molecule (R=H, CH3). This process gains importance with decreasing atomic number of the halides and with increasing the size of the alkane. Thus, it constitutes the major pathway in the reactions of NiF+ with propane and n-butane, whereas it is not observed for any of the NiI+/RH couples investigated. Concerning the regioselectivity of the reactions with propane and n-butane, heterolytic cleavage of secondary carbon--hydrogen bonds is clearly preferred compared to that of primary ones, as revealed by deuterium labeling studies. For the NiF+/C3H8 couple, the selectivity of the hydride transfer is as large as 360 in favor of the secondary positions. Though smaller, large preferences for the activation of secondary C--H bonds are also operative in homolytic bond activation of RH (R=nC3H7, n

  20. Detection of flavonoids in Alpinia purpurata (Vieill. K. Schum. leaves using high-performance liquid chromatography Detecção de flavonóides em folhas de Alpinia purpurata (Vieill. K. Schum. por cromatografia líquida de alta eficiência

    Directory of Open Access Journals (Sweden)

    C.P. Victório


    Full Text Available The species Alpinia purpurata is scarcely cited as to ethnopharmacology and phytochemistry. This study aimed to analyze bioactive compounds through high-performance liquid chromatography (HPLC. Hydroalcoholic crude extract was obtained from A. purpurata dried leaves. Folin-Ciocalteau method was used to quantify total phenols, using gallic acid as standard. The obtained result was 15.6 mg GAE g-1. The crude extract was partitioned with the solvents ethyl acetate and butanol, followed by thin-layer chromatography (TLC and HPLC. The flavonoids kaempferol-3-O-glucuronide and rutin were detected at a higher concentration in ethyl acetate and butanolic extracts. The butanolic extract contains the highest flavonoid percentage (94.3%. A. purpurata presents important flavonoids of therapeutic use, already verified for A. zerumbet. This is the first study verifying the presence of flavonoids in A. purpurata extracts.A espécie Alpinia purpurata apresenta poucas citações referentes a etnofarmacologia e fitoquímica. Este estudo propõe a análise de substâncias bioativas através da técnica de cromatografia líquida de alta eficiência (CLAE. O extrato bruto hidroalcóolico foi obtido a partir de folhas secas de A. purpurata. A quantificação de fenóis totais foi realizada pelo método de Folin-Ciocalteau, usando ácido gálico como padrão. Como resultado, foi verificado 15,6 mg EAG g-1. O extrato bruto foi particionado com os solventes acetato de etila e butanol e depois analisado por cromatografia em camada delgada e CLAE. Nos extratos acetato de etila e butanólico foi detectada a presença dos flavonóides kaempferol-3-O-glicuronídeo e rutina, em maior concentração. O extrato butanólico contém a maior porcentagem de flavonóides (94,3%. Esta espécie possui flavonóides importantes no uso terapêutico, já antes verificados para a espécie A. zerumbet. Este é o primeiro trabalho que verifica a presença de flavonóides em extratos de A

  1. Di-, tri-, and tetranuclear nickel(II) complexes with oximato bridges: magnetism and catecholase-like activity of two tetranuclear complexes possessing rhombic topology. (United States)

    Das, Lakshmi Kanta; Biswas, Apurba; Kinyon, Jared S; Dalal, Naresh S; Zhou, Haidong; Ghosh, Ashutosh


    Oxime-based tridentate Schiff base ligands 3-[2-(diethylamino)ethylimino]butan-2-one oxime (HL(1)) and 3-[3-(dimethylamino)propylimino]butan-2-one oxime (HL(2)) produced the dinuclear complex [Ni2L(1)2](ClO4)2 (1) and trinuclear complex [Ni3(HL(2))3(μ3-O)](ClO4)4·CH3CN (2), respectively, upon reaction with Ni(ClO4)2·6H2O. However, in a slightly alkaline medium, both of the ligands underwent hydrolysis and resulted in tetranuclear complexes [{Ni(deen)(H2O)}2(μ3-OH)2{Ni2(moda)4}](ClO4)2·2CH3CN (3) and [{Ni(dmpn)(CH3CN)2}2(μ3-OH)2{Ni2(moda)4}](ClO4)2·CH3CN (4), where deen = 2-(diethylamino)ethylamine, dmpn = 3-(dimethylamino)-1-propylamine, and modaH = diacetyl monoxime. All four complexes have been structurally characterized. Complex 1 is a centrosymmetric dimer where the square planar nickel(II) atoms are joined solely by the oximato bridges. In complex 2, three square planar nickel atoms form a triangular core through a central oxido (μ3-O) and peripheral oximato bridges. Tetranuclear complexes 3 and 4 consist of four distorted octahedral nickel(II) ions held together in a rhombic chair arrangement by two central μ3-OH and four peripheral oximato bridges. Magnetic susceptibility measurements indicated that dinuclear 1 and trinuclear 2 exhibited diamagnetic behavior, while tetranuclear complexes 3 and 4 were found to have dominant antiferromagnetic intramolecular coupling with concomitant ferromagnetic interactions. Despite its singlet ground state, both 3 and 4 serve as useful examples of Kahn's model for competing spin interactions. High-frequency EPR studies were also attempted, but no signal was detected, likely due to the large energy gap between the ground and first excited state. Complexes 3 and 4 exhibited excellent catecholase-like activity in the aerial oxidation of 3,5-di-tert-butylcatechol to the corresponding o-quinone, whereas 1 and 2 did not show such catalytic activity. Kinetic data analyses of this oxidation reaction in acetonitrile

  2. Inter-laboratory calibration of natural gas round robins for δ2H and δ13C using off-line and on-line techniques (United States)

    Dai, Jinxing; Xia, Xinyu; Li, Zhisheng; Coleman, Dennis D.; Dias, Robert F.; Gao, Ling; Li, Jian; Deev, Andrei; Li, Jin; Dessort, Daniel; Duclerc, Dominique; Li, Liwu; Liu, Jinzhong; Schloemer, Stefan; Zhang, Wenlong; Ni, Yunyan; Hu, Guoyi; Wang, Xiaobo; Tang, Yongchun


    Compound-specific carbon and hydrogen isotopic compositions of three natural gas round robins were calibrated by ten laboratories carrying out more than 800 measurements including both on-line and off-line methods. Two-point calibrations were performed with international measurement standards for hydrogen isotope ratios (VSMOW and SLAP) and carbon isotope ratios (NBS 19 and L-SVEC CO2). The consensus δ13C values and uncertainties were derived from the Maximum Likelihood Estimation (MLE) based on off-line measurements; the consensus δ2H values and uncertainties were derived from MLE of both off-line and on-line measurements, taking the bias of on-line measurements into account. The calibrated consensus values in ‰ relative to VSMOW and VPDB are: NG1 (coal-related gas): Methane: δ2HVSMOW = − 185.1‰ ± 1.2‰, δ13CVPDB = − 34.18‰ ± 0.10‰ Ethane: δ2HVSMOW = − 156.3‰ ± 1.8‰, δ13CVPDB = − 24.66‰ ± 0.11‰ Propane: δ2HVSMOW = − 143.6‰ ± 3.3‰, δ13CVPDB = − 22.21‰ ± 0.11‰ i-Butane: δ13CVPDB = − 21.62‰ ± 0.12‰ n-Butane: δ13CVPDB = − 21.74‰ ± 0.13‰ CO2: δ13CVPDB = − 5.00‰ ± 0.12‰ NG2 (biogas): Methane: δ2HVSMOW = − 237.0‰ ± 1.2‰, δ13CVPDB = − 68.89‰ ± 0.12‰ NG3 (oil-related gas): Methane: δ2HVSMOW = − 167.6‰ ± 1.0‰, δ13CVPDB = − 43.61‰ ± 0.09‰ Ethane: δ2HVSMOW = − 164.1‰ ± 2.4‰, δ13CVPDB = − 40.24‰ ± 0.10‰ Propane: δ2HVSMOW = − 138.4‰ ± 3.0‰, δ13CVPDB = − 33.79‰ ± 0.09‰ All of the assigned values are traceable to the international carbon isotope standard of VPDB and hydrogen isotope standard of VSMOW.

  3. Monitoring of an esterification reaction by on-line direct liquid sampling mass spectrometry and in-line mid infrared spectrometry with an attenuated total reflectance probe

    Energy Technology Data Exchange (ETDEWEB)

    Owen, Andrew W.; McAulay, Edith A.J. [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Nordon, Alison, E-mail: [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Littlejohn, David, E-mail: [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Lynch, Thomas P. [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Lancaster, J. Steven [Hull Research and Technology Centre, BP Chemicals, Hull, HU12 8DS (United Kingdom); Wright, Robert G. [Thermo Fisher Scientific, Winsford, Cheshire, CW7 3GA (United Kingdom)


    Highlights: • High efficiency thermal vaporiser designed and used for on-line reaction monitoring. • Concentration profiles of all reactants and products obtained from mass spectra. • By-product formed from the presence of an impurity detected by MS but not MIR. • Mass spectrometry can detect trace and bulk components unlike molecular spectrometry. - Abstract: A specially designed thermal vaporiser was used with a process mass spectrometer designed for gas analysis to monitor the esterification of butan-1-ol and acetic anhydride. The reaction was conducted at two scales: in a 150 mL flask and a 1 L jacketed batch reactor, with liquid delivery flow rates to the vaporiser of 0.1 and 1.0 mL min{sup −1}, respectively. Mass spectrometry measurements were made at selected ion masses, and classical least squares multivariate linear regression was used to produce concentration profiles for the reactants, products and catalyst. The extent of reaction was obtained from the butyl acetate profile and found to be 83% and 76% at 40 °C and 20 °C, respectively, at the 1 L scale. Reactions in the 1 L reactor were also monitored by in-line mid-infrared (MIR) spectrometry; off-line gas chromatography (GC) was used as a reference technique when building partial least squares (PLS) multivariate calibration models for prediction of butyl acetate concentrations from the MIR spectra. In validation experiments, good agreement was achieved between the concentration of butyl acetate obtained from in-line MIR spectra and off-line GC. In the initial few minutes of the reaction the profiles for butyl acetate derived from on-line direct liquid sampling mass spectrometry (DLSMS) differed from those of in-line MIR spectrometry owing to the 2 min transfer time between the reactor and mass spectrometer. As the reaction proceeded, however, the difference between the concentration profiles became less noticeable. DLSMS had advantages over in-line MIR spectrometry as it was easier to

  4. Geomicrobiological linkages between short-chain alkane consumption and sulfate reduction rates in seep sediments. (United States)

    Bose, Arpita; Rogers, Daniel R; Adams, Melissa M; Joye, Samantha B; Girguis, Peter R


    Marine hydrocarbon seeps are ecosystems that are rich in methane, and, in some cases, short-chain (C2-C5) and longer alkanes. C2-C4 alkanes such as ethane, propane, and butane can be significant components of seeping fluids. Some sulfate-reducing microbes oxidize short-chain alkanes anaerobically, and may play an important role in both the competition for sulfate and the local carbon budget. To better understand the anaerobic oxidation of short-chain n-alkanes coupled with sulfate-reduction, hydrocarbon-rich sediments from the Gulf of Mexico (GoM) were amended with artificial, sulfate-replete seawater and one of four n-alkanes (C1-C4) then incubated under strict anaerobic conditions. Measured rates of alkane oxidation and sulfate reduction closely follow stoichiometric predictions that assume the complete oxidation of alkanes to CO2 (though other sinks for alkane carbon likely exist). Changes in the δ(13)C of all the alkanes in the reactors show enrichment over the course of the incubation, with the C3 and C4 incubations showing the greatest enrichment (4.4 and 4.5‰, respectively). The concurrent depletion in the δ(13)C of dissolved inorganic carbon (DIC) implies a transfer of carbon from the alkane to the DIC pool (-3.5 and -6.7‰ for C3 and C4 incubations, respectively). Microbial community analyses reveal that certain members of the class Deltaproteobacteria are selectively enriched as the incubations degrade C1-C4 alkanes. Phylogenetic analyses indicate that distinct phylotypes are enriched in the ethane reactors, while phylotypes in the propane and butane reactors align with previously identified C3-C4 alkane-oxidizing sulfate-reducers. These data further constrain the potential influence of alkane oxidation on sulfate reduction rates (SRRs) in cold hydrocarbon-rich sediments, provide insight into their contribution to local carbon cycling, and illustrate the extent to which short-chain alkanes can serve as electron donors and govern microbial community

  5. Smoke Point in Co-flow Experiment (United States)

    Urban, David L.; Sunderland, Peter B.; Yuan, Zeng-Guang


    The Smoke Point In Co-flow Experiment (SPICE) determines the point at which gas-jet flames (similar to a butane-lighter flame) begin to emit soot (dark carbonaceous particulate formed inside the flame) in microgravity. Studying a soot emitting flame is important in understanding the ability of fires to spread and in control of soot in practical combustion systems space. Previous experiments show that soot dominates the heat emitted from flames in normal gravity and microgravity fires. Control of this heat emission is critical for prevention of the spread of fires on Earth and in space for the design of efficient combustion systems (jet engines and power generation boilers). The onset of soot emission from small gas jet flames (similar to a butane-lighter flame) will be studied to provide a database that can be used to assess the interaction between fuel chemistry and flow conditions on soot formation. These results will be used to support combustion theories and to assess fire behavior in microgravity. The Smoke Point In Co-flow Experiment (SPICE) will lead to a o improved design of practical combustors through improved control of soot formation; o improved understanding of and ability to predict heat release, soot production and emission in microgravity fires; o improved flammability criteria for selection of materials for use in the next generation of spacecraft. The Smoke Point In Co-flow Experiment (SPICE) will continue the study of fundamental phenomena related to understanding the mechanisms controlling the stability and extinction of jet diffusion flames begun with the Laminar Soot Processes (LSP) on STS-94. SPICE will stabilize an enclosed laminar flame in a co-flowing oxidizer, measure the overall flame shape to validate the theoretical and numerical predictions, measure the flame stabilization heights, and measure the temperature field to verify flame structure predictions. SPICE will determine the laminar smoke point properties of non-buoyant jet

  6. Distribution of VOCs between air and snow at the Jungfraujoch high alpine research station, Switzerland, during CLACE 5 (winter 2006

    Directory of Open Access Journals (Sweden)

    E. Starokozhev


    Full Text Available Volatile organic compounds (VOCs were analyzed in air and snow samples at the Jungfraujoch high alpine research station in Switzerland as part of CLACE 5 (CLoud and Aerosol Characterization Experiment during February/March 2006. The fluxes of individual compounds in ambient air were calculated from gas phase concentrations and wind speed. The highest concentrations and flux values were observed for the aromatic hydrocarbons benzene (14.3 μg.m−2 s−1, 1,3,5-trimethylbenzene (5.27 μg.m−2 s−1, toluene (4.40 μg.m−2 −1, and the aliphatic hydrocarbons i-butane (7.87 μg.m−2 s−1, i-pentane (3.61 μg.m−2 s−1 and n-butane (3.23 μg.m−2 s−1. The measured concentrations and fluxes were used to calculate the efficiency of removal of VOCs by snow, which is defined as difference between the initial and final concentration/flux values of compounds before and after wet deposition. The removal efficiency was calculated at −24°C (−13.7°C and ranged from 37% (35% for o-xylene to 93% (63% for i-pentane. The distribution coefficients of VOCs between the air and snow phases were derived from published poly-parameter linear free energy relationship (pp-LFER data, and compared with distribution coefficients obtained from the simultaneous measurements of VOC concentrations in air and snow at Jungfraujoch. The coefficients calculated from pp-LFER exceeded those values measured in the present study, which indicates more efficient snow scavenging of the VOCs investigated than suggested by theoretical predictions.

  7. Analysis of Volatile Components in Semen Sojae Praepatum with Automatic Static Headspace and Gas Chromatography-Mass Spectrometry%静态顶空-气质联用分析淡豆豉中挥发性成分

    Institute of Scientific and Technical Information of China (English)

    柴川; 于生; 崔小兵; 张爱华; 朱栋; 单晨啸; 文红梅


    It was the first report on the volatile components contained in Semen Sojae Praepatum. For the analysis, the Semen Sojae Praepatum was analyzed by automatic static headspace and gas Chromatography-mass Spectrometry. A total of 27 compounds were identified in Semen Sojae Praepatum through the computer retrieval on the NIST5 mass spectral library. They consisted of 11 generality components, such as 2-Butanone, Butanal 3-methyl-, Butanal 2-methyl-, Limonene and 16 special components, such as copaene, Pyrazine, tetramethyl-, 2,3,5-Trimethyl-6-ethylpyrazine, Bicyclo[2.2.1]heptan-2-ol,1,7,7-trimethyl-,acetate,(1S-endo)-. Meanwhile, the quantitative analysis was taken using area normalization method, which showed that some difference was detected among six batches of Semen Sojae Praepatum. The results indicated that automatic static headspace and gas chromatography-mass spectrometry was a fast,easy,efficient and accurate method to analyze the volatile components in Semen Sojae Praepatum , and we thought that the findings may promote the fingerprint research of the volatile components in Semen Sojae Praepatum , to provide a scientific basis for the establishment of the quality standard.%  采用自动化静态顶空(HS)-气质联用(GC-MS)技术对6个批次淡豆豉的挥发性成分进行快速分析鉴定。从测定到的40多种成分中确定了2-丁酮、3-甲基丁醛、2-甲基丁醛、香芹烯等11种共有化合物及2,3,5-三甲基吡嗪、L-乙酸冰片酯、古巴烯、四甲基吡嗪等16种非共有化合物;同时使用峰面积归一化法计算了27种挥发性成分的相对含量,各组分的质量分数存在一定差异。研究表明,使用自动化静态顶空气质联用法测定淡豆豉的挥发性成分快速简便,且在一定程度上促进了淡豆豉挥发性成分的指纹图谱构建,为淡豆豉质量标准的建立提供了参考。

  8. Biogenesis of «fusty» defect in virgin olive oils

    Directory of Open Access Journals (Sweden)

    Angerosa, F.


    Full Text Available The biogenesis of «fusty» defect was studied by chemical and microbial analyses on olives stored in piles for different times and their resulting oils. The fusty defect was perceived by tasters after four days of storage. The quali-quantitative composition of oil volatile fraction was a very suitable way to emphasize metabolites produced by microorganisms involved during the fruit storage. Some volatile compounds, such as 2- and 3- methyl butan-1-al, their corresponding alcohols and propionic acid, 2- methyl propionic acid and 3-methyl butanoic acid, were produced. At the same time, it was observed a dramatic development of Clostridium sp. and, in a lower proportion, of Pseudomonas sp. Furthermore, during the storage the evident softening of fruits has to be attributed to microorganisms in rapid growth belonging to Enterobacter sp. and moulds, that have in its enzymatic store pectinolytic enzymes.

    La biogénesis del atrojado ha sido estudiada química y microbiológicamente en aceitunas amontonadas durante diferentes períodos de tiempo; además ha sido evaluado el aceite procedente de la elaboración de dichos frutos. La percepción de atrojado era percibida por el panel de catadores sólo después de cuatro días de almacenamiento de las aceitunas. La determinación cuanti-cualitativa de los compuestos aromáticos del aceite resultante se ha relacionado con los microorganismos implicados en la degradación de los frutos. Se han encontrado algunos compuestos volátiles como el 2- y 3- metil butan-1-al y sus correspondientes alcoholes, el ácido propiónico, el ácido 2-metil propiónico y el 3-metil butanoico. Al mismo tiempo, ha sido observado el fuerte desarrollo de especies del género Clostridium y, en menor proporción, de Pseudomonas. Asimismo, durante el almacenamiento se produjo un ablandamiento de los frutos a causa de la acción de las enzimas pectolíticas de microorganismos de r

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

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


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

  10. High-resolution infrared flash kinetic spectroscopy of OH radicals

    Energy Technology Data Exchange (ETDEWEB)

    Schiffman, A.; Nelson, D.D. Jr.; Robinson, M.S.; Nesbitt, D.J. (Univ. of Colorado, Boulder (United States) National Inst. of Standards and Tech., Boulder, CO (United States))


    A high-resolution infrared flash kinetic spectrometer is used for time- and frequency-resolved studies of the OH radical. OH is produced by 193-nm excimer laser photolysis of HNO{sub 3}/buffer gas mixtures in a 100-cm flow tube and is probed via weak fractional absorption of light from a widely tunable (2.35-3.59 {mu}m) single-mode ({Delta}{nu} {le} 2 MHz) color center laser. The IR absorption technique allows fast ({le}10{sup {minus}6} s), sensitive (<10{sup 9} radicals/cm{sup 3} per quantum state) detection of OH and is designed to permit determination of absolute OH number densities. The spectrometer is used to measure rate constants for the reactions of OH with ethane (k{sub 1}), propane (k{sub 2}), n-butane (k{sub 3}), and isobutane (k{sub 4}). The reliability of these measurements is tested on a variety of rotational, spin-orbit, and {lambda}-doublet states, with several buffer gases, and over more than an order of magnitude of alkane concentrations. The resulting rate constants are, in units of 10{sup {minus}12} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}, k{sub 1} = 0.243 {plus minus} 0.012, k{sub 2} = 1.02 {plus minus} 0.05, k{sub 3} = 2.35 {plus minus} 0.08, and k{sub 4} = 2.11 {plus minus} 0.09. The rate constants for the ethane, n-butane, and isobutane reactions agree with some previous determinations but are found to be between 10% and 25% lower than values currently used in atmospheric modeling; it is recommended that these values be revised to reflect the lower rates from this study. Current models of atmospheric air flow based on these rate constants, as well as those previously accepted values, are found to be inconsistent with daily changes in observed atmospheric alkane concentrations.

  11. Gas and Gas Hydrate Potential Offshore Amasra,Bartin and Zonguldak and Possible Agent for Multiple BSR Occurrence (United States)

    Mert Küçük, Hilmi; Dondurur, Derman; Özel, Özkan; Sınayuç, Çağlar; Merey, Şükrü; Parlaktuna, Mahmut; Çifçi, Günay


    Gas hydrates, shallow gases and mud volcanoes have been studied intensively in the Black Sea in recent years. Researches have shown that the Black Sea region has an important potential about hydrocarbon. BSR reflections in the seismic sections and seabed sampling studies also have proven the formations of hydrates clearly. In this respect, total of 2400 km multichannel seismic reflection, chirp and multibeam bathymetry data were collected along shelf to abyssal plain in 2010 and 2012 offshore Amasra, Bartın, Zonguldak-Kozlu in the central Black Sea.. Collected data represent BSRs, bright spots and transparent zones. It has been clearly observed that possible gas chimneys cross the base of gas hydrate stability zones as a result of possible weak zones in the gas hydrate bearing sediments. Seabed samples were collected closely to possible gas chimneys due to shallow gas anomalies in the data. Head space gas cromatography was applied to seabed samples to observe gas composition and the gas cromatography results represented hydrocarbon gases such as Methane, Ethane, Propane, i-Butane, n-Butane, i-Pentane, n-Pentane and Hexane. Thermogenic gas production by Turkish Petroleum Corp. from Akçakoca-1 and Ayazlı-1 well is just located at the southwest of the study area and the observations of the study area point out there is also thermogenic gas potential at the eastern side of the Akçakoca. In addition, multiple-BSRs were observed in the study area and it is thought the key point of the multiple-BSRs are different gas compositions. This suggests that hydrate formations can be formed by gas mixtures. Changing of the thermobaric conditions can trigger dissociation of the gas hydrates in the marine sediments due to sedimentary load and changing of the water temperature around seabed. Our gas hydrate modelling study suggest that gas hydrates are behaving while their dissociation process if the gas hydrates are generated by gas mixture. Monitoring of our gas hydrate

  12. Thermodynamic evaluation of methanol steam reforming for hydrogen production (United States)

    Faungnawakij, Kajornsak; Kikuchi, Ryuji; Eguchi, Koichi

    Thermodynamic equilibrium of methanol steam reforming (MeOH SR) was studied by Gibbs free minimization for hydrogen production as a function of steam-to-carbon ratio (S/C = 0-10), reforming temperature (25-1000 °C), pressure (0.5-3 atm), and product species. The chemical species considered were methanol, water, hydrogen, carbon dioxide, carbon monoxide, carbon (graphite), methane, ethane, propane, i-butane, n-butane, ethanol, propanol, i-butanol, n-butanol, and dimethyl ether (DME). Coke-formed and coke-free regions were also determined as a function of S/C ratio. Based upon a compound basis set MeOH, CO 2, CO, H 2 and H 2O, complete conversion of MeOH was attained at S/C = 1 when the temperature was higher than 200 °C at atmospheric pressure. The concentration and yield of hydrogen could be achieved at almost 75% on a dry basis and 100%, respectively. From the reforming efficiency, the operating condition was optimized for the temperature range of 100-225 °C, S/C range of 1.5-3, and pressure at 1 atm. The calculation indicated that the reforming condition required from sufficient CO concentration (<10 ppm) for polymer electrolyte fuel cell application is too severe for the existing catalysts (T r = 50 °C and S/C = 4-5). Only methane and coke thermodynamically coexist with H 2O, H 2, CO, and CO 2, while C 2H 6, C 3H 8, i-C 4H 10, n-C 4H 10, CH 3OH, C 2H 5OH, C 3H 7OH, i-C 4H 9OH, n-C 4H 9OH, and C 2H 6O were suppressed at essentially zero. The temperatures for coke-free region decreased with increase in S/C ratios. The impact of pressure was negligible upon the complete conversion of MeOH.

  13. Simplification of a complex microbial antilisterial consortium to evaluate the contribution of its flora in uncooked pressed cheese. (United States)

    Callon, Cécile; Saubusse, Marjorie; Didienne, Robert; Buchin, Solange; Montel, Marie-Christine


    inoculated with lactic acid bacteria differed from those without by higher levels of ethyl formiate, pentane and alcohols (2-butanol, 2-pentanol), and lower levels of ketones (2-hexanone, 2,3-butanedione) and aldehydes (2-methyl-butanal). Levels of 2-methyl-butanal, 2-butanol and 2-pentanol were higher in ABCD and AB cheeses than in AD cheeses. Beside their contribution to the inhibition, their effect on cheese flavour must be evaluated.

  14. Production of carbon molecular sieves from Illinois coal (United States)

    Lizzio, A.A.; Rostam-Abadi, M.


    Carbon molecular sieves (CMS) have become an increasingly important class of adsorbents for application in the separation of gas molecules that vary in size and shape. A study is in progress at the Illinois State Geological Survey to determine whether Illinois basin coals are suitable feedstocks for the production of CMS and to evaluate their potential application in gas separation processes of commercial importance. Chars were prepared from Illinois coal in a fixed-bed reactor under a wide range of heat treatment and activation conditions. The effects of various coal/char pretreatments, including coal demineralization, preoxidation, char activation, and carbon deposition, on the molecular sieve properties of the chars were also investigated. Chars with commercially significant BET surface areas of 1500 m2/g were produced by chemical activation using potassium hydroxide as the activant. These high-surface-area (HSA) chars had more than twice the adsorption capacity of commercial carbon and zeolite molecular sieves. The kinetics of adsorption of various gases, e.g., N2, O2, CO2, CH4, CO and H2, on these chars at 25??C was measured. The O2/N2 molecular sieve properties of one char prepared without chemical activation were similar to those of a commercial CMS. On the other hand, the O2/N2 selectivity of the HSA char was comparable to that of a commercial activated carbon, i.e., essentially unity. Carbon deposition, using methane as the cracking gas, increased the O2/N2 selectivity of the HSA char, but significantly decreased its adsorption capacity. Several chars showed good potential for efficient CO2/CH4 separation; both a relatively high CO2 adsorption capacity and CO2/CH4 selectivity were achieved. The micropore size distribution of selected chars was estimated by equilibrium adsorption of carbon dioxide, n-butane and iso-butane at O??C. The extent of adsorption of each gas corresponded to the effective surface area contained in pores with diameters greater than 3

  15. 六元瓜环与含双苯并咪唑功能基烷烃的自组装模式及晶体结构%Self-assembly binding models and crystal structure of cucurbit[6]uril with dibenzimidazoly-bearing alkane compoud

    Institute of Scientific and Technical Information of China (English)

    易君明; 张云黔; 薛赛凤; 陶朱


    以含有双苯并咪唑功能基的烷烃化合物二氯化1,4-二(2,2′-苯并咪唑基)丁烷(SBB)为客体,普通六元瓜环(Q[6])为主体,利用1H NMR技术、荧光发射光谱和X-单晶衍射实验等考察了主客体的自组装模式.1 H NMR技术结果显示,当主客体的比例为1∶1时,在水溶液中,1个Q[6]包结1个客体分子的一端苯并咪唑基团;在结晶固态条件下,X-单晶衍射实验测试结果是Q[6]包结客体分子的烷基链.荧光发射光谱表明,当主客体比例为2∶1时,2个Q[6]分别包结1个客体分子的两端苯并咪唑基团形成哑铃型的实体配合物.%The self-assembly binding models and crystal structure of cucurbitC6]uril with 2 ,2'-(butane-1,4-dily) dibenzimidazolium dichloride were investigated by means of 1H NMR spectroscopy, fluorescence spectrophotometry and single crystal X-ray diffraction determination. The experimental results of 1H NMR and fluorescence spectra revealed that cucurbit[6]uril(Q[6]) can interact with guest salt of 2,2'-(butane-l ,4-dily) dibenzimidazolium dichloride(SBB) with two ratios of 1:1 and 2 :1. The 1H NMR experimental results shows that the host Q[6] includes include guest benzimidozlyl moieties of the protonated SBB to form a simple 1:1 interaction model at a lower ratio of nq[6]/nsbb in water medium, but in solid-crystal state, single crystal X-ray diffraction shows that the host include the lon ger bridged alkylene chain of the guest. While at higher ratios of Q[6] to guest, fluorescence spectra results suggest that a chain shape guest could be borne two Q[6] molecules and form a dumbbell shape inclusion complex.

  16. Geomicrobiological linkages between short-chain alkane consumption and sulfate reduction rates in seep sediments.

    Directory of Open Access Journals (Sweden)

    Arpita eBose


    Full Text Available Marine hydrocarbon seeps are ecosystems that are rich in methane, and, in some cases, short-chain (C2-C5 and longer alkanes. C2-C4 alkanes such as ethane, propane and butane can be significant components of seeping fluids. Some sulfate-reducing microbes oxidize short-chain alkanes anaerobically, and may play an important role in both the competition for sulfate and the local carbon budget. To better understand the anaerobic oxidation of short-chain n-alkanes coupled with sulfate-reduction, hydrocarbon-rich sediments from the Gulf of Mexico were amended with artificial, sulfate-replete seawater and one of four n-alkanes (C1-C4 then incubated under strict anaerobic conditions. Measured rates of alkane oxidation and sulfate reduction closely follow stoichiometric predictions that assume the complete oxidation of alkanes to CO2 (though other sinks for alkane carbon likely exist. Changes in the δ13C of all the alkanes in the reactors show enrichment over the course of the incubation, with the C3 and C4 incubations showing the greatest enrichment (4.4‰ and 4.5‰ respectively. The concurrent depletion in the δ13C of dissolved inorganic carbon (DIC implies a transfer of carbon from the alkane to the DIC pool (-3.5 and -6.7‰ for C3 and C4 incubations, respectively. Microbial community analyses reveal that certain members of the class Deltaproteobacteria are selectively enriched as the incubations degrade C1-C4 alkanes. Phylogenetic analyses indicate that distinct phylotypes are enriched in the ethane reactors, while phylotypes in the propane and butane reactors align with previously identified C3-C4 alkane-oxidizing sulfate-reducers. These data further constrain the potential influence of alkane oxidation on sulfate reduction rates in cold hydrocarbon-rich sediments, provide insight into their contribution to local carbon cycling, and illustrate the extent to which short-chain alkanes can serve as electron donors and govern microbial community

  17. 炼厂碳四资源的利用途径%Utilization ways of refinery C4

    Institute of Scientific and Technical Information of China (English)



    对国内炼厂碳四的利用状况进行了分析,对混合碳四与甲醇合成甲基叔丁基醚,正丁烯经水合、脱氢反应制备甲乙酮和正丁烯与乙酸反应制备乙酸仲丁酯的生产情况进行了介绍;对醚后混合碳四制丙烯和乙烯、异构化制异丁烯、芳构化、与乙酸反应制备乙酸仲丁酯的应用和研究状况进行了分析,认为利用醚后混合碳四制备丙烯和制备乙酸仲丁酯是未来的发展方向;对异丁烷脱氢、异丁烷选择氧化、正丁烷制顺酐等技术研究进展和使用现状进行简述,认为异丁烷的利用是未来的研究重点。%This paper analyzes utilization of C4 in China,and introduces the manufactures of methyl tert-butyl ether synthesized from mixed C4 and methanol,methyl ethyl ketone prepared by n-butene through hydration reaction and dehydrogenation reaction,sec-butyl acetate from n-butene and acetic acid. Also,it briefly describes the investigations on reactions of mixed C4 after production of MTBE to prepare propylene and ethylene,isobutene by isomerization,sec-butyl acetate by reaction with acetic acid,and aromatization. Accordingly,it forecasts their market prospects respectively. Preparations of propylene and sec-butyl acetate from mixed C4 are proved to be the most promising ways. Through comparing the technologies of isobutane dehydrogenation,selective oxidation of isobutane,and reaction of n-butane to prepare maleic anhydride,utilization of iso-butane is thought to be future research focus.

  18. Origin of natural gas; Tennen gas no kigen

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Y. [The Institute of Applied Energy, Tokyo (Japan)


    Natural gas, which is a general term of flammable hydrocarbon gases such as methane, is classified by origin into the following categories : (1) oil field gas (oil gas), (2) aquifers (bacteria-fermented methane), (3) coal gas (coal field gas), and (4) abiogenetic gas. The natural gas which has (1-4) origins and is now used as resource in a large quantity is (1) oil field gas. This gas is a hydrocarbon gas recovered in the production process of petroleum and contains components such as ethane, propane and butane. To the contrary, (2) aquifers and (3) coal gas have methane as main component. As (4) abiogenetic methane, there are gas formed in inorganic reaction in activities of submarine volcanos and deep gas (earth origin gas). Oil field gas has kerogen origin. Aquifers were formed by fermentation of organic matters. Coal gas was formed by coalification of vitrinite. As abiogenetic methane, there are inorganic reaction formation gas and deep gas, the latter of which exists little as resource. 7 refs., 11 figs., 1 tab.

  19. Comparison of spectral analysis of vibration using commercial knock sensor and 3-axis acceleration sensor (United States)

    Zieliński, Ł.; Walczak, D.; Szczurowski, K.; Radkowski, S.


    With the development of internal combustion engines, engineers attempt to reduce the noise and vibration generated. Due to the high cost of fuel, are increasingly looking for new sources of power in order to reduce costs. In diesel engines, an increasingly popular method is the admixture of propane-butane. This follows because of the price of the fuel as well as to improve the efficiency of combustion. With the development of this type of dual fuel power seems to be a reasonable study of the effects of LPG to generate noise and vibration, as well as an attempt to evaluate the combustion process. Unfortunately, too much addition of LPG causes a phenomenon called knock consisting in abnormal, uneven, explosive combustion of fuels in reciprocating engines. This phenomenon may lead to a reduction in engine performance and permanent damage. Control of the knock detection uses vibration acceleration sensors recording the high frequency ranges. Within the framework of the research conducted by the team of authors, an attempt was made to compare the vibroacoustic signals originating from the commercial knocking sensor with a three-axis acceleration sensor. These signals were subject to a quick Fourier transform in the purpose of analysing the amplitude spectra.

  20. Structural evolution of SnO 2 nanostructure from core-shell faceted pyramids to nanorods and its gas-sensing properties (United States)

    Das, Soumen; Kim, Dae-Young; Choi, Cheol-Min; Hahn, Y. B.


    Tin oxide (SnO 2) nanorods were synthesized through an aqueous hexamethylenetetramine (HMTA) assisted synthesis route and their structural evolution from core-shell type faceted pyramidal assembly was investigated. Structural analysis revealed that the as-synthesized faceted SnO 2 structures were made of randomly arranged nanocrystals with diameter of 2-5 nm. The shell thickness (0-80 nm) was dependent on the molar concentration of HMTA (1-10 mM) in aqueous solution. It was revealed that the self-assembly was possible only with tin (II) chloride solution as precursor and not with tin (IV) chloride solution. At longer synthesis hours, the pyramidal nanostructures were gradually disintegrated into single crystalline nanorods with diameter of about 5-10 nm and length of about 100-200 nm. The SnO 2 nanorods showed high sensitivity towards acetone, but they were relatively less sensitive to methane, butane, sulfur dioxide, carbon monoxide and carbon dioxide. Possible mechanisms for the growth and sensing properties of the nanostructures were discussed.

  1. Valorisation de la coupe C4 de vapocraquage via l'hydrogénation du butadiène, l'isomérisation des butènes et la métathèse, en MTBE ou en propylène Upgrading the C4 Cut from Steam Cracking via the Hydrogenation of Butadiene, the Isomerization of Butenes and Metathesis Into Mtbe Or Propylene

    Directory of Open Access Journals (Sweden)

    Chaumette S.


    Full Text Available Le surplus de butadiène au niveau mondial contraint les pétrochimistes à recycler la coupe C4 au vapocraqueur. De plus en plus, le butadiène est hydrogéné avant de recraquer toute la coupe. Une fois hydrogénée, cette coupe peut être beaucoup mieux valorisée, soit en MTBE avec isomérisation des n-butènes (procédé ISO-4, soit en propylène et MTBE en utilisant le procédé META-4. L'étude technico-économique montre que cette dernière voie offre la meilleure rentabilité (TRI = 21,5 %. Si le vapocraqueur est intégré à une raffinerie, les butènes peuvent également être transformés en alkylats ou en MTBE, pour répondre à une demande en octane ou en oxygénés pour les carburants. Ces diverses voies de valorisation sont plus intéressantes que la production de MTBE à partir des butanes via la déshydrogénation de l'isobutane ou que la production du propylène par déshydrogénation du propane. Une étude de sensibilité aux différents prix des produits envisagés permet d'établir des courbes d'isorentabilités, délimitant des zones de prix favorables à l'un ou l'autre des produits, pris deux à deux. The evolution of the outlets for C4 cuts from steam cracking shows quite contradictory results. On one hand, European and Asian petrochemists are more constrained to recycle this type of effluent, which contains butadiene and isobutene, to the steam cracker. Likewise, the demand for isobutene for MTBE production is such that it has to be produced by the dehydrogenation of isobutane. This situation is effectively caused by the surplus of butadiene, a by-product of ethylene, and for which the demand is not increasing as fast as the demand for ethylene. To improve cracking performances during the recycling of the C4 Cut, butadiene is more and more selectively hydrogenated. Under these conditions, rather than cracking it, the new processes could make it possible to better upgrade it. Indeed, after selective hydrogenation, most

  2. Multifunctional amaranth cystatin inhibits endogenous and digestive insect cysteine endopeptidases: A potential tool to prevent proteolysis and for the control of insect pests. (United States)

    Valdés-Rodríguez, Silvia; Galván-Ramírez, Juan Pablo; Guerrero-Rangel, Armando; Cedro-Tanda, Alberto


    In a previous study, the amaranth cystatin was characterized. This cystatin is believed to provide protection from abiotic stress because its transcription is induced in response to heat, drought, and salinity. It has also been shown that recombinant amaranth cystatin inhibits bromelain, ficin, and cysteine endopeptidases from fungal sources and also inhibits the growth of phytopathogenic fungi. In the present study, evidence is presented regarding the potential function of amaranth cystatin as a regulator of endogenous proteinases and insect digestive proteinases. During amaranth germination and seedling growth, different proteolytic profiles were observed at different pH levels in gelatin-containing SDS-PAGE. Most of the proteolytic enzymes detected at pH 4.5 were mainly inhibited by trans-epoxysuccinyl-leucyl amido(4-guanidino)butane (E-64) and the purified recombinant amaranth cystatin. Furthermore, the recombinant amaranth cystatin was active against insect proteinases. In particular, the E-64-sensitive proteolytic digestive enzymes from Callosobruchus maculatus, Zabrotes subfasciatus, and Acanthoscelides obtectus were inhibited by the amaranth cystatin. Taken together, these results suggest multiple roles for cystatin in amaranth, specifically during germination and seedling growth and in the protection of A. hypochondriacus against insect predation. Amaranth cystatin represents a promising tool for diverse applications in the control of insect pest and for preventing undesirable proteolytic activity.

  3. Web Based Embedded Robot for Safety and Security Applications Using Zigbee

    Directory of Open Access Journals (Sweden)

    V. Ramya


    Full Text Available This project proposed an embedded system for safety and security purpose robot using zigbee communication and web server. The robot has sensors for detecting Gas leakage and intruder detection. MQ6 Gas sensor detects the presence of bio hazardous gases like LPG, iso-butane, propane, LNG and alcohol, and the PIR sensor detects only the living organism (Intruder. The sensor details are first sent to the microcontroller which resides at the robotic side and then sent to the local system through Zigbee. The system also provides an audio and visual alarm to alert about the critical situation for the safety and security purpose. This robot also has a battery powered wireless AV camera which provides robotic in front environment information to the Local and remote system and performs the audio and video streaming through web server. The robotic movement is controlled remotely from the local system by using the front end application VB 6.0. The Zigbee (IEEE 802.15.4 supports a frequency range of 2.4GHZ, 9600 baud rate with 256Kb of flash memory. It supports the range of 400m in open-air, line-ofsight, outdoor environment. This proposed system is used wherever people cannot go or where things doing too dangerous for humans to do safely. That is the robot can move and reach to the high destiny gas leakage region.

  4. Polyol mediated nano size zinc oxide and nanocomposites with poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)


    Full Text Available Organophilic nano ZnO particles have been synthesized in various diols (ethylene glycol – EG, 1,2 propane diol – PD, 1,4 butane diol – BD and tetra(ethylene glycol – TEG in the presence of p-toluenesulfonic acid, p-TsOH, as an end capping agent. The addition of p-TsOH reduces the ZnO particle size and increases its crystallite size. With increasing diol main chain length the ZnO particle size increases (EG (32 nm < PD (33 nm < BD (72 nm < TEG (86 nm. Using the assynthesized and unmodified ZnO nanocomposites with poly(methyl methacrylate, PMMA, matrix have been prepared by the in-situ bulk polymerization of methyl methacrylate, MMA. The addition of surface modifiers is avoided which is an advantage for the application since they can influence other properties of the material. ZnO particles, especially those with smaller particle sizes (EG – 32 nm, PD – 33 nm showed enhanced effect on the thermal stability of PMMA, ultraviolet, UV, absorption and transparency for visible light. Transparent materials with high UV absorption and with enhanced resistance to sunlight were obtained by optimizing the nanocomposite preparation procedure using ZnO particles of about 30 nm size in concentrations between 0.05 and 0.1 wt%. The reported nanocomposite preparation procedure is compatible with the industrial process of PMMA sheet production.

  5. Inhibition of DD-peptidases by a specific trifluoroketone: crystal structure of a complex with the Actinomadura R39 DD-peptidase. (United States)

    Dzhekieva, Liudmila; Adediran, S A; Herman, Raphael; Kerff, Frédéric; Duez, Colette; Charlier, Paulette; Sauvage, Eric; Pratt, R F


    Inhibitors of bacterial DD-peptidases represent potential antibiotics. In the search for alternatives to β-lactams, we have investigated a series of compounds designed to generate transition state analogue structures upon reaction with DD-peptidases. The compounds contain a combination of a peptidoglycan-mimetic specificity handle and a warhead capable of delivering a tetrahedral anion to the enzyme active site. The latter includes a boronic acid, two alcohols, an aldehyde, and a trifluoroketone. The compounds were tested against two low-molecular mass class C DD-peptidases. As expected from previous observations, the boronic acid was a potent inhibitor, but rather unexpectedly from precedent, the trifluoroketone [D-α-aminopimelyl(1,1,1-trifluoro-3-amino)butan-2-one] was also very effective. Taking into account competing hydration, we found the trifluoroketone was the strongest inhibitor of the Actinomadura R39 DD-peptidase, with a subnanomolar (free ketone) inhibition constant. A crystal structure of the complex between the trifluoroketone and the R39 enzyme showed that a tetrahedral adduct had indeed formed with the active site serine nucleophile. The trifluoroketone moiety, therefore, should be considered along with boronic acids and phosphonates as a warhead that can be incorporated into new and effective DD-peptidase inhibitors and therefore, perhaps, antibiotics.

  6. Untangling the multiple monooxygenases of Mycobacterium chubuense strain NBB4, a versatile hydrocarbon degrader. (United States)

    Coleman, Nicholas V; Yau, Sheree; Wilson, Neil L; Nolan, Laura M; Migocki, Margaret D; Ly, Mai-Anh; Crossett, Ben; Holmes, Andrew J


    Mycobacterium strain NBB4 was isolated on ethene as part of a bioprospecting study searching for novel monooxygenase (MO) enzymes of interest to biocatalysis and bioremediation. Previous work indicated that strain NBB4 contained an unprecedented diversity of MO genes, and we hypothesized that each MO type would support growth on a distinct hydrocarbon substrate. Here, we attempted to untangle the relationships between MO types and hydrocarbon substrates. Strain NBB4 was shown to grow on C2 -C4 alkenes and C2 -C16 alkanes. Complete gene clusters encoding six different monooxygenases were recovered from a fosmid library, including homologues of ethene MO (etnABCD), propene MO (pmoABCD), propane MO (smoABCD), butane MO (smoXYB1C1Z), cytochrome P450 (CYP153; fdx-cyp-fdr) and alkB (alkB-rubA1-rubA2). Catabolic enzymes involved in ethene assimilation (EtnA, EtnC, EtnD, EtnE) and alkane assimilation (alcohol and aldehyde dehydrogenases) were identified by proteomics, and we showed for the first time that stress response proteins (catalase/peroxidase, chaperonins) were induced by growth on C2 -C5 alkanes and ethene. Surprisingly, none of the identified MO genes could be specifically associated with oxidation of small alkanes, and thus the nature of the gaseous alkane MO in NBB4 remains mysterious.

  7. Carbon isotope characteristics, origin and distribution of the natural gases from the Tertiary salty lacustrine facies in the West Depression Region in the Qaidam Basin

    Institute of Scientific and Technical Information of China (English)

    张晓宝; 胡勇; 马立元; 孟自芳; 段毅; 周世新; 彭德华


    The Tertiary in the West Depression Region of the Qaidam Basin has the typical inland salty lacustrine deposits in China. 34 natural gas samples were collected from 13 oil fields in the West Depression Region in the basin, the chemical compositions and carbon isotopes of methane, ethane, propane, and butane were measured. According to the carbon isotope characteristics of natural gases in combination with geochemical characteristics of the source rocks and crude oils, the natural gases can be divided into sapropelic associated gas, mixed organic matter-derived associated gas, coal-derived gas and mixed gas. The carbon isotope characteristics, origin and distribution of the natural gases are considered to be related with the types and distribution of organic inputs in lake environments with different salinities. The lake salinity can regionally forecast the distribution of the different genetic types of natural gas. Compared with the different genetic types of natural gas from other Chinese basins, the carbon isotopes of the heavy hydrocarbons of the natural gas from the Tertiary salt lacustrine facies in the Qaidam Basin are extremely heavier. Therefore, this should be considered when natural gases are genetically classified in the basin.

  8. Electropolymerized supramolecular tetraruthenated porphyrins applied as a voltammetric sensor

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Monize M. da; Ribeiro, Gabriel H.; Faria, Anizio M. de; Bogado, Andre L.; Dinelli, Luis R., E-mail: [Universidade Federal de Uberlandia (UFU), Ituiutaba, MG (Brazil). Faculdade de Ciencias Integradas do Pontal; Batista, Alzir A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica


    Porphyrin 5,10,15,20-Tetra(4-pyridyl)manganese(III), [Mn-TPyP(H{sub 2}O){sub 2}]PF{sub 6}, and electropolymerized supramolecular porphyrins (ESP), {l_brace}Mn-TPyP(H{sub 2}O){sub 2}[RuCl{sub 3}(dppb)]{sub 4}{r_brace}PF{sub 6} (dppb = 1,4-bis(diphenylphosphine)butane), were synthesized and characterized. A thin solid film of ESP was obtained on a glass carbon electrode surface by a cyclic voltammetry method. The peak current increased with the number of voltammetric cycles, which shows a typical behavior of the species being adsorbed on the surface of the electrode. Cyclic voltammetry was also employed for acetaminophen quantification using an ESP modified electrode. The modified electrode shows a linear relationship between the anodic peak current and the concentration of acetaminophen (in the rage 0.05 to 0.7 mmol L{sup -1}. The performance of the modified electrode was verified by the determination of acetaminophen in a commercial pharmaceutical product and the results were in good agreement with those obtained by a control HPLC method. (author)

  9. Biological monitoring to determine worker dose in a butadiene processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Bechtold, W.E.; Hayes, R.B. [National Cancer Inst., Bethesda, MD (United States)


    Butadiene (BD) is a reactive gas used extensively in the rubber industry and is also found in combustion products. Although BD is genotoxic and acts as an animal carcinogen, the evidence for carcinogenicity in humans is limited. Extrapolation from animal studies on BD carcinogenicity to risk in humans has been controversial because of uncertainties regarding relative biologic exposure and related effects in humans vs. experimental animals. To reduce this uncertainty, a study was designed to characterize exposure to BD at a polymer production facility and to relate this exposure to mutational and cytogenetic effects. Biological monitoring was used to better assess the internal dose of BD received by the workers. Measurement of 1,2-dihydroxy-4-(N-acetylcysteinyl) butane (M1) in urine served as the biomarker in this study. M1 has been shown to correlate with area monitoring in previous studies. Most studies that relate exposure to a toxic chemical with its biological effects rely on exposure concentration as the dose metric; however, exposure concentration may or may not reflect the actual internal dose of the chemical.

  10. Nasal pungency and odor of homologous aldehydes and carboxylic acids. (United States)

    Cometto-Muñiz, J E; Cain, W S; Abraham, M H


    Airborne substances can stimulate both the olfactory and the trigeminal nerve in the nose, giving rise to odor and pungent (irritant) sensations, respectively. Nose, eye, and throat irritation constitute common adverse effects in indoor environments. We measured odor and nasal pungency thresholds for homologous aliphatic aldehydes (butanal through octanal) and carboxylic acids (formic, acetic, butanoic, hexanoic, and octanoic). Nasal pungency was measured in subjects lacking olfaction (i.e., anosmics) to avoid odor biases. Similar to other homologous series, odor and pungency thresholds declined (i.e., sensory potency increased) with increasing carbon chain length. A previously derived quantitative structure-activity relationship (QSAR) based on solvation energies predicted all nasal pungency thresholds, except for acetic acid, implying that a key step in the mechanism for threshold pungency involves transfer of the inhaled substance from the vapor phase to the receptive biological phase. In contrast, acetic acid - with a pungency threshold lower than predicted - is likely to produce threshold pungency through direct chemical reaction with the mucosa. Both in the series studied here and in those studied previously, we reach a member at longer chain-lengths beyond which pungency fades. The evidence suggests a biological cut-off, presumably based upon molecular size, across the various series.

  11. Thermoplastic Polyurethanes with Isosorbide Chain Extender

    Energy Technology Data Exchange (ETDEWEB)

    Javni, Ivan; Bilic, Olivera; Bilic, Nikola; Petrovic, Zoran; Eastwood, Eric; Zhang, Fan; Ilavsky, Jan


    Isosorbide, a renewable diol derived from starch, was used alone or in combination with butane diol (BD) as the chain extender in two series of thermoplastic polyurethanes (TPU) with 50 and 70% polytetramethylene ether glycol (PTMEG) soft segment concentration (SSC), respectively. In the synthesized TPUs, the hard segment composition was systematically varied in both series following BD/isosorbide molar ratios of 100 : 0; 75 : 25; 50 : 50; 25 : 75, and 0 : 100 to examine in detail the effect of chain extenders on properties of segmented polyurethane elastomers with different morphologies. We found that polyurethanes with 50% SSC were hard elastomers with Shore D hardness of around 50, which is consistent with assumed co-continuous morphology. Polymers with 70% SSC displayed lower Shore A hardness of 74–79 (Shore D around 25) as a result of globular hard domains dispersed in the soft matrix. Insertion of isosorbide increased rigidity, melting point and glass transition temperature of hard segments and tensile strength of elastomers with 50% SSC. These effects were weaker or non-existent in 70% SSC series due to the short hard segments and low content of isosorbide. We also found that the thermal stability was lowered by increasing isosorbide content in both series.

  12. In Situ Bioremediation of Perchlorate in Vadose Zone Soil Using Gaseous Electron Donors (United States)


    12.1 CDM-CB9-50-120208 NA SW 1500 0.5 9.3 CDM-CB10-10-120208 NA GW 26000 0.1 10.5 CDM-CB10-20-120208 NA CL 11000 0.1 16.3 CDM-CB10-30-120208 NA GW 270...40-120308 NA ML 26000 0.5 13.3 CDM-CB11-50-120308 NA GW 11000 0.9 8.4 CDM-CB12-10-120308 NA CL 7500 0.5 31.1 CDM-CB12-20-120308 NA GM 7600 3.4 27.9 CDM...0.96 6.7% N 10.00 9.50 -5.0% N 2.00 1.80 -10.0% N * iso -butane used as standard. Low level was reported either as percent (0.9%) or percent of LEL (49

  13. Thermal Degradation Studies of Polyurethane/POSS Nanohybrid Elastomers

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, J P; Pielichowski, K; TremblotDeLaCroix, P; Janowski, B; Todd, D; Liggat, J J


    Reported here is the synthesis of a series of Polyurethane/POSS nanohybrid elastomers, the characterization of their thermal stability and degradation behavior at elevated temperatures using a combination of Thermal Gravimetric Analysis (TGA) and Thermal Volatilization Analysis (TVA). A series of PU elastomers systems have been formulated incorporating varying levels of 1,2-propanediol-heptaisobutyl-POSS (PHIPOSS) as a chain extender unit, replacing butane diol. The bulk thermal stability of the nanohybrid systems has been characterized using TGA. Results indicate that covalent incorporation of POSS into the PU elastomer network increase the non-oxidative thermal stability of the systems. TVA analysis of the thermal degradation of the POSS/PU hybrid elastomers have demonstrated that the hybrid systems are indeed more thermally stable when compared to the unmodified PU matrix; evolving significantly reduced levels of volatile degradation products and exhibiting a {approx}30 C increase in onset degradation temperature. Furthermore, characterization of the distribution of degradation products from both unmodified and hybrid systems indicate that the inclusion of POSS in the PU network is directly influencing the degradation pathways of both the soft and hard block components of the elastomers: The POSS/PU hybrid systems show reduced levels of CO, CO2, water and increased levels of THF as products of thermal degradation.

  14. On the controlling mechanism of the upper turnover states in the NTC regime

    KAUST Repository

    Ji, Weiqi


    Using n-butane, n-heptane and iso-octane as representative fuels exhibiting NTC (negative temperature coefficient) behavior, comprehensive computational studies with detailed mechanisms and theoretical analysis were performed to investigate the upper stationary point, denoted as turnover states, on the NTC curve near the higher temperature regime, where the ignition delay τ exhibits a local maximum. It is found that the global behavior of the turnover states exhibits distinctive thermodynamic and kinetic characteristics under different pressures, in that the ignition delay at the turnover states shows an Arrhenius dependence on the temperature T and an approximate inverse quadratic power law dependence on the pressure P. These global behaviors imply that the temperature and pressure of the turnover states are not independent and can be correlated by Arrhenius dependence, as ln P ∝ 1/T. Further theoretical analyses demonstrate that such turnover states result from the competition between the low-temperature chain branching reactions and the decomposition of the intermediate species, and therefore correspond to a critical value, α, of the ratio of OH production from low-temperature chemistry. In addition, the ignition delay at the turnover state can be well correlated by the analytical expression derived by Peters et al., with the further demonstration that the pressure dependence of the turnover ignition delay mainly result from the H2O2 decomposition reaction. Comparison of the present results with the literature experimental data of n-heptane ignition delay time shows very good agreement.

  15. Application of geo-microbial prospecting method for finding oil and gas reservoirs (United States)

    Rasheed, M. A.; Hasan, Syed Zaheer; Rao, P. L. Srinivasa; Boruah, Annapurna; Sudarshan, V.; Kumar, B.; Harinarayana, T.


    Microbial prospecting of hydrocarbons is based on the detection of anomalous population of hydrocarbon oxidizing bacteria in the surface soils, indicates the presence of subsurface oil and gas accumulation. The technique is based on the seepage of light hydrocarbon gases such as C1-C4 from the oil and gas pools to the shallow surface that provide the suitable conditions for the development of highly specialized bacterial population. These bacteria utilize hydrocarbon gases as their only food source and are found enriched in the near surface soils above the hydrocarbon bearing structures. The methodology involves the collection of soil samples from the survey area, packing, preservation and storage of samples in pre-sterilized sample bags under aseptic and cold conditions till analysis and isolation and enumeration of hydrocarbon utilizing bacteria such as methane, ethane, propane, and butane oxidizers. The contour maps for the population density of hydrocarbon oxidizing bacteria are drawn and the data can be integrated with geological, geochemical, geophysical methods to evaluate the hydrocarbon prospect of an area and to prioritize the drilling locations thereby reducing the drilling risks and achieve higher success in petroleum exploration. Microbial Prospecting for Oil and Gas (MPOG) method success rate has been reported to be 90%. The paper presents details of microbial prospecting for oil and gas studies, excellent methodology, future development trends, scope, results of study area, case studies and advantages.

  16. Tuning the microstructures of decavanadate-based supramolecular hybrids via regularly changing the spacers of bis(triazole) ligands (United States)

    Wang, Mo; Sun, Wenlong; Pang, Haijun; Ma, Huiyuan; Yu, Jia; Zhang, Zhuanfang; Niu, Ying; Yin, Mingming


    With tuning the ligands from bte, btp, btb to bth, four new decavanadate-based metal-organic hybrid compounds, [Zn(bte)(H2O)4][Zn2(bte)(H2O)10](V10O28)·8H2O, [Zn2(btp)4(H2O)6](H2V10O28)·4H2O, [Zn(H2O)6][Zn2(btb)2V10O28(H2O)6]·4H2O, and [Zn2(bth)(H2O)10](H2V10O28)·6H2O (bte=1,2-bis(1,2,4-triazol-1-yl)ethane, btp=1,3-bis(1,2,4-triazol-1-y1)propane, btb=1,4-bis(1,2,4-triazol-1-y1)butane, bth=1,6-bis(1,2,4-triazol-1-y1)hexane), have been synthesized under conventional conditions. The four compounds represent the first examples of decavanadate-based metal-organic hybrids constructed by Zn-bis(triazole) complexes. Their structural analyses show that the four compounds possess different Zn-bis(triazole) structural motifs and various finally structures, which verifies that regular changing the spacers of ligands is an effective strategy to tuning the structures of polyoxometalate-based hybrids. Also, the electrochemical studies show that the compounds have good electrocatalytic activities towards oxidation of nitrite molecules ascribed to V-centers.

  17. Synthesis, properties and surface self-assembly of a pentanuclear cluster based on the new π-conjugated TTF-triazole ligand (United States)

    Cui, Long; Geng, Yan-Fang; Leong, Chanel F.; Ma, Qian; D'Alessandro, Deanna M.; Deng, Ke; Zeng, Qing-Dao; Zuo, Jing-Lin


    The new π-extended redox-active ligand with both TTF and triazole units, 6-(4,5-bis(propylthio)-1,3-dithiol-2-ylidene)-1H-[1,3]dithiolo[4‧,5‧:4,5]benzo [1,2-d] [1-3]triazole, has been successfully prepared. Based on the versatile ligand and Cu(tta)2 precursors (tta- = 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione), a TTF-based pentanuclear CuII cluster (Cu5(tta)4(TTFN3)6) is synthesized and structurally characterized. Their absorption and electrochemical properties are investigated. Antiferromagnetic couplings are operative between metal ion centers bridged by triazoles in the complex. The self-assembled structure of the cluster complex on a highly oriented pyrolytic graphite (HOPG) surface was observed using scanning tunneling microscopy and density functional theory (DFT) calculations have been performed to provide insight into the formation mechanism. The introduction of the redox-active TTF unit into the cluster complexes with interesting magnetic properties renders them promising candidates for new multifunctional materials.

  18. Economic benefits of carbon isotope fingerprint-logs used to determine source depths of migrating gas in heavy oil fields of Alberta and Saskatchewan

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, D.; Muehlenbachs, K. [Alberta Univ., Edmonton, AB (Canada); Jensen, E. [Amoco Canada Petroleum Co. Ltd., Calgary, AB (Canada)


    A method by which to identify the sources of gas migration from wells in heavy oil reservoirs was presented. Natural gas migration to surface presents an environmental and financial liability in oil fields in Alberta and Saskatchewan, particularly in those fields that have very close well spacings. Traditional geophysical or logging techniques have been unable to identify the source of these undesired gas emissions. This study showed that the problem does not originate from the heavy oil reservoirs, but from the shallower overlying shales. In this study, isotopic profiles of gases extracted from drilling muds were used to identify two gas sources and their depth. The gases associated with heavy oils originated as thermal cracking products. The shale gases are a mixture of bacterial methane and traces of ethane, propane and butane produced by incipient thermal cracking. Carbon isotope fingerprint logs in heavy oil fields were found to be useful in assessing potential environmental risks and ensure that remedial efforts are more cost efficient. 2 figs.

  19. Cool flames at terrestrial, partial, and near-zero gravity

    Energy Technology Data Exchange (ETDEWEB)

    Foster, Michael; Pearlman, Howard [Department of Mechanical Engineering and Mechanics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)


    Natural convection plays an important role in all terrestrial, Lunar, and Martian-based, unstirred, static reactor cool flame and low-temperature autoignitions, since the Rayleigh number (Ra) associated with the self-heating of the reaction exceeds the critical Ra (approximately 600) for onset of convection. At near-zero gravity, Ra<600 can be achieved and the effects of convection suppressed. To systematically vary the Ra without varying the mixture stoichiometry, reactor pressure, or vessel size, cool flames are studied experimentally in a closed, unstirred, static reactor subject to different gravitational accelerations (terrestrial, 1g; Martian, 0.38g; Lunar, 0.16g; and reduced gravity, {approx}10{sup -2}g). Representative results show the evolution of the visible light emission using an equimolar n-butane:oxygen premixture at temperatures ranging from 320 to 350? deg C (593-623 K) at subatmospheric pressures. For representative reduced-gravity, spherically propagating cool flames, the flame radius based on the peak light intensity is plotted as a function of time and the flame radius (and speed) is calculated from a polynomial fit to data. A skeletal chemical kinetic Gray-Yang model developed previously for a one-dimensional, reactive-diffusive system by Fairlie and co-workers is extended to a two-dimensional axisymmetric, spherical geometry. The coupled species, energy, and momentum equations are solved numerically and the spatio-temporal variations in the temperature profiles are presented. A qualitative comparison is made with the experimental results. (author)

  20. Near-surface hydrogen depletion of diamond-like carbon films produced by direct ion deposition

    Energy Technology Data Exchange (ETDEWEB)

    Markwitz, Andreas, E-mail: [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Gupta, Prasanth [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Mohr, Berit [GNS Science, Lower Hutt (New Zealand); Hübner, René [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Leveneur, Jerome; Zondervan, Albert [GNS Science, Lower Hutt (New Zealand); Becker, Hans-Werner [RUBION, Ruhr-University Bochum (Germany)


    Amorphous atomically flat diamond-like carbon (DLC) coatings were produced by direct ion deposition using a system based on a Penning ion source, butane precursor gas and post acceleration. Hydrogen depth profiles of the DLC coatings were measured with the 15N R-NRA method using the resonant nuclear reaction {sup 1}H({sup 15}N, αγ){sup 12}C (E{sub res} = 6.385 MeV). The films produced at 3.0–10.5 kV acceleration voltage show two main effects. First, compared to average elemental composition of the film, the near-surface region is hydrogen depleted. The increase of the hydrogen concentration by 3% from the near-surface region towards the bulk is attributed to a growth model which favours the formation of sp{sup 2} hybridised carbon rich films in the film formation zone. Secondly, the depth at which the maximum hydrogen concentration is measured increases with acceleration voltage and is proportional to the penetration depth of protons produced by the ion source from the precursor gas. The observed effects are explained by a deposition process that takes into account the contributions of ion species, hydrogen effusion and preferential displacement of atoms during direct ion deposition.