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Sample records for residual hydrocarbon mixture

  1. Thermophysical Properties of Hydrocarbon Mixtures

    Science.gov (United States)

    SRD 4 NIST Thermophysical Properties of Hydrocarbon Mixtures (PC database for purchase)   Interactive computer program for predicting thermodynamic and transport properties of pure fluids and fluid mixtures containing up to 20 components. The components are selected from a database of 196 components, mostly hydrocarbons.

  2. Thermal Adsorption Processing Of Hydrocarbon Residues

    Directory of Open Access Journals (Sweden)

    Sudad H. Al.

    2017-04-01

    Full Text Available The raw materials of secondary catalytic processes must be pre-refined. Among these refining processes are the deasphalting and demetallization including their thermo adsorption or thermo-contact adsorption variety. In oil processing four main processes of thermo-adsorption refining of hydrocarbon residues are used ART Asphalt Residual Treating - residues deasphaltizing 3D Discriminatory Destructive Distillation developed in the US ACT Adsorption-Contact Treatment and ETCC Express Thermo-Contact Cracking developed in Russia. ART and ACT are processes with absorbers of lift type reactor while 3D and ETCC processes are with an adsorbing reactor having ultra-short contact time of the raw material with the adsorbent. In all these processes refining of hydrocarbon residues is achieved by partial Thermo-destructive transformations of hydrocarbons and hetero-atomic compounds with simultaneous adsorption of the formed on the surface of the adsorbents resins asphaltene and carboids as well as metal- sulphur - and nitro-organic compounds. Demetallized and deasphalted light and heavy gas oils or their mixtures are a quality raw material for secondary deepening refining processes catalytic and hydrogenation cracking etc. since they are characterized by low coking ability and low content of organometallic compounds that lead to irreversible deactivation of the catalysts of these deepening processes.

  3. Toxicity of Flare and Crude Hydrocarbon Mixtures

    Directory of Open Access Journals (Sweden)

    Sonja V. Cook

    2002-01-01

    Full Text Available The toxicity of whole, saturate, and aromatic hydrocarbon mixtures from flare pit and crude oil sources were evaluated using Lumbricus terrestris. Body burden analysis was used to analyze the intrinsic toxicity of the six hydrocarbon mixtures. The major fractions of the whole mixtures, the saturate, and aromatic fractions had different intrinsic toxicities; the aromatics were more toxic than the saturates. The toxicity of the saturate and aromatic fractions also differed between the mixtures. The flare saturate mixture was more toxic than the crude saturate mixture, while the crude aromatic mixture was more toxic than the flare aromatic mixture. The most dramatic difference in toxicity of the two sources was between the flare whole and crude whole mixtures. The crude whole mixture was very toxic; the toxicity of this mixture reflected the toxicity of the crude aromatic fraction. However, the flare whole mixture was not toxic, due to a lack of partitioning from the whole mixture into the lipid membrane of the exposed worms. This lack of partitioning appears to be related to the relatively high concentrations of asphaltenes and polar compounds in the flare pit whole mixture.

  4. Nitrocarburising in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammoniapropene- hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

  5. Nitrocarburizing in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammonia-propene-hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

  6. hydrocarbon mixtures: Phase strength analysis

    Indian Academy of Sciences (India)

    Unknown

    In case of each type of binary mixture, there were five samples with different molar ratio (MR) ... Philips X-ray diffractometer, type PW1710. The operating conditions were: 25 mA current at 40 kV potential; Co- ..... ned only as a dream of the authors. The authors are since- rely thankful to Dr D Banerjee, Director, Defence.

  7. Pool Boiling of Hydrocarbon Mixtures on Water

    Energy Technology Data Exchange (ETDEWEB)

    Boee, R.

    1996-09-01

    In maritime transport of liquefied natural gas (LNG) there is a risk of spilling cryogenic liquid onto water. The present doctoral thesis discusses transient boiling experiments in which liquid hydrocarbons were poured onto water and left to boil off. Composition changes during boiling are believed to be connected with the initiation of rapid phase transition in LNG spilled on water. 64 experimental runs were carried out, 14 using pure liquid methane, 36 using methane-ethane, and 14 using methane-propane binary mixtures of different composition. The water surface was open to the atmosphere and covered an area of 200 cm{sup 2} at 25 - 40{sup o}C. The heat flux was obtained by monitoring the change of mass vs time. The void fraction in the boiling layer was measured with a gamma densitometer, and a method for adapting this measurement concept to the case of a boiling cryogenic liquid mixture is suggested. Significant differences in the boil-off characteristics between pure methane and binary mixtures revealed by previous studies are confirmed. Pure methane is in film boiling, whereas the mixtures appear to enter the transitional boiling regime with only small amounts of the second component added. The results indicate that the common assumption that LNG will be in film boiling on water because of the high temperature difference, may be questioned. Comparison with previous work shows that at this small scale the results are influenced by the experimental apparatus and procedures. 66 refs., 76 figs., 28 tabs.

  8. Performance of a Throttle Cycle Refrigerator with Nitrogen-Hydrocarbon and Argon-Hydrocarbon Mixtures

    Science.gov (United States)

    Venkatarathnam, G.; Senthil Kumar, P.; Srinivasa Murthy, S.

    2004-06-01

    Throttle cycle refrigerators are a class of vapor compression refrigerators that can provide refrigeration at cryogenic temperatures and operate with refrigerant mixtures. The performance of our prototype refrigerators with nitrogen-hydrocarbon, nitrogen-hydrocarbon-helium and argon-hydrocarbon refrigerant mixtures is presented in this paper.

  9. Detecting chlorinated hydrocarbon residues: Rachel Carson's villains.

    Science.gov (United States)

    Travis, Anthony S

    2012-07-01

    In 1962, Rachel Carson's Silent Spring drew the public's attention to the deleterious effects of chlorinated hydrocarbons employed as economic poisons in agriculture. However, she did not discuss how their residues could be routinely identified and quantified. In part, this was because the introduction of instruments for use in environmental analysis had only just begun, and she was probably unaware of their existence. The development of the instrumental methods began in industry, particularly at Dow and Shell, in the mid-1950s. Dow scientists, by combining mass spectrometry with gas chromatography, developed the most powerful technique, then and now, for the separation, quantitation and identification of chlorinated hydrocarbons. Shell scientists were no less innovative, particularly with the application of highly sensitive gas chromatography detectors to trace analysis. The first of these detectors, the electron capture detector, was invented by James Lovelock at the National Institute of Medical Research, North London, at the end of the 1950s. Around the same time, Dale Coulson in the USA developed his microcoulometric detector.

  10. Superlattice configurations in linear chain hydrocarbon binary mixtures

    Indian Academy of Sciences (India)

    Unknown

    of n-C28H58 hydrocarbon, through an angle mθ, where m = 1, 2, 3 … and angle θ has an average value of. 3.3°. Supporting literature ... Keywords. Long-chain alkanes; binary mixtures; superlattices; discrete orientational changes. 1. Introduction ... tem and a model of superlattice configuration was proposed4, in terms of ...

  11. Interpreting residues of petroleum hydrocarbons in wildlife tissues

    International Nuclear Information System (INIS)

    Hall, R.J.; Coon, N.C.

    1988-08-01

    This report is the first publication in the field of environmental-contaminant effects on wildlife to tell the reader how to interpret the results of analytical chemical results. Specifically, the publication describes how to interpret residues of petroleum hydrocarbons in wildlife tissues. Pollutant oil residues in avian species are emphasized

  12. Solvation of hydrocarbons in aqueous-organic mixtures

    International Nuclear Information System (INIS)

    Sedov, I.A.; Magsumov, T.I.; Solomonov, B.N.

    2016-01-01

    Highlights: • Thermodynamic functions of solvation in mixtures of water with acetone and acetonitrile are measured at T = 298.15 K. • Solvation of n-octane and toluene in aqueous-organic mixtures is studied. • When increasing water content, Gibbs free energies grow up steadily, while enthalpies have a maximum. • Hydrocarbons are preferentially solvated with organic cosolvent even in mixtures with rather high water content. • Acetonitrile suppresses the hydrophobic effect less than acetone. - Abstract: We study the solvation of two hydrocarbons, n-octane and toluene, in binary mixtures of water with organic cosolvents. Two polar aprotic cosolvents that are miscible with water in any proportions, acetonitrile and acetone, were considered. We determine the magnitudes of thermodynamic functions of dissolution and solvation at T = 298.15 K in the mixtures with various compositions. Solution calorimetry was used to measure the enthalpies of solution, and GC headspace analysis was applied to obtain limiting activity coefficients of solutes in the studied systems. For the first time, the enthalpies of solution of alkane in the mixtures with high water content were measured directly. We observed well-pronounced maxima of the dependencies of enthalpies of solvation from the composition of solvent and no maxima for the Gibbs free energies of solvation. Two factors are concluded to be important to explain the observed tendencies: high energy cost of reorganization of binary solvent upon insertion of solute molecules and preferential surrounding of hydrocarbons with the molecules of organic cosolvent. Enthalpy-entropy compensation leads to a steady growth of the Gibbs free energies with increasing water content. On the other hand, consideration of the plots of the Gibbs free energy against enthalpy of solvation clearly shows that the solvation properties are changed dramatically after addition of a rather small amount of organic cosolvents. It is shown that they

  13. Surfactant Membrane Phases Containing Mixtures of Hydrocarbon and Fluorocarbon Surfactants

    International Nuclear Information System (INIS)

    de Campo, Liliana; Warr, G.G.

    2005-01-01

    Full text: We describe the structure and stability of sponge and lamellar phases comprising mixtures of hydrocarbon and fluorocarbon surfactants. Such mixtures can show limited miscibility with each other, forming for example coexisting populations of hydrocarbon rich and fluorocarbon rich micelles under some circumstances. Our system is based on the well-characterised lamellar and sponge phases of cetylpyridinium chloride, hexanol and 0.2M brine, into which the partially fluorinated surfactant N-1H,1H,2H,2H-tridecafluorooctylpyridinium chloride is incorporated. By probing the structures with SAXS (small angle x-ray scattering) and SANS (small angle neutron scattering) using contrast variation, and by characterizing the dynamic properties with dynamic light scattering, we will describe the effect of incorporating the fluorinated surfactant on the phase equilibria and properties of the surfactant membrane structures. (authors)

  14. Viscosity Prediction of Hydrocarbon Mixtures Based on the Friction Theory

    DEFF Research Database (Denmark)

    Zeberg-Mikkelsen, Claus Kjær; Cisneros, Sergio; Stenby, Erling Halfdan

    2001-01-01

    The application and capability of the friction theory (f-theory) for viscosity predictions of hydrocarbon fluids is further illustrated by predicting the viscosity of binary and ternary liquid mixtures composed of n-alkanes ranging from n-pentane to n-decane for wide ranges of temperature and from...... low to high pressures. In the f-theory viscosity predictions the SRK and the PRSV EOS have respectively been used. Further, a comparison with the widely used LBC viscosity model shows that better results are obtained with the f-theory models. The obtained AAD% is within or close to the experimental...

  15. Performance prediction of rotary compressor with hydrocarbon refrigerant mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Park, M.W.; Chung, Y.G. [Hanyang University Graduate School, Seoul (Korea); Park, K.W. [LG Industrial System Corporation Limited (Korea); Park, H.Y. [Hanyang University, Seoul (Korea)

    1999-04-01

    This paper presents the modeling approach that can be predicted transient behavior of rotary compressor. Mass and energy conservation laws are applied to the control volume, and real gas state equation is used to obtain thermodynamic properties of refrigerant. The valve equation is solved to analyze discharge process also. Dynamic analysis of vane and roller is carried out to gain friction work. From above modeling, the performance of rotary compressor with radial clearance and friction loss is investigated numerically. The performance of each refrigerant and the possibility of using the hydrocarbon refrigerant mixtures in an existing rotary compressor are estimated by applying R12, R134a, R290/R600a mixture also. (author). 6 refs., 13 figs., 1 tab.

  16. Residual-based model diagnosis methods for mixture cure models.

    Science.gov (United States)

    Peng, Yingwei; Taylor, Jeremy M G

    2017-06-01

    Model diagnosis, an important issue in statistical modeling, has not yet been addressed adequately for cure models. We focus on mixture cure models in this work and propose some residual-based methods to examine the fit of the mixture cure model, particularly the fit of the latency part of the mixture cure model. The new methods extend the classical residual-based methods to the mixture cure model. Numerical work shows that the proposed methods are capable of detecting lack-of-fit of a mixture cure model, particularly in the latency part, such as outliers, improper covariate functional form, or nonproportionality in hazards if the proportional hazards assumption is employed in the latency part. The methods are illustrated with two real data sets that were previously analyzed with mixture cure models. © 2016, The International Biometric Society.

  17. Properties of Direct Coal Liquefaction Residue Modified Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    Jie Ji

    2017-01-01

    Full Text Available The objectives of this paper are to use Direct Coal Liquefaction Residue (DLCR to modify the asphalt binders and mixtures and to evaluate the performance of modified asphalt mixtures. The dynamic modulus and phase angle of DCLR and DCLR-composite modified asphalt mixture were analyzed, and the viscoelastic properties of these modified asphalt mixtures were compared to the base asphalt binder SK-90 and Styrene-Butadiene-Styrene (SBS modified asphalt mixtures. The master curves of the asphalt mixtures were shown, and dynamic and viscoelastic behaviors of asphalt mixtures were described using the Christensen-Anderson-Marasteanu (CAM model. The test results show that the dynamic moduli of DCLR and DCLR-composite asphalt mixtures are higher than those of the SK-90 and SBS modified asphalt mixtures. Based on the viscoelastic parameters of CAM models of the asphalt mixtures, the high- and low-temperature performance of DLCR and DCLR-composite modified asphalt mixtures are obviously better than the SK-90 and SBS modified asphalt mixtures. In addition, the DCLR and DCLR-composite modified asphalt mixtures are more insensitive to the frequency compared to SK-90 and SBS modified asphalt mixtures.

  18. Kinetics of biodegradation of mixtures of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Lotfabad, S.K.; Gray, M.R. [Alberta Univ., Edmonton (Canada). Dept. of Chemical and Materials Engineering

    2002-11-01

    The kinetics of biodegradation of polycyclic aromatic hydrocarbons (PAHs) by a mixed culture were determined in a creosote-contaminated soil and in a pristine soil. A competitive-inhibition model was able to represent the kinetics of degradation of PAHs from the creosote-contaminated soil, from the lag phase through to active degradation, but not data from pristine soil with the same PAHs alone and in mixtures. The presence of phenanthrene introduced a lag phase of 4.5 days in the degradation of fluoranthene and 5 days for chrysene. Rapid degradation of pyrene followed a lag phase of circa 5 days, regardless of the presence of other PAHs. These results show that even when kinetics of PAH degradation by mixed cultures appear to follow competitive-inhibition kinetics, the underlying mechanisms may be more complex. (orig.)

  19. 40 CFR Table 2b to Subpart E of... - Reactivity Factors for Aliphatic Hydrocarbon Solvent Mixtures

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Reactivity Factors for Aliphatic Hydrocarbon Solvent Mixtures 2B Table 2B to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Averageboiling point * (degrees F) Criteria Reactivityfactor 1 80-205 Alkanes...

  20. 40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Boiling range (degrees F) Criteria Reactivityfactor 21 280-290 Aromatic...

  1. Experimental study of hydrocarbon mixtures to replace HFC-134a in a domestic refrigerator

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Chimres, Nares

    2005-01-01

    This work presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in a domestic refrigerator. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). A refrigerator designed to work with HFC-134a with a gross capacity of 239 l is used in the experiment. The consumed energy, compressor power and refrigerant temperature and pressure at the inlet and outlet of the compressor are recorded and analysed as well as the distributions of temperature at various positions in the refrigerator. The refrigerant mixtures used are divided into three groups: the mixture of three hydrocarbons, the mixture of two hydrocarbons and the mixture of two hydrocarbons and HFC-134a. The experiments are conducted with the refrigerants under the same no load condition at a surrounding temperature of 25 deg. C. The results show that propane/butane 60%/40% is the most appropriate alternative refrigerant to HFC-134a

  2. Irresolvable complex mixture of hydrocarbons in soybean oil deodorizer distillate.

    Science.gov (United States)

    Ju, Yi-Hsu; Huynh, Lien-Huong; Gunawan, Setiyo; Chern, Yaw-Terng; Kasim, Novy S

    2012-01-01

    Aliphatic hydrocarbons (HCs) can be used as a fingerprint of a given seed oil. Only by characterization of aliphatic HCs could contamination by mineral oil in that seed oil be confirmed. During the isolation of squalene from soybean oil deodorizer distillate, a significant amount of unknown HCs, ca. 44 wt%, was obtained. These seemingly-easy-to-identify HCs turned out to be much more difficult to elucidate due to the presence of an irresolvable complex mixture (ICM). The objective of this study was to purify and identify the unknown ICM of aliphatic HCs from soybean oil deodorizer distillate. Purification of the ICM was successfully achieved by using modified Soxhlet extraction, followed by modified preparative column chromatography, and finally by classical preparative column chromatography. FT-IR, TLC, elemental analysis, GC/FID, NMR and GC-MS analyses were then performed on the purified HCs. The GC chromatogram detected the presence of ICM peaks comprising two major peaks and a number of minor peaks. Validation methods such as IR and NMR justified that the unknowns are saturated HCs. This work succeeded in tentatively identifying the two major peaks in the ICM as cycloalkane derivatives. Copyright © 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Compendium of shock wave data. Section C. Organic compounds excluding hydrocarbons. Section D. Mixtures. Section E. Mixtures and solutions without chemical characterization. Compendium index

    International Nuclear Information System (INIS)

    van Thiel, M.; shaner, J.; Salinas, E.

    1977-06-01

    This volume lists thermodynamic data for organic compounds excluding hydrocarbons, mixtures, and mixtures and solutions without chemical characterization. Alloys and some minerals are included among the mixtures. This volume also contains the index for the three-volume compendium

  4. Epigenetic toxicity of a mixture of polycyclic aromatic hydrocarbons on gap functional intercellular communication before and after biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Ghoshal, S. [McGill Univ., Montreal, Quebec (Canada). Dept. of Civil Engineering and Applied Mechanics; Weber, W.J. Jr. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Civil and Environmental Engineering; Rummel, A.M.; Trosko, J.E.; Upham, B.L. [Michigan State Univ., East Lansing, MI (United States)

    1999-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are known carcinogens, but most research on their toxicity in the development of human-risk assessment models has focused on genotoxicity. Many nongenotoxic PAHs, however, have been shown to be epigenetically toxic by disrupting gap junctional intercellular communication (GJIC), an effect which has been affiliated with tumor promotion. The authors therefore used GJIC as an epigenetic biomarker to assess the toxic effect of a nonaqueous phase liquid (NAPL) mixture of PAHs commonly found in coal tar and creosote products. The NAPL mixture consisted of toluene, naphthalene, 1-methylnaphthalene, 2-ethylnaphthalene, acenaphthene, fluorene, phenanthrene, fluoranthene, and pyrene. This mixture reversibly inhibited GJIC at a maximal and noncytotoxic dose of 60 {micro}M. Inhibition occurred within 5 min, indicating a post-translational modification of gap junction proteins. Biodegradation of globules of this mixture suspended in mineral media by a microorganism isolated from creosote-contaminated soils resulted in the removal of all but three heavy PAHs: acenaphthene, pyrene, and fluoranthene. A reconstituted mixture of these three compounds showed results on GJIC activity identical to the original mixture relative to dose-, rate-, and time-responses, indicating that the toxicity of the PAHs was additive. The results suggest that bioremediation techniques that leave residual components of such NAPL mixtures in contaminated media can quantitatively but not qualitatively reduce their epigenetic toxic risk. Nonetheless, such bioresistant residuals may be environmentally less mobile than the biodegraded components of the precursor NAPLs.

  5. Improving exposure assessment of complex hydrocarbon mixtures in the aquatic environment

    NARCIS (Netherlands)

    Muijs, B.

    2011-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) and oil are complex organic mixtures which are ubiquitously present in the aquatic environment. To prevent adverse effects on organisms exposed to these contaminants adequate risk assessment is of vital importance. However, current available methods are

  6. A study of low hydrocarbon content gas mixtures for streamer tubes

    International Nuclear Information System (INIS)

    Baldini Celio, R.; Bencivenni, G.; Bossi, F.

    1988-01-01

    Several gas mixtures have been tested in order to reduce the hydrocarbon content for the operation of 1x1 cm 2 streamer tubes for the Aleph hadron calorimeter. It has been found that the use of n-hexane in place of n-pentane allow a safer operation of streamer tubes at reduced fractions of hydrocarbon. The use of non flammable gas mixtures is discussed

  7. Biodegradation pattern of hydrocarbons from a fuel oil-type complex residue by an emulsifier-producing microbial consortium.

    Science.gov (United States)

    Nievas, M L; Commendatore, M G; Esteves, J L; Bucalá, V

    2008-06-15

    The biodegradation of a hazardous waste (bilge waste), a fuel oil-type complex residue from normal ship operations, was studied in a batch bioreactor using a microbial consortium in seawater medium. Experiments with initial concentrations of 0.18 and 0.53% (v/v) of bilge waste were carried out. In order to study the biodegradation kinetics, the mass of n-alkanes, resolved hydrocarbons and unresolved complex mixture (UCM) hydrocarbons were assessed by gas chromatography (GC). Emulsification was detected in both experiments, possibly linked to the n-alkanes depletion, with differences in emulsification start times and extents according to the initial hydrocarbon concentration. Both facts influenced the hydrocarbon biodegradation kinetics. A sequential biodegradation of n-alkanes and UMC was found for the higher hydrocarbon content. Being the former growth associated, while UCM biodegradation was a non-growing process showing enzymatic-type biodegradation kinetics. For the lower hydrocarbon concentration, simultaneous biodegradation of n-alkanes and UMC were found before emulsification. Nevertheless, certain UCM biodegradation was observed after the medium emulsification. According to the observed kinetics, three main types of hydrocarbons (n-alkanes, biodegradable UCM and recalcitrant UCM) were found adequate to represent the multicomponent substrate (bilge waste) for future modelling of the biodegradation process.

  8. The application of hydrocarbon refrigerant mixtures in a hermetic reciprocating compressor for high back pressure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.M.; Pak, H.Y. [Hanyang University, Seoul (Korea)

    1999-03-01

    The application of hydrocarbon refrigerant mixtures in a hermetic reciprocating compressor for dehumidifier is investigated. The selected refrigerants are R12, R134a, HC-Blend(R290/R600a), CX(R152a/R600a) and OS-12a. Both theoretical and experimental investigations have been performed for the selected refrigerants. The test results of hydrocarbon refrigerants have been compared to traditional refrigerant(R12) and R134a. The results show that hydrocarbon refrigerant mixtures(HC-Blend, CX and OS-12a) are very good alternatives in the refrigeration system for R12 and R134a. 11 refs., 3 fig., 12 tabs.

  9. A novel approach to predict the excess volume of hydrocarbon mixtures

    NARCIS (Netherlands)

    Finkers, H. J.; Bosma, J. C.; Broekhuis, A. A.

    2011-01-01

    This paper explores whether principles obtained for the packing of solid macroscopic particles can be applied to the study of excess volumes of liquid mixtures. The approach is applied to mixtures of 'pure' hydrocarbons, i.e. containing only C- and H-atoms. In this new approach a set of equations

  10. Occurrence and Toxicity of Hydrocarbon Residues in Crab ...

    African Journals Online (AJOL)

    To elucidate seasonal changes in hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) due to oil spill, tissues of blue crab (Callinectes sapidus) were investigated. Total petroleum hydrocarbons (n-alkanes) concentrations ranged from 0.17-0.32ìg/gdw and 0.28-0.62ìg/gdw during the dry and wet seasons ...

  11. Superlattice configurations in linear chain hydrocarbon binary mixtures

    Indian Academy of Sciences (India)

    monoclinic, monoclinic-monoclinic) are realizable, because of discrete orientational changes in the alignment of molecules of -C28H58 hydrocarbon, through an angle , where = 1, 2, 3 … and angle has an average value of 3.3°.

  12. Liquid + liquid equilibria for ternary mixtures of (solvent + aromatic hydrocarbon + alkane)

    International Nuclear Information System (INIS)

    Mohsen-Nia, M.; Modarress, H.; Doulabi, F.; Bagheri, H.

    2005-01-01

    Liquid + liquid equilibrium (LLE) results for the ternary mixtures of (solvent + aromatic hydrocarbon + alkane) at different temperatures from (298.15 to 313.15) K are reported, where the aromatic hydrocarbon is toluene or m-xylene and the alkane is n-heptane or n-octane or cyclohexane and the solvent is tetramethylene sulfone (i.e., sulfolane) or dimethyl sulfoxide (DMSO) or ethylene carbonate. The data were correlated with the UNIQUAC and NRTL equations. The partition coefficients and the selectivity factor of the solvents are calculated. Then, the selectivity of solvents for the extraction of aromatic hydrocarbons from alkanes has been compared. The phase diagrams for the ternary mixtures are presented and the correlated tie line results have been compared with the experimental data. The comparisons indicate the applicability of the UNIQUAC and NRTL activity coefficients model for liquid + liquid equilibrium calculations of the studied mixtures

  13. Carbon/Hydrogen ratio determination in hydrocarbons and its mixtures by electron backscattering technique

    International Nuclear Information System (INIS)

    Padron, I.; Desdin, L.F.; Navarro, A.; Fuentes, M.

    1996-01-01

    A method carbon/hydrogen ratio (C/H) determination in hydrocarbons and its mixtures was improved using the electron backscattering technique. Besides the hetero atoms (S,O and N) influence in petroleum is studied for being able to determinate the C/H ratio in cuban petroleum with high sulphur contents

  14. Application of the cubic-plus-association (CPA) equation of state to complex mixtures with aromatic hydrocarbons

    DEFF Research Database (Denmark)

    Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2006-01-01

    The cubic-plus-association (CPA) equation of state is applied to phase equilibria of mixtures containing alcohols, glycols, water, and aromatic or olefinic hydrocarbons. Previously, CPA has been successfully used for mixtures containing various associating compounds (alcohols, glycols, amines...... of the model (the Soave-Redlich-Kwong (SRK) equation of state) can be obtained from mixtures with aliphatic hydrocarbons. For mixtures of glycols with aromatic hydrocarbons, two parameters have been fitted to experimental data, one in the physical (SRK) part and one in the association part of the model...

  15. Gas-liquid-liquid equilibria in mixtures of water, light gases, and hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Chao, K.C.

    1990-01-01

    Phase equilibrium in mixtures of water + light gases and water + heavy hydrocarbons has been investigated with the development of new local composition theory, new equations of state, and new experimental data. The preferential segregation and orientation of molecules due to different energies of molecular interaction has been simulated with square well molecules. Extensive simulation has been made for pure square well fluids and mixtures to find the local composition at wide ranges of states. A theory of local composition has been developed and an equation of state has been obtained for square well fluids. The new local composition theory has been embedded in several equations of state. The pressure of water is decoupled into a polar pressure and non-polar pressure according to the molecular model of water of Jorgensen et al. The polar pressure of water is combined with the BACK equation for the general description of polar fluids and their mixtures. Being derived from the steam table, the Augmented BACK equation is particularly suited for mixtures of water + non-polar substances such as the hydrocarbons. The hydrophobic character of the hydrocarbons had made their mixtures with water a special challenge. A new group contribution equation of state is developed to describe phase equilibrium and volumetric behavior of fluids while requiring only to know the molecular structure of the components. 15 refs., 1 fig.

  16. Experimental investigation of hydrocarbon mixtures to replace HFC-134a in an automotive air conditioning system

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Kamboon, Amnouy; Orachon, Banchob

    2006-01-01

    This paper presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in automotive air conditioners. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). The measured data are obtained from an automotive air conditioning test facility utilizing HFC-134a as the refrigerant. The air conditioner, with a capacity of 3.5 kW driven by a Diesel engine, is charged and tested with four different ratios of hydrocarbon mixtures. The experiments are conducted at the same surrounding conditions. The temperature and pressure of the refrigerant at every major position in the refrigerant loop, the temperature, flow rate and humidity of air, torque and engine speed are recorded and analyzed. The parameters investigated are the refrigeration capacity, the compressor power and the coefficient of performance (COP). The results show that propane/butane/isobutane: 50%/40%/10% is the most appropriate alternative refrigerant to replace HFC-134a, having the best performance of all the hydrocarbon mixtures investigated

  17. Mineral mixtures from solid salt residues for lambs

    Directory of Open Access Journals (Sweden)

    Daniel Bomfim Manera

    2014-09-01

    Full Text Available The objective of this study was to evaluate water, mineral, feed and nutrient voluntary intakes, in addition to dry matter and nutrient digestibility and the nitrogen balance of lambs fed three mineral supplements. The first treatment consisted of solid salt residue (SSR from an aquaculture tank; the second contained SSR from desalination waste; and the third treatment was control, which corresponded to the supplementation of a commercial mineral supplement. The study lasted 20 days, the first 15 of which were used for animals to adapt to the pens and diets, and the last five days were used for data collection. Twenty-four castrated male lambs with a body weight of 19.72±2.52 kg were utilized in the experiment. The mineral supplements evaluated did not affect the intake and digestibility of the dry matter and nutrients, the water and mineral-salt intake or nitrogen balance. Mineral supplements produced from the SSR from aquaculture tanks and from the desalination waste did not reduce feed, nutrient and water intakes or nutrient digestibility, which suggests that these raw materials can be used in the elaboration of mineral mixtures for lambs.

  18. Numerical investigation of boiling heat transfer on hydrocarbon mixture refrigerant in vertical rectangular minichannel

    OpenAIRE

    Huixing Li; Yu Liu

    2016-01-01

    In order to investigate the characteristics of boiling heat transfer for hydrocarbon mixture refrigerant in plate-fin heat exchanger which is used in the petrochemical industry field, a model was established on boiling heat transfer in vertical rectangular channel. The simulated results were compared with the experimental data from literature. The results show that the deviation between the simulated results and experimental data is within ±15%. Meanwhile, the characteristic of boiling heat t...

  19. Taguchi Method for Development of Mass Flow Rate Correlation Using Hydrocarbon Refrigerant Mixture in Capillary Tube

    OpenAIRE

    Sulaimon, Shodiya; Nasution, Henry; Aziz, Azhar Abdul; Abdul-Rahman, Abdul-Halim; Darus, Amer N

    2014-01-01

    The capillary tube is an important control device used in small vapor compression refrigeration systems such as window air-conditioners, household refrigerators and freezers. This paper develops a non-dimensional correlation based on the test results of the adiabatic capillary tube for the mass flow rate through the tube using a hydrocarbon refrigerant mixture of 89.3% propane and 10.7% butane (HCM). The Taguchi method, a statistical experimental design approach, was employed. This approach e...

  20. Biodegradation testing of hydrophobic chemicals in mixtures at low concentrations – covering the chemical space of petroleum hydrocarbons

    DEFF Research Database (Denmark)

    Birch, Heidi; Hammershøj, Rikke Høst; Mayer, Philipp

    Petroleum products are complex mixtures of varying composition containing thousands of hydrocarbons each with their own physicochemical properties and degradation kinetics. One approach for risk assessment of these products is therefore to group the hydrocarbons by carbon number and chemical class...

  1. DETERMINATION OF SOLID-LIQUID EQUILIBRIA DATA FOR MIXTURES OF HEAVY HYDROCARBONS IN A LIGHT SOLVENT

    Energy Technology Data Exchange (ETDEWEB)

    F.V. Hanson; J.V. Fletcher; Karthik R.

    2003-06-01

    A methodology was developed using an FT-IR spectroscopic technique to obtain solid-liquid equilibria (SLE) data for mixtures of heavy hydrocarbons in significantly lighter hydrocarbon diluents. SLE was examined in multiple Model Oils that were assembled to simulate waxes. The various Model oils were comprised of C-30 to C-44 hydrocarbons in decane. The FT-IR technique was used to identify the wax precipitation temperature (WPT). The DSC technique was also used in the identification of the onset of the two-phase equilibrium in this work. An additional Model oil made up of C-20 to C-30 hydrocarbons in decane was studied using the DSC experiment. The weight percent solid below the WPT was calculated using the FT-IR experimental results. The WPT and the weight percent solid below the WPT were predicted using an activity coefficient based thermodynamic model. The FT-IR spectroscopy method is found to successfully provide SLE data and also has several advantages over other laboratory-based methods.

  2. Analysis of ORC (Organic Rankine Cycle) systems with pure hydrocarbons and mixtures of hydrocarbon and retardant for engine waste heat recovery

    International Nuclear Information System (INIS)

    Song, Jian; Gu, Chun-wei

    2015-01-01

    The Organic Rankine Cycle (ORC) has been demonstrated to be a promising technology for the recovery of engine waste heat. Systems with hydrocarbons as the working fluids exhibit good thermal performance. However, the flammability of hydrocarbons limits their practical applications because of safety concerns. This paper examines the potential of using mixtures of a hydrocarbon and a retardant in an ORC system for engine waste heat recovery. Refrigerants R141b and R11 are selected as the retardants and blended with the hydrocarbons to form zeotropic mixtures. The flammability is suppressed, and in addition, zeotropic mixtures provide better temperature matches with the heat source and sink, which reduces the exergy loss within the heat exchange processes, thereby increasing the cycle efficiency. Energetic and exergetic analysis of ORC systems with pure hydrocarbons and with mixtures of a hydrocarbon and a retardant are conducted and compared. The net power output and the second law efficiency are chosen as the evaluation criteria to select the suitable working fluid compositions and to define the optimal set of thermodynamic parameters. The simulation results reveal that the ORC system with cyclohexane/R141b (0.5/0.5) is optimal for this engine waste heat recovery case, thereby increasing the net power output of the system by 13.3% compared to pure cyclohexane. - Highlights: • ORC with zeotropic mixtures for engine waste heat recovery is discussed. • Energetic and exergetic analysis of ORC system are conducted. • Optimal mixture working fluid composition is identified. • Greater utilization of jacket water and lower irreversible loss are important.

  3. [Biodegradability of the components of natural hydrocarbon mixtures previously submitted to landfarming].

    Science.gov (United States)

    Pucci, G N; Pucci, O H

    2003-01-01

    The complex composition of the crude oil and the hydrocarbons that integrate the waste of the different stages of the oil industry turn this product a mixture that presents different difficulties for its elimination by biological methods. The objective of this paper was to study the biodegradation potential of autochthonous bacterial communities on hydrocarbons obtained from four polluted places and subjected to landfarming biorremediation system during a decade. The results showed a marked difference in biodegradability of the three main fractions of crude oil, aliphatic, aromatic, and polar fractions, obtained by column chromatography. All fractions were used as carbon source and energy. There were variations in the production of biomass among the different fractions as well as in the kinetics of biodegradation, according to the composition of each fraction.

  4. Micellar Enhanced Ultrafiltration for the Removal of Polycyclic Aromatic Hydrocarbons (PAHs Mixtures in Underground Contaminated Water in Oman

    Directory of Open Access Journals (Sweden)

    Mohamed Aoudia

    2011-12-01

    Full Text Available In an attempt to analyze polycyclic aromatic hydrocarbons (PAHs in diesel contaminated underground water in Oman (Rustaq, Gas chromatography-Mass spectrometry was first used to determine the different concentrations in a standard mixture containing 16 PAHs. Retention time and calibration curves were obtained for all aromatic compounds and were used to identify a given analyte as well as its concentration in the contaminated underground water. Micellar enhanced ultrafiltration (MEUF was then used to treat standard aqueous solution of PAHs at low concentration (~ 1 ppb using an edible nonionic surfactant (Tween 80. The totality of the mixture components was completely rejected. Within the experimental detection limit (± 0.01 ppb, the residual PAH concentrations were less than 0.01 ppb in accord with the allowed concentrations in drinking water. Likewise, excellent rejections of PAHs in MEUF treatment of diesel contaminated underground water at an Omani site (Rustaq were observed. The concentration of PAHs was reduced to less than 0.01 ppb, the accepted limit for the most toxic member of the PAH group (benzo(apyrene.

  5. Mutagenic hazards of complex polycyclic aromatic hydrocarbon mixtures in contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, C.L.; Lambert, A.B.; Lundstedt, S.; Tysklind, M.; White, P.A. [Health Canada, Ottawa, ON (Canada). Safe Environment Program

    2008-04-15

    The objective of the present study was to evaluate hazard/risk assessment methods for complex environmental mixtures that involve a targeted, priority chemical approach based on the cumulative hazard/risk of known mixture components or analyses of sufficiently similar mixtures. Ten polycyclic aromatic hydrocarbon (PAH)-contaminated soils were separated into nonpolar and semipolar fractions, and both fractions elicited positive responses on the Salmonella reverse mutation assay. Targeted and nontargeted methods of hazard prediction routinely overestimated mutagenic activities for the nonpolar soil fractions, suggesting nonadditive interactions of PAHs in complex mixtures. This suggests that current risk assessment methods for complex mixtures may provide conservative estimates regarding soils contaminated with priority PAHs alone. Significant underestimations of total risk, however, will be obtained if the soils also contain unidentified PAHs as well as polycyclic aromatic compounds and related compounds that contribute to the total mutagenic activity. Furthermore, estimates of excess lifetime cancer risk associated with the nondietary ingestion of the PAH-contaminated soils studied here indicate that a traditional risk assessment model based on identified priority PAHs and an assumption of additivity generally underestimates the risk associated with the nonpolar soil fractions (in comparison to bioassay-derived risk estimates). Additional cancer risk may be associated with the more polar compounds that also are found at these contaminated sites and that rarely are included in the standard risk assessment methodology.

  6. Estimation of Freezing Point of Hydrocarbon and Hydrofluorocarbon Mixtures for Mixed Refrigerant jt Cryocooler

    Science.gov (United States)

    Hwang, G.; Lee, J.; Jeong, S.

    2010-04-01

    Estimating the freezing point of refrigerant is an essential part in designing an MR JT (Mixed refrigerant Joule-Thomson) cryocooler to prevent itself from clogging and to operate with stability. There were researches on estimating freezing point, but some of them resulted in the wrong prediction of clogging. In this paper, the freezing point of the MR is precisely estimated with caution of clogging. The solubility of HC (hydrocarbon) and HFC (hydrofluorocarbon) mixture components are obtained with their activity coefficients, which represent the molecular interaction among the components. The freezing points of the MR JT cryocooler are systematically investigated in the operating temperature range from 70 K to 90 K.

  7. Development of Reference Equations of State for Refrigerant Mixtures Including Hydrocarbons

    Science.gov (United States)

    Miyamoto, Hiroyuki; Watanabe, Koichi

    In recent years, most accurate equations of state for alternative refrigerants and their mixtures can easily be used via convenient software package, e.g., REFPROP. In the present paper, we described the current state-of-the-art equations of state for refrigerant mixtures including hydrocarbons as components. Throughout our discussion, the limitation of the available experimental data and the necessity of the improvement against the arbitrary fitting of recent modeling were confirmed. The enough number of reliable experimental data, especially for properties in the higher pressures and temperatures and for derived properties, should be accumulated in the near future for the development of the physically-sound theoretical background. The present review argued about the possibility of the progress for the future thermodynamic property modeling throughout the detailed discussion regarding the several types of the equations of state as well as the recent innovative measurement technique.

  8. Zeolitic imidazolate framework membranes and methods of making and using same for separation of c2- and c3+ hydrocarbons and separation of propylene and propane mixtures

    KAUST Repository

    Lai, Zhiping

    2012-12-06

    Certain embodiments are directed to processes for fabrication of zeolitic imidazolate framework (ZIF) membranes. These ZIF membranes can be used in separating C2-hydrocarbons from C3+ hydrocarbons and propylene/propane mixtures.

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

    Science.gov (United States)

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

    2017-11-21

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

  10. Short-term residual N unaffected by forbs in grass-clover mixtures

    DEFF Research Database (Denmark)

    Dhamala, Nawa Raj; Rasmussen, Jim; Cong, Wenfeng

    2017-01-01

    We determined the effect on residual nitrogen (N) of including forbs (chicory, ribwort plantain and caraway) in perennial ryegrass-red clover mixtures. Although soil N inputs during the grassland phase differed markedly between mixtures, in a pot experiment we found no differences...... in the potentially mineralizable N of the soil or in the dry matter production and N content of the spring barley test crop. The fertilizer value of the grassland mixtures corresponded to 10 g N/m2, irrespective of forb inclusion. Thus, the inclusion of nonlegume forbs did not negatively affect short-term residual N...

  11. Mixture of residual fish hydrolysate and fish extract hydrolysate to ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-06-07

    Jun 7, 2010 ... similar fashion (Table 4). Mixing fish extract hydrolysate to residual fish hydrolysate in the volume ratio of 32.6: 1 gave highest α-amylase production. To find whether the total amino acid content has any influence on B. licheni- formis, activation media with same amino acid concen- trations were prepared.

  12. Comparative analysis of different methods of extraction of present hydrocarbons in industrial residual waters

    International Nuclear Information System (INIS)

    Santa, Judith Rocio; Serrano, Martin; Stashenko, Elena

    2002-01-01

    A comparison among four extraction techniques such as: liquid - liquid (LLE) continuous and for lots, solid phase extraction (SPE), solid phase micro extraction (SPME) and static headspace (S-HS) was carried out. The main purpose of this research was to determine the highest recovery efficiencies and how reproducible the tests are while varying parameters such as time, extraction technique, type of solvents and others. Chromatographic parameters were optimized in order to carry out the analyses. Hydrocarbon's quantification of residual waters was achieved by using a high-resolution gas chromatography with a gas flame ionization detector (HRGC-FID). Validation of the method was carried out by analyzing real samples taken in different sampling places of the residual waters treatment plant of Ecopetrol - Barrancabermeja. The use of extraction methods that require big solvent quantities and long time for analysis are losing validity day by day. Techniques such as the HS-SPME and static HS are offered as alternatives for quantifying hydrocarbons. They show total lack of solvents, high sensibility, selectivity and the techniques are reproducible. Solid phase micro extraction (SPME) and static headspace (static HS) techniques were chosen as the extraction techniques to validate the method in real samples. Both techniques showed similar results for the determination of total hydrocarbons (in the gasoline range)

  13. Removal of polycyclic aromatic hydrocarbons from aqueous solution using plant residue materials as a biosorbent

    Energy Technology Data Exchange (ETDEWEB)

    Chen Baoliang, E-mail: blchen@zju.edu.cn [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Yuan Miaoxin; Liu Hao [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

    2011-04-15

    Graphical abstract: The structure-effect relationship provides a reference to select and modify plant residues as a biosorbent with high efficiency to tackle organic pollutants. Research highlights: {yields} Polycyclic aromatic hydrocarbons are effectively removed by plant residues. {yields} Biosorption mechanism of plant residues to abate PAHs is a partitioning process. {yields} Partition coefficients are negatively related with sugar contents of biosorbent. {yields} The aromatic component and K{sub ow} exhibit positive effects on biosorption. {yields} The structure-effect relationship guides plant residue using as a biosorbent. - Abstract: To elucidate biosorption mechanism and removal efficiency of plant residues as a biosorbent to abate polycyclic aromatic hydrocarbons (PAHs) in wastewater, sorption of PAHs onto wood chips (WC), ryegrass roots (RR), orange peels (OP), bamboo leaves (BL), and pine needles (PN) were investigated. The structural characterization of the biosorbents was analyzed by elemental composition, BET-N{sub 2} surface area, and Fourier transform infrared spectroscopy. PAHs sorption to the selected biosorbents were compared and correlated with their structures. Biosorption isotherms fit well with Freundlich equation and the mechanism was dominated by partition process. The magnitude of phenanthrene partition coefficients (K{sub d}) followed the order of PN > BL > OP > RR > WC, ranged from 2484 {+-} 24.24 to 5306 {+-} 92.49 L/kg. Except the WC sample, the K{sub d} values were negatively correlated with sugar content, polar index [(N + O)/C] of the biosorbents, while the aromatic component exhibited positive effects. For a given biosorbent of bamboo leaves, the carbon-normalized partition coefficients (K{sub oc}) were linearly correlated with octanol-water partition coefficients (K{sub ow}) of PAHs, i.e., log K{sub oc} = 1.16 log K{sub ow} - 1.21. The structure-effect relationship provides a reference to select and modify plant residues as a

  14. Thermodynamic characterization of bio-fuels: Excess functions for binary mixtures containing ETBE and hydrocarbons

    International Nuclear Information System (INIS)

    Segovia, Jose J.; Villamanan, Rosa M.; Martin, M. Carmen; Chamorro, Cesar R.; Villamanan, Miguel A.

    2010-01-01

    European energy policy is promoting the use of bio-fuels for transportation. Bioethers and bioalcohols are used as blending agents for enhancing the octane number. They make gasoline work harder, help the engine last longer and reduce air pollution. They also cause changes in the fuel properties. Development of renewable fuels needs both knowledge of new thermodynamic data and improvement of clean energy technologies. In this context, the use of ethanol of vegetable origin in its manufacture process, increases the interest of ETBE or bio-ETBE as an oxygenated additive. A complete study of the behaviour of ETBE + hydrocarbons mixtures is presented. Some experimental data concerning vapor-liquid equilibria and heats of mixing were determined in our laboratory. All the techniques have a high accuracy. The data were reduced by well-known models, such as NRTL and used to model the thermodynamic properties.

  15. Modeling the exposure functions of atmospheric polycyclic aromatic hydrocarbon mixtures in occupational environments.

    Science.gov (United States)

    Petit, Pascal; Maître, Anne; Persoons, Renaud; Bicout, Dominique J

    2017-04-15

    The health risk assessment associated with polycyclic aromatic hydrocarbon (PAH) mixtures faces three main issues: the lack of knowledge regarding occupational exposure mixtures, the accurate chemical characterization and the estimation of cancer risks. To describe industries in which PAH exposures are encountered and construct working context-exposure function matrices, to enable the estimation of both the PAH expected exposure level and chemical characteristic profile of workers based on their occupational sector and activity. Overall, 1729 PAH samplings from the Exporisq-HAP database (E-HAP) were used. An approach was developed to (i) organize E-HAP in terms of the most detailed unit of description of a job and (ii) structure and subdivide the organized E-HAP into groups of detailed industry units, with each group described by the distribution of concentrations of gaseous and particulate PAHs, which would result in working context-exposure function matrices. PAH exposures were described using two scales: phase (total particulate and gaseous PAH distribution concentrations) and congener (16 congener PAH distribution concentrations). Nine industrial sectors were organized according to the exposure durations, short-term, mid-term and long-term into 5, 36 and 47 detailed industry units, which were structured, respectively, into 2, 4, and 7 groups for the phase scale and 2, 3, and 6 groups for the congener scale, corresponding to as much distinct distribution of concentrations of several PAHs. For the congener scale, which included groups that used products derived from coal, the correlations between the PAHs were strong; for groups that used products derived from petroleum, all PAHs in the mixtures were poorly correlated with each other. The current findings provide insights into both the PAH emissions generated by various industrial processes and their associated occupational exposures and may be further used to develop risk assessment analyses of cancers

  16. Flow boiling heat transfer coefficients at cryogenic temperatures for multi-component refrigerant mixtures of nitrogen-hydrocarbons

    Science.gov (United States)

    Ardhapurkar, P. M.; Sridharan, Arunkumar; Atrey, M. D.

    2014-01-01

    The recuperative heat exchanger governs the overall performance of the mixed refrigerant Joule-Thomson cryocooler. In these heat exchangers, the non-azeotropic refrigerant mixture of nitrogen-hydrocarbons undergoes boiling and condensation simultaneously at cryogenic temperature. Hence, the design of such heat exchanger is crucial. However, due to lack of empirical correlations to predict two-phase heat transfer coefficients of multi-component mixtures at low temperature, the design of such heat exchanger is difficult.

  17. Compositional changes of aromatic steroid hydrocarbons in naturally weathered oil residues in the Egyptian western desert

    International Nuclear Information System (INIS)

    Barakat, A.O.; Qian, Y.; Kim, M.; Kennicutt, M.C. II

    2002-01-01

    Aromatic steranes are geochemical markers that can be used to study the maturation of organic matter of sediments and to correlate crude oils and source rocks. In this study, naturally weathered oil residues from an arid waste disposal site in Al-Alamein, Egypt, were analyzed for monoaromatic and triaromatic steranes to show the usefulness of biomarker compounds in assessing changes in chemical composition during the degradation of oil residues that have been released onto terrestrial environments. Gas chromatography and mass spectrometry were used to characterize the individual aromatic compounds. Results indicate that triaromatic sterane distributions are similar in oil residues with varying extents of weathering. The distribution correlated with a fresh crude oil sample from Western Desert-sourced oil. Molecular ratios of triaromatic sterane compounds were found to be suitable for source identification. The major changes in chemical compositions resulting from the weathering of the oil included the depletion of short chain mono- and tri-aromatic steranes in extremely weathered samples. The results of the triaromatic sterane distribution correspond with weathering classifications based on the analyses of saturated and aromatic hydrocarbons and the ratios of n-alkanes, polycyclic aromatic hydrocarbons, and saturate biomarker compounds. 15 refs., 3 tabs., 3 figs

  18. Improved Resolution of Hydrocarbon Structures and Constitutional Isomers in Complex Mixtures Using Gas Chromatography-Vacuum Ultraviolet-Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Isaacman, Gabriel [Univ. of California, Berkeley, CA (United States); Wilson, Kevin R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chan, Arthur W. H. [Univ. of California, Berkeley, CA (United States); Worton, David R. [Univ. of California, Berkeley, CA (United States). Aerosol Dynamics Inc., Berkeley, CA (United States); Kimmel, Joel R. [Aerodyne Research, Inc., Billerica, MA (United States); Univ. of Colorado, Boulder, CO (United States). Tofwerk AG, Thun (Switzerland); Nah, Theodora [Univ. of California, Berkeley, CA (United States); Hohaus, Thorsten [Aerodyne Research, Inc., Billerica, MA (United States); Gonin, Marc [Tofwerk AG, Thun (Switzerland); Kroll, Jesse H. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Worsnop, Douglas R. [Aerodyne Research, Inc., Billerica, MA (United States); Goldstein, Allen H. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-01-30

    Understanding the composition of complex hydrocarbon mixtures is important for environmental studies in a variety of fields, but many prevalent compounds cannot be confidently identified using traditional gas chromatography/mass spectrometry (GC/MS) techniques. In this study, we use vacuum-ultraviolet (VUV) ionization to elucidate the structures of a traditionally “unresolved complex mixture” by separating components by GC retention time, tR, and mass-to-charge ratio, m/z, which are used to determine carbon number, NC, and the number of rings and double bonds, NDBE. Constitutional isomers are resolved on the basis of tR, enabling the most complete quantitative analysis to date of structural isomers in an environmentally relevant hydrocarbon mixture. Unknown compounds are classified in this work by carbon number, degree of saturation, presence of rings, and degree of branching, providing structural constraints. The capabilities of this analysis are explored using diesel fuel, in which constitutional isomer distribution patterns are shown to be reproducible between carbon numbers and follow predictable rules. Nearly half of the aliphatic hydrocarbon mass is shown to be branched, suggesting branching is more important in diesel fuel than previously shown. Lastly, the classification of unknown hydrocarbons and the resolution of constitutional isomers significantly improves resolution capabilities for any complex hydrocarbon mixture.

  19. THE PENALIZED OPTIMAL EXPERIMENTAL DESIGN: THE PRECISE ESTIMATION OF AN INTERACTION THRESHOLD IN A MIXTURE OF EIGHTEEN POLYHALOGENATED AROMATIC HYDROCARBONS.

    Science.gov (United States)

    Crofton et al. (EHP, 2005) conducted a study of 18 polyhalogenated aromatic hydrocarbons (PHAHs) on serum total thyroxine (T4). Young female Long-Evans rats were dosed with the 18 single agents or a fixed-ratio mixture, and serum total T4 was measured via radioimmunoassay. The i...

  20. Study of mixtures based on hydrocarbons used in ORC (Organic Rankine Cycle) for engine waste heat recovery

    International Nuclear Information System (INIS)

    Shu, Gequn; Gao, Yuanyuan; Tian, Hua; Wei, Haiqiao; Liang, Xingyu

    2014-01-01

    For high temperature ORC (Organic Rankine Cycle) used in engine waste heat recovery, it's very critical to select a high temperature working fluid. HCs (Hydrocarbons) usually have excellent cycle performance, but the flammability limits their practical application. Considering that some retardants can be used to suppress flammability, the paper presents an application of mixtures based on hydrocarbons blending with refrigerant retardants to engine waste heat ORC. Three pure hydrocarbons (cyclopentane, cyclohexane, benzene) and two retardants (R11, R123) are selected for combination. Thermal efficiency and exergy loss are selected as the main objective functions. Based on thermodynamic model, the effects of retardants mass fraction, evaporation temperature and IHE (internal heat exchanger) are investigated. Results show that zeotropic mixtures do have higher thermal efficiency and lower exergy loss than pure fluids, at a certain mixture ratio. There exists the OMR (optimal mixture ratio) for different mixtures, and it changes with the evaporation temperature. When adding IHE to system, cycle performance could be obviously improved, and for benzene/R11 (0.7/0.3), the efficiency growth is about 7.12%∼9.72%. Using it, the maximum thermal efficiency of the system can achieve 16.7%, and minimum exergy loss is only 30.76 kW. - Highlights: • A theoretical analysis of Organic Rankine Cycle for engine exhaust heat recovery is proposed. • Mixtures based on hydrocarbons as working fluids have been suggested. • Effects of the IHE (internal heat exchanger) on ORC system are investigated. • OMR (Optimal mixture ratio) changes with the evaporation temperature. • Using the system, maximum thermal efficiency can achieve 16.7%

  1. Petroleum hydrocarbon residues in the marine environment of Bassein-Mumbai

    Digital Repository Service at National Institute of Oceanography (India)

    Chouksey, M.K.; Kadam, A.N.; Zingde, M.D.

    /$ - see front matter C211 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.marpolbul.2004.04.007 in the marine environment Kadam b , M.D. Zingde b , Versova, Mumbai 400 061, India Bungalows, Andheri (West), Mumbai 400 053, India www... and grease and petroleum hydrocarbons in the Straits of Johor, Peninsular Malaysia. Bulletin of Environment Contamination and Toxicology 55, 155–162. Agard, J.B.R., Boodoosingh, M., Gobin, J., 1988. Petroleum residues in surficial sediments from the Gulf...

  2. Degradation of volatile hydrocarbons from steam-classified solid waste by a mixture of aromatic hydrocarbon-degrading bacteria.

    Science.gov (United States)

    Leahy, Joseph G; Tracy, Karen D; Eley, Michael H

    2003-03-01

    Steam classification is a process for treatment of solid waste that allows recovery of volatile organic compounds from the waste via steam condensate and off-gases. A mixed culture of aromatic hydrocarbon-degrading bacteria was used to degrade the contaminants in the condensate, which contained approx. 60 hydrocarbons, of which 38 were degraded within 4 d. Many of the hydrocarbons, including styrene, 1,2,4-trimethylbenzene, naphthalene, ethylbenzene, m-/p-xylene, chloroform, 1,3-dichloropropene, were completely or nearly completely degraded within one day, while trichloroethylene and 1,2,3-trichloropropane were degraded more slowly.

  3. Use of residual hydrocarbons treated by Thermal Plasma (recovery of energy by-products)

    International Nuclear Information System (INIS)

    Carreno B, J.A.; Pacheco S, J.O.; Ramos F, F.; Cruz A, A.; Duran G, M.

    2001-01-01

    The emergence of new technologies is getting greater importance for the control of pollution. One of them is the destruction of hazardous wastes treated by thermal plasma, which is of special interest for the efficient treatment of the hazardous wastes since the heat generated by thermal plasma is able to destroy the molecular bonds generating solids and gaseous products which do not represent danger for the human being and the environment. The thermal plasma is the suitable technology for treating a wide range of hazardous wastes, including the residual hydrocarbons from the refinement process of petroleum, plasma exceeds the barrier of 3000 Centigrade. The efficiency of the degradation of residues is greater than 99.99%. Toxic emissions are not generated to environment as SO 2 , NO x and CO 2 neither dioxins and furans by being a pyrolysis process. The use of hydrogen as fuel does not generate pollution to environment. (Author)

  4. Passive dosing of polycyclic aromatic hydrocarbon (PAH) mixtures to terrestrial springtails: Linking mixture toxicity to chemical activities, equilibrium lipid concentrations, and toxic units

    DEFF Research Database (Denmark)

    Schmidt, Stine Nørgaard; Holmstrup, Martin; Smith, Kilian E. C.

    2013-01-01

    could be fitted to one sigmoidal exposure-response relationship. The effective lethal chemical activity (La50) of 0.027 was well within the expected range for baseline toxicity of 0.01-0.1. Linking the effects to the lipid-based exposure parameter yielded an effective lethal concentration (LClipid eq......In the present study, a 7-day mixture toxicity experiment with the terrestrial springtail Folsomia candida was conducted, and the effects linked to three different mixture exposure parameters. Passive dosing from silicone was applied to tightly control exposure levels and compositions of 12 mixture...... treatments, containing the polycyclic aromatic hydrocarbons (PAHs) naphthalene, phenanthrene, and pyrene. Springtail lethality was then linked to sum chemical activities (∑a), sum equilibrium lipid concentrations (∑Clipid eq.), and sum toxic units (∑TU). In each case, the effects of all 12 mixture treatments...

  5. Pyrolysis kinetics of olive residue/plastic mixtures by non-isothermal thermogravimetry

    Energy Technology Data Exchange (ETDEWEB)

    Aboulkas, A.; El harfi, K. [Laboratoire de Recherche sur la Reactivite des Materiaux et l' Optimisation des Procedes, Departement de chimie, Faculte des Sciences Semlalia, Universite Cadi Ayyad, BP 2390, 40001 Marrakech (Morocco); Laboratoire Interdisciplinaire de Recherche en Sciences et en Techniques, Faculte polydisciplinaire de Beni-Mellal, Universite Sultan Moulay Slimane, BP 592, 23000 Beni-Mellal (Morocco); El bouadili, A. [Laboratoire de Chimie Organique et Analytique, Departement de chimie, Faculte des Sciences et Techniques de Beni-Mellal, Universite Sultan Moulay Slimane, BP 523, 23000 Beni-Mellal (Morocco); Nadifiyine, M.; Benchanaa, M.; Mokhlisse, A. [Laboratoire de Recherche sur la Reactivite des Materiaux et l' Optimisation des Procedes & lt; & lt; REMATOP& gt; & gt; , Departement de chimie, Faculte des Sciences Semlalia, Universite Cadi Ayyad, BP 2390, 40001 Marrakech (Morocco)

    2009-05-15

    The TGA studies of a pyrolytic decomposition of mixtures of olive residue/plastic were carried out. The investigation was made at the temperature ranging from 300 to 1273 K) in the nitrogen atmosphere at four heating rates {beta} = 2, 10, 20 and 50 K min{sup -} {sup 1}. High density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS) were selected as plastic samples. Based on the results obtained, three thermal stages were identified during the thermal degradation. The first two were dominated by the olive residue pyrolysis, while the third was linked to the plastics pyrolysis, which occurred at much higher temperatures. Discrepancies between the experimental and calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on pyrolysis olive residue/plastic mixtures. The maximum degradation temperatures of each component in the mixture were higher than those of the individual components. These experimental results indicate a significant synergistic effect during olive residue and plastic co-pyrolysis at the high temperature region. In addition, a kinetic analysis was performed to fit thermogravimetric data. A reasonable fit to the experimental data was obtained for all materials and their mixtures. (author)

  6. Optimization for microwave-assisted direct liquefaction of bamboo residue in glycerol/methanol mixtures

    Science.gov (United States)

    Jiulong Xie; Jinqiu Qi; Chungyun Hse; Todd F. Shupe

    2015-01-01

    Bamboo residues were liquefied in a mixture of glycerol and methanol in the presence of sulfuric acid using microwave energy. We investigated the effects of liquefaction conditions, including glycerol/methanol ratio, liquefaction temperature, and reaction time on the conversion yield. The optimal liquefaction conditions were under the temperature of 120

  7. Removal of polycyclic aromatic hydrocarbons in soil spiked with model mixtures of petroleum hydrocarbons and heterocycles using biosurfactants from Rhodococcus ruber IEGM 231.

    Science.gov (United States)

    Ivshina, Irina; Kostina, Ludmila; Krivoruchko, Anastasiya; Kuyukina, Maria; Peshkur, Tatyana; Anderson, Peter; Cunningham, Colin

    2016-07-15

    Removal of polycyclic aromatic hydrocarbons (PAHs) in soil using biosurfactants (BS) produced by Rhodococcus ruber IEGM 231 was studied in soil columns spiked with model mixtures of major petroleum constituents. A crystalline mixture of single PAHs (0.63g/kg), a crystalline mixture of PAHs (0.63g/kg) and polycyclic aromatic sulfur heterocycles (PASHs), and an artificially synthesized non-aqueous phase liquid (NAPL) containing PAHs (3.00g/kg) dissolved in alkanes C10-C19 were used for spiking. Percentage of PAH removal with BS varied from 16 to 69%. Washing activities of BS were 2.5 times greater than those of synthetic surfactant Tween 60 in NAPL-spiked soil and similar to Tween 60 in crystalline-spiked soil. At the same time, amounts of removed PAHs were equal and consisted of 0.3-0.5g/kg dry soil regardless the chemical pattern of a model mixture of petroleum hydrocarbons and heterocycles used for spiking. UV spectra for soil before and after BS treatment were obtained and their applicability for differentiated analysis of PAH and PASH concentration changes in remediated soil was shown. The ratios A254nm/A288nm revealed that BS increased biotreatability of PAH-contaminated soils. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Graphitized carbon in gas-liquid-solid chromatography and gas chromatography/mass spectrometric analysis of high boiling hydrocarbon mixtures

    International Nuclear Information System (INIS)

    Ciccioli, P.; Hayes, J.M.; Rinaldi, G.; Denson, K.B.; Meinschein, W.G.

    1979-01-01

    Gas--liquid--solid chromatography (GLSC) employing a poly(phenyl ether) (PPE 20) liquid phase on graphitized carbon black (GCB) is applicable to the analyses of crude oils and distillates of sedimentary rocks. The elution of C 4 to C 40 hydrocarbons which consist of n-alkanes, isoprenoid-type alkanes, steranes, olefins, and aromatic hydrocarbons can be handled in a single GC run. A GLSC column in tandem with a mass spectrometer provides an excellent means for the identification of geochemically significant organic compounds in complex natural mixtures. 8 figures, 4 tables

  9. Numerical investigation of boiling heat transfer on hydrocarbon mixture refrigerant in vertical rectangular minichannel

    Directory of Open Access Journals (Sweden)

    Huixing Li

    2016-05-01

    Full Text Available In order to investigate the characteristics of boiling heat transfer for hydrocarbon mixture refrigerant in plate-fin heat exchanger which is used in the petrochemical industry field, a model was established on boiling heat transfer in vertical rectangular channel. The simulated results were compared with the experimental data from literature. The results show that the deviation between the simulated results and experimental data is within ±15%. Meanwhile, the characteristic of boiling heat transfer was investigated in vertical rectangular minichannel of plate-fin heat exchanger. The results show that the boiling heat transfer coefficient increases with the increase in quality and mass flux and is slightly impacted by the heat flux. This is because that the main boiling mechanism is forced convective boiling while the contribution of nucleate boiling is slight. The correlation of Liu and Winterton is in good agreement with the simulation results. The deviation between correlation calculations and simulation results is mostly less than ±15%. These results will provide some constructive instructions for the understanding of saturated boiling mechanism in a vertical rectangular minichannel and the prediction of heat transfer performance in plate-fin heat exchanger.

  10. Taguchi Method for Development of Mass Flow Rate Correlation using Hydrocarbon Refrigerant Mixture in Capillary Tube

    Directory of Open Access Journals (Sweden)

    Shodiya Sulaimon

    2014-07-01

    Full Text Available The capillary tube is an important control device used in small vapor compression refrigeration systems such as window air-conditioners, household refrigerators and freezers. This paper develops a non-dimensional correlation based on the test results of the adiabatic capillary tube for the mass flow rate through the tube using a hydrocarbon refrigerant mixture of 89.3% propane and 10.7% butane (HCM. The Taguchi method, a statistical experimental design approach, was employed. This approach explores the economic benefit that lies in studies of this nature, where only a small number of experiments are required and yet valid results are obtained. Considering the effects of the capillary tube geometry and the inlet condition of the tube, dimensionless parameters were chosen. The new correlation was also based on the Buckingham Pi theorem. This correlation predicts 86.67% of the present experimental data within a relative deviation of -10% to +10%. The predictions by this correlation were also compared with results in published literature.

  11. Studies on capillary tube expansion device used in J-T refrigerators operating with nitrogen-hydrocarbon mixtures

    Science.gov (United States)

    Harish Kruthiventi, S. S.; Venkatarathnam, G.

    2017-10-01

    Capillary tube expansion devices are used extensively in small closed cycle J-T refrigerators operating with refrigerant mixtures due to its low cost and the absence of any moving parts. It is possible for J-T refrigerators operating with mixtures that the velocity of refrigerant mixture at capillary tube outlet reaches a value where it equals the speed of sound at certain conditions. The variation of the speed of sound of nitrogen-hydrocarbon mixtures used in J-T refrigerators has been studied in two phase (vapour-liquid) and three-phase (Vapour-liquid-liquid) region as a function of temperature and pressure in this work. Also the conditions under which choking occurs in practical J-T refrigerators is investigated.

  12. Passive dosing of polycyclic aromatic hydrocarbon (PAH) mixtures to terrestrial springtails: linking mixture toxicity to chemical activities, equilibrium lipid concentrations, and toxic units.

    Science.gov (United States)

    Schmidt, Stine N; Holmstrup, Martin; Smith, Kilian E C; Mayer, Philipp

    2013-07-02

    A 7-day mixture toxicity experiment with the terrestrial springtail Folsomia candida was conducted, and the effects were linked to three different mixture exposure parameters. Passive dosing from silicone was applied to tightly control exposure levels and compositions of 12 mixture treatments, containing the polycyclic aromatic hydrocarbons (PAHs) naphthalene, phenanthrene, and pyrene. Springtail lethality was then linked to sum chemical activities (∑a), sum equilibrium lipid concentrations (∑C(lipid eq.)), and sum toxic units (∑TU). In each case, the effects of all 12 mixture treatments could be fitted to one sigmoidal exposure-response relationship. The effective lethal chemical activity (La50) of 0.027 was well within the expected range for baseline toxicity of 0.01-0.1. Linking the effects to the lipid-based exposure parameter yielded an effective lethal concentration (LC(lipid eq 50)) of 133 mmol kg(-1) lipid in good correspondence with the lethal membrane burden for baseline toxicity (40-160 mmol kg(-1) lipid). Finally, the effective lethal toxic unit (LTU50) of 1.20 was rather close to the expected value of 1. Altogether, passive dosing provided tightly controlled mixture exposure in terms of both level and composition, while ∑a, ∑C(lipid eq.), and ∑TU allowed baseline toxicity to be linked to mixture exposure.

  13. Detection of trans-isomers of hydrocarbon residues of lipid molecules by IR absorption

    Science.gov (United States)

    Mikhalovsky, I. S.; Samoylov, M. V.; Wileishikova, N. P.

    2009-01-01

    IR spectroscopy is used for a comparative analysis of the trans-isomerization of double bonds in hydrocarbon residuals of lactic and hydrogenated lipids. The maximum of the absorption band of the trans-isomers for all the lipid samples is found to lie at 965 cm-1. An absorption band at 970 cm-1 is discovered in the spectra of the lactic lipids near the analytic band of the trans-isomers at 965 cm-1. Based on a gaussian approximation for their absorption spectral bands, the trans-isomer content in the lactic lipid samples is 10-11%. The absorption by lipid molecules at 970 cm-1 has to be taken into account when determining the trans-isomer content of fat and oil products.

  14. Comparative study of the physicochemical properties of aqueous solutions of the hydrocarbon and fluorocarbon surfactants and their ternary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Szymczyk, Katarzyna, E-mail: katarzyna.szymczyk@poczta.umcs.lublin.pl

    2014-03-03

    Highlights: • Acoustic properties of hydrocarbon and fluorocarbon surfactants were studied. • Auerbach’s relation is not proper for mixtures with fluorocarbon surfactants. • Values of the hydration number decreases at concentrations higher than CMC. • FSO100 and its mixtures are the strongest chaotropes. - Abstract: Speed of sound and density of aqueous solutions of hydrocarbon p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethyleneglycols) (Triton X-100 (TX100), Triton X-165 (TX165)) and fluorocarbon (Zonyl FSN-100 (FSN100), Zonyl FSO-100 (FSO100)) surfactants as well as their ternary mixtures were measured at 293 K. Taking into account these values and the literature data of the surface tension and viscosity of the studied systems, the values of the isentropic compressibility, apparent specific adiabatic compressibility, hydration number, apparent specific volume and Jones Dole’s A and B-coefficients were determined. For the systems containing FSO100 also the values of dB/dT were determined on the basis of the values of viscosity measured at different temperatures. Next, the calculated thermodynamic properties have been discussed in the term of intermolecular interactions between the components of the mixtures.

  15. Sharp separation of C2/C3 hydrocarbon mixtures by zeolitic imidazolate framework-8 (ZIF-8) membranes synthesized in aqueous solutions

    KAUST Repository

    Pan, Yichang

    2011-01-01

    Exceptional high quality ZIF-8 membranes prepared through a novel seeded growth method in aqueous solutions at near room temperature exhibit excellent separation performance for C2/C3 hydrocarbon mixtures. The separation factors for mixtures of ethane/propane, ethylene/propylene and ethylene/propane are ∼80, ∼10 and ∼167, respectively. © 2011 The Royal Society of Chemistry.

  16. Densities and excess volumes of binary mixtures of N,N-dimethylformamide with aromatic hydrocarbon at different temperature

    International Nuclear Information System (INIS)

    Peng Sanjun; Hou Haiyun; Zhou Congshan; Yang Tao

    2007-01-01

    Density of three binary mixtures formed by N,N-dimethylformamide (DMF) with aromatic hydrocarbon (one of benzene, toluene, and ethylbenzene) has been determined over the full range of compositions at the temperatures range (293.15 to 353.15)K and atmospheric pressure using a vibrating-tube densimeter. From these experiments, excess molar volumes (V m E ) could be calculated and fitted by the fourth-order Redlich-Kister equation, so the coefficients and the standard error (σ) could be got. Our result shows V m E decreases when temperature increases in the studied systems

  17. Aqueous Solubility of Hydrocarbon Mixtures Solubilité dans l'eau de mélanges d'hydrocarbures

    Directory of Open Access Journals (Sweden)

    De Hemptinne J. C.

    2006-12-01

    Full Text Available The solubility of hydrocarbon components in water is of great importance for the environmental sciences. Its prediction is usually based on using the pure component solubilities and the mole fraction of the components in the mixture. While the pure component solubilities are generally well known, few data exist on the solubility of mixtures. Using a simple relationship leads to an underestimation of the true solubility. This paper presents some new data on the aqueous solubility of binary hydrocarbon mixtures. Using a rigorous thermodynamic analysis, we explain the observed behavior, as well as other data from the literature, including the solubility of jet fuel mixtures in water. The activity coefficient models used for this purpose are NRTL, UNIQUAC and UNIFAC. Considering the small concentration in oil of some very soluble substances, the activity coefficient can become significant and thus explain the fact that solubilities of some component may be as much as twice as large as expected. La solubilité de composés hydrocarbonés dans l'eau est d'une importance cruciale pour les sciences environnementales. Sa prévision est généralement basée sur la solubilité des constituants purs et de leur fraction molaire en mélange. La solubilité des composés purs est généralement bien connue, mais peu de données ont été publiées concernant les mélanges. L'utilisation d'une relation simple conduit à une sous-estimation de la solubilité réelle. Cet article présente quelques données nouvelles de solubilités de mélanges hydrocarbonés simples. Une analyse thermodynamique rigoureuse permet de décrire la solubilité observée, aussi bien pour des mélanges modèles que pour des kérosènes. Les modèles de coefficient d'activité utilisés dans ce but sont NRTL, UNIQUAC et UNIFAC. Étant donné la faible concentration de certains constituants dans l'huile, leurs coefficients d'activité peut devenir important. Ceci explique une

  18. Investigation of non-volatile additives on the process of distillation of hydrocarbon mixtures

    Directory of Open Access Journals (Sweden)

    М.Б. Степанов

    2009-02-01

    Full Text Available  The given results of researches of influence of nonvolatile additives on processes of distillation of individual hydrocarbons and their mixes, including petroleum and mineral oil. With the help of the developed computer system of the continuous control of distillation it is shown, that at the presence of small amounts of the additive decrease of temperature of the beginning of boiling of hydrocarbons is observed, their speeds of banish and exits of light fuel mineral oil grow during initial oil refining

  19. Improved Separation of Complex Polycyclic Aromatic Hydrocarbon Mixtures Using Novel Column Combinations in GC×GC/ToF-MS

    Science.gov (United States)

    Manzano, Carlos; Hoh, Eunha; Simonich, Staci L. Massey

    2012-01-01

    Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are difficult to resolve because of the high degree of overlap in compound vapor pressures, boiling points and mass spectral fragmentation patterns. The objective of this research was to improve the separation of complex PAH mixtures (including 97 different parent, alkyl-, nitro-, oxy-, thio-, chloro-, bromo-, and high molecular weight PAHs) using GC×GC/ToF-MS by maximizing the orthogonality of different GC column combinations and improving the separation of PAHs from the sample matrix interferences, including unresolved complex mixtures (UCM). Four different combinations of non-polar, polar, liquid crystal and nano-stationary phase columns were tested. Each column combination was optimized and evaluated for orthogonality using a method based on conditional entropy that considers the quantitative peak distribution in the entire two-dimensional space. Finally, an atmospheric particulate matter with diameter column in the first dimension and a 1.2 m × 0.10 mm × 0.10 µm NSP-35 nano-stationary phase column in the second dimension. In addition, the use of this column combination in GC×GC/ToF-MS resulted in significantly shorter analysis times (176 min) for complex PAH mixtures compared to one-dimensional GC/MS (257 min), as well as potentially reduced sample preparation time. PMID:22769970

  20. An In Silico Approach for Evaluating a Fraction-Based, Risk Assessment Method for Total Petroleum Hydrocarbon Mixtures

    Directory of Open Access Journals (Sweden)

    Nina Ching Y. Wang

    2012-01-01

    Full Text Available Both the Massachusetts Department of Environmental Protection (MADEP and the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG developed fraction-based approaches for assessing human health risks posed by total petroleum hydrocarbon (TPH mixtures in the environment. Both organizations defined TPH fractions based on their expected environmental fate and by analytical chemical methods. They derived toxicity values for selected compounds within each fraction and used these as surrogates to assess hazard or risk of exposure to the whole fractions. Membership in a TPH fraction is generally defined by the number of carbon atoms in a compound and by a compound's equivalent carbon (EC number index, which can predict its environmental fate. Here, we systematically and objectively re-evaluate the assignment of TPH to specific fractions using comparative molecular field analysis and hierarchical clustering. The approach is transparent and reproducible, reducing inherent reliance on judgment when toxicity information is limited. Our evaluation of membership in these fractions is highly consistent (̃80% on average across various fractions with the empirical approach of MADEP and TPHCWG. Furthermore, the results support the general methodology of mixture risk assessment to assess both cancer and noncancer risk values after the application of fractionation.

  1. Predicting the vapor–liquid equilibrium of hydrocarbon binary mixtures and polymer solutions using predetermined pure component parameters

    International Nuclear Information System (INIS)

    Ryu, Sang Kyu; Bae, Young Chan

    2012-01-01

    Highlights: ► We have developed a close-packed lattice model for chain-like molecules. ► The chain length dependence determined from Monte-Carlo simulation results were used. ► To consider the volume effect, hole theory and two mixing steps were used. ► A lattice fluid equation of state (LF-EoS) is presented for VLE of hydrocarbon mixtures. ► Correlation of pure polymer solutions data with use of the LF-EoS. - Abstract: In our previous work, a new close-packed lattice model was developed for multi-component system of chain fluids with taking the chain length dependence from Monte-Carlo (MC) simulation results into account. In this work, we further extend this model to describe pressure, volume and temperature (PVT) properties, such as vapor–liquid equilibrium (VLE). To consider the effect of pressure on the phase behavior, the volume change effect is taken into account by introducing holes into the incompressible lattice model with two mixing steps. The corresponding new lattice fluid equation of state (LF-EoS) is applied to predict the thermodynamic properties of pure and binary mixtures of hydrocarbons as well as pure polymer solutions. The results of the proposed model are compared to other predictive approaches based on VLE calculations using predetermined pure model parameters without further adjustment. Thermodynamic properties predicted using the method developed in this work are consistent with the experimental data.

  2. Alternative Gas Mixtures in Arc Spraying: A Chance to Improve Coating Properties and Residual Stress States

    Science.gov (United States)

    Hauer, Michél; Henkel, Knuth Michael; Krebs, Sebastian; Kroemmer, Werner

    2018-01-01

    The highly cavitation erosion-resistant propeller alloys CuAl9Ni5Fe4Mn (Ni-Al-Bronze) and CuMn13Al8Fe3Ni2 (Mn-Al-Bronze) were arc-sprayed using a mixture of nitrogen and 2% of hydrogen as atomizing gas and different traverse speeds. The objective was to identify the influences of the different spraying conditions, such as temperature regime and melting loss, on the resulting residual stress states and coating properties. Residual stresses were measured by the incremental hole-drilling method using ESPI. Temperature measurements were carried out by thermographic imaging. Microstructural, chemical and mechanical analyses were realized to examine adhesive and cohesive properties. Additionally, the cavitation erosion behavior was investigated to analyze cohesive coating properties. The spraying process itself was improved, which was apparent by mainly enhanced deposition efficiency and reduced surface temperatures. The amount of oxides and pores as well as the melting loss of alloying elements were reduced. Moreover, an increased cavitation erosion resistance and thus coating cohesion as well as less residual stresses were identified. The change in atomizing gas diminished the impact of the quenching stresses on the coating properties. In contrast, the adhesive strength, Young's moduli and partially the hardness were slightly reduced. With regard to materials, Ni-Al-Bronze revealed superior coating properties in comparison with Mn-Al-Bronze.

  3. Partial Oxidation of High-Boiling Hydrocarbon Mixtures in the Pilot Unit

    Czech Academy of Sciences Publication Activity Database

    Hanika, Jiří; Lederer, J.; Nečesaný, F.; Poslední, W.; Tukač, V.; Veselý, Václav

    2014-01-01

    Roč. 68, č. 12 (2014), s. 1701-1706 ISSN 0366-6352 Institutional support: RVO:67985858 Keywords : partial oxidation * high-boiling hydrocarbons * pilot plant Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.468, year: 2014

  4. Microbial community response to a release of neat ethanol onto residual hydrocarbons in a pilot-scale aquifer tank.

    Science.gov (United States)

    Cápiro, Natalie L; Da Silva, Marcio L B; Stafford, Brent P; Rixey, William G; Alvarez, Pedro J J

    2008-09-01

    The microbial community response to a neat ethanol release (E100, 76 l) onto residual hydrocarbons in sandy soil was evaluated in a continuous-flow 8 m(3) pilot-scale aquifer tank, simulating a release at a bulk fuel terminal. Microbial genotypic shifts were assessed using quantitative real-time PCR analysis. High ethanol concentrations in the capillary fringe at potentially toxic levels, exceeding 100,000 mg l(-1), were tolerated by the microbial community. The high biochemical oxygen demand exerted by ethanol rapidly induced anaerobic conditions, and both methane production (up to 1.2 mg l(-1)) and growth of putative methanogenic Archaea (up to 10(6) gene copies per g of soil) were observed in shallow groundwater and soil samples 75 cm down gradient from the source. Aerobic conditions returned after ethanol was flushed out of the system, approximately 45 days after the spill (less than 7.5 pore volumes flushed). Total Bacteria growth coincided with ethanol migration and availability, which was restricted to a relatively thin layer at the capillary fringe and water table interface. The concentrations of bacteria harbouring the aerobic catabolic genes dmpN (coding for phenol hydroxylase) and to dC1 (coding for toluene dioxygenase) increased (up to 100x) down gradient from the source, likely as a result of both fortuitous growth on ethanol and on aromatic hydrocarbons mobilized by ethanol. Growth of hydrocarbon degraders was corroborated by denaturing gradient gel electrophoresis analysis showing proliferation of Azospirillum and Brevundimonas spp., which are bacteria commonly associated with microaerophilic hydrocarbon degradation. Nevertheless, the relative abundance of hydrocarbon-specific degraders (as a fraction of total Bacteria) decreased as other bacteria grew to a higher extent. Overall, the observed growth of hydrocarbon degraders suggests a potential enhancement in aerobic natural attenuation in shallow aquifers after ethanol and its degradation by

  5. Studies on the production of hydrocarbon mixtures from waste methyl ethyl ketone

    International Nuclear Information System (INIS)

    Kokitkar, P.B.; Roth, O.B.; Debelak, K.A.

    1992-01-01

    Large quantities of waste solvents are generated annually around the world in a large number of diverse industries, the paints and plastics industry being the largest consumer. The management of these waste solvents is becoming more and more difficult due to stricter environmental regulations by the EPA. The paint and allied products industry is expected to shift its solvent use from aliphatics and aromatics to oxygenated solvents to meet emissions and disposal standards. Many researchers have studied the dehydration reactions of oxygenated solvents to produce dehydration. However, most researchers have obtained only low molecular weight compounds (C 3 - C 4 hydrocarbons) from C 1 - C 4 alcohols and ketones. The kinetics of this class of reactions are not available in the open literature. The objective of this paper is to investigate the thermodynamic feasibility of this class of reactions and to compare the hydrocarbon products obtained using methylethyl ketone with regular unleaded gasoline

  6. Residue pattern of polycyclic aromatic hydrocarbons during green tea manufacturing and their transfer rates during tea brewing.

    Science.gov (United States)

    Gao, Guanwei; Chen, Hongping; Liu, Pingxiang; Hao, Zhenxia; Ma, Guicen; Chai, Yunfeng; Wang, Chen; Lu, Chengyin

    2017-06-01

    Residues of polycyclic aromatic hydrocarbons (PAHs) in green tea and tea infusion were determined using gas chromatography-tandem mass spectrometry to study their dissipation pattern during green tea processing and infusion. Concentration and evaporation of PAHs during tea processing were the key factors affecting PAH residue content in product intermediates and in green tea. PAH residues in tea leaves increased by 2.4-3.1 times during the manufacture of green tea using the electric heating model. After correction to dry weight, PAH residue concentrations decreased by 33.5-48.4% during green tea processing because of PAH evaporation. Moreover, spreading and drying reduced PAH concentrations. The transfer rates of PAH residues from green tea to infusion varied from 4.6% to 7.2%, and PAH leaching was higher in the first infusion than in the second infusion. These results are useful for assessing exposure to PAHs from green tea and in formulating controls for the maximum residue level of PAHs in green tea.

  7. Initiation of unconfined gas detonations in hydrocarbon-air mixtures by a sympathetic mechanism

    International Nuclear Information System (INIS)

    Bull, D.C.; Elsworth, J.E.

    1981-01-01

    The considered investigation is concerned with the study of the factors which influence detonation propagation in a gas of heterogeneous composition. The conducted experiments assess the ability of a blast wave, emerging from a donor gas detonation and crossing an air gap, to initiate detonation in a second, similar, acceptor gas mixture. Stoichiometric mixtures of both ethylene-air and propane-air are found to exhibit 'sympathetic' gas detonation only across small air gaps. Conditions critical to sympathetic gas detonation agree with predictions of a simple theory taking account of the net shock decay occurring across two acoustic interfaces bounded by an air gap. Sympathetic detonation occurs only if the strength of the shock upon entering the acceptor exceeds a threshold value for the particular gas mixture. Reinitiation of detonation is not satisfactorily explained by planar blast wave decay and autoignition considerations

  8. Preparation of standard mixtures of gas hydrocarbons in air by the diffusion dilution method

    International Nuclear Information System (INIS)

    Garcia, M. R.; Perez, M. M.

    1979-01-01

    An original diffusion system able to produce continuously gaseous samples is described. This system can generate samples with concentrations of benzene in air from 0.1 to 1 ppm a reproducible way. The diffusion dilution method used Is also studied. The use of this diffusion system has been extended to the preparation of binary mixtures (benzene-toluene). Whit a secondary dilution device is possible preparing these mixtures over a wide range of concentrations (0.11 to 0.04 ppm for benzene and 0.06 to 0.02 for toluene). (Author) 7 refs

  9. Experimental study of the overpressures generated by the detonation of spherical air-hydrocarbon gaseous mixtures

    International Nuclear Information System (INIS)

    Brossard, J.

    1978-01-01

    The characteristics of the pressure waves transmitted by detonation of gaseous mixtures to the surrounding air were measured by tests made near the ground level in 1 to 54 m 3 spherical balloons containing air-acetylene or air-ethylene mixtures. As concerns the peak overpressure Δp, a theoretical dimensional analysis in accordance with the experimental results shows that Δp can be expressed as a function of two independent variables, which are the radial distance R and the volume V of the balloon . A semi-empirical formula, including ground effects, is proposed and its present validity range is given. (author)

  10. Predicting the vapor-liquid equilibrium of hydrocarbon binary mixtures and polymer solutions using predetermined pure component parameters

    Science.gov (United States)

    Ryu, Sang Kyu; Bae, Young Chan

    2012-05-01

    In our previous work, a new close-packed lattice model was developed for multi-component system of chain fluids with taking the chain length dependence from Monte-Carlo (MC) simulation results into account. In this work, we further extend this model to describe pressure, volume and temperature (PVT) properties, such as vapor-liquid equilibrium (VLE). To consider the effect of pressure on the phase behavior, the volume change effect is taken into account by introducing holes into the incompressible lattice model with two mixing steps. The corresponding new lattice fluid equation of state (LF-EoS) is applied to predict the thermodynamic properties of pure and binary mixtures of hydrocarbons as well as pure polymer solutions. The results of the proposed model are compared to other predictive approaches based on VLE calculations using predetermined pure model parameters without further adjustment. Thermodynamic properties predicted using the method developed in this work are consistent with the experimental data.

  11. Analytical method validation of GC-FID for the simultaneous measurement of hydrocarbons (C2-C4) in their gas mixture

    OpenAIRE

    Oman Zuas; Harry budiman; Muhammad Rizky Mulyana

    2016-01-01

    An accurate gas chromatography coupled to a flame ionization detector (GC-FID) method was validated for the simultaneous analysis of light hydrocarbons (C2-C4) in their gas mixture. The validation parameters were evaluated based on the ISO/IEC 17025 definition including method selectivity, repeatability, accuracy, linearity, limit of detection (LOD), limit of quantitation (LOQ), and ruggedness. Under the optimum analytical conditions, the analysis of gas mixture revealed that each target comp...

  12. Performance and energy saving analysis of a refrigerator using hydrocarbon mixture (HC-R134a) as working fluid

    Science.gov (United States)

    Mohtar, M. N.; Nasution, H.; Aziz, A. A.

    2015-12-01

    The use of hydrocarbon mixture as a working fluid in a refrigerator system is rarely explored. Almost all domestic refrigerators use hydroflourocarbon R134a (HFC-R134a) as refrigerants. In this study, hydrocarbon gas (HC-R134a) is used as the alternative refrigerant to replace HFC-R134a. It has a composition of R290 (56%), R600a (54.39%) and additive (0.1%wt) blended for the trials. The experiments were conducted with 105 g and 52.5 g refrigerant mass charge, subjected to internal heat load of 0, 1, 2, 3 and 4 kg respectively. The study investigates the coefficient of performance of the refrigerator (COPR) and energy consumption. The results show that the use of HC-R134a as the replaceable refrigerant can save energy ranging from 2.04% to 7.09%, as compared to the conventional HFC-R134a refrigerant. Naturally, the COPR improvement and temperature distribution using HC-R134a are much better than HFC-R134a

  13. NON-EQUILIBRIUM MOLECULAR DYNAMICS USED TO OBTAIN SORET COEFFICIENTS OF BINARY HYDROCARBON MIXTURES

    Directory of Open Access Journals (Sweden)

    F. A. Furtado

    2015-09-01

    Full Text Available AbstractThe Boundary Driven Non-Equilibrium Molecular Dynamics (BD-NEMD method is employed to evaluate Soret coefficients of binary mixtures. Using a n-decane/n-pentane mixture at 298 K, we study several parameters and conditions of the simulation procedure such as system size, time step size, frequency of perturbation, and the undesired warming up of the system during the simulation. The Soret coefficients obtained here deviated around 20% when comparing with experimental data and with simulated results from the literature. We showed that fluctuations in composition gradients and the consequent deviations of the Soret coefficient may be due to characteristic fluctuations of the composition gradient. Best results were obtained with the smallest time steps and without using a thermostat, which shows that there is room for improvement and/or development of new BD-NEMD algorithms.

  14. An improved molecular dynamics algorithm to study thermodiffusion in binary hydrocarbon mixtures

    Science.gov (United States)

    Antoun, Sylvie; Saghir, M. Ziad; Srinivasan, Seshasai

    2018-03-01

    In multicomponent liquid mixtures, the diffusion flow of chemical species can be induced by temperature gradients, which leads to a separation of the constituent components. This cross effect between temperature and concentration is known as thermodiffusion or the Ludwig-Soret effect. The performance of boundary driven non-equilibrium molecular dynamics along with the enhanced heat exchange (eHEX) algorithm was studied by assessing the thermodiffusion process in n-pentane/n-decane (nC5-nC10) binary mixtures. The eHEX algorithm consists of an extended version of the HEX algorithm with an improved energy conservation property. In addition to this, the transferable potentials for phase equilibria-united atom force field were employed in all molecular dynamics (MD) simulations to precisely model the molecular interactions in the fluid. The Soret coefficients of the n-pentane/n-decane (nC5-nC10) mixture for three different compositions (at 300.15 K and 0.1 MPa) were calculated and compared with the experimental data and other MD results available in the literature. Results of our newly employed MD algorithm showed great agreement with experimental data and a better accuracy compared to other MD procedures.

  15. Mixture

    Directory of Open Access Journals (Sweden)

    Silva-Aguilar Martín

    2011-01-01

    Full Text Available Metals are ubiquitous pollutants present as mixtures. In particular, mixture of arsenic-cadmium-lead is among the leading toxic agents detected in the environment. These metals have carcinogenic and cell-transforming potential. In this study, we used a two step cell transformation model, to determine the role of oxidative stress in transformation induced by a mixture of arsenic-cadmium-lead. Oxidative damage and antioxidant response were determined. Metal mixture treatment induces the increase of damage markers and the antioxidant response. Loss of cell viability and increased transforming potential were observed during the promotion phase. This finding correlated significantly with generation of reactive oxygen species. Cotreatment with N-acetyl-cysteine induces effect on the transforming capacity; while a diminution was found in initiation, in promotion phase a total block of the transforming capacity was observed. Our results suggest that oxidative stress generated by metal mixture plays an important role only in promotion phase promoting transforming capacity.

  16. Analysis of Polycyclic Aromatic Hydrocarbon (PAH Mixtures Using Diffusion-Ordered NMR Spectroscopy and Adsorption by Powdered Activated Carbon and Biochar

    Directory of Open Access Journals (Sweden)

    Dong An

    2018-03-01

    Full Text Available Analysis of polycyclic aromatic hydrocarbons (PAHs in air and water sources is a key part of environmental chemistry research, since most PAHs are well known to be associated with negative health impacts on humans. This study explores an approach for analyzing PAH mixtures with advanced nuclear magnetic resonance (NMR spectroscopic techniques including high-resolution one-dimensional (1D NMR spectroscopy and diffusion-ordered NMR spectroscopy (DOSY NMR. With this method, different kinds of PAHs can be detected and differentiated from a mixture with high resolution. The adsorption process of PAH mixtures by PAC and biochar was studied to understand the mechanism and assess the method.

  17. Normal alkanes and the unresolved complex mixture as diagnostic indicators of hydrocarbon source contributions to marine sediments of the Northern Gulf of Alaska

    International Nuclear Information System (INIS)

    Short, J.W.; Heintz, R.A.

    2003-01-01

    Coal beds, hydrocarbon source rocks, and natural oil seeps represent potentially significant sources of hydrocarbons contamination of marine sediments in the northern Gulf of Alaska. Intensive studies of several supposedly diagnostic polycyclic aromatic (PAH) and aliphatic hydrocarbon compounds have been conducted to solve the controversy of whether the hydrocarbons come from natural or anthropogenic sources. These hydrocarbons could be associated with a refractory matrix not biologically available, as strongly suggested by the n-alkane profile characteristic of the marine sediments. There are similarities between the unresolved complex mixture (UCM) profile of the marine sediments and those of eroding coals and source rocks. However, there were differences with the UCM of seep oils entering the Gulf of Alaska. The seep-oils possess low concentrations of n-alkanes due to biodegradation before entering the Gulf of Alaska, and have large UCM and PAH concentrations. Additional strong constraints are placed on hydrocarbon contributions from natural sources to the marine sediments of the northern portion of the Gulf of Alaska as a result of inclusion of n-alkane and UCM results into hydrocarbon source allocation models. The authors indicated that seep-oils are unlikely to be significant contributors. 19 refs., 1 tab., 6 figs

  18. The influence of dissolved petroleum hydrocarbon residues on natural phytoplankton biomass

    Digital Repository Service at National Institute of Oceanography (India)

    Shailaja, M.S.

    The effect of dissolved petroleum hydrocarbons in the environment on phytoplankton biomass measured as chlorophyll a was studied near the oil tanker route in the southern Bay of Bengal. In the transect from 5 degrees N, 77 degrees E to 5 degrees N...

  19. Prediction of vapour-liquid and vapour-liquid-liquid equilibria of nitrogen-hydrocarbon mixtures used in J-T refrigerators

    Science.gov (United States)

    Narayanan, Vineed; Venkatarathnam, G.

    2018-03-01

    Nitrogen-hydrocarbon mixtures are widely used as refrigerants in J-T refrigerators operating with mixtures, as well as in natural gas liquefiers. The Peng-Robinson equation of state has traditionally been used to simulate the above cryogenic process. Multi parameter Helmholtz energy equations are now preferred for determining the properties of natural gas. They have, however, been used only to predict vapour-liquid equilibria, and not vapour-liquid-liquid equilibria that can occur in mixtures used in cryogenic mixed refrigerant processes. In this paper the vapour-liquid equilibrium of binary mixtures of nitrogen-methane, nitrogen-ethane, nitrogen-propane, nitrogen-isobutane and three component mixtures of nitrogen-methane-ethane and nitrogen-methane-propane have been studied with the Peng-Robinson and the Helmholtz energy equations of state of NIST REFPROP and compared with experimental data available in the literature.

  20. Performance analysis of the reciprocating compressor with hydrocarbon refrigerant mixtures, R290/R600a

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H.; Chung, Y.G.; Pak, H.Y. [Hanyang University, Seoul (Korea); Park, K.W. [LG Industrial Systems, Seoul (Korea)

    1999-03-01

    A performance analysis simulation program that can be applied to a hermetic reciprocating compressor with various refrigerants has been developed. For the numerical analysis, the passage of refrigerant in compressor is subdivided into control volumes. Instead of the ideal gas assumption, CSD equation of state is applied to calculate the thermodynamic properties of refrigerants. To verify the validity of developed program, the result has been compared with the experimental data served by the compressor supplier. The performance of each refrigerant and the possibility of direct application are estimated by applying R12, 134a, R290, R600a and R290/R600a mixture to an existing compressor. Also, parametric study for various crank rotating speeds and the mole fractions of refrigerant has been performed. 22 refs., 12 figs., 5 tabs.

  1. Analytical method validation of GC-FID for the simultaneous measurement of hydrocarbons (C2-C4 in their gas mixture

    Directory of Open Access Journals (Sweden)

    Oman Zuas

    2016-09-01

    Full Text Available An accurate gas chromatography coupled to a flame ionization detector (GC-FID method was validated for the simultaneous analysis of light hydrocarbons (C2-C4 in their gas mixture. The validation parameters were evaluated based on the ISO/IEC 17025 definition including method selectivity, repeatability, accuracy, linearity, limit of detection (LOD, limit of quantitation (LOQ, and ruggedness. Under the optimum analytical conditions, the analysis of gas mixture revealed that each target component was well-separated with high selectivity property. The method was also found to be precise and accurate. The method linearity was found to be high with good correlation coefficient values (R2 ≥ 0.999 for all target components. It can be concluded that the GC-FID developed method is reliable and suitable for determination of light C2-C4 hydrocarbons (including ethylene, propane, propylene, isobutane, and n-butane in their gas mixture. The validated method has successfully been applied to the estimation of hydrocarbons light C2-C4 hydrocarbons in natural gas samples, showing high performance repeatability with relative standard deviation (RSD less than 1.0% and good selectivity with no interference from other possible components could be observed.

  2. Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

    Science.gov (United States)

    Riedel, Theran P.; DeMarini, David M.; Zavala, Jose; Warren, Sarah H.; Corse, Eric W.; Offenberg, John H.; Kleindienst, Tadeusz E.; Lewandowski, Michael

    2018-04-01

    Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are not. Thus, we examined the mutagenicity in Salmonella TA100 of photochemical atmospheres generated in a steady-state atmospheric simulation chamber by irradiating mixtures of single aromatic VOCs, NOx, and ammonium sulfate seed aerosol in air. The 10 VOCs examined were benzene; toluene; ethylbenzene; o-, m-, and p-xylene; 1,2,4- and 1,3,5-trimethylbenzene; m-cresol; and naphthalene. Salmonella were exposed at the air-agar interface to the generated atmospheres for 1, 2, 4, 8, or 16 h. Dark-control exposures produced non-mutagenic atmospheres, illustrating that the gas-phase precursor VOCs were not mutagenic at the concentrations tested. Under irradiation, all but m-cresol and naphthalene produced mutagenic atmospheres, with potencies ranging from 2.0 (p-xylene) to 11.4 (ethylbenzene) revertants m3 mgC-1 h-1. The mutagenicity was due exclusively to direct-acting late-generation products of the photooxidation reactions. Gas-phase chemical analysis showed that a number of oxidized organic chemical species enhanced during the irradiated exposure experiments correlated (r ≥ 0.81) with the mutagenic potencies of the atmospheres. Molecular formulas assigned to these species indicated that they likely contained peroxy acid, aldehyde, alcohol, and other functionalities.

  3. Free Energy-Based Coarse-Grained Force Field for Binary Mixtures of Hydrocarbons, Nitrogen, Oxygen, and Carbon Dioxide.

    Science.gov (United States)

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

    2017-01-23

    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.

  4. Assessment of the chlorinated hydrocarbons residues contamination in edible mushrooms from the North-Eastern part of Poland.

    Science.gov (United States)

    Gałgowska, Michalina; Pietrzak-Fiećko, Renata; Felkner-Poźniakowska, Barbara

    2012-11-01

    The aim of the study was to determine the content of chlorinated hydrocarbon residues in edible mushrooms from the north-eastern part of Poland. Material consisted of two species of fungi: Xerocomus mushrooms (Xerocomus badius), Boletus mushrooms (Boletus edulis). The dried samples (cups and cut-up material) were extracted with Soxhlet method in order to obtain lipid substances. In the fat chlorinated hydrocarbons were determined by Ludwicki et al. (1996) method. The separation and quantitative determination of DDT, DDE, DDD and γ-HCH were conducted with the method of gas chromatography using an electron capture detector - ECD. In all tested samples the presence of γ-HCH, DDT and its metabolites (DDE, DDD) was detected. The higher content of γ-HCH was found in Xerocomus mushrooms (average 0.125 μg/kg of mushrooms); in the Boletus mushrooms -0.11 μg/kg of mushrooms. The content of ΣDDT in cups of Xerocomus mushrooms was more than 2-fold higher than in those of Boletus mushrooms (3.78:1.71 mg/kg of mushrooms). The opposite relationship was observed for cut-up material. The higher concentration of ΣDDT was found in Boletus mushrooms (2.26 mg/kg of mushrooms) while in Xerocomus mushrooms this content was 0.91 mg/kg of mushrooms. Despite the fact that chlorinated hydrocarbons were determined in all samples under study, their contents do not exceed acceptable levels indicating that the consumption of mushrooms does not pose a health risk to consumers from the organochlorine compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Juhasz, Albert L., E-mail: albert.juhasz@unisa.edu.a [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Smith, Euan [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Waller, Natasha [CSIRO Land and Water, Glen Osmond, SA 5064 (Australia); Stewart, Richard [Remediate, Kent Town, SA 5067 (Australia); Weber, John [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia)

    2010-02-15

    The impact of residual PAHs (2250 +- 71 mug total PAHs g{sup -1}) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 +- 1286 mug total PAHs g{sup -1}) was assessed using a variety of ecological assays. Microtox{sup TM} results for aqueous soil extracts indicated that there was no significant difference in EC{sub 50} values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. - Residual PAHs in creosote-contaminated soil following enhanced natural attenuation impacted negatively on ecological receptors.

  6. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil

    International Nuclear Information System (INIS)

    Juhasz, Albert L.; Smith, Euan; Waller, Natasha; Stewart, Richard; Weber, John

    2010-01-01

    The impact of residual PAHs (2250 ± 71 μg total PAHs g -1 ) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 ± 1286 μg total PAHs g -1 ) was assessed using a variety of ecological assays. Microtox TM results for aqueous soil extracts indicated that there was no significant difference in EC 50 values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. - Residual PAHs in creosote-contaminated soil following enhanced natural attenuation impacted negatively on ecological receptors.

  7. Biodegradation of hydrocarbon mixtures in surface waters at environmentally relevant levels - Effect of inoculum origin on kinetics and sequence of degradation.

    Science.gov (United States)

    Birch, Heidi; Hammershøj, Rikke; Comber, Mike; Mayer, Philipp

    2017-10-01

    Biodegradation is a dominant removal process for many organic pollutants, and biodegradation tests serve as tools for assessing their environmental fate within regulatory risk assessment. In simulation tests, the inoculum is not standardized, varying in microbial quantity and quality, thereby potentially impacting the observed biodegradation kinetics. In this study we investigated the effect of inoculum origin on the biodegradation kinetics of hydrocarbons for five inocula from surface waters varying in urbanization and thus expected pre-exposure to petroleum hydrocarbons. A new biodegradation method for testing mixtures of hydrophobic chemicals at trace concentrations was demonstrated: Aqueous solutions containing 9 hydrocarbons were generated by passive dosing and diluted with surface water resulting in test systems containing native microorganisms exposed to test substances at ng-μg/L levels. Automated Headspace Solid Phase Microextraction coupled to GC-MS was applied directly to these test systems to determine substrate depletion relative to abiotic controls. Lag phases were generally less than 8 days. First order rate constants were within one order of magnitude for each hydrocarbon in four of the five waters but lower in water from a rural lake. The sequence of degradation between the 9 hydrocarbons showed similar patterns in the five waters indicating the potential for using selected hydrocarbons for benchmarking between biodegradation tests. Degradation half-times were shorter than or within one order of magnitude of BioHCwin predictions for 8 of 9 hydrocarbons. These results showed that location choice is important for biodegradation kinetics and can provide a relevant input to aquatic exposure and fate models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Maximum conversion of heavy hydrocarbons. Product stability dictates thermal and catalytic conversion rates of residues

    Energy Technology Data Exchange (ETDEWEB)

    Hennico, A.; Peries, J.P. (Institut Francais du Petrole, 92 - Rueil Malmaison (France)); Laurent, J.; Espeillac, M.

    1992-01-01

    The maximum conversion achieved by thermal cracking is limited by the fuel stability. The same holds for catalytic hydrotreating. ASVAHL has studied for many years the relation between conversion and product stability in thermal and catalytic processes. Thermal Mode: Several solutions are proposed to increase the conversion of the TERVAHL T visbreaking process such as the use of hydrogen (TERVAHL H) and possibly the addition of a few ppm of a dispersed catalyst (TERVAHL C). Catalytic Mode: The conversion of the HYVAHL residue hydrotreating process may be increased either by adding a hydrovisbreaking furnace before the hydrotreating step (HYVAHL T) or by adding an existing visbreaking downstream the hydrotreating step. These various routes enable the ASVAHL processes to maximize the marketable light product quantities in function of the residue to be upgraded and the fuel qualities to be assured. (orig.).

  9. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil.

    Science.gov (United States)

    Juhasz, Albert L; Smith, Euan; Waller, Natasha; Stewart, Richard; Weber, John

    2010-02-01

    The impact of residual PAHs (2250 +/- 71 microg total PAHs g(-1)) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 +/- 1286 microg total PAHs g(-1)) was assessed using a variety of ecological assays. Microtox results for aqueous soil extracts indicated that there was no significant difference in EC(50) values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  10. Genotoxicity evaluation of multi-component mixtures of polyaromatic hydrocarbons (PAHs), arsenic, cadmium, and lead using flow cytometry based micronucleus test in HepG2 cells.

    Science.gov (United States)

    Muthusamy, Sasikumar; Peng, Cheng; Ng, Jack C

    2018-03-01

    Some polyaromatic hydrocarbons (PAHs) and metals are known human carcinogens and the combined toxicity data of these co-contaminants are important for assessing their health risk. In this study, we have evaluated the combined genotoxicity, AhR activity and cell cycle parameters of four PAHs (benzo[a]pyrene (Ba]P), naphthalene (Nap), phenanthrene (Phe) and pyrene (Pyr)) and three metals (arsenic (As), cadmium (Cd), and lead (Pb)) in HepG2 cells using a flow cytometry based micronucleus (MN) test CAFLUX assay and nuclear fluorescence assay, respectively. The mixtures of B[a]P and metals induced a maximum of four fold increase in the MN formation compared to B[a]P alone. The higher combination of PAHs and metals did not significantly increase the MN formation. The mixtures of metals or non-carcinogenic PAHs were found to increase or decrease the aryl hydrocarbon receptor (AhR) activation of B[a]P in HepG2 cell based CAFLUX assay. Overall, the results showed that combined genotoxicity of PAHs and metals in HepG2 cells vary depending on the concentrations and number of the chemicals that are present in the mixtures and the effects of higher order combinations appear to be largely unpredictable from binary combinations. In this study, we have demonstrated the use of flow cytometry based MN test to screen the genotoxicity of environmental chemicals and its mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Emission factors of polycyclic and nitro-polycyclic aromatic hydrocarbons from residential combustion of coal and crop residue pellets.

    Science.gov (United States)

    Yang, Xiaoyang; Liu, Shijie; Xu, Yisheng; Liu, Yu; Chen, Lijiang; Tang, Ning; Hayakawa, Kazuichi

    2017-12-01

    Polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) are toxic pollutants mainly produced during fossil fuel combustion. Domestic coal stoves, which emit large amounts of PAHs and NPAHs, are widely used in the Chinese countryside. In this study, emission factors (Efs) for 13 PAH species and 21 NPAH species for four raw coal (three bituminous and one anthracite), one honeycomb briquette, and one crop residue pellet (peanut hulls) samples burned in a typical Chinese rural cooking stove were determined experimentally. The PAH and NPAH Efs for the six fuels were 3.15-49 mg/kg and 0.32-100 μg/kg, respectively. Peanut hulls had very high Efs for both PAHs and NPAHs, and honeycomb briquettes had the lowest Efs. 2-Nitropyrene and 2-nitrofluoranthene, which are NPAHs typically found in secondary organic aerosol, were detected in the emissions from some fuels, suggesting that chemical reactions may have occurred in the dilution tunnel between the flue gas leaving the stove and entering the sampler. The 1-nitropyrene to pyrene diagnostic ratios for coal and peanut hulls were 0.0001 ± 0.0001 and 0.0005, respectively. These were in the same order of magnitude as reference ratios for emissions during coal combustion. The 6-nitrobenzo[a]pyrene to benzo[a]pyrene ratios for the fuels were determined, and the ratios for coal and peanut hulls were 0.0010 ± 0.0001 and 0.0014, respectively. The calculated potential toxic risks indicated that peanut hull emissions were very toxic, especially in terms of NPAHs, compared with emissions from the other fuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Polycyclic aromatic hydrocarbon residues in human milk, placenta, and umbilical cord blood in Beijing, China.

    Science.gov (United States)

    Yu, Yanxin; Wang, Xilong; Wang, Bin; Tao, Shu; Liu, Wenxin; Wang, Xuejun; Cao, Jun; Li, Bengang; Lu, Xiaoxia; Wong, Ming H

    2011-12-01

    This paper provides the results of an investigation on dietary intakes and internal doses of polycyclic aromatic hydrocarbons (PAHs) for nonsmoking women from Beijing, China. Concentrations of PAHs were measured by gas chromatography/mass spectrometry (GC/MS) for human milk, placenta, and umbilical cord blood samples from 40 nonsmoking women and for 144 composite food samples covering major food categories. Information on food consumption and estimated ingestion doses of PAHs by the cohort was also collected individually. Relationship among the studied human samples and relative importance of breastfeeding to the total exposure dose of infants were addressed. The median (mean and standard deviation) total concentrations of 15 PAHs in human milk, placenta, and umbilical cord blood with (or without) fat normalization were 278 (9.30 ± 5.75), 819 (35.9 ± 15.4), and 1370 (5.521 ± 3.71) ng/g of fat, respectively, and the corresponding levels of benzo[a]pyrene equivalent (B[a]P(equiv)) were 11.2 (0.473 ± 0.605), 16.2 (0.717 ± 0.318), and 13.1 (0.140 ± 0.225) ng/g of fat, respectively. The calculated intake of B[a]P(equiv) by Beijing cohort varied from 0.609 to 4.69 ng·kg(-1)·day(-1) with a median value of 1.93 (2.09 ± 0.921 mean ± standard deviation) ng·kg(-1)·day(-1). Significant correlations were found among human milk, placenta, and umbilical cord blood (p 0.05). Ingested doses of PAHs (3.00-102 ng·kg(-1)·day(-1)), which were much higher than the inhaled doses (0.152-8.50 ng·kg(-1)·day(-1)), were 3-4 orders of magnitude lower than the recommended reference doses, unlikely to impose any obvious risk based on current knowledge.

  13. A framework for the use of single-chemical transcriptomics data in predicting the hazards associated with complex mixtures of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Labib, Sarah; Williams, Andrew; Kuo, Byron; Yauk, Carole L; White, Paul A; Halappanavar, Sabina

    2017-07-01

    The assumption of additivity applied in the risk assessment of environmental mixtures containing carcinogenic polycyclic aromatic hydrocarbons (PAHs) was investigated using transcriptomics. MutaTMMouse were gavaged for 28 days with three doses of eight individual PAHs, two defined mixtures of PAHs, or coal tar, an environmentally ubiquitous complex mixture of PAHs. Microarrays were used to identify differentially expressed genes (DEGs) in lung tissue collected 3 days post-exposure. Cancer-related pathways perturbed by the individual or mixtures of PAHs were identified, and dose-response modeling of the DEGs was conducted to calculate gene/pathway benchmark doses (BMDs). Individual PAH-induced pathway perturbations (the median gene expression changes for all genes in a pathway relative to controls) and pathway BMDs were applied to models of additivity [i.e., concentration addition (CA), generalized concentration addition (GCA), and independent action (IA)] to generate predicted pathway-specific dose-response curves for each PAH mixture. The predicted and observed pathway dose-response curves were compared to assess the sensitivity of different additivity models. Transcriptomics-based additivity calculation showed that IA accurately predicted the pathway perturbations induced by all mixtures of PAHs. CA did not support the additivity assumption for the defined mixtures; however, GCA improved the CA predictions. Moreover, pathway BMDs derived for coal tar were comparable to BMDs derived from previously published coal tar-induced mouse lung tumor incidence data. These results suggest that in the absence of tumor incidence data, individual chemical-induced transcriptomics changes associated with cancer can be used to investigate the assumption of additivity and to predict the carcinogenic potential of a mixture.

  14. Excess enthalpies of ternary mixtures of (oxygenated additives + aromatic hydrocarbon) mixtures in fuels and bio-fuels: (Dibutyl-ether + 1-propanol + benzene), or toluene, at T = (298.15 and 313.15) K

    International Nuclear Information System (INIS)

    Alaoui, Fatima E.M.; Aguilar, Fernando; González-Fernández, María Jesús; Dakkach, Mohamed; Montero, Eduardo A.

    2015-01-01

    Highlights: • New excess enthalpy data for ternary mixtures of (dibutyl ether + aromatic hydrocarbon + 1-propanol) are reported. • 2 ternary systems at T = (298.15 and 313.15) K were measured by means of an isothermal flow calorimeter. • 230 data were fitted to a Redlich–Kister rational equation. • Intermolecular and association effects involved in these systems have been discussed. - Abstract: New experimental excess molar enthalpy data of the ternary systems (dibutyl ether + 1-propanol + benzene, or toluene), and the corresponding binary systems at T = (298.15 and 313.15) K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and ternary systems show endothermic character at both temperatures. The experimental data for the systems have been fitted using the Redlich–Kister rational equation. Considerations with respect the intermolecular interactions amongst ether, alcohol and hydrocarbon compounds are presented

  15. Correspondence of soldier defense secretion mixtures with cuticular hydrocarbon phenotypes for chemotaxonomy of the termite genus Reticulitermes in North America.

    Science.gov (United States)

    Nelson, L J; Cool, L G; Forschler, B T; Haverty, M I

    2001-07-01

    Soldier defense secretions from samples of Reticulitermes collected in California, Nevada, Arizona, New Mexico, and Georgia were characterized and correlated with cuticular hydrocarbon phenotypes. Twenty-seven cuticular hydrocarbon phenotypes have been defined, and soldier defense secretion (SDS) phenotypes have been described for 25 of these. Forty-five terpenoid compounds were found, including monoterpenes, sesquiterpenes, and a few diterpenes. The monoterpenes include (-)-alpha-pinene, (-)-beta-pinene, (-)-camphene, myrcene, (Z)- and (E)-ocimene, and (-)-limonene. The major sesquiterpenes produced are (+)-gamma-cadinene, (+)-gamma-cadinene aldehyde, (-)-germacrene A, germacrene B, gamma-himachalene, and beta-bisabolene. Some SDS phenotypes pair with more than one cuticular hydrocarbon phenotype; however, with two exceptions, each hydrocarbon phenotype is associated with only one SDS phenotype. These chemical characterizations lend support to the conclusion that there are numerous undescribed species of Reticulitermes in North America.

  16. Activation of the aryl hydrocarbon receptor is the major toxic mode of action of an organic extract of a reference urban dust particulate matter mixture: The role of polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Andrysik, Zdenek; Vondracek, Jan; Marvanova, Sona; Ciganek, Miroslav; Neca, Jiri; Pencikova, Katerina; Mahadevan, Brinda; Topinka, Jan; Baird, William M.; Kozubik, Alois; Machala, Miroslav

    2011-01-01

    Highlights: → SRM1649a extract and its fractions are potent activators of AhR in a model of epithelial cells. → AhR-dependent effects include both induction of CYP1 enzymes and disruption of cell proliferation control. → Polycyclic aromatic hydrocarbons present in the neutral SRM1649a fraction are major contributors to the AhR-mediated toxic effects. → Activation of AhR and related nongenotoxic effects occur at significantly lower doses than the formation of DNA adducts and activation of DNA damage response. → More attention should be paid to the AhR-dependent nongenotoxic events elicited by urban particulate matter constituents. - Abstract: Many of the toxic and carcinogenic effects of urban air pollution have been linked to polycyclic aromatic hydrocarbons (PAHs) adsorbed to airborne particulate matter (PM). The carcinogenic properties of PAHs in complex organic mixtures derived from PM have been chiefly attributed to their mutagenicity. Nevertheless, PAHs are also potent activators of the aryl hydrocarbon receptor (AhR), which may contribute to their nongenotoxic effects, including tumor promotion. As the genotoxicity of carcinogenic PAHs in complex mixtures derived from urban PM is often inhibited by other mixture constituents, the AhR-mediated activity of urban PM extracts might significantly contribute to the carcinogenic activity of such mixtures. In the present study, we used an organic extract of the urban dust standard reference material, SRM1649a, as a model mixture to study a range of toxic effects related to DNA damage and AhR activation. Both the organic extract and its neutral aromatic fraction formed a low number of DNA adducts per nucleotide in the liver epithelial WB-F344 cells model, without inducing DNA damage response, such as tumor suppressor p53 activation and apoptosis. In contrast, we found that this extract, as well as its neutral and polar fractions, were potent inducers of a range of AhR-mediated responses, including induction

  17. Weathering and toxicity of marine sediments contaminated with oils and polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Jonker, M.T.O.; Sinke, A.; Brils, J.M.; Murk, A.J.; Koelmans, A.A.

    2006-01-01

    Many sediments are contaminated with mixtures of oil residues and polycyclic aromatic hydrocarbons (PAHs), but little is known about the toxicity of such mixtures to sediment-dwelling organisms and the change in toxicity on weathering. In the present study, we investigated the effects of a

  18. Formation of polycyclic aromatic hydrocarbons from tobacco: the link between low temperature residual solid (char) and PAH formation.

    Science.gov (United States)

    McGrath, Thomas E; Wooten, Jan B; Geoffrey Chan, W; Hajaligol, Mohammad R

    2007-06-01

    The formation of condensed ring polycyclic aromatic hydrocarbons (PAHs) from the pyrolysis of ground tobacco in helium over the temperature range of 350-600 degrees C was investigated. PAH yields in the ng/g range were detected and the maximum yields of all PAHs studied including benzo[a]pyrene (B[a]P) and benzo[a]anthracene (B[a]A) occurred between 500 and 550 degrees C. The pathway to PAH formation in the 350-600 degrees C temperature range is believed to proceed via a carbonization process where the residual solid (char) undergoes a chemical transformation and rearrangement to give a more condensed polycyclic aromatic structure that upon further heating evolves PAH moieties. Extraction of tobacco with water led to a two fold increase in the yields of most PAHs studied. The extraction process removed low temperature non-PAH-forming components, such as alkaloids, organic acids and inorganic salts, and concentrated instead (on a per unit weight basis) tobacco components such as cell wall bio-polymers and lipids. Hexane extraction of the tobacco removed lipophilic components, previously identified as the main source of PAH precursors, but no change in PAH yields was observed from the hexane-extracted tobacco. Tobacco cell wall components such as cellulose, hemicellulose, and lignin are identified as major low temperature PAH precursors. A link between the formation of a low temperature char that evolves PAHs upon heating is established and the observed ng/g yields of PAHs from tobacco highlights a low temperature solid phase formation mechanism that may be operable in a burning cigarette.

  19. Maximising municipal solid waste--legume trimming residue mixture degradation in composting by control parameters optimization.

    Science.gov (United States)

    Cabeza, I O; López, R; Ruiz-Montoya, M; Díaz, M J

    2013-10-15

    Composting is one of the most successful biological processes for the treatment of the residues enriched in putrescible materials. The optimization of parameters which have an influence on the stability of the products is necessary in order to maximize recycling and recovery of waste components. The influence of the composting process parameters (aeration, moisture, C/N ratio, and time) on the stability parameters (organic matter, N-losses, chemical oxygen demand, nitrate, biodegradability coefficient) of the compost was studied. The composting experiment was carried out using Municipal Solid Waste (MSW) and Legume Trimming Residues (LTR) in 200 L isolated acrylic barrels following a Box-Behnken central composite experimental design. Second-order polynomial models were found for each of the studied compost stability parameter, which accurately described the relationship between the parameters. The differences among the experimental values and those estimated by using the equations never exceeded 10% of the former. Results of the modelling showed that excluding the time, the C/N ratio is the strongest variable influencing almost all the stability parameters studied in this case, with the exception of N-losses which is strongly dependent on moisture. Moreover, an optimized ratio MSW/LTR of 1/1 (w/w), moisture content in the range of 40-55% and moderate to low aeration rate (0.05-0.175 Lair kg(-)(1) min(-1)) is recommended to maximise degradation and to obtain a stable product during co-composting of MSW and LTR. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Lipid Production of Heterotrophic Chlorella sp. from Hydrolysate Mixtures of Lipid-Extracted Microalgal Biomass Residues and Molasses.

    Science.gov (United States)

    Zheng, Hongli; Ma, Xiaochen; Gao, Zhen; Wan, Yiqin; Min, Min; Zhou, Wenguang; Li, Yun; Liu, Yuhuan; Huang, He; Chen, Paul; Ruan, Roger

    2015-10-01

    This study investigated the feasibility of lipid production of Chlorella sp. from waste materials. Lipid-extracted microalgal biomass residues (LMBRs) and molasses were hydrolyzed, and their hydrolysates were analyzed. Five different hydrolysate mixture ratios (w/w) of LMBRs/molasses (1/0, 1/1, 1/4, 1/9, and 0/1) were used to cultivate Chlorella sp. The results showed that carbohydrate and protein were the two main compounds in the LMBRs, and carbohydrate was the main compound in the molasses. The highest biomass concentration of 5.58 g/L, Y biomass/sugars of 0.59 g/g, lipid productivity of 335 mg/L/day, and Y lipids/sugars of 0.25 g/g were obtained at the hydrolysate mixture ratio of LMBRs/molasses of 1/4. High C/N ratio promoted the conversion of sugars into lipids. The lipids extracted from Chlorella sp. shared similar lipid profile of soybean oil and is therefore a potential viable biodiesel feedstock. These results showed that Chlorella sp. can utilize mixed sugars and amino acids from LMBRs and molasses to accumulate lipids efficiently, thus reducing the cost of microalgal biodiesel production and improving its economic viability.

  1. Modeling and simulation of cooling-induced residual stresses in heated particulate mixture depositions in additive manufacturing

    Science.gov (United States)

    Zohdi, T. I.

    2015-10-01

    One key aspect of many additive manufacturing processes is the deposition of heated mixtures of particulate materials onto surfaces, which then bond and cool, leading to complex microstructures and possible residual stresses. The overall objective of this work is to construct a straightforward computational approach that researchers in the field can easily implement and use as a numerically-efficient simulation and design tool. Specifically because multifield coupling is present, a recursive, staggered, temporally-adaptive, finite difference time domain scheme is developed to resolve the internal microstructural thermal and mechanical fields, accounting for the simultaneous elasto-plasticity and damage. The time step adaptation allows the numerical scheme to iteratively resolve the changing physical fields by refining the time-steps during phases of the process when the system is undergoing large changes on a relatively small time-scale and can also enlarge the time-steps when the processes are relatively slow. The spatial discretization grids are uniform and dense. The deposited microstructure is embedded into spatial discretization. The regular grid allows one to generate a matrix-free iterative formulation which is amenable to rapid computation and minimal memory requirements, making it ideal for laptop computation. Numerical examples are provided to illustrate the approach. This formulation is useful for material scientists who seek ways to deposit such materials while simultaneously avoiding inadvertent excessive residual stresses.

  2. On the Rule of Mixtures for Predicting Stress-Softening and Residual Strain Effects in Biological Tissues and Biocompatible Materials

    Directory of Open Access Journals (Sweden)

    Alex Elías-Zúñiga

    2014-01-01

    Full Text Available In this work, we use the rule of mixtures to develop an equivalent material model in which the total strain energy density is split into the isotropic part related to the matrix component and the anisotropic energy contribution related to the fiber effects. For the isotropic energy part, we select the amended non-Gaussian strain energy density model, while the energy fiber effects are added by considering the equivalent anisotropic volumetric fraction contribution, as well as the isotropized representation form of the eight-chain energy model that accounts for the material anisotropic effects. Furthermore, our proposed material model uses a phenomenological non-monotonous softening function that predicts stress softening effects and has an energy term, derived from the pseudo-elasticity theory, that accounts for residual strain deformations. The model’s theoretical predictions are compared with experimental data collected from human vaginal tissues, mice skin, poly(glycolide-co-caprolactone (PGC25 3-0 and polypropylene suture materials and tracheal and brain human tissues. In all cases examined here, our equivalent material model closely follows stress-softening and residual strain effects exhibited by experimental data.

  3. Residual effect of mixture of glyphosate and 2,4-D in winter maize in different soil textures

    Directory of Open Access Journals (Sweden)

    Schaianne A. Gomes

    Full Text Available ABSTRACT To increase the efficiency in the control of weeds, it is common the use of a mixture of the herbicides glyphosate and 2,4-D in the desiccation. This paper aimed to evaluate the residual effect of these two herbicides on the development of maize plants, in soils of different textures. The experiment was conducted in a greenhouse, in 2015, in a completely randomized design in a 2 x 2 x 7 factorial scheme, corresponding to two soils (Red Yellow Latosol and Quartzarenic Neosol, two herbicide application times (5 and 10 days before maize sowing and seven doses of herbicides (recommended dose of glyphosate, recommended dose of 2,4-D; mixing the recommended doses of glyphosate and 2,4-D; two, ten and fifty times the recommended doses in admixture; and one control, with 4 replicates. After emergence of maize plants, the following variables were evaluated: phytotoxicity, plant height, chlorophyll a and chlorophyll b, shoot fresh and dry matter and root dry matter. In general, there was lower residual effect on the Red Yellow Latosol at all the doses of the herbicides and in the interval of 10 days between the desiccation and sowing.

  4. Immunotoxicity of environmentally relevant mixtures of polychlorinated aromatic hydrocarbons with methyl mercury on rat lymphocytes in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Omara, F.O.; Brochu, C.; Flipo, D.; Denizeau, F.; Fournier, M. [Univ. of Quebec, Montreal, Quebec (Canada)

    1997-03-01

    The immunosuppressive effects of methyl mercury (MHg), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) are well established at higher exposure levels but unclear at low exposure levels. The authors exposed Fischer 344 rat splenocytes, thymocytes, and peripheral blood lymphocytes in vitro for 72 h to MHg of three PCDDs and two PCDFs PCB mixtures, or combinations of MHg/PCB/PCDD/PCDF mixtures Mitogenic responses of lymphocytes to concanavalin A, phytohemagglutinin, or lipopolysaccharide/dextran sulfate were determined by {sup 3}H-thymidine uptake; cytotoxicity and intracellular Ca{sup 2+} were determined by flow cytometry. Methylmercury mixtures with 2 {micro}g/ml MHg decreased the viability of splenocytes to 57 and 40% at 4 and 24 h, respectively. Basal intracellular calcium ion levels were unaffected by the treatments. Methylmercury suppressed the responses of lymphocytes to T and B cell mitogens. All combinations of MHg/PCB/PCDD/PCDF mixtures decreased mitogenic responses to levels similar to those to MHg alone. In contrast, PCB and PCDD/PCDF mixtures did not suppress but augmented responses of splenocytes and peripheral blood lymphocytes to T cell mitogens. Overall, no interactive toxicity was observed with MHg/PCB/PCDD/PCDF mixtures on cytotoxicity and lymphocyte mitogenic responses. Therefore, MHg may pose a greater threat than organochlorines to the mammalian immune system.

  5. A method for determining allowable residual contamination levels of radionuclide mixtures in soil

    International Nuclear Information System (INIS)

    Napier, B.A.

    1982-05-01

    An important consideration in the disposal of radioactive wastes, and consequently in the preparation of plans for remedial actions at contaminated sites, is the amount of radioactive contamination that may be allowed to remain at any particular waste site. The allowable residual contamination level (ARCL) is dependent on the radiation dose limit imposed, the physical and environmental characteristics of the waste site, and the time at which exposure to the wastes is assumed to occur. The steps in generating an ARCL are generally as follows: (1) develop plausible, credible site-specific exposure scenario; (2) calculate maximum annual radiation doses to an individual for each radionuclide based on the existing physical characteristics of the waste site and the site-specific exposure scenario; (3) calculate the ARCL for the dose limit desired, including all radionuclides present, uncorrected for site cleanup or barrier considerations; and (4) apply any corrections for proposed cleanup activity or addition of barriers to waste migration or uptake to obtain the ARCL applicable to the proposed action. Use of this method allows appropriate application of resources to achieve uniform compliance with a single regulatory standard, i.e., a radiation dose rate limit. Application and modification of the ARCL method requires appropriate models of the environmental transport and fate of radionuclides. Example calculations are given for several specific waste forms and waste site types in order to demonstrate the technique and generate comparisons with other approaches

  6. Distribution of trichloroethylene and selected aliphatic and aromatic hydrocarbons between ''weathered'' and ''unweathered'' fuel mixtures and groundwater: Equilibrium and kinetic considerations

    International Nuclear Information System (INIS)

    Doucette, W.J.; Dupont, R.R.

    1995-01-01

    The distribution of trichloroethylene and several aliphatic and aromatic fuel components between 46 weathered and 11 unweathered fuel mixtures and groundwater was investigated using a slow stirring method. The weathered fuel mixtures were obtained from several contaminated field sites. Both unlabeled and 14C-labeled test compounds were used in the distribution experiments. Analyses of the test compound concentrations over time was performed by gas chromatograph or liquid scintillation counting. The time required to reach equilibrium varied from about 24 to 72 hours. Generally, the greater the hydrophobicity of the test compounds the longer time that was required to reach equilibrium. It was also observed that the fuel/water distribution coefficients were generally larger for the weathered fuels than those measured for the unweathered fuels, in some cases by a factor of 100. The weathered fuel mixtures obtained from the field site were depleted of the more water soluble compounds over time and became significantly more enriched in long chain aliphatic hydrocarbons. The ability of several models to describe the observed distribution behavior was examined

  7. The PERICLES research program: An integrated approach to characterize the combined effects of mixtures of pesticide residues to which the French population is exposed

    International Nuclear Information System (INIS)

    Crépet, A.; Héraud, F.; Béchaux, C.; Gouze, M.E.; Pierlot, S.; Fastier, A.; Leblanc, J.Ch.; Le Hégarat, L.; Takakura, N.; Fessard, V.; Tressou, J.; Maximilien, R.; Sousa, G. de; Nawaz, A.; Zucchini-Pascal, N.; Rahmani, R.; Audebert, M.; Graillot, V.; Cravedi, J.P.

    2013-01-01

    Due to the broad spectrum of pesticide usages, consumers are exposed to mixtures of residues, which may have combined effects on human health. The PERICLES research program aims to test the potential combined effects of pesticide mixtures, which are likely to occur through dietary exposure. The co-exposure of the French general population to 79 pesticide residues present in the diet was first assessed. A Bayesian nonparametric model was then applied to define the main mixtures to which the French general population is simultaneously and most heavily exposed. Seven mixtures made of two to six pesticides were identified from the exposure assessment. An in vitro approach was used for investigating the toxicological effects of these mixtures and their corresponding individual compounds, using a panel of cellular models, i.e. primary rat and human hepatocytes, liver, intestine, kidney, colon and brain human cell lines. A set of cell functions and corresponding end-points were monitored such as cytotoxicity, real-time cell impedance, genotoxicity, oxidative stress, apoptosis and PXR nuclear receptor transactivation. The mixtures were tested in equimolar concentrations. Among the seven mixtures, two appeared highly cytotoxic, five activated PXR and depending on the assay one or two were genotoxic. In some experiments, the mixture effect was quantitatively different from the effect expected from the addition concept. The PERICLES program shows that, for the most pesticides mixtures to which the French general population is exposed, the toxic effects observed on human cells cannot be easily predicted based on the toxic potential of each compound. Consequently, additional studies should be carried on in order to more accurately define the mixtures of chemicals to which the consumers are exposed, as well as to improve the investigation, prediction and monitoring of their potential human health effects

  8. Effects of currently used pesticides and their mixtures on the function of thyroid hormone and aryl hydrocarbon receptor in cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Ghisari, Mandana; Long, Manhai; Tabbo, Agnese; Bonefeld-Jørgensen, Eva Cecilie, E-mail: ebj@mil.au.dk

    2015-05-01

    Evidence suggest that exposure to pesticides can interfere with the endocrine system by multiple mechanisms. The endocrine disrupting potential of currently used pesticides in Denmark was analyzed as single compounds and in an equimolar mixture of 5 selected pesticides. The pesticides were previously analyzed for effects on the function of estrogen and androgen receptors, the aromatase enzyme and steroidogenesis in vitro. In this study, the effect on thyroid hormone (TH) function and aryl hydrocarbon receptor (AhR) transactivity was assessed using GH3 cell proliferation assay (T-screen) and AhR responsive luciferase reporter gene bioassay, respectively. Thirteen pesticides were analyzed as follows: 2-methyl-4-chlorophenoxyacetic acid, terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb and its metabolite ethylene thiourea, cypermethrin, tau-fluvalinate, and malathion (currently banned in DK). In the T-screen, prothioconazole, malathion, tau-fluvalinate, cypermethrin, terbuthylazine and mancozeb significantly stimulated and bitertanol and propiconazole slightly reduced the GH3 cell proliferation. In the presence of triiodothyronine (T3), prothioconazole, tau-fluvalinate, propiconazole, cypermethrin and bitertanol significantly antagonized the T3-induced GH3 cell proliferation. Eleven of the tested pesticides agonized the AhR function, and bitertanol and prothioconazole inhibited the basal AhR activity. Bitertanol, propiconazole, prothioconazole and cypermethrin antagonized the TCDD-induced AhR transactivation at the highest tested concentration. The 5-component mixture had inducing effect but the combined effect could not be predicted due to the presence of bitertanol eliciting inhibitory effect. Upon removal of bitertanol from the mixture, the remaining four pesticides acted additively. In conclusion, our data suggest that pesticides currently used in Denmark

  9. Enzymatic hydrolyses of pretreated eucalyptus residues, wheat straw or olive tree pruning, and their mixtures towards flexible sugar-based biorefineries

    DEFF Research Database (Denmark)

    Silva-Fernandes, Talita; Marques, Susana; Rodrigues, Rita C. L. B.

    2016-01-01

    Eucalyptus residues, wheat straw, and olive tree pruning are lignocellulosic materials largely available in Southern Europe and have high potential to be used solely or in mixtures in sugar-based biorefineries for the production of biofuels and other bio-based products. Enzymatic hydrolysis of ce...

  10. The high pressure liquid chromatography and its application to the separation of polynuclear aromatic hydrocarbons in atmospheric dust and burning residues

    International Nuclear Information System (INIS)

    Lopez, M.-C.

    1975-09-01

    A new technique of analysis is described: the high speed liquid chromatography or more exactly the high performance liquid chromatography because of the progress achieved on the new packings of the columns. The main types of chromatography, according to the phenomena involved are described: adsorption, partition, ion-exchange and exclusion chromatography. A brief outline is given of the theory for determination of stationary and mobile phases in order to obtain the optimum conditions of separation. Some exemples of possible applications are given, particularly the use of this technique for the separation of polycyclic aromatic hydrocarbons in atmospheric pollution and burning residues [fr

  11. Catalytic upgrading nitrogen-riched wood syngas to liquid hydrocarbon mixture over Fe-Pd/ZSM-5 catalyst

    Science.gov (United States)

    Qiangu Yan; Fei Yu; Zhiyong Cai; Jilei Zhang

    2012-01-01

    Biomass like wood chips, switchgrass and other plant residues are first converted to syngas through gasification process using air, oxygen or steam. A downdraft gasifier is performed for syngas production in Mississippi State. The syngas from the gasifier contains up to 49% (vol) N2. High-level nitrogen-containing (nitrogen can be up to 60%)...

  12. Thermodynamics of organic mixtures containing amines. X. Phase equilibria for binary systems formed by imidazoles and hydrocarbons: Experimental data and modelling using DISQUAC

    International Nuclear Information System (INIS)

    Domanska, Urszula; Zawadzki, Maciej; Gonzalez, Juan Antonio

    2010-01-01

    (Solid + liquid) equilibrium (SLE) temperatures have been determined using a dynamic method for the systems (1H-imidazole, + benzene, + toluene, + hexane, or + cyclohexane; 1-methylimidazole + benzene, or + toluene, 2-methyl-1H-imidazole + benzene, + toluene, or + cyclohexane, and benzimidazole + benzene). In addition (liquid + liquid) equilibrium (LLE) temperatures have been obtained using a cloud point method for (1H-imidazole, + hexane, or + cyclohexane; 1-methylimidazole + toluene, and 2-methyl-1H-imidazole + cyclohexane). The measured systems show positive deviations from the Raoult's law, due to strong dipolar interactions between amine molecules related to the high dipole moment of imidazoles. On the other hand, DISQUAC interaction parameters for the contacts present in these solutions and for the amine/hydroxyl contacts in (1H-imidazole + 1-alkanol) mixtures have been determined. The model correctly represents the available data for the examined systems. Deviations between experimental and calculated SLE temperatures are similar to those obtained using the Wilson or NRTL equations, or the UNIQUAC association solution model. The quasichemical interaction parameters are the same for mixtures containing 1H-imidazole, 1-methylimidazole, or 2-methyl-1H-imidazole and hydrocarbons. This may be interpreted assuming that they are members of a homologous series. Benzimidazole behaves differently.

  13. Thermodynamics of organic mixtures containing amines. X. Phase equilibria for binary systems formed by imidazoles and hydrocarbons: Experimental data and modelling using DISQUAC

    Energy Technology Data Exchange (ETDEWEB)

    Domanska, Urszula; Zawadzki, Maciej [Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, 00-664 Warsaw (Poland); Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.e [G.E.T.E.F., Grupo Especializado en Termodinamica de Equilibrio entre Fases, Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, E-47071, Valladolid (Spain)

    2010-04-15

    (Solid + liquid) equilibrium (SLE) temperatures have been determined using a dynamic method for the systems (1H-imidazole, + benzene, + toluene, + hexane, or + cyclohexane; 1-methylimidazole + benzene, or + toluene, 2-methyl-1H-imidazole + benzene, + toluene, or + cyclohexane, and benzimidazole + benzene). In addition (liquid + liquid) equilibrium (LLE) temperatures have been obtained using a cloud point method for (1H-imidazole, + hexane, or + cyclohexane; 1-methylimidazole + toluene, and 2-methyl-1H-imidazole + cyclohexane). The measured systems show positive deviations from the Raoult's law, due to strong dipolar interactions between amine molecules related to the high dipole moment of imidazoles. On the other hand, DISQUAC interaction parameters for the contacts present in these solutions and for the amine/hydroxyl contacts in (1H-imidazole + 1-alkanol) mixtures have been determined. The model correctly represents the available data for the examined systems. Deviations between experimental and calculated SLE temperatures are similar to those obtained using the Wilson or NRTL equations, or the UNIQUAC association solution model. The quasichemical interaction parameters are the same for mixtures containing 1H-imidazole, 1-methylimidazole, or 2-methyl-1H-imidazole and hydrocarbons. This may be interpreted assuming that they are members of a homologous series. Benzimidazole behaves differently.

  14. Analysis of binary mixtures of aqueous aromatic hydrocarbons with low-phase-noise shear-horizontal surface acoustic wave sensors using multielectrode transducer designs.

    Science.gov (United States)

    Bender, Florian; Mohler, Rachel E; Ricco, Antonio J; Josse, Fabien

    2014-11-18

    The present work investigates a compact sensor system that provides rapid, real-time, in situ measurements of the identities and concentrations of aromatic hydrocarbons at parts-per-billion concentrations in water through the combined use of kinetic and thermodynamic response parameters. The system uses shear-horizontal surface acoustic wave (SH-SAW) sensors operating directly in the liquid phase. The 103 MHz SAW sensors are coated with thin sorbent polymer films to provide the appropriate limits of detection as well as partial selectivity for the analytes of interest, the BTEX compounds (benzene, toluene, ethylbenzene, and xylenes), which are common indicators of fuel and oil accidental releases in groundwater. Particular emphasis is placed on benzene, a known carcinogen and the most challenging BTEX analyte with regard to both regulated levels and its solubility properties. To demonstrate the identification and quantification of individual compounds in multicomponent aqueous samples, responses to binary mixtures of benzene with toluene as well as ethylbenzene were characterized at concentrations below 1 ppm (1 mg/L). The use of both thermodynamic and kinetic (i.e., steady-state and transient) responses from a single polymer-coated SH-SAW sensor enabled identification and quantification of the two BTEX compounds in binary mixtures in aqueous solution. The signal-to-noise ratio was improved, resulting in lower limits of detection and improved identification at low concentrations, by designing and implementing a type of multielectrode transducer pattern, not previously reported for chemical sensor applications. The design significantly reduces signal distortion and root-mean-square (RMS) phase noise by minimizing acoustic wave reflections from electrode edges, thus enabling limits of detection for BTEX analytes of 9-83 ppb (calculated from RMS noise); concentrations of benzene in water as low as ~100 ppb were measured directly. Reliable quantification of BTEX

  15. Indoor residual spraying with a mixture of clothianidin (a neonicotinoid insecticide) and deltamethrin provides improved control and long residual activity against pyrethroid resistant Anopheles gambiae sl in Southern Benin.

    Science.gov (United States)

    Ngufor, Corine; Fongnikin, Augustin; Rowland, Mark; N'Guessan, Raphael

    2017-01-01

    There is an urgent need for new insecticides for indoor residual spraying (IRS) which can provide improved and prolonged control of malaria vectors that have developed resistance to existing insecticides. The neonicotinoid, clothianidin represents a class of chemistry new to public health. Clothianidin acts as an agonist on nicotinic acetyl choline receptors. IRS with a mixture of Clothianidin and another WHO approved insecticide such as deltamethrin could provide improved control of insecticide resistant malaria vector populations and serve as a tool for insecticide resistance management. The efficacy and residual activity of a novel IRS mixture of deltamethrin and clothianidin was evaluated against wild pyrethroid resistant An. gambiae sl in experimental huts in Cove, Benin. Two application rates of the mixture were tested and comparison was made with clothianidin and deltamethrin applied alone. To assess the residual efficacy of the treatments on different local wall substrates, the inner walls of the experimental huts were covered with either cement, mud or plywood. Clothianidin demonstrated a clear delayed expression in mortality of wild pyrethroid resistant An. gambiae sl in the experimental huts which reached its full effect 120 hours after exposure. Overall mortality over the 12-month hut trial was 15% in the control hut and 24-29% in the deltamethrin-treated huts. The mixture of clothianidin 200mg/m2 and deltamethrin 25mg/m2 induced high overall hut mortality rates (87% on mud walls, 82% on cement walls and 61% on wooden walls) largely due to the clothianidin component and high hut exiting rates (67-76%) mostly due to the deltamethrin component. Mortality rates remained >80% for 8-9 months on mud and cement walls. The residual activity trend was confirmed by results from monthly in situ cone bioassays with laboratory susceptible An. gambiae Kisumu strain. IRS campaigns with the mixture of clothianidin plus deltamethrin have the potential to provide

  16. Indoor residual spraying with a mixture of clothianidin (a neonicotinoid insecticide and deltamethrin provides improved control and long residual activity against pyrethroid resistant Anopheles gambiae sl in Southern Benin.

    Directory of Open Access Journals (Sweden)

    Corine Ngufor

    Full Text Available There is an urgent need for new insecticides for indoor residual spraying (IRS which can provide improved and prolonged control of malaria vectors that have developed resistance to existing insecticides. The neonicotinoid, clothianidin represents a class of chemistry new to public health. Clothianidin acts as an agonist on nicotinic acetyl choline receptors. IRS with a mixture of Clothianidin and another WHO approved insecticide such as deltamethrin could provide improved control of insecticide resistant malaria vector populations and serve as a tool for insecticide resistance management.The efficacy and residual activity of a novel IRS mixture of deltamethrin and clothianidin was evaluated against wild pyrethroid resistant An. gambiae sl in experimental huts in Cove, Benin. Two application rates of the mixture were tested and comparison was made with clothianidin and deltamethrin applied alone. To assess the residual efficacy of the treatments on different local wall substrates, the inner walls of the experimental huts were covered with either cement, mud or plywood.Clothianidin demonstrated a clear delayed expression in mortality of wild pyrethroid resistant An. gambiae sl in the experimental huts which reached its full effect 120 hours after exposure. Overall mortality over the 12-month hut trial was 15% in the control hut and 24-29% in the deltamethrin-treated huts. The mixture of clothianidin 200mg/m2 and deltamethrin 25mg/m2 induced high overall hut mortality rates (87% on mud walls, 82% on cement walls and 61% on wooden walls largely due to the clothianidin component and high hut exiting rates (67-76% mostly due to the deltamethrin component. Mortality rates remained >80% for 8-9 months on mud and cement walls. The residual activity trend was confirmed by results from monthly in situ cone bioassays with laboratory susceptible An. gambiae Kisumu strain.IRS campaigns with the mixture of clothianidin plus deltamethrin have the potential to

  17. Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentrations on honey bee physiology (Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Yu Cheng Zhu

    Full Text Available Imidacloprid is the most widely used insecticide in agriculture. In this study, we used feeding methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equal to maximal residue detection of 912 ppb active ingredient [a.i.] in pollen induced 36% mortality and 56% feeding suppression after 2-week feeding. Treatments with individual Bracket (acephate, Karate (λ-cyhalothrin, Vydate (oxamyl, Domark (tetraconazole, and Roundup (glyphosate at residue level had a mortality range of 1.3-13.3%, statistically similar to that of control (P>0.05. The additive/synergistic toxicity was not detected from binary mixtures of Advise with different classes of pesticides at residue levels. The feeding of the mixture of all seven pesticides increased mortality to 53%, significantly higher than Advise only but still without synergism. Enzymatic data showed that activities of invertase, glutathione S-transferase, and acetylcholinesterase activities in imidacloprid-treated survivors were mostly similar to those found in control. Esterase activity mostly increased, but was significantly suppressed by Bracket (acephate. The immunity-related phenoloxidase activity in imidacloprid-treated survivors tended to be lower, but most treatments were statistically similar to the control. Increase of cytochrome P450 activity was correlated with Advise concentrations and reached significant difference at 56 mg/L (12 ppm a.i.. Our data demonstrated that residue levels of seven pesticide in pollens/hive may not adversely affect honey bees, but long term exclusive ingestion of the maximal residue levels of imidacloprid (912 ppb and sulfoxaflor (3 ppm a.i. may induce substantial bee mortality. Rotating with other insecticides is a necessary and practical way to reduce the residue level of any given pesticide.

  18. Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentrations on honey bee physiology (Apis mellifera).

    Science.gov (United States)

    Zhu, Yu Cheng; Yao, Jianxiu; Adamczyk, John; Luttrell, Randall

    2017-01-01

    Imidacloprid is the most widely used insecticide in agriculture. In this study, we used feeding methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL) alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equal to maximal residue detection of 912 ppb active ingredient [a.i.] in pollen) induced 36% mortality and 56% feeding suppression after 2-week feeding. Treatments with individual Bracket (acephate), Karate (λ-cyhalothrin), Vydate (oxamyl), Domark (tetraconazole), and Roundup (glyphosate) at residue level had a mortality range of 1.3-13.3%, statistically similar to that of control (P>0.05). The additive/synergistic toxicity was not detected from binary mixtures of Advise with different classes of pesticides at residue levels. The feeding of the mixture of all seven pesticides increased mortality to 53%, significantly higher than Advise only but still without synergism. Enzymatic data showed that activities of invertase, glutathione S-transferase, and acetylcholinesterase activities in imidacloprid-treated survivors were mostly similar to those found in control. Esterase activity mostly increased, but was significantly suppressed by Bracket (acephate). The immunity-related phenoloxidase activity in imidacloprid-treated survivors tended to be lower, but most treatments were statistically similar to the control. Increase of cytochrome P450 activity was correlated with Advise concentrations and reached significant difference at 56 mg/L (12 ppm a.i.). Our data demonstrated that residue levels of seven pesticide in pollens/hive may not adversely affect honey bees, but long term exclusive ingestion of the maximal residue levels of imidacloprid (912 ppb) and sulfoxaflor (3 ppm a.i.) may induce substantial bee mortality. Rotating with other insecticides is a necessary and practical way to reduce the residue level of any given pesticide.

  19. Hyperspectral remote sensing detection of petroleum hydrocarbons in mixtures with mineral substrates: Implications for onshore exploration and monitoring

    Science.gov (United States)

    Scafutto, Rebecca Del'Papa Moreira; de Souza Filho, Carlos Roberto; de Oliveira, Wilson José

    2017-06-01

    Remote detection and mapping of hydrocarbons (PHCs) in situ in continental areas is still an operational challenge due to the small scale of the occurrences and the mix of spectral signatures of PHCs and mineral substrates in imagery pixels. Despite the increasing development of new technologies, the use of hyperspectral remote sensing data as a complementary tool for both oil exploration and environmental monitoring is not standard in the oil industry, despite its potential. The high spectral resolution of hyperspectral images allows the direct identification of PHCs on the surface and provides valuable information regarding the location and spread of oil spills that can assist in containment and cleanup operations. Combining the spectral information with statistical techniques also offers the potential to improve exploration programs focused on the discovery of new exploration fields through the qualitative and quantitative characterization of oil occurrences in onshore areas. In this scenario, the aim of this work was to develop methods that can assist the detection of continental areas affected by natural oil seeps or leaks (crude oils and fuels). A field experiment was designed by impregnating several mineral substrates with crude oils and fuels in varying concentrations. Simultaneous measurements of soil-PHC combinations were taken using both a hand-held spectrometer and an airborne hyperspectral imager. Classification algorithms were used to directly map the PHCs on the surface. Spectral information was submitted to a PLS (partial least square regression) to create a prediction model for the estimation of the concentrations of PHCs in soils. The developed model was able to detect three impregnation levels (low, intermediate, high), predicting values close to the concentrations used in the experiment. Given the quality of the results in controlled experiments, the methods developed in this research show the potential to support the oil industry in the

  20. Indoor residual spraying with a mixture of clothianidin (a neonicotinoid insecticide) and deltamethrin provides improved control and long residual activity against pyrethroid resistant Anopheles gambiae sl in Southern Benin.

    OpenAIRE

    Ngufor, C; Fongnikin, A; Rowland, M; N'Guessan, R

    2017-01-01

    There is an urgent need for new insecticides for indoor residual spraying (IRS) which can provide improved and prolonged control of malaria vectors that have developed resistance to existing insecticides. The neonicotinoid, clothianidin represents a class of chemistry new to public health. Clothianidin acts as an agonist on nicotinic acetyl choline receptors. IRS with a mixture of Clothianidin and another WHO approved insecticide such as deltamethrin could provide improved control of insectic...

  1. Resolution and quantification of complex mixtures of polycyclic aromatic hydrocarbons in heavy fuel oil sample by means of GC × GC-TOFMS combined to multivariate curve resolution.

    Science.gov (United States)

    Parastar, Hadi; Radović, Jagoš R; Jalali-Heravi, Mehdi; Diez, Sergi; Bayona, Josep Maria; Tauler, Roma

    2011-12-15

    Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) combined to multivariate curve resolution-alternating least-squares (MCR-ALS) is proposed for the resolution and quantification of very complex mixtures of compounds such as polycyclic aromatic hydrocarbons (PAHs) in heavy fuel oil (HFO). Different GC × GC-TOFMS data slices acquired during the analysis of HFO samples and PAH standards were simultaneously analyzed using the MCR-ALS method to resolve the pure component elution profiles in the two chromatographic dimensions as well as their pure mass spectra. Outstandingly, retention time shifts within and between GC × GC runs were not affecting the results obtained using the proposed strategy and proper resolution of strongly coeluted compounds, baseline and background contributions was achieved. Calibration curves built up with standard samples of PAHs allowed the quantification of ten of them in HFO aromatic fractions. Relative errors in their estimated concentrations were in all cases below 6%. The obtained results were compared to those obtained by commercial software provided with GC × GC-TOFMS instruments and to Parallel Factor Analysis (PARAFAC). Inspection of these results showed improvement in terms of data fitting, elution process description, concentration relative errors and relative standard deviations.

  2. Polycyclic aromatic hydrocarbons residues in Gentile di maiale, a smoked meat product typical of some mountain areas in Latina province (Central Italy

    Directory of Open Access Journals (Sweden)

    Giuseppe Carrabs

    2014-05-01

    Full Text Available Gentile di maiale is a typical meat product prepared in some traditional plants of Latina Province (Central Italy. It is obtained from dehydration, salting, smoking and ripening of swine rectum. Aim of this study was to evaluate the influence of the traditional smoking process on polycyclic aromatic hydrocarbons (PAHs content by means of high-performance liquid chromatographic/fluorescence detection. Polycyclic aromatic hydrocarbons detected in 8 samples of raw material (swine rectum and samples of smoked gentile were: benzo[a]anthracene, chrisene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a] pyrene, benzo[a,h]anthracene. Their residues were detected in all samples of finished product. European Regulation 835/2011 established two levels of PAHs content in meat products. According to first levels, in force until September 2014, only 2 out of 8 samples exceeded legal limit. According to the subsequent, more restrictive, limits all samples would be non-compliant. An improvement and a standardisation of traditional smoking procedures are recommended.

  3. Design of a process for the use of residual hydrocarbons coming from the ships arriving at Moin for obtaining of a fuel

    International Nuclear Information System (INIS)

    Madrigal Calderon, Adolfo

    2015-01-01

    A process is designed to carry out the obtaining of a fuel from the residual mixture of residual oils coming from the ships arriving at Moin, Limon, Costa Rica . A sampling of the residual oil in different ships is realized for a month to quantify the water content and basic sediment, as well as the heavy metal content. The results obtained have been 20,4 ± 4,6 % v/v of water and sediment, and 6,939 ppm of heavy metals as a minimum, this value may be higher depending on the quality of lubricant. The production volume of the residual oil is estimated according to historical data of the company ACASE S.A. (company responsible for collecting the oil residue of ships arriving at dock of Moin, Limon); therefore, the plant must process 25,000 liters of dirty oil per day. The main technologies (thermal process, treatment with chemical reaction, vacuum distillation and solvent extraction) to perform the process are compared and studied through a selection matrix. The technical and economic parameters chosen for the matrix have been: environmental impact, cost of operation, cost of equipment, safety of operation, maintenance of equipment, by-products obtained, waste generated, quality of the product obtained and ease of operation. The study has concluded that the treatment with chemical reaction has been the best option for the project of used oil utilization, as well as other physical methods of cleaning as the centrifugation of the same one. The installation of a waste oil processing plant has been a project that environmentally represents a benefit and economically viable, as currently the residual oil is left untreated for later use [es

  4. Kinetic Studies of the Cometabolism of 1,4-DIOXANE and Chlorinated Aliphatic Hydrocarbon Mixtures by Rhodococcus Rhodochrous Grown on Isobutane

    Science.gov (United States)

    Rolston, H. M.; Semprini, L.; Thankitkul, S.; Azizian, M.; Hyman, M. R.

    2016-12-01

    1,4-dioxane (1,4-D) is a frequently observed groundwater contaminant due to its use as a stabilizer in commercial solvent formulations. In situ bioremediation could potentially provide a large cost savings for treatment of mixtures of chlorinated aliphatic hydrocarbons (CAHs) that include 1,4-D. Aerobic cometabolism is a particularly attractive option, as microorganisms can be stimulated in situ using specific primary substrates. Results will be presented that show the model isobutane-metabolizing bacteria, Rhodococcus rhodochrous (ATCC 21198), has the ability to transform 14-D at high rates and transformation capacities to concentrations below the drinking water screening level of 0.67 µg L-1. Resting cell transformation tests showed 1,4-D and a broad range of CAHs can be cometabolized by ATCC 21198. The maximum transformation rate (kmax) and the half-substrate coefficient (Ks) were determined for isobutane (the growth substrate), 1,4-D, 1,1,1-trichloroethane (1,1,1-TCA), 1,1,2-trichloroethane (1,1,2-TCA), 1,1-dichloroethane (1,1-DCA); 1,2-dichloroethane ((1,2-DCA) and 1,1-dichloroethene (1,1-DCE). Of the CAHs tested, 1,1-DCA had the highest kmax, approximately 25% of that for isobutane utilization, while 1,1,1-TCA had the lowest kmax, approximately 2% of isobutane's. 1,4-D was rapidly transformed and had a kmax 25% of that of isobutane. ATCC 21198 effectively transformed mixtures of 1,4-D, 1,1-DCE, 1,2-DCA and 1,1,1-TCA, both in the presence and absence isobutane. Model simulations were performed for the simultaneous cometabolism of 1,4-D and CAH mixtures by ATCC 21198, that included inhibition among the contaminants and isobutane , and terms for a limited transformation capacity. A good match to experimental observations was obtaining using the independently measured rate parameters. Results of model simulations will also be presented using a reactive transport model to evaluate conditions of in situ bioremediation using strain ATCC 21198.

  5. Effect of SO2 concentration on SOA formation in a photorreactor from a mixture of anthropogenic hydrocarbons and HONO

    Science.gov (United States)

    García Vivanco, Marta; Santiago, Manuel; García Diego, Cristina; Borrás, Esther; Ródenas, Milagros; Martínez-Tarifa, Adela

    2010-05-01

    Sulfur dioxide (SO2) is an important urban atmospheric pollutant, mainly produced by the combustion of fossil fuels containing sulfur. In the atmosphere, SO2 can react with OH radicals to form sulfuric acid, which can condense to form acidic aerosol. Sulfuric acid particles act as an acid catalyst for some heterogeneous carbonyl reactions like hydration, polymerization or acetals formation, which may lead to a large increase on SOA mass. In order to evaluate the effect of the SO2 concentration on SOA formation, 3 experiments were performed during the campaign carried out by CIEMAT on the EUPHORE facility (CEAM, Valencia, Spain) during June- July 2008. The objective of the campaign was to evaluate the effect of different experimental conditions on SOA formation from the photooxidation of some anthropogenic and biogenic VOCs using HONO as oxidant. Experiment on 6/17/08 was selected as base case (no SO2 was introduced) and experiments 6/26/08 and 7/1/08 were selected as high SO2 (2600 ug/m3) and low SO2 (60 ug/m3) concentration experiments respectively. In the three experiments a mixture of toluene, 1,3,5-TMB (trimethylbenzene), o-xylene and octane was selected as the parent VOCs. Single and coupled to mass spectroscopy gas cromatography (GC and GC/MS), as well as high performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR) were used to measure the initial VOCs and oxidant concentrations decay and the formation of gas phase oxidation products through the experiments. Aerosol size distribution and concentration were measured with SMPS (scanning mobility particle sizer) and TEOM (tapered element oscillating monitor) respectively. In addition, analysis of the organic and inorganic aerosol content was also performed via filter sampling followed by GC/MS and ionic chromatography (for organic and inrganic content respectively). Comparing the filters collected in the three experiments, clearly the largest mass aerosol formation is observed

  6. Hydrocarbons as food contaminants:

    OpenAIRE

    Lommatzsch, Martin

    2018-01-01

    The contamination of foods with hydrocarbon mixtures migrating from food contact materials (FCM) was first observed for jute and sisal bags treated with batching oil in the 1990s. Since the millennium, the focus has shifted to printing inks and recycled cardboard packaging as most recognized sources for hydrocarbon contamination from FCM. Mineral oil containing printing inks can either release hydrocarbons directly from the printing of folding boxes into food or indirectly entering the recycl...

  7. Optimal design for the precise estimation of an interaction threshold: the impact of exposure to a mixture of 18 polyhalogenated aromatic hydrocarbons.

    Science.gov (United States)

    Yeatts, Sharon D; Gennings, Chris; Crofton, Kevin M

    2012-10-01

    Traditional additivity models provide little flexibility in modeling the dose-response relationships of the single agents in a mixture. While the flexible single chemical required (FSCR) methods allow greater flexibility, its implicit nature is an obstacle in the formation of the parameter covariance matrix, which forms the basis for many statistical optimality design criteria. The goal of this effort is to develop a method for constructing the parameter covariance matrix for the FSCR models, so that (local) alphabetic optimality criteria can be applied. Data from Crofton et al. are provided as motivation; in an experiment designed to determine the effect of 18 polyhalogenated aromatic hydrocarbons on serum total thyroxine (T(4)), the interaction among the chemicals was statistically significant. Gennings et al. fit the FSCR interaction threshold model to the data. The resulting estimate of the interaction threshold was positive and within the observed dose region, providing evidence of a dose-dependent interaction. However, the corresponding likelihood-ratio-based confidence interval was wide and included zero. In order to more precisely estimate the location of the interaction threshold, supplemental data are required. Using the available data as the first stage, the Ds-optimal second-stage design criterion was applied to minimize the variance of the hypothesized interaction threshold. Practical concerns associated with the resulting design are discussed and addressed using the penalized optimality criterion. Results demonstrate that the penalized Ds-optimal second-stage design can be used to more precisely define the interaction threshold while maintaining the characteristics deemed important in practice. © 2012 Society for Risk Analysis.

  8. Relevance of urinary 3-hydroxybenzo(a)pyrene and 1-hydroxypyrene to assess exposure to carcinogenic polycyclic aromatic hydrocarbon mixtures in metallurgy workers.

    Science.gov (United States)

    Barbeau, Damien; Persoons, Renaud; Marques, Marie; Hervé, Claire; Laffitte-Rigaud, Gilbert; Maitre, Anne

    2014-06-01

    In metallurgy, workers are exposed to mixtures of polycyclic aromatic hydrocarbons (PAHs) in which some compounds are carcinogenic. Biomonitoring of PAH exposure has been performed by measuring urinary 1-hydroxypyrene (1-OHP), a metabolite of pyrene which is not carcinogenic. This study investigated the use of 3-hydroxybenzo(a)pyrene (3-OHBaP), a metabolite of benzo(a)pyrene (BaP) which is the main carcinogenic component in PAHs, to improve carcinogen exposure assessment. We included 129 metallurgy workers routinely exposed to PAHs during working hours. Urinary samples were collected at three sampling times at the beginning and at the end of the working week for 1-OHP and 3-OHBaP analyses. Workers in anode production showed greater exposure to both biomarkers than those in cathode or silicon production, with respectively, 71, 40, and 30% of 3-OHBaP concentrations exceeding the value of 0.4 nmol mol(-1) creatinine. No difference was observed between the 3-OHBaP levels found at the end of the penultimate workday shift and those at the beginning of the last workday shift. Within these plants, the 1-OHP/3-OHBaP ratios varied greatly according to the workers' activity and emission sources. Using linear regression between these two metabolites, the 1-OHP level corresponding to the guidance value for 3-OHBaP ranged from 0.7 to 2.4 µmol mol(-1) creatinine, depending on the industrial sector. This study emphasizes the interest of monitoring urinary 3-OHBaP at the end of the last workday shift when working week exposure is relatively steady, and the irrelevance of a single guideline value for 1-OHP when assessing occupational health risk. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  9. Metabolism of Benzene, Toluene, and Xylene Hydrocarbons in Soil†

    OpenAIRE

    Tsao, C.-W.; Song, H.-G.; Bartha, R.

    1998-01-01

    Enrichment cultures obtained from soil exposed to benzene, toluene, and xylene (BTX) mineralized benzene and toluene but cometabolized only xylene isomers, forming polymeric residues. This observation prompted us to investigate the metabolism of 14C-labeled BTX hydrocarbons in soil, either individually or as mixtures. BTX-supplemented soil was incubated aerobically for up to 4 weeks in a sealed system that automatically replenished any O2 consumed. The decrease in solvent vapors and the produ...

  10. Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentrations on honey bee physiology (Apis mellifera)

    OpenAIRE

    Zhu, Yu Cheng; Yao, Jianxiu; Adamczyk, John; Luttrell, Randall

    2017-01-01

    Imidacloprid is the most widely used insecticide in agriculture. In this study, we used feeding methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL) alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equal to maximal residue detection of 912 ppb active ingredient [a.i.] in pollen) induced 36% mortality and 56% feeding suppression after 2-week feeding. Treatments with individual Bracket (acephate), Karate (λ-cyhalothr...

  11. 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.

    2004-11-15

    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)

  12. Spatial distribution of polycyclic aromatic hydrocarbons in soil, sediment, and combusted residue at an e-waste processing site in southeast China.

    Science.gov (United States)

    Leung, Anna O W; Cheung, Kwai Chung; Wong, Ming Hung

    2015-06-01

    The environmental pollution and health impacts caused by the primitive and crude recycling of e-waste have become urgent global issues. Guiyu, China is a major hotspot of e-waste recycling. In this study, the levels and distribution of polycyclic aromatic hydrocarbons in soil in Guiyu were determined to investigate the effect of e-waste activities on the environment and to identify possible sources of these pollutants. Sediment samples from a local duck pond, water gullies, a river tributary, and combusted residue from e-waste burning sites were also investigated. The general trend found in soil (Σ16 PAHs) was acid leaching site > duck pond > rice field > printer roller dump site > reservoir (control site) and ranged from 95.2 ± 54.2 to 5,210 ± 89.6 ng/g (dry wt). The highest average total PAH concentrations were found in combusted residues of wires, cables, and other computer electrical components located at two e-waste open burning sites (18,600 and 10,800 ± 3,940 ng/g). These were 195- and 113-fold higher than the PAH concentrations of soil at the control site. Sediment PAH concentrations ranged from 37.2 ± 6 to 534 ± 271 ng/g. Results of this study provide further evidence of significant input of PAHs to the environment attributed to crude e-waste recycling.

  13. Four-dimensional data coupled to alternating weighted residue constraint quadrilinear decomposition model applied to environmental analysis: Determination of polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Liu, Tingting; Zhang, Ling; Wang, Shutao; Cui, Yaoyao; Wang, Yutian; Liu, Lingfei; Yang, Zhe

    2018-03-01

    Qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) was carried out by three-dimensional fluorescence spectroscopy combining with Alternating Weighted Residue Constraint Quadrilinear Decomposition (AWRCQLD). The experimental subjects were acenaphthene (ANA) and naphthalene (NAP). Firstly, in order to solve the redundant information of the three-dimensional fluorescence spectral data, the wavelet transform was used to compress data in preprocessing. Then, the four-dimensional data was constructed by using the excitation-emission fluorescence spectra of different concentration PAHs. The sample data was obtained from three solvents that are methanol, ethanol and Ultra-pure water. The four-dimensional spectral data was analyzed by AWRCQLD, then the recovery rate of PAHs was obtained from the three solvents and compared respectively. On one hand, the results showed that PAHs can be measured more accurately by the high-order data, and the recovery rate was higher. On the other hand, the results presented that AWRCQLD can better reflect the superiority of four-dimensional algorithm than the second-order calibration and other third-order calibration algorithms. The recovery rate of ANA was 96.5% 103.3% and the root mean square error of prediction was 0.04 μgL- 1. The recovery rate of NAP was 96.7% 115.7% and the root mean square error of prediction was 0.06 μgL- 1.

  14. Four-dimensional data coupled to alternating weighted residue constraint quadrilinear decomposition model applied to environmental analysis: Determination of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Liu, Tingting; Zhang, Ling; Wang, Shutao; Cui, Yaoyao; Wang, Yutian; Liu, Lingfei; Yang, Zhe

    2018-03-15

    Qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) was carried out by three-dimensional fluorescence spectroscopy combining with Alternating Weighted Residue Constraint Quadrilinear Decomposition (AWRCQLD). The experimental subjects were acenaphthene (ANA) and naphthalene (NAP). Firstly, in order to solve the redundant information of the three-dimensional fluorescence spectral data, the wavelet transform was used to compress data in preprocessing. Then, the four-dimensional data was constructed by using the excitation-emission fluorescence spectra of different concentration PAHs. The sample data was obtained from three solvents that are methanol, ethanol and Ultra-pure water. The four-dimensional spectral data was analyzed by AWRCQLD, then the recovery rate of PAHs was obtained from the three solvents and compared respectively. On one hand, the results showed that PAHs can be measured more accurately by the high-order data, and the recovery rate was higher. On the other hand, the results presented that AWRCQLD can better reflect the superiority of four-dimensional algorithm than the second-order calibration and other third-order calibration algorithms. The recovery rate of ANA was 96.5%~103.3% and the root mean square error of prediction was 0.04μgL -1 . The recovery rate of NAP was 96.7%~115.7% and the root mean square error of prediction was 0.06μgL -1 . Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Evaluating the suitability of Hydrobia ulvae as a test species for sediment metal toxicity testing applying a tissue residue approach to metal mixtures in laboratory and field exposures.

    Science.gov (United States)

    Campana, Olivia; Rodríguez, Antonio; Blasco, Julián

    2013-05-01

    A major weakness in evaluating the suitability of a biomonitor organism is the poor ability to predict the variability of the bioavailability of metals from measured environmental concentrations. In this study, the intertidal gastropod Hydrobia ulvae was used to evaluate its suitability as a test organism for assessing sediment metal toxicity. Toxicity tests were run with sediments spiked with copper, cadmium and zinc applied both as single metal and as a mixture to investigate toxicological interactions evaluating different lethal and sublethal effects. Dose-response relationships were constructed based both on tissue residue approach and particulate metal concentrations. Because metal-spiked sediments used in routine toxicity tests often do not exhibit the same adsorption/desorption kinetics as the natural sediments, the laboratory results were compared to 10-d bioassays conducted with natural field sediments collected from the Guadalete estuary (SW Spain). Highly significant correlations between tissue residue concentrations and particulate metal concentrations were found for all metal-spiked or field-collected and demonstrated that: (i) H. ulvae readily accumulated copper and cadmium in response to contamination and (ii) dietary uptake was determined to be the most significant route of metal exposure. The comparison of the modeled tissue residue-response curve developed from the mixture tests was in good agreement with the results from the bioassay conducted with field sediments and strongly demonstrated that H. ulvae is also a suitable test organism for assessing copper sediment toxicity. In contrast, the dose-response curve expressed as a function of total particulate metal concentrations would fail in predicting effect, erroneously assessing higher metal toxicity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Development of an efficient method for multi residue analysis of 160 pesticides in herbal plant by ethyl acetate hexane mixture with direct injection to GC-MS/MS.

    Science.gov (United States)

    Taha, Sherif M; Gadalla, Sohair A

    2017-11-01

    A simple and efficient multi residue method was developed, for the analysis of 160 pesticides by GC-MS/MS in herbal plants. The developed method employs pesticide residue extraction by EtAC/ n. hexane (6:4) with a cleanup step using florisil/ PSA mixture. The optimized conditions have resulted in lower co-extracted matrix components than those extracted using EtAC or MeCN (QuEChERS method), according to FTIR and full scan GC/MS analyses. In addition, the developed method (EtAC/ Hexane) eliminates the evaporation step that is usually performed when using MeCN as an extraction solvent prior to the GC-MS/MS injection. The developed method was fully validated on chamomile, based on SANTE/11945/2015 guidelines. Where, intraday recoveries were estimated at three concentration levels of 10, 50 and 250μgkg -1 . However, interday recoveries have also been carried out, at 250μgkg -1 . In addition, intraday recoveries were estimated for two other herbal plants (thyme and marjoram), at 250μgkg -1 . Three point calibration mixtures were prepared in ethyl acetate solvent and in the blank extracts of chamomile, thyme, and marjoram, in order to check the linearity and matrix effect. The average recoveries for most of the studied pesticides ranged from 70% to 100% at 50 and 250μgkg -1 with relative standard deviations below 20%. The validated method was successfully applied for determination of pesticide residues in 20 herb samples, collected from the Egyptian market. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Density and Comparative Refractive Index Study on Mixing Properties of Binary Liquid Mixtures of Eucalyptol with Hydrocarbons at 303.15, 308.15 and 313.15 K

    OpenAIRE

    Sharma, Sangita; Patel, Pragnesh B.; Patel, Rignesh S.; Vora, J. J.

    2007-01-01

    Density and refractive index have been experimentally determined for binary liquid mixtures of eucalyptol with hydrocarbons (o-xylene,m-xylene and toluene) at 303.15 K, 308.15 K and 313.15 K. A comparative study of Lorentz-Lorenz (L-L), Weiner (W), Heller (H), Gladstone-Dale (G-D), Arago-Biot (A-B), Eykman (Eyk), Newton (Nw), Eyring-John (E-J) and Oster (Os) relations for determining the refractive index of a liquid has been carried out to test their validity for the three binaries over the e...

  18. The Galeta Oil Spill. III. Chronic Reoiling, Long-term Toxicity of Hydrocarbon Residues and Effects on Epibiota in the Mangrove Fringe

    Science.gov (United States)

    Levings, Sally C.; Garrity, Stephen D.; Burns, Kathryn A.

    1994-04-01

    In April 1986, 75 000-100 000 barrels of medium-weight crude oil (˜ 10 000-13 500 metric tons) spilled into Bahía las Minas, a large mangrove-lined bay on the Caribbean coast of Panamá. Between 1986 and 1991, biological and chemical effects of this spill were studied. The epibiota of fringing mangroves ( Rhizophora mangle L.) were examined in three habitats: (1) the shoreward margins of reef flats that fronted the open sea, (2) the edges of channels and lagoons, and (3) the banks of streams and man-made cuts that drained interior mangroves or uplands into lagoons. Chemical analyses of bivalves collected from submerged prop roots (oysters and false mussels) and records of slicks and tarry deposits on artificial roots documented chronic reoiling. Each habitat was repeatedly oiled between 1986 and 1991, with petroleum residues identified as the oil spilled in 1986. There was a decline in the release of tarry oils recorded as slicks and on roots over time, but not in tissue burdens of hydrocarbons in bivalves. This suggested that the processes that released these different types of oil residues were at least partially independent and that toxic hydrocarbons were likely to be released from sediments over the long term. The submerged prop roots of fringing mangroves in each habitat had a characteristic epibiota. On the open coast, roots were covered with a diverse assemblage of sessile invertebrates and algae. In channels, the most abundant species on roots was the edible oyster Crassostrea virginica ( rhizophorae morph). In streams, the false mussel Mytilopsis sallei covered the most space on roots. Cover of sessile invertebrates was significantly reduced at oiled compared with unoiled sites on the open coast for 4 years after oiling, while oysters and false mussels were reduced in cover at oiled sites in channels and streams through at least 1991, when observations ended. False mussels transplanted from an unoiled stream to oiled and unoiled streams were

  19. Bioavailability of polycyclic aromatic hydrocarbons from buried shoreline oil residues thirteen years after the Exxon Valdez oil spill: a multispecies assessment.

    Science.gov (United States)

    Neff, Jerry M; Bence, A Edward; Parker, Keith R; Page, David S; Brown, John S; Boehm, Paul D

    2006-04-01

    Seven taxa of intertidal plants and animals were sampled at 17 shoreline sites in Prince William Sound ([PWS]; AK, USA), that were heavily oiled in 1989 by the Exxon Valdez oil spill (EVOS) to determine if polycyclic aromatic hydrocarbons (PAH) from buried oil in intertidal sediments are sufficiently bioavailable to intertidal prey organisms that they might pose a health risk to populations of birds and wildlife that forage on the shore. Buried residues of EVOS oil are present in upper and middle intertidal sediments at 16 sites. Lower intertidal (0 m) sediments contain little oil. Much of the PAH in lower intertidal sediments are from combustion sources. Mean tissue total PAH (TPAH) concentrations in intertidal clams, mussels, and worms from oiled sites range from 24 to 36 ng/g (parts per billion) dry weight; sea lettuce, whelks, hermit crabs, and intertidal fish contain lower concentrations. Concentrations of TPAH are similar or slightly lower in biota from unoiled reference sites. The low EVOS PAH concentrations detected in intertidal biota at oiled shoreline sites indicate that the PAH from EVOS oil buried in intertidal sediments at these sites have a low bioavailability to intertidal plants and animals. Individual sea otters or shorebirds that consumed a diet of intertidal clams and mussels exclusively from the 17 oiled shores in 2002 were at low risk of significant health problems. The low concentrations of EVOS PAH found in some intertidal organisms at some oiled shoreline sites in PWS do not represent a health risk to populations of marine birds and mammals that forage in the intertidal zone.

  20. The extraction of aged polycyclic aromatic hydrocarbon (PAH) residues from a clay soil using sonication and a Soxhlet procedure: a comparative study.

    Science.gov (United States)

    Guerin, T F

    1999-02-01

    A sonication method was compared with Soxhlet extraction for recovering polycyclic aromatic hydrocarbons (PAH) from a clay soil that had been contaminated with tar materials for several decades. Using sonication over an 8 h extraction period, maximum extraction of the 16 US EPA priority PAH was obtained with dichloromethane (DCM)-acetone (1 + 1). The same procedure using hexane-acetone (1 + 1) recovered 86% of that obtained using DCM-acetone (1 + 1). PAH recovery was dependent on time of extraction up to a period of 8 h. The sonication procedure showed that individual PAH are extracted at differing rates depending on the number of fused rings in the molecule. Soxhlet extraction [with DCM-acetone (1 + 1)] over an 8 h period recovered 95% of the PAH removed by the sonication procedure using DCM-acetone (1 + 1), indicating that rigorous sonication can achieve PAH recoveries similar to those obtained by Soxhlet extraction. The lower recovery with the Soxhlet extraction was explained by the observed losses of the volatile PAH components after 1-4 h of extraction. The type of solvent used, the length of time of extraction and extraction method influenced the quantification of PAH in the soil. Therefore, the study has implications for PAH analyses in soils and sediments, and particularly for contaminated site assessments where the data from commercial laboratories are being used. The study emphasizes the importance of establishing (and being consistent in the application of) a vigorous extraction, particularly for commercial laboratories that handle samples of soil in batches (at different times) from a single site investigation or remediation process. The strong binding of PAH to soil, forming aged residues, has significant implications for extraction efficiency. This paper illustrates the problem of the underestimation of PAH using the US EPA method 3550, specifically where a surrogate spike is routinely employed and the efficiency of the extraction procedure for aged

  1. Reactivity of hydrocarbons in response to injection of a CO2/O2 mixture under depleted reservoir conditions: experimental and numerical modeling

    International Nuclear Information System (INIS)

    Pacini-Petitjean, Claire

    2015-01-01

    The geological storage of CO 2 (CO 2 Capture-Storage - CCS) and the Enhanced Oil Recovery (EOR) by CO 2 injection into petroleum reservoirs could limit CO 2 atmospheric accumulation. However, CO 2 can be associated with oxygen. To predict the hydrocarbon evolution under these conditions involves the study of oxidation mechanisms. Oxidation experiment and kinetic detailed modeling were carried out with pure compounds. The comparison between experimental and modeling results led to the construction of a hydrocarbon oxidation kinetic model and emphasized the parameters leading to auto ignition. The good agreement between our experiments and modeling are promising for the development of a tool predicting the critical temperature leading to auto-ignition and the evolution of hydrocarbon composition, to estimate the stability of a petroleum system in CO 2 injection context. (author) [fr

  2. Impact of Liquid-Vapor to Liquid-Liquid-Vapor Phase Transitions on Asphaltene-Rich Nanoaggregate Behavior in Athabasca Vacuum Residue + Pentane Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Long, Bingwen; Chodakowski, Martin; Shaw, John M. [Alberta; (Beijing U)

    2013-06-05

    The bulk phase behavior of heavy oil + alkane mixtures and the behavior of the asphaltenes that they contain are topics of importance for the design and optimization of processes for petroleum production, transport, and refining and for performing routine saturates, aromatics, resins, and asphaltenes (SARA) analyses. In prior studies, partial phase diagrams and phase behavior models for Athabasca vacuum residue (AVR) comprising 32 wt % pentane asphaltenes + n-alkanes were reported. For mixtures with pentane, observed phase behaviors included single-phase liquid as well as liquid–liquid, liquid–liquid–vapor, and liquid–liquid–liquid–vapor regions. Dispersed solids were detected under some conditions as well but not quantified. In this work, small-angle X-ray scattering (SAXS) is used to study nanostructured materials in liquid phases present in AVR + n-pentane mixtures from 50 to 170 °C at mixture bubble pressure. The investigation focuses on the impact of the transition from a single AVR-rich liquid to co-existing pentane-rich and AVR-rich liquids on the nanostructure and the nanostructures most resistant to aggregation as the pentane composition axis is approached. Background scattering subtraction was performed using global mixture composition. The robustness of this assumption with respect to values obtained for coefficients appearing in a two level Beaucage unified equation fit is demonstrated. The nanostructured material is shown to arise at two length scales from 1 to 100 wt % AVR. Smaller nanostructures possess mean radii less than 50 Å, while the larger nanostructures possess mean radii greater than 250 Å. The addition of pentane to the AVR causes an increasingly large fraction of the large and small nanostructures to grow in size. Only nanostructures resistant to aggregation remain in the pentane-rich phase as the 0 wt % AVR axis is approached. Step changes in aggregation identified from changes in average radius of gyration, scattering

  3. The relationship between multilevel models and non-parametric multilevel mixture models: Discrete approximation of intraclass correlation, random coefficient distributions, and residual heteroscedasticity.

    Science.gov (United States)

    Rights, Jason D; Sterba, Sonya K

    2016-11-01

    Multilevel data structures are common in the social sciences. Often, such nested data are analysed with multilevel models (MLMs) in which heterogeneity between clusters is modelled by continuously distributed random intercepts and/or slopes. Alternatively, the non-parametric multilevel regression mixture model (NPMM) can accommodate the same nested data structures through discrete latent class variation. The purpose of this article is to delineate analytic relationships between NPMM and MLM parameters that are useful for understanding the indirect interpretation of the NPMM as a non-parametric approximation of the MLM, with relaxed distributional assumptions. We define how seven standard and non-standard MLM specifications can be indirectly approximated by particular NPMM specifications. We provide formulas showing how the NPMM can serve as an approximation of the MLM in terms of intraclass correlation, random coefficient means and (co)variances, heteroscedasticity of residuals at level 1, and heteroscedasticity of residuals at level 2. Further, we discuss how these relationships can be useful in practice. The specific relationships are illustrated with simulated graphical demonstrations, and direct and indirect interpretations of NPMM classes are contrasted. We provide an R function to aid in implementing and visualizing an indirect interpretation of NPMM classes. An empirical example is presented and future directions are discussed. © 2016 The British Psychological Society.

  4. Sensitive determination of mixtures of neonicotinoid and fungicide residues in pollen and single bumblebees using a scaled down QuEChERS method for exposure assessment.

    Science.gov (United States)

    David, Arthur; Botías, Cristina; Abdul-Sada, Alaa; Goulson, Dave; Hill, Elizabeth M

    2015-10-01

    To accurately estimate exposure of bees to pesticides, analytical methods are needed to enable quantification of nanogram/gram (ng/g) levels of contaminants in small samples of pollen or the individual insects. A modified QuEChERS extraction method coupled with ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis was tested to quantify residues of 19 commonly used neonicotinoids and fungicides and the synergist, piperonyl butoxide, in 100 mg samples of pollen and in samples of individual bumblebees (Bombus terrestris). Final recoveries ranged from 71 to 102 % for most compounds with a repeatability of below 20 % for both pollen and bumblebee extracts spiked at 5 and 40 ng/g. The method enables the detection of all compounds at sub-ng/g levels in both matrices and the method detection limits (MDL) ranged from 0.01 to 0.84 ng/g in pollen and 0.01 to 0.96 ng/g in individual bumblebees. Using this method, mixtures of neonicotinoids (thiamethoxam, clothianidin, imidacloprid and thiacloprid) and fungicides (carbendazim, spiroxamine, boscalid, tebuconazole, prochloraz, metconazole, fluoxastrobin, pyraclostrobin and trifloxystrobin) were detected in pollens of field bean, strawberry and raspberry at concentrations ranging from neonicotinoids and from MDL, and in some bees, the fungicides carbendazim, boscalid, tebuconazole, flusilazole and metconazole were present at concentrations between 0.80 to 30 ng/g. This new method allows the analysis of mixtures of neonicotinoids and fungicides at trace levels in small quantities of pollen and individual bumblebees and thus will facilitate exposure assessment studies.

  5. Mixture design and Doehlert matrix for the optimization of the extraction of Phenolic Compounds from Spondias mombin L Apple Bagasse Agro-industrial Residues

    Science.gov (United States)

    Santos Felix, Antonio C.; Novaes, Cleber G.; Pires Rocha, Maísla; Barreto, George E.; do Nascimento, Baraquizio B.; Giraldez Alvarez, Lisandro D.

    2017-12-01

    In this study, we have determined, using RSM (mixture design and Doehlert matrix), the optimum values of the independent variables to achieve the maximum response for the extraction of total phenolic compounds from Spondias mombin L bagasse agroindustrial residues, preserving its antioxidant activity. The assessment with reference to the extraction of phenolic compounds, as well as their capacity to scavenge ABTS and the antioxidant capacity, determined by the modified DPPH method were investigated based on distinct combinations of time, temperature, velocity of rotation and solvents concentration. It was investigated that the optimum condition for the highest antioxidant yield was obtained using water (60.84%), acetone (30.31%) and ethanol (8.85%) at 30 ºC during 20 min at 50 rpm. We have found that the maximum yield of total phenolics was 355.63 ± 9.77 (mg GAE/100 g), showing an EC50 of 3962.24 ± 41.20 (g fruit/g of DPPH) and 8.36 ± 0.30 (µM trolox/g fruit), which were measured using DPPH and ABTS assays. These results suggest that RSM was successfully applied for optimizing the extraction of phenolics compounds preserving its antioxidant activity. This method does not require expensive reagents or high quantities of organic solvents.

  6. Densities and volumetric properties of (N-acetylmorpholine + aromatic hydrocarbon) binary mixtures from T = (293.15 to 343.15) K

    International Nuclear Information System (INIS)

    Abu-Daabes, Malyuba A.; Awwad, Akl M.; Al-Ani, Hawzen A.

    2009-01-01

    The experimental densities, ρ for binary mixtures of (N-acetylmorpholine + benzene, +toluene, +ethylbenzene, and +mesitylene) have been measured at temperatures from (293.15 to 343.15) K and atmospheric pressure over the whole mole fraction range. From these results, excess molar volumes V E have been calculated and fitted to the Redlich-Kister polynomial equation. The V E values are negative over the whole mole fraction range and at all temperatures. Thermal expansion coefficients α i , apparent molar volumes Vφ i , and partial molar volumes at infinite dilution V i ∞ have been calculated. The variation of these properties with composition and temperature of the binary mixtures are discussed in terms of molecular interactions

  7. Thermodynamic properties of biofuels: Heat capacities of binary mixtures containing ethanol and hydrocarbons up to 20 MPa and the pure compounds using a new flow calorimeter

    International Nuclear Information System (INIS)

    Vega-Maza, David; Segovia, Jose J.; Carmen Martin, M.; Villamanan, Rosa M.; Villamanan, Miguel A.

    2011-01-01

    Highlights: → Isobaric heat capacities for heptane, ethanol, and the mixtures of ethanol with heptane and toluene are reported. → They have been measured at 5 pressures over the range (0 to 20) MPa. → An automated flow calorimeter has been developed for the measurements. → The experimental data are fitted to Redlich-Kister equations. → Excess isobaric heat capacities are calculated. - Abstract: Heat capacities are of great significance in the design of new processes and the improvement of existing ones in R and D in production plants as well as the adaptation of new products, in this case, biofuels to their use in a variety of engines and technical devices. An automated flow calorimeter has been developed for the accurate measurement of isobaric heat capacities for pure compounds and mixtures over the range (250 to 400) K and (0 to 20) MPa. In this paper, isobaric heat capacities for heptane, ethanol and the binary mixtures of ethanol with heptane and toluene are reported.

  8. Comparison of two association models (Elliott-Suresh-Donohue and simplified PC-SAFT) for complex phase equilibria of hydrocarbon-water and amine-containing mixtures

    DEFF Research Database (Denmark)

    Grenner, Andreas; Schmelzer, Jürgen; von Solms, Nicolas

    2006-01-01

    , and water. Furthermore, the predictive capabilities of the models are investigated for four ternary systems composed of these components, which exhibit complex liquid-liquid(-liquid) equilibria (LLLE). Various aspects of association models which have an influence in the results are studied for the PC......, both models perform overall similarly for the binary systems, although ESD shows a remarkably good behavior despite its simplicity and the use of only the two-site scheme for all associating compounds. The prediction of the LLE in the ternary systems water + octane + aniline and water + CHA + aniline......Two Wertheim-based association models, the simplified PC-SAFT and the Elliott-Suresh-Donohue (ESD) equation of state, are compared in this work for the description of vapor-liquid equilibria (VLE) and liquid-liquid equilibria (LLE) in binary systems of aniline, cyclohexylamine (CHA), hydrocarbons...

  9. Phase equilibria at low temperature for light hydrocarbons-methanol-water-acid gases mixtures: measurements and modelling; Equilibres de phases a basse temperature de systemes complexes CO{sub 2} - hydrocarbures legers - methanol - eau: mesures et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Ruffine, L.

    2005-10-15

    The need to develop and improve natural gas treatment processes is real. The petroleum industry usually uses separation processes which require phase equilibrium phenomena. Yet, the complexity of the phase equilibria involved results in a lack of data, which in turn limits the development of thermodynamic models. The first part of this work is devoted to experimental investigations for systems containing light hydrocarbons, methanol, water and acid gases. We present a new apparatus that was developed to measure vapor-liquid and vapor-liquid-liquid equilibria. It allowed us to obtain new phase composition data for the methanol-ethane binary system and different mixtures, and also to determine a part of the three phases equilibrium envelope of the same systems. In the second part of this work, we have developed a thermodynamic model based on the CPA equation of state. This choice may be justified by the presence of associating components like methanol, hydrogen sulfide and water in the systems. Such model is necessary for the design of gas treatment plants. Our model provides good results for phase equilibrium calculations for binaries systems without binary interaction parameter in many cases, and describes correctly the vapour-liquid and vapor-liquid-liquid equilibria for complex mixtures. (author)

  10. Assessing fuel spill risks in polar waters: Temporal dynamics and behaviour of hydrocarbons from Antarctic diesel, marine gas oil and residual fuel oil.

    Science.gov (United States)

    Brown, Kathryn E; King, Catherine K; Kotzakoulakis, Konstantinos; George, Simon C; Harrison, Peter L

    2016-09-15

    As part of risk assessment of fuel oil spills in Antarctic and subantarctic waters, this study describes partitioning of hydrocarbons from three fuels (Special Antarctic Blend diesel, SAB; marine gas oil, MGO; and intermediate grade fuel oil, IFO 180) into seawater at 0 and 5°C and subsequent depletion over 7days. Initial total hydrocarbon content (THC) of water accommodated fraction (WAF) in seawater was highest for SAB. Rates of THC loss and proportions in equivalent carbon number fractions differed between fuels and over time. THC was most persistent in IFO 180 WAFs and most rapidly depleted in MGO WAF, with depletion for SAB WAF strongly affected by temperature. Concentration and composition remained proportionate in dilution series over time. This study significantly enhances our understanding of fuel behaviour in Antarctic and subantarctic waters, enabling improved predictions for estimates of sensitivities of marine organisms to toxic contaminants from fuels in the region. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Bioremediation of oil sludge contaminated soil using bulking agent mixture enriched consortia of microbial inoculants based by irradiated compost

    International Nuclear Information System (INIS)

    Tri Retno, D.L.; Mulyana, N.

    2013-01-01

    Bulking agent mixture enriched consortia of microbial inoculants based by irradiated compost was used on bioremediation of microcosm scale contaminated by hydrocarbon soil. Bioremediation composting was carried out for 42 days. Composting was done with a mixture of bulking agent (sawdust, residual sludge biogas and compost) by 30%, mud petroleum (oil sludge) by 20% and 50% of soil. Mixture of 80% soil and 20% oil sludge was used as a control. Irradiated compost was used as a carrier for consortia of microbial inoculants (F + B) which biodegradable hydrocarbons. Treatment variations include A1, A2, B1, B2, C1, C2, D1 and D2. Process parameters were observed to determine the optimal conditions include: temperature, pH, water content, TPC (Total Plate Count) and degradation of % TPH (Total Petroleum Hydrocarbon). Optimal conditions were achieved in the remediation of oil sludge contamination of 20% using the B2 treatment with the addition consortia of microbial inoculants based by irradiated compost of sawdust (bulking agentby 30% at concentrations of soil by 50% with TPH degradation optimal efficiency of 81.32%. The result of GC-MS analysis showed that bioremediation for 42 days by using a sawdust as a mixture of bulking agents which enriched consortia of microbial inoculants based by irradiated compost is biodegradeable, so initial hydrocarbons with the distribution of the carbon chain C-7 to C-54 into final hydrocarbons with the distribution of carbon chain C-6 to C-8. (author)

  12. Excess enthalpies of ternary mixtures of oxygenated additives + hydrocarbon mixtures in fuels and bio-fuels: Dibutyl ether (DBE) and 1-butanol and 1-hexene or cyclohexane or 2,2,4 trimethylpentane at 298.15 K and 313.15 K

    International Nuclear Information System (INIS)

    Aguilar, Fernando; Alaoui, Fatima E.M.; Segovia, José J.; Montero, Eduardo A.

    2013-01-01

    Highlights: ► New excess enthalpy data for ternary mixtures of dibutyl ether + hydrocarbon + 1-butanol are reported. ► Four ternary systems at 298.15 K and 313.15 K were measured by means of an isothermal flow calorimeter. ► 420 Data were fitted to a Redlich–Kister rational equation. ► Intermolecular and association effects involved in these systems have been discussed. - Abstract: New experimental excess molar enthalpy data (420 points) of the ternary systems dibutyl ether (DBE) and 1-butanol and 1-hexene at 298.15 K and 313.15 K, and DBE and 1-butanol and cyclohexane or 2,2,4-trimethylpentane (TMP) at 313.15 K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the ternary systems show endothermic character. The experimental data for the ternary systems have been fitted using the Redlich–Kister rational equation. Considerations with respect the intermolecular interactions amongst ether, alcohol and hydrocarbon compounds are presented.

  13. Study of the viscosity of hydrocarbon mixtures under pressure and temperature: A critical model of the corresponding states to double reference in the modeling domain.

    Science.gov (United States)

    Ettahir, Aziz; Boned, Christian; Lagourette, Bernard; Kettani, Kamal; Amarrayi, Khaoula; Garoumi, Mohammed

    2017-10-01

    The studied predictive model of behavior viscosimetric is the model of K.A. Petersen [1]. The dominant idea of this method is to characterize the viscosity of a fluid from two models taken as a reference in passing through a reduced pressure. The method is corresponding state with two references. This study shows that this method is dependent on the choice of reference and for each of the possibilities of C10/C6H6 and C1/C10 references . The results were investigated for four different weight ratios. It shows that the introduction of an adjusted coefficient does not improve significantly compared to results without adjustment factor, which appears to be the best choice. Regarding the influence of the choice of references, generally the two couples appear suitable but we noted that the choice is not necessary. In the case of mixtures containing at least one aromatic, the results are correct, especially if one takes the ratio of adjustment and our ratio without adjustment compared to that of K. A. PETERSEN[1]. The experimental results of the viscosity exhibit a good agreement with the calculated values. We can predict that the relative improvement is the finding that the introduction of the second body of reference (C10) from the model states corresponding to a reference (C1) of the authors.

  14. Density and Comparative Refractive Index Study on Mixing Properties of Binary Liquid Mixtures of Eucalyptol with Hydrocarbons at 303.15, 308.15 and 313.15 K

    Directory of Open Access Journals (Sweden)

    Sangita Sharma

    2007-01-01

    Full Text Available Density and refractive index have been experimentally determined for binary liquid mixtures of eucalyptol with hydrocarbons (o-xylene,m-xylene and toluene at 303.15 K, 308.15 K and 313.15 K. A comparative study of Lorentz-Lorenz (L-L, Weiner (W, Heller (H, Gladstone-Dale (G-D, Arago-Biot (A-B, Eykman (Eyk, Newton (Nw, Eyring-John (E-J and Oster (Os relations for determining the refractive index of a liquid has been carried out to test their validity for the three binaries over the entire mole fraction range of eucalyptol at 303.15 K, 308.15 K and 313.15 K. Comparison of various mixing rules has been expressed in terms of average deviation. From the experimentally measured values, refractive index deviations at different temperatures have been computed and fitted to the Redlich-Kister polynomial equation to derive the binary coefficients and standard deviations.

  15. MOLECULAR DIAGNOSTIC RATIOS TO ASSESS THE APPORTIONMENT OF PETROLEUM HYDROCARBONS CONTAMINANTION IN MARINE SEDIMENT

    Directory of Open Access Journals (Sweden)

    Agung Dhamar Syakti

    2016-11-01

    Full Text Available As maritime fulcrum nation, in Indonesia, marine environmental analytical chemistry field is still under developed. So that why, this review paper aims to provide basic understanding of the use some molecular diagnostic indices using n-alkanes indexes and polycyclic aromatic hydrocarbons (PAHs diagnostic ratios to estimate the source of apportionment of the hydrocarbons contamination and origin. The n-alkane chromatograms were then used to characterize the predominance of petrogenic or biogenic either terrestrial or aquatic. Furthermore, characterization allowed to discriminate riverine versus marine input. The occurrence of a broad unresolved complex mixture can be an evidence of biodegraded petroleum residues. For aromatic compounds, the prevalence of petrogenic, pyrolitic, and combustion-derived can be easily plotted by using isomers ratio calculation. This paper thus provides useful information on the hydrocarbon contamination origin, especially in marine sediments. Further researches should be undertaken in order to validate the use of molecular diagnostic ratio with isotopic approach.

  16. Effects of polycyclic aromatic hydrocarbons on germination and subsequent growth of grasses and legumes in freshly contaminated soil and soil with aged PAHs residues

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.J.; Flowers, T.H.; Duncan, H.J.; Alder, J. [University of Glasgow, Glasgow (United Kingdom). Glasgow Marine Technological Centre

    2006-06-15

    The relevance of germination trials for screening plants that may have potential for use in the phytoremediation of PAH contaminated land was evaluated. The germination and subsequent growth of 7 grass and legume species were evaluated in soil spiked with a pure PAH mixture or coal tar and soil from a former coking plant heavily contaminated with aged PAHs. None of these treatments adversely affected germination of the plants. However, apart from Lolium perenne all species exhibited reduced growth in the coking plant soil after 12 weeks growth when compared to the untreated soil. In the coal tar spiked soil 4 out of the 7 species showed reduced growth, as did 3 out of the 7 in the soil spiked with a mixture of 7 PAHs. Therefore, germination studies alone would not predict the success of subsequent growth of the species tested in the ranges of soil PAH levels studied.

  17. Controle de plantas daninhas através da palha de cana-de-açúcar associada à mistura dos herbicidas trifloxysulfuron sodium + ametrina Weed control through green cane harvesting residue combined with the herbicide mixture trifloxysulfuron sodium + ametryne

    Directory of Open Access Journals (Sweden)

    R. Gravena

    2004-09-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da palha de cana-de-açúcar resultante da colheita sem queima e da mistura comercial dos herbicidas trifloxysulfuron sodium + ametrina, na emergência e no acúmulo de biomassa seca de nove espécies de plantas daninhas. Os tratamentos foram distribuídos em esquema fatorial 3 x 3, sendo três quantidades de palha resultantes da colheita da cana-de-açúcar sem queima (0, 10 e 15 t ha-1, e três doses da mistura formulada dos herbicidas trifloxysulfuron sodium + ametrina (0, 1,75 e 2,00 kg ha-1, aplicados em condições de pós-emergência das plantas daninhas. As densidades das plantas daninhas foram avaliadas aos 15, 60 e 90 dias após a aplicação (DAA da mistura dos herbicidas, e a biomassa seca das plantas daninhas, aos 90 DAA. A presença de palha sobre o solo suprimiu as densidades das populações de Brachiaria plantaginea, Digitaria horizontalis, Panicum maximum, Sida glaziovii e Amaranthus hybridus a níveis de infestação considerados satisfatórios de controle. A palhada também reduziu as populações de Senna obtusifolia, Ipomoea hederifolia, I. grandifolia e I. nil, porém em níveis insatisfatórios de controle. A mistura de herbicidas nas doses estudadas controlou todas as espécies de plantas daninhas avaliadas. Na presença da palha, o controle das plantas de S. obtusifolia, I. nil, I. hederifolia e I. grandifolia somente foi satisfatório quando foi aplicada a mistura de herbicidas. Para o controle de P. maximum, houve vantagem na integração dos dois métodos de controle, em relação à aplicação isolada da menor quantidade de palha estudada ou à aplicação da mistura de herbicidas.This work aimed to evaluate the effects of green cane harvesting residue and of the herbicide mixture trifloxysulfuron sodium + ametryne on the emergence and dry biomass accumulation of nine weed species. The treatments were arranged in a 3 x 3 factorial design, with three green cane

  18. Petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Farrington, J.W.; Teal, J.M.; Parker, P.L.

    1976-01-01

    Methods for analysis of petroleum hydrocarbons in marine samples are presented. Types of hydrocarbons present and their origins are discussed. Principles and methods of analysis are outlined. Infrared spectrometry, uv spectrometry, gas chromatography, mass spectroscopy, and carbon 14 measurements are described

  19. Characterisation of polycyclic aromatic hydrocarbons in flue gas and residues of a full scale fluidized bed combustor combusting non-hazardous industrial waste.

    Science.gov (United States)

    Van Caneghem, J; Vandecasteele, C

    2014-11-01

    This paper studies the fate of PAHs in full scale incinerators by analysing the concentration of the 16 EPA-PAHs in both the input waste and all the outputs of a full scale Fluidized Bed Combustor (FBC). Of the analysed waste inputs i.e. Waste Water Treatment (WWT) sludge, Refuse Derived Fuel (RDF) and Automotive Shredder Residue (ASR), RDF and ASR were the main PAH sources, with phenanthrene, fluoranthene and pyrene being the most important PAHs. In the flue gas sampled at the stack, naphthalene was the only predominant PAH, indicating that the PAHs in FBC's combustion gas were newly formed and did not remain from the input waste. Of the other outputs, the boiler and fly ash contained no detectable levels of PAHs, whereas the flue gas cleaning residue contained only low concentrations of naphthalene, probably adsorbed from the flue gas. The PAH fingerprint of the bottom ash corresponded rather well to the PAH fingerprint of the RDF and ASR, indicating that the PAHs in this output, in contrast to the other outputs, were mainly remainders from the PAHs in the waste inputs. A PAH mass balance showed that the total PAH input/output ratio of the FBC ranged from about 100 to about 2600 depending on the waste input composition and the obtained combustion conditions. In all cases, the FBC was clearly a net PAH sink. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Frozen Hydrocarbon Particles of Cometary Halos as Carriers of ...

    Indian Academy of Sciences (India)

    The possible nature of unidentified cometary emissions is under discussion. We propose a new model of the ice particles in cometary halos as a mixture of frozen polycyclic aromatic hydrocarbons and acyclic hydrocarbons.We describe principal properties of frozen hydrocarbon particles (FHPs) and suggest interpreting ...

  1. Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentrations on honey bee (Apis mellifera)

    Science.gov (United States)

    Imidacloprid is the most widely used insecticide in agricultural. In this study, we used both feeding and spraying methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL) alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equa...

  2. Conversion of oligomeric starch, cellulose, hydrolysates or sugars to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Silks, Louis A; Sutton, Andrew; Kim, Jin Kyung; Gordon, John Cameron; Wu, Ruilian; Kimball, David B.

    2017-09-05

    Embodiments of the present invention are directed to the conversion of a source material (e.g., a depolymerized oligosaccharide mixture, a monomeric sugar, a hydrolysate, or a mixture of monomeric sugars) to intermediate molecules containing 7 to 26 contiguous carbon atoms. These intermediates may also be converted to saturated hydrocarbons. Such saturated hydrocarbons are useful as, for example, fuels.

  3. Identification of amino acid residues in the ligand-binding domain of the aryl hydrocarbon receptor causing the species-specific response to omeprazole: possible determinants for binding putative endogenous ligands.

    Science.gov (United States)

    Shiizaki, Kazuhiro; Ohsako, Seiichiroh; Kawanishi, Masanobu; Yagi, Takashi

    2014-02-01

    Omeprazole (OME) induces the expression of genes encoding drug-metabolizing enzymes, such as CYP1A1, via activation of the aryl hydrocarbon receptor (AhR) both in vivo and in vitro. However, the precise mechanism of OME-mediated AhR activation is still under investigation. While elucidating species-specific susceptibility to dioxin, we found that OME-mediated AhR activation was mammalian species specific. Moreover, we previously reported that OME has inhibitory activity toward CYP1A1 enzymes. From these observations, we speculated that OME-mediated AhR target gene transcription is due to AhR activation by increasing amounts of putative AhR ligands in serum by inhibition of CYP1A1 activity. We compared the amino acid sequences of OME-sensitive rabbit AhR and nonsensitive mouse AhR to identify the residues responsible for the species-specific response. Chimeric AhRs were constructed by exchanging domains between mouse and rabbit AhRs to define the region required for the response to OME. OME-mediated transactivation was observed only with the chimeric AhR that included the ligand-binding domain (LBD) of the rabbit AhR. Site-directed mutagenesis revealed three amino acids (M328, T353, and F367) in the rabbit AhR that were responsible for OME-mediated transactivation. Replacing these residues with those of the mouse AhR abolished the response of the rabbit AhR. In contrast, substitutions of these amino acids with those of the rabbit AhR altered nonsensitive mouse AhR to become sensitive to OME. These results suggest that OME-mediated AhR activation requires a specific structure within LBD that is probably essential for binding with enigmatic endogenous ligands.

  4. Performance of an auto refrigerant cascade refrigerator operating in gas refrigerant supply (GRS) mode with nitrogen-hydrocarbon and argon-hydrocarbon refrigerants

    Science.gov (United States)

    Gurudath Nayak, H.; Venkatarathnam, G.

    2009-07-01

    There is a worldwide interest in the development of auto refrigerant cascade (ARC) refrigerators operating with refrigerant mixtures. Both flammable and non-flammable refrigerant mixtures can be used in these systems. The performance of an ARC system with optimum nitrogen-hydrocarbon and argon-hydrocarbon mixtures between 90 and 160 K is presented in this paper.

  5. Corrélations entre la composition des mélanges d'hydrocarbures et leurs propriétés physiques Correlations Betweenthe Composition of Hydrocarbon Mixtures and Their Physical Properties.

    Directory of Open Access Journals (Sweden)

    Gouel P.

    2006-11-01

    Full Text Available L'optimisation de l'exploitation des gisements d'hydrocarbures est devenue aujourd'hui,avec la grave crise énergétique que nous traversons, le problème numéro un du mondepétrolier. Afin d'améliorer la production on est obligé de mettre en ceuvre des techniques derécupération assistée qui coûtent très cher et dont le choix est basé sur les propriétés physiques du pétrole, de la roche réservoir et l'état d'exploitation même du gisement.Nous avons donc étudié le comportement volumétrique et viscosimétrique de la fraction lourde d'hydrocarbures ainsi que la mise au point d'une technique d'analyse de cette fraction. Nos mesures ont porté essentiellement sur les corps purs suivants : nCe, nC, nC, nC9, nClo, nC12, nC14, nCls, cyclo Ce, cyclo C" cyclo Cs, méthyl cyclo Cg, benzène, toluène, xylène et triméthylbenzène dans un domaine de température et de pression s'étendant de 20 à 120 °C et de la pression atmosphérique à 400 bars.A partir de ces données expérimentales nous avons développé deux modèles prévisionnels : l'un pour la masse volumique des mélanges basé sur l'équation d'état de Redlich-Kwong et l'introduction de coefficients d'interaction binaire, l'autre sur les viscosités des mélanges à partir d'une équation d'Andrade modi-fiée et de la loi de mélange d'Arrhénius. The principal problem facing the petroleum industry during the present severe energy crisis is ta optimise production from hydrocarbon fields. In order to improve production, enhanced recovery techniques must be used. These are extremely expensive and are chosen on the basis of physical properties of the ail, the réservoir rocks and working conditions of the field. The volumetric and viscometric behovior of the heavy hydrocarbon fraction was therefore studied. A technique for analyzing this fraction was also developed. M~asurements essentially concerned the following pure substances : nC, nC, nC, nC, nC1e,nC,,, nC14,nC18, cyclo C

  6. Bioremediation of soils contaminated by hydrocarbons at the coastal zone of “Punta Majagua”.

    Directory of Open Access Journals (Sweden)

    Jelvys Bermúdez Acosta

    2012-03-01

    Full Text Available The purpose of this research was to describe and assess the main results in the process of bioremediation of 479 m3 of petroleum residuals spilled on the soil and restrained into four deposits of fuel on the coastal zone of “Punta Majagua”, Cienfuegos. The volume of hydrocarbons spilled and contained into the tanks was determined by means of their previous mixture with fertile ground in a ratio of 3/1. The hydrocarbons were disposed in a bioremediation area of 115 m X 75m built in situ. In turn 54, 5 m3 of BIOIL - FC were applied, which were fermented in an industrial bioreactor of 12000 L. An initial sampling was carried out registering values of total hydrocarbons (HTP higher than 41880 mg/kg, with high concentrations of Saturated hydrocarbons, aromatics, resins, asphaltens (SARA. Three subsequent samples were taken with a sampling interval of 0, 45, 90 and 120 days of the application. An average concentration of 1884.57 mg/kg of total hydrocarbons was obtained at 120 days with an average removal rate of 94.8%, moreover values of 94.6%, 90.78%, 86.99% y 79.9% of SARA were respectively reported.

  7. Investigation of the ionization mechanism of polycyclic aromatic hydrocarbons using an ethanol/bromobenzene/chlorobenzene/anisole mixture as a dopant in liquid chromatography/atmospheric pressure photoionization mass spectrometry

    KAUST Repository

    Amad, Maan H.

    2012-09-23

    RATIONALE An ethanol-based multicomponent dopant consisting of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v/v/v) has been used as a dopant for atmospheric pressure photoionization (APPI) of polycyclic aromatic hydrocarbons (PAHs). In this study the mechanism of ionization of PAHs assisted by the ethanol-based multicomponent dopant is investigated. METHODS The reactant background cluster ions of the ethanol-based multicomponent dopant observed in the positive ion APPI were studied. These studies were performed to investigate the mechanism behind the generation of a molecular radical cation (M +•) for PAHs by APPI assisted by the ethanol-based multicomponent dopant. Full scan and MS/MS analyses were conducted using an LTQ Orbitrap mass spectrometer. The effect of acidification of the mobile phase on the dopant cluster ion formation was also investigated. RESULTS With the ethanol-based multicomponent dopant, a single type of molecular radical cation M +• was observed for the studied PAHs. The characteristic ion signal of the multicomponent dopant mixture consisted of mainly anisole photoions at m/z 108.05697 and its adduct ions at m/z 124.05188 and 164.07061. The anisole ion response at m/z 108.05697 was stable in the presence of acetonitrile, methanol, water and 0.1% formic acid mobile phase composition. CONCLUSIONS The abundance formation of anisole photoions shows the universality of this multicomponent dopant in ionizing compounds with ionization energy ranging from 7.1-8.2 eV. Since the ionization energy of anisole is 8.2 eV and is lower than those of chlorobenzene (9.07 eV) and bromobenzene (9.0 eV), the mechanism of formation of anisole photoions even with its very minute amounts was not only governed by its photoionization by the krypton lamp photon energy (10.0 eV and 10.6 eV), but also by charge transfer from bromobenzene and chlorobenzene radical cations. PAH molecules were mainly ionized by charge transfer reaction from

  8. Separation of alcohols from organic liquid mixtures by pervaporation

    NARCIS (Netherlands)

    Park, Hyun-Chae

    1993-01-01

    In the chemical industry, distillation is generally the preferred technique to separate a liquid mixture. However some liquid mixtures such as azeotropic mixtures, close-boiling hydrocarbons, and various isomers are difficult to separate by simple distillation. For the separation of these mixtures

  9. Methods for the isolation and identification of polycyclic aromatic hydrocarbons found in complex mixtures and the determination of their possible toxicity by means of a host mediated bioassay technique. Progress report, July 1, 1976--February 1, 1977. [Cultured mouse leumemia cell bioassay system

    Energy Technology Data Exchange (ETDEWEB)

    Lipsky, S.R.; Alexander, G.; McMurray, W.; Capizzi, R.

    1977-02-01

    Techniques were developed to produce excellent high performance glass capillary columns for gas chromatographic analyses of a wide range of complex mixtures of organic compounds, including those containing a wide array of polycyclic aromatic hydrocarbons (PAH) derived from a coal liquefaction process. Work was begun to assess the potential mutogenicity and/or carcinogenicity of the various isolated PAH fractions utilizing a unique host mediated bioassay system. Preliminary results indicate that further efforts will be required to determine dose response parameters of cultured mouse leukemia cells, as well as suitable vehicles for the satisfactory introduction of certain PAH fractions into this particular bioassay system.

  10. Mixture Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.

    2007-12-01

    A mixture experiment involves combining two or more components in various proportions or amounts and then measuring one or more responses for the resulting end products. Other factors that affect the response(s), such as process variables and/or the total amount of the mixture, may also be studied in the experiment. A mixture experiment design specifies the combinations of mixture components and other experimental factors (if any) to be studied and the response variable(s) to be measured. Mixture experiment data analyses are then used to achieve the desired goals, which may include (i) understanding the effects of components and other factors on the response(s), (ii) identifying components and other factors with significant and nonsignificant effects on the response(s), (iii) developing models for predicting the response(s) as functions of the mixture components and any other factors, and (iv) developing end-products with desired values and uncertainties of the response(s). Given a mixture experiment problem, a practitioner must consider the possible approaches for designing the experiment and analyzing the data, and then select the approach best suited to the problem. Eight possible approaches include 1) component proportions, 2) mathematically independent variables, 3) slack variable, 4) mixture amount, 5) component amounts, 6) mixture process variable, 7) mixture of mixtures, and 8) multi-factor mixture. The article provides an overview of the mixture experiment designs, models, and data analyses for these approaches.

  11. Petroleum hydrocarbon concentration in sediments along northern west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Kadam, A.N.

    Gas chromatography revealed that nonpolar material extracted from surface sediments collected along the northern west coast of India was originated from petroleum hydrocarbon residue. Petroleum hydrocarbon levels as determinEd. by fluorescence...

  12. Valorization of Waste Lipids through Hydrothermal Catalytic Conversion to Liquid Hydrocarbon Fuels with in Situ Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongwook; Vardon, Derek R.; Murali, Dheeptha; Sharma, Brajendra K.; Strathmann, Timothy J.

    2016-03-07

    We demonstrate hydrothermal (300 degrees C, 10 MPa) catalytic conversion of real waste lipids (e.g., waste vegetable oil, sewer trap grease) to liquid hydrocarbon fuels without net need for external chemical inputs (e.g., H2 gas, methanol). A supported bimetallic catalyst (Pt-Re/C; 5 wt % of each metal) previously shown to catalyze both aqueous phase reforming of glycerol (a triacylglyceride lipid hydrolysis coproduct) to H2 gas and conversion of oleic and stearic acid, model unsaturated and saturated fatty acids, to linear alkanes was applied to process real waste lipid feedstocks in water. For reactions conducted with an initially inert headspace gas (N2), waste vegetable oil (WVO) was fully converted into linear hydrocarbons (C15-C17) and other hydrolyzed byproducts within 4.5 h, and H2 gas production was observed. Addition of H2 to the initial reactor headspace accelerated conversion, but net H2 production was still observed, in agreement with results obtained for aqueous mixtures containing model fatty acids and glycerol. Conversion to liquid hydrocarbons with net H2 production was also observed for a range of other waste lipid feedstocks (animal fat residuals, sewer trap grease, dry distiller's grain oil, coffee oil residual). These findings demonstrate potential for valorization of waste lipids through conversion to hydrocarbons that are more compatible with current petroleum-based liquid fuels than the biodiesel and biogas products of conventional waste lipid processing technologies.

  13. Multi-class, multi-residue analysis of pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers and novel flame retardants in fish using fast, low-pressure gas chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sapozhnikova, Yelena, E-mail: yelena.sapozhnikova@ars.usda.gov [US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 193038 (United States); Lehotay, Steven J. [US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 193038 (United States)

    2013-01-03

    Highlights: Black-Right-Pointing-Pointer A method for analysis of POPs and novel flame retardants in catfish was developed. Black-Right-Pointing-Pointer The method is based on a QuEChERS extraction, d-SPE clean-up and low pressure GC/MS-MS. Black-Right-Pointing-Pointer The method validation demonstrated good recoveries and low detection limits. Black-Right-Pointing-Pointer The method was successfully applied for analysis of catfish samples from the market. - Abstract: A multi-class, multi-residue method for the analysis of 13 novel flame retardants, 18 representative pesticides, 14 polychlorinated biphenyl (PCB) congeners, 16 polycyclic aromatic hydrocarbons (PAHs), and 7 polybrominated diphenyl ether (PBDE) congeners in catfish muscle was developed and evaluated using fast low pressure gas chromatography triple quadrupole tandem mass spectrometry (LP-GC/MS-MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with acetonitrile and dispersive solid-phase extraction (d-SPE) clean-up with zirconium-based sorbent prior to LP-GC/MS-MS analysis. The developed method was evaluated at 4 spiking levels and further validated by analysis of NIST Standard Reference Materials (SRMs) 1974B and 1947. Sample preparation for a batch of 10 homogenized samples took about 1 h/analyst, and LP-GC/MS-MS analysis provided fast separation of multiple analytes within 9 min achieving high throughput. With the use of isotopically labeled internal standards, recoveries of all but one analyte were between 70 and 120% with relative standard deviations less than 20% (n = 5). The measured values for both SRMs agreed with certified/reference values (72-119% accuracy) for the majority of analytes. The detection limits were 0.1-0.5 ng g{sup -1} for PCBs, 0.5-10 ng g{sup -1} for PBDEs, 0.5-5 ng g{sup -1} for select pesticides and PAHs and 1-10 ng g{sup -1} for flame retardants. The developed method was successfully applied for analysis of catfish samples

  14. Occurrence and sources of aliphatic hydrocarbons in soils within the ...

    African Journals Online (AJOL)

    The isoprenoid ratios and CPI values of the samples closer ( 20 m from the HMA plants showed mixture of both anthropogenic and biogenic sources. Keywords: Asphalt Plants; Soil; Aliphatic hydrocarbons; Pristane; Phytane.

  15. Hydrocarbon exploration

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, I. (South Carolina Univ., Columbia, SC (United States). Dept. of Geological Sciences)

    1993-01-01

    This special issue of the journal examines various aspects of the on-going search for hydrocarbons, ranging from frontier basins where little data are available, to more mature areas where considerable data are available. The incentives underlying the search for oil are roughly: the social, economic and industrial needs of a nation; the incentive of a corporation to be profitable; and the personal incentives of individuals in the oil industry and governments, which range from financial wealth to power and which are as diverse as the individuals who are involved. From a geopolitical perspective, the needs, requirements, goals, strategies, and philosophies of nations, and groups of nations, also impact on the oil exploration game. Strategies that have been employed have ranged from boycott to austerity and rationing, to physical intervention, to global ''flooding'' with oil by over-production. (author)

  16. Artificial Neural Networks and Concentration Residual Augmented ...

    African Journals Online (AJOL)

    Artificial Neural Networks and Concentration Residual Augmented Classical Least Squares for the Simultaneous Determination of Diphenhydramine, Benzonatate, Guaifenesin and Phenylephrine in their Quaternary Mixture.

  17. Modeling phase equilibria for acid gas mixtures using the CPA equation of state. Part II: Binary mixtures with CO2

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2011-01-01

    In Part I of this series of articles, the study of H2S mixtures has been presented with CPA. In this study the phase behavior of CO2 containing mixtures is modeled. Binary mixtures with water, alcohols, glycols and hydrocarbons are investigated. Both phase equilibria (vapor–liquid and liquid–liqu...

  18. Radiolytic decomposition of water-ethanol mixtures

    International Nuclear Information System (INIS)

    Baquey, Charles

    1968-07-01

    This research thesis addresses the study of the behaviour of binary mixtures submitted to ionizing radiations, and notably aims, by studying the case of water-ethanol mixtures, at verifying solutions proposed by previously published works on the origin of hydrogen atoms and of molecular hydrogen, on the intervention of excited atoms, and on the origin of products appearing under radiolysis. The experimental part of this work consists in the dosing of products formed in water-ethanol mixtures irradiated in presence or absence of nitrate, hydrogen, hydrocarbon, acetaldehyde, 2-3 butanediol and nitrite. Results are discussed and interpreted in terms of acetaldehyde efficiency, 2-3 butanediol efficiencies, and hydrocarbon efficiencies in pure ethanol, and in water-ethanol mixtures. The influence of the presence of nitrate ions in mixtures is also discussed

  19. Catalytic conversion of alcohols to hydrocarbons with low benzene content

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2016-03-08

    A method for converting an alcohol to a hydrocarbon fraction having a lowered benzene content, the method comprising: converting said alcohol to a hydrocarbon fraction by contacting said alcohol, under conditions suitable for converting said alcohol to said hydrocarbon fraction, with a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon fraction, and contacting said hydrocarbon fraction with a benzene alkylation catalyst, under conditions suitable for alkylating benzene, to form alkylated benzene product in said hydrocarbon fraction. Also described is a catalyst composition useful in the method, comprising a mixture of (i) a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon, and (ii) a benzene alkylation catalyst, in which (i) and (ii) may be in a mixed or separated state. A reactor for housing the catalyst and conducting the reaction is also described.

  20. Catalytic conversion of alcohols to hydrocarbons with low benzene content

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2016-09-06

    A method for converting an alcohol to a hydrocarbon fraction having a lowered benzene content, the method comprising: converting said alcohol to a hydrocarbon fraction by contacting said alcohol, under conditions suitable for converting said alcohol to said hydrocarbon fraction, with a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon fraction, and contacting said hydrocarbon fraction with a benzene alkylation catalyst, under conditions suitable for alkylating benzene, to form alkylated benzene product in said hydrocarbon fraction. Also described is a catalyst composition useful in the method, comprising a mixture of (i) a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon, and (ii) a benzene alkylation catalyst, in which (i) and (ii) may be in a mixed or separated state. A reactor for housing the catalyst and conducting the reaction is also described.

  1. Novel Electrochemical Treatment of Spent Caustic from the Hydrocarbon Industry Using Ti/BDD

    Directory of Open Access Journals (Sweden)

    Alejandro Medel

    2015-01-01

    Full Text Available During the crude oil refining process, NaOH solutions are used to remove H2S, H2Saq, and sulfur compounds from different hydrocarbon streams. The residues obtained are called “spent caustics.” These residues can be mixed with those obtained in other processes, adding to its chemical composition naphthenic acids and phenolic compounds, resulting in one of the most dangerous industrial residues. In this study, the use of electrochemical technology (ET, using BDD with Ti as substrate (Ti/BDD, is evaluated in electrolysis of spent caustic mixtures, obtained through individual samples from different refineries. In this way, the Ti/BDD’s capability of carrying out the electrochemical destruction of spent caustics in an acidic medium is evaluated having as key process a chemical pretreatment phase. The potential production of •OHs, as the main reactive oxygen species electrogenerated over Ti/BDD surface, was evaluated in HCl and H2SO4 through fluorescence spectroscopy, demonstrating the reaction medium’s influence on its production. The results show that the hydrocarbon industry spent caustics can be mineralized to CO2 and water, driving the use of ET and of the Ti/BDD to solve a real problem, whose potential and negative impact on the environment and on human health is and has been the environmental agencies’ main focus.

  2. Residual deposits (residual soil)

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    Residual soil deposits is accumulation of new formate ore minerals on the earth surface, arise as a result of chemical decomposition of rocks. As is well known, at the hyper genes zone under the influence of different factors (water, carbonic acid, organic acids, oxygen, microorganism activity) passes chemical weathering of rocks. Residual soil deposits forming depends from complex of geologic and climatic factors and also from composition and physical and chemical properties of initial rocks

  3. Compost bioremediation of hydrocarbon-contaminated soil ...

    African Journals Online (AJOL)

    Contaminated soil (FAO: Lithosol) containing >380 000 mg kg-1 total petroleum hydrocarbons (TPH) was bioremediated by composting. The soil was inoculated with sewage sludge and incubated for 19 months. The soil was mixed in a ratio of 1:1 (v/v) with wood chips. The soil-wood chips mixture was then mixed in a ratio ...

  4. Compost bioremediation of hydrocarbon-contaminated soil ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... Contaminated soil (FAO: Lithosol) containing >380 000 mg kg-1 total petroleum hydrocarbons (TPH) was bioremediated by composting. The soil was inoculated with sewage sludge and incubated for 19 months. The soil was mixed in a ratio of 1:1 (v/v) with wood chips. The soil-wood chips mixture was.

  5. Mycoremediation of petroleum hydrocarbon polluted soil by ...

    African Journals Online (AJOL)

    A set of control treatment was used where different concentrations of the petroleum hydrocarbon were added to all soils but no inoculation with the fungus. The results showed that the initial organic matter content of the soil increased with increase in the concentration of petroleum mixture added to the soil. The highest ...

  6. Preparation of standard mixtures of gas hydrocarbons in air by the diffusion dilution method; Preparacion de mezclas patrones de hidrocarburos gaseosos en aire por el metodo de dilucion por difusion

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. R.; Perez, M. M.

    1979-07-01

    An original diffusion system able to produce continuously gaseous samples is described. This system can generate samples with concentrations of benzene in air from 0.1 to 1 ppm a reproducible way. The diffusion dilution method used Is also studied. The use of this diffusion system has been extended to the preparation of binary mixtures (benzene-toluene). Whit a secondary dilution device is possible preparing these mixtures over a wide range of concentrations (0.11 to 0.04 ppm for benzene and 0.06 to 0.02 for toluene). (Author) 7 refs.

  7. Petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in Hong Kong marine sediments

    International Nuclear Information System (INIS)

    Zheng, G.J.; Richardson, B.J.

    1999-01-01

    A total of 20 surficial sediment samples, obtained from Hong Kong coastal waters, were analysed for petroleum hydrocarbons (PHCs) and a suite of 15 polycyclic aromatic hydrocarbons (PAHs). The results indicate that Hong Kong coastal sediments are often seriously polluted with petroleum related hydrocarbons. This is especially so in heavily urbanised or industrialized localities, such as Kowloon Bay (Victoria Harbour), Tsing Yi North and Tolo Harbour. Petroleum hydrocarbon pollutants in marine sediments are believed to be mainly derived from the transportation of oil, shipping activities, spillages, and industrial, stormwater and waste wastewater discharge. The ratio of unresolved complex mixture (UCM) to n-alkanes, carbon preference index (CPI), and n-C 16 values indicate that the main contribution to petroleum hydrocarbon contamination is via oil and its products. Pollutant sources appear to be stable and continuing when compared with previous data. (author)

  8. The Viscosity of Organic Liquid Mixtures

    Science.gov (United States)

    Len, C. W.; Trusler, J. P. M.; Vesovic, V.; Wakeham, W. A.

    2006-01-01

    The paper reports measurements of the viscosity and density of two heavy hydrocarbon mixtures, Dutrex and Arab Light Flashed Distillate (ALFD), and of their mixtures with hydrogen. The measurements have been carried out with a vibrating-wire device over a range of temperatures from 399 to 547 K and at pressures up to 20 MPa. Measurements have also been carried out on systems in which hydrogen at different concentrations has been dissolved in the liquids. The measurements have an estimated uncertainty of ±5% for viscosity and ±2% for density and represent the first results on these prototypical heavy hydrocarbons. The results reveal that the addition of hydrogen reduces both the density and viscosity of the original hydrocarbon mixture at a particular temperature and pressure.

  9. BIODEGRADATION OF HYDROCARBON VAPORS IN THE UNSATURATED ZONE

    Science.gov (United States)

    The time-averaged concentration of hydrocarbon and oxygen vapors were measured in the unsaturated zone above the residually contaminated capillary fringe at the U.S. Coast Guard Air Station in Traverse City, Michigan. Total hydrocarbon and oxygen vapor concentrations were observe...

  10. Cuticular hydrocarbons of Chagas disease vectors in Mexico

    Directory of Open Access Journals (Sweden)

    M Patricia Juárez

    2002-09-01

    Full Text Available Capillary gas-liquid chromatography was used to analyse the cuticular hydrocarbons of three triatomine species, Triatoma dimidiata, T. barberi and Dipetalogaster maxima, domestic vectors of Chagas disease in Mexico. Mixtures of saturated hydrocarbons of straight and methyl-branched chains were characteristic of the three species, but quantitatively different. Major methylbranched components mostly corresponded to different saturated isomers of monomethyl, dimethyl and trimethyl branched hydrocarbons ranging from 29 to 39 carbon backbones. Sex-dependant, quantitative differences in certain hydrocarbons were apparent in T. dimidiata.

  11. Critical body residues in the marine amphipod Ampelisca abdita: Sediment exposures with nonionic organic contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Fay, A.A.; Brownawell, B.J.; Elskus, A.A.; McElroy, A.E.

    2000-04-01

    Body residues associated with acute toxicity were determined in the marine amphipod Ampelisca abdita exposed to spiked sediments. Nonylphenol and 2,2{prime},4,4{prime}-tetrachlorobiphenyl critical body residues (CBRs, body residue of contaminant at 50% mortality) were 1.1 {micro}mol/g wet tissue and 0.57 {micro}mol/g wet tissue, respectively, values near the low end of the CBR range expected for compounds acting via narcosis. The polycyclic aromatic hydrocarbons tested, benzo[a]pyrene (BaP) and benz[a]anthracene (BaA), were not acutely toxic at exposure concentrations of up to 43 and 1,280 {micro}g/g dry sediment for BaA and BaP respectively, and body burdens up to 1.2 {micro}mol/g wet tissue (for BaP). Neither polycyclic aromatic hydrocarbon (PAH) was significantly metabolized by A. abdita. The microextraction technique employed here allowed residue analysis of samples containing as few as three amphipods (0.33 mg dry wt). The CBR approach avoids confounding factors such as variations in bioavailability and uptake kinetics and could be employed to assess the relative contribution of specific contaminants or contaminant classes in mixtures to effects observed in toxicity tests with Ampelisca and other organisms.

  12. Methods for reformation of gaseous hydrocarbons using electrical discharge

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Methods for the reformation of gaseous hydrocarbons are provided. The methods can include forming a bubble containing the gaseous hydrocarbon in a liquid. The bubble can be generated to pass in a gap between a pair of electrodes, whereby an electrical discharge is generated in the bubble at the gap between the electrodes. The electrodes can be a metal or metal alloy with a high melting point so they can sustain high voltages of up to about 200 kilovolts. The gaseous hydrocarbon can be combined with an additive gas such as molecular oxygen or carbon dioxide. The reformation of the gaseous hydrocarbon can produce mixtures containing one or more of H2, CO, H2O, CO2, and a lower hydrocarbon such as ethane or ethylene. The reformation of the gaseous hydrocarbon can produce low amounts of CO2 and H2O, e.g. about 15 mol-% or less.

  13. Investigation of a Gamma model for mixture STR samples

    DEFF Research Database (Denmark)

    Christensen, Susanne; Bøttcher, Susanne Gammelgaard; Lauritzen, Steffen L.

    The behaviour of PCR Amplification Kit, when used for mixture STR samples, is investigated. A model based on the Gamma distribution is fitted to the amplifier output for constructed mixtures, and the assumptions of the model is evaluated via residual analysis.......The behaviour of PCR Amplification Kit, when used for mixture STR samples, is investigated. A model based on the Gamma distribution is fitted to the amplifier output for constructed mixtures, and the assumptions of the model is evaluated via residual analysis....

  14. Etude de l'état des asphaltènes dans les mélanges d'hydrocarbures : taille des amas moléculaires Research on the State of Asphaltenes in Hydrocarbon Mixtures: Size of Molecular Clusters

    Directory of Open Access Journals (Sweden)

    Briant J.

    2006-11-01

    Full Text Available On expose dans cet article les mesures, par différentes méthodes expérimentales (tonométrie, viscosimétrie, ultrafiltration, des poids et des tailles moléculaires des asphaltènes dans divers mélanges de diluants. Les variations des poids et des tailles moléculaires en fonction de la concentration en soluté et de la composition du mélange de diluants sont expliquées en relation avec le modèle de Yen et ses différentes structures et sous-structures. This article describes the different experimental methods (tonometry, viscosimetry, ultrafiltration used to measure the molecular weights and sizes of asphaltenes in different diluent mixtures. Variations in molecular weights and sizes as a function of the solute concentration and the composition of the diluent mixture are explained in relation to Yen's model and its different structures and substructures.

  15. EVALUATION OF PETROLEUM HYDROCARBONS ELUTION FROM SOIL

    Directory of Open Access Journals (Sweden)

    Janina Piekutin

    2015-06-01

    Full Text Available The paper presents studies on oil removal from soil by means of water elution with a help of shaking out the contaminants from the soil. The tests were performed on simulated soil samples contaminated with a mixture of petroleum hydrocarbons. The study consisted in recording the time influence and the number of elution cycles to remove contaminants from the soil. The samples were then subject to the determination of petroleum hydrocarbons, aliphatic hydrocarbons, and BTEX compounds (benzene, toluene, ethylbenzene, xylene. Due to adding various concentrations of petroleum into particular soil samples and applying different shaking times, it was possible to find out the impact of petroleum content and sample shaking duration on the course and possibility of petroleum substances removal by means of elution process.

  16. Mixture preparation by cool flames for diesel-reforming technologies

    Science.gov (United States)

    Hartmann, L.; Lucka, K.; Köhne, H.

    The separation of the evaporation from the high-temperature reaction zone is crucial for the reforming process. Unfavorable mixtures of liquid fuels, water and air lead to degradation by local hot spots in the sensitive catalysts and formation of unwanted by-products in the reformer. Furthermore, the evaporator has to work with dynamic changes in the heat transfer, residence times and educt compositions. By using exothermal pre-reactions in the form of cool flames it is possible to realize a complete and residue-free evaporation of liquid hydrocarbon mixtures. The conditions whether cool flames can be stabilised or not is related to the heat release of the pre-reactions in comparison to the heat losses of the system. Examinations were conducted in a flow reactor at atmospheric pressure and changing residence times to investigate the conditions under which stable cool flame operation is possible and auto-ignition or quenching occurs. An energy balance of the evaporator should deliver the values of heat release by cool flames in comparison to the heat losses of the system. The cool flame evaporation is applied in the design of several diesel-reforming processes (thermal and catalytic partial oxidation, autothermal reforming) with different demands in the heat management and operation range (air ratio λ, steam-to-carbon ratio, SCR). The results are discussed at the end of this paper.

  17. Cuticular hydrocarbons of Chagas disease vectors in Mexico

    OpenAIRE

    Juárez M Patricia; Carlson David A; Salazar Schettino Paz María; Mijailovsky Sergio; Rojas Gloria

    2002-01-01

    Capillary gas-liquid chromatography was used to analyse the cuticular hydrocarbons of three triatomine species, Triatoma dimidiata, T. barberi and Dipetalogaster maxima, domestic vectors of Chagas disease in Mexico. Mixtures of saturated hydrocarbons of straight and methyl-branched chains were characteristic of the three species, but quantitatively different. Major methylbranched components mostly corresponded to different saturated isomers of monomethyl, dimethyl and trimethyl branched hydro...

  18. Hydrocarbons and air pollution

    International Nuclear Information System (INIS)

    Herz, O.

    1992-01-01

    This paper shows the influence of hydrocarbons vapors, emitted by transports or by volatile solvents using, on air pollution. Hydrocarbons are the principal precursors of photochemical pollution. After a brief introduction on atmospheric chemistry and photochemical reactions, the author describes the french prevention program against hydrocarbons emissions. In the last chapter, informations on international or european community programs for photochemical pollution study are given. 5 figs., 10 tabs

  19. The origin of aliphatic hydrocarbons in olive oil.

    Science.gov (United States)

    Pineda, Manuel; Rojas, María; Gálvez-Valdivieso, Gregorio; Aguilar, Miguel

    2017-11-01

    There are many substances that can interfere with olive oil quality. Some of them are well characterized, but many others have an unknown origin. Saturated hydrocarbons make an extraordinary complex family of numerous molecules, some of them present naturally in vegetable oils. When major natural saturated hydrocarbons are analyzed by standard chromatographic methods, this complex mixture of saturated hydrocarbons appears as a hump in the chromatogram and is commonly named as unresolved complex mixture (UCM), whose origin remains unknown. In this work we studied the occurrence and the origin of aliphatic saturated hydrocarbons in olive oil. Hydrocarbons were analyzed in olive oil and along the industrial process of oil extraction. We also analyzed n-alkanes and the UCM fraction of hydrocarbons in leaf, fruit and oil from different varieties and different locations, and we also analyzed the soils at these locations. We conclude that the hydrocarbons present in olive oil do not necessarily have their origin in a contamination during olive oil elaboration; they seem to have a natural origin, as a result of olive tree metabolism and/or as the result of an intake and accumulation by the olive tree directly from the environment during its entire life cycle. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  20. Risk analysis associated with petroleum hydrocarbons: is everything running smoothly?

    International Nuclear Information System (INIS)

    Morin, D.

    1999-01-01

    Petroleum products represent one of the main sources of environmental contamination, and these products are complex, composed of several hundred individual hydrocarbons. The evaluation of the risks associated with petroleum products is often limited by certain specific parameters such as benzene. The petroleum hydrocarbons running from C(10) to C(50) are not often integrated in an analysis of the toxological risks since the toxological characterization of a complex mixture of hydrocarbons is difficult to carry out. There exist in the United States two approaches that were developed recently that allow the integration of various hydrocarbons comprising a mixture. In this presentation, two of these approaches are described and compared. An overview of these approaches related to Canadian regulatory bodies is included, and a case study completes the account. The two approaches that are most well known in this area are: 1) that of the Massachusetts Dept. of Environmental Protection, and 2) that of the Total Petroleum Hydrocarbon Criteria Working Group. The integration of petroleum hydrocarbons in a quantitative evaluation of their toxological risk is possible by present methods. This integration allows a reduction in the uncertainty associated with the use of an integrating parameter in the case of these petroleum hydrocarbons in the C(10) to the C(50) range

  1. Bioremediation of petroleum hydrocarbons in soil environments

    International Nuclear Information System (INIS)

    Rowell, M.J.; Ashworth, J.; Qureshi, A.A.

    1992-12-01

    The bioremediation of petroleum hydrocarbons in soil environments was reviewed via a literature survey and discussions with workers in relevant disciplines. The impacts of hydrocarbons on soil are discussed along with a range of methods available to assist in their decomposition by soil microorganisms. The range of petroleum-based materials considered includes conventional and synthetic crude oils, refined oils, sludges, asphalts and bitumens, drilling mud residues, creosote tars, and some pesticides. The degradability of hydrocarbons largely depends upon their aqueous solubility and their adsorption on soil surfaces and, therefore, is related to their molecular structures. The ease of decomposition decreases with increasing complexity of structure, in the order aliphatics > aromatics > heterocyclics and asphaltenes (most recalcitrant). Most soils contain an adequate population of microorganisms and hence bioaugmentation may only be needed in special circumstances. Decomposition is fastest in soils where the hydrocarbon loading rate, aeration, nutrition, moisture, and pH are all optimized. At spill sites there is little control over the application rate, although containment measures can assist in either limiting contamination or distributing it more evenly. The enhancement of bioremediation is discussed in light of all these factors. Other techniques such as enhanced aeration, hydrocarbon decomposition by anaerobic processes, surfactants, and burning are also discussed. 211 refs., 11 figs., 10 tabs

  2. Mixtures Research at NIEHS: An Evolving Program

    Science.gov (United States)

    Rider, Cynthia V; Carlin, Danielle J; DeVito, Micheal J; Thompson, Claudia L; Walker, Nigel J

    2014-01-01

    The National Institute of Environmental Health Sciences (NIEHS) has a rich history in evaluating the toxicity of mixtures. The types of mixtures assessed by the Division of the National Toxicology Program (DNTP) and the extramural community (through the Division of Extramural Research and Training (DERT)) have included a broad range of chemicals and toxicants, with each study having a unique set of questions and design considerations. Some examples of the types of mixtures studied include: groundwater contaminants, pesticides/fertilizers, dioxin-like chemicals (assessing the toxic equivalency approach), drug combinations, air pollution, metals, polycyclic aromatic hydrocarbons, technical mixtures (e.g. pentachlorophenol, flame retardants), and mixed entities (e.g. herbals, asbestos). These endeavors have provided excellent data on the toxicity of specific mixtures and have been informative to the human health risk assessment process in general (e.g. providing data on low dose exposures to environmental chemicals). However, the mixtures research effort at NIEHS, to date, has been driven by test article nominations to the DNTP or by investigator-initiated research through DERT. Recently, the NIEHS has embarked upon an effort to coordinate mixtures research across both intramural and extramural divisions in order to maximize mixtures research results. A path forward for NIEHS mixtures research will be based on feedback from a Request for Information (RFI) designed to gather up-to-date views on the knowledge gaps and roadblocks to evaluating mixtures and performing cumulative risk assessment, and a workshop organized to bring together mixtures experts from risk assessment, exposure science, biology, epidemiology, and statistics. The future of mixtures research at NIEHS will include projects from nominations to DNTP, studies by extramural investigators, and collaborations across government agencies that address high-priority questions in the field of mixtures research

  3. Plant hydrocarbon recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Dzadzic, P.M.; Price, M.C.; Shih, C.J.; Weil, T.A.

    1982-01-26

    A process for production and recovery of hydrocarbons from hydrocarbon-containing whole plants in a form suitable for use as chemical feedstocks or as hydrocarbon energy sources which process comprises: (A) pulverizing by grinding or chopping hydrocarbon-containing whole plants selected from the group consisting of euphorbiaceae, apocynaceae, asclepiadaceae, compositae, cactaceae and pinaceae families to a suitable particle size, (B) drying and preheating said particles in a reducing atmosphere under positive pressure (C) passing said particles through a thermal conversion zone containing a reducing atmosphere and with a residence time of 1 second to about 30 minutes at a temperature within the range of from about 200* C. To about 1000* C., (D) separately recovering the condensable vapors as liquids and the noncondensable gases in a condition suitable for use as chemical feedstocks or as hydrocarbon fuels.

  4. Agro-industrial residues as low-price feedstock for diesel-like fuel production by thermal cracking.

    Science.gov (United States)

    Santos, Andre L F; Martins, Danilo U; Iha, Osvaldo K; Ribeiro, Rafael A M; Quirino, Rafael L; Suarez, Paulo A Z

    2010-08-01

    Pyrolysis of industrial fatty wastes (soybean soapstock, beef tallow, and poultry industry waste) was carried out in the absence of catalysts. In all cases, organic mixtures of hydrocarbons and oxygenated compounds were obtained. These mixtures were distilled and diesel-like fractions were isolated and characterized by GC-FID, GC-MS and FT-IR, showing the formation of olefins, paraffins, and some oxygenated compounds such as carboxylic acids and esters. The main physical-chemical properties of those isolated diesel-like fuels (density, viscosity, distillation curve, carbon residue, copper corrosion test, cetane index, cold finger plugging point, acid index and heating value) were determined using ASTM standard methods and matched the Brazilian specification for diesel fuel. (c) 2010 Elsevier Ltd. All rights reserved.

  5. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  6. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M

    1972-01-01

    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  7. Catalysts and process for liquid hydrocarbon fuel production

    Science.gov (United States)

    White, Mark G.; Ranaweera, Samantha A.; Henry, William P.

    2016-08-02

    The present invention provides a novel process and system in which a mixture of carbon monoxide and hydrogen synthesis gas, or syngas, is converted into hydrocarbon mixtures composed of high quality distillates, gasoline components, and lower molecular weight gaseous olefins in one reactor or step. The invention utilizes a novel supported bimetallic ion complex catalyst for conversion, and provides methods of preparing such novel catalysts and use of the novel catalysts in the process and system of the invention.

  8. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Sediments from four different hydrocarbon polluted sites in Ogala-Bonny, Rivers State Nigeria and water samples from effluent discharge points of four different flow stations in Delta State were sampled. They were analyzed for presence of indigenous fungi. This was to establish possible fungal involvement in ...

  9. Unsaturated medium hydrocarbons pollution evaluation

    International Nuclear Information System (INIS)

    Di Luise, G.

    1991-01-01

    When the so called porous unsaturated medium, that's the vertical subsoil section between both the ground and water-table level, is interested by a hydrocarbons spill, the problem to evaluate the pollution becomes difficult: considering, essentially, the natural coexistence in it of two fluids, air and water, and the interactions between them. This paper reports that the problems tend to increase when a third fluid, the pollutant, immiscible with water, is introduced into the medium: a three-phases flow, which presents several analogies with the flow conditions present in an oil-reservoir, will be established. In such a situation, it would be very useful to handle the matter by the commonly used parameters in the oil reservoirs studies such as: residual saturation, relative permeability, phases mobility, to derive a first semiquantitative estimation of the pollution. The subsoil pollution form hydrocarbons agents is one of the worldwide more diffused causes of contamination: such events are generally referable to two main effects: accidental (oil pipeline breakdowns, e.g.), and continuous (underground tanks breaks, industrial plants leakages, e.g.)

  10. Characterization of the thermotropic behavior and lateral organization of lipid-peptide mixtures by a combined experimental and theoretical approach: Effects of hydrophobic mismatch and role of flanking residues

    DEFF Research Database (Denmark)

    Morein, S.; Killian, J.A.; Sperotto, Maria Maddalena

    2002-01-01

    bilayer hydrophobic thickness, and to investigate the potential role of flanking residues. The results show that both the WALP and the KALP peptides tend to favor the liquid-crystal line (or fluid) phase of the system; i.e., they tend to depress the main-transition temperature, T-m, of pure DPPC. However...

  11. Complex mixtures biostudies

    International Nuclear Information System (INIS)

    Springer, D.L.

    1987-01-01

    The objective of the project is to identify potential adverse biological activities associated with human exposures to complex organic mixtures (COM) from energy-related industries. Studies to identify the influence of chemical class fractions from a COM on the initiating activity of a known carcinogen, benzo(a)pyrene (BaP), demonstrated that the polycyclic aromatic hydrocarbons (PAH) and nitrogen-containing polycyclic aromatic compound (NPAC) fractions were the most effective inhibitors of initiation. In an effort to determine the contribution of BaP to the initiating activity of the COM, binding of radiolabeled BaP to mouse skin DNA was measured. Results indicated that binding of BaP to DNA decreased in the presence of the COM so that at initiating COM doses, BaP binding was near the limit detection. Addition of unlabeled BaP to the COM at an amount similar to that originally present in the COM did not significantly increase the binding. Studies to determine the rates of disappearance of carcinogenic PAH from the site of application on the skin indicated that half-lives for PAH differed by a factor of about 2. Analytical methods developed to identify PAH from COM which covalently bind to DNA demonstrated that the lower level of detection is approximately 200 picograms. Developmental studies demonstrated that both pregnant rats and mice treated dermally with a high-boiling COM developed fetuses with major malformations including cleft palate, small lungs, edema, and sagittal suture hemorrhages. 3 figures, 5 tables

  12. ANALYSIS OF THE KINETICS OF SOLVOLYSIS OF P-NITROPHENYLSULFONYLMETHYL PERCHLORATE IN BINARY ALCOHOLIC MIXTURES IN TERMS OF THE THERMODYNAMIC PROPERTIES OF THE SOLVENT MIXTURES

    NARCIS (Netherlands)

    Wijnen, J W; Engberts, J B F N; Blandamer, Michael J

    Rate constants are reported for the solvolysis of p-nitrophenylsulfonylmethyl perchlorate in binary ethanolic and methanolic mixtures at 298.2 K. Co-solvents include hydrocarbons, chlorinated hydrocarbons and 1,4-dioxane. The kinetic data are examined in terms of the effect of decreasing mole

  13. Recovering hydrocarbons with surfactants from lignin

    Energy Technology Data Exchange (ETDEWEB)

    Naae, D.G.; Whittington, L.E.; Ledoux, W.A.; Debons, F.E.

    1988-11-29

    This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation through an injection well a surfactant slug comprising about 0.1% to about 10% by weight of surfactants produced from lignin, the surfactants produced by placing lignin in contact with water, converting the lignin into low molecular weight lignin phenols by reducing the lignin in the presence of a reducing agent of carbon monoxide or hydrogen creating a reduction reaction mixture comprising oil soluble lignin phenols, the reduction occurring at a temperature greater than about 200/sup 0/C and a pressure greater than about 100 psi, recovering the oil soluble lignin phenols from the reduction mixture, and converting the lignin phenols into lignin surfactants by a reaction selected from the group consisting of alkoxylation, sulfonation, sulfation, aklylation, sulfomethylation, and alkoxysulfation; injecting into the formation through the injection well a drive fluid to push the surfactant slug towards a production well; and recovering hydrocarbons at the production well.

  14. Hydrocarbon toxicity: A review.

    Science.gov (United States)

    Tormoehlen, L M; Tekulve, K J; Nañagas, K A

    2014-06-01

    Clinical effects of hydrocarbon exposure have been reported since 1897. These substances are ubiquitous, and their exposures are common. The specific hydrocarbon and route of exposure will determine the clinical effect, and an understanding of this is helpful in the care of the hydrocarbon-exposed patient. To complete a comprehensive review of the literature on hydrocarbon toxicity and summarize the findings. Relevant literature was identified through searches of Medline (PubMed/OVID) and Cochrane Library databases (inclusive of years 1975-2013), as well as from multiple toxicology textbooks. Bibliographies of the identified articles were also reviewed. Search terms included combinations of the following: hydrocarbons, inhalants, encephalopathy, coma, cognitive deficits, inhalant abuse, huffing, sudden sniffing death, toluene, renal tubular acidosis, metabolic acidosis, arrhythmia, dermatitis, and aspiration pneumonitis. All pertinent clinical trials, observational studies, and case reports relevant to hydrocarbon exposure and published in English were reviewed. Chronic, occupational hydrocarbon toxicity was not included. Exposure to hydrocarbons occurs through one of the following routes: inhalation, ingestion with or without aspiration, or dermal exposure. Inhalational abuse is associated with central nervous system depression, metabolic acidosis, and arrhythmia. The exact mechanism of the CNS depression is unknown, but experimental evidence suggests effects on NMDA, dopamine, and GABA receptors. Chronic toluene inhalation causes a non-anion gap metabolic acidosis associated with hypokalemia. Halogenated hydrocarbon abuse can cause a fatal malignant arrhythmia, termed "sudden sniffing death". Individuals who regularly abuse hydrocarbons are more likely to be polysubstance users, exhibit criminal or violent behavior, and develop memory and other cognitive deficits. Heavy, long-term use results in cerebellar dysfunction, encephalopathy, weakness, and dementia

  15. Coal-water mixture fuel burner

    Science.gov (United States)

    Brown, T.D.; Reehl, D.P.; Walbert, G.F.

    1985-04-29

    The present invention represents an improvement over the prior art by providing a rotating cup burner arrangement for use with a coal-water mixture fuel which applies a thin, uniform sheet of fuel onto the inner surface of the rotating cup, inhibits the collection of unburned fuel on the inner surface of the cup, reduces the slurry to a collection of fine particles upon discharge from the rotating cup, and further atomizes the fuel as it enters the combustion chamber by subjecting it to the high shear force of a high velocity air flow. Accordingly, it is an object of the present invention to provide for improved combustion of a coal-water mixture fuel. It is another object of the present invention to provide an arrangement for introducing a coal-water mixture fuel into a combustion chamber in a manner which provides improved flame control and stability, more efficient combustion of the hydrocarbon fuel, and continuous, reliable burner operation. Yet another object of the present invention is to provide for the continuous, sustained combustion of a coal-water mixture fuel without the need for a secondary combustion source such as natural gas or a liquid hydrocarbon fuel. Still another object of the present invention is to provide a burner arrangement capable of accommodating a coal-water mixture fuel having a wide range of rheological and combustion characteristics in providing for its efficient combustion. 7 figs.

  16. Fingerprinting analysis and characterization of hydrocarbons in sediments of the Pearl River Delta in China

    International Nuclear Information System (INIS)

    Yang, C.; Wang, Z.; Hollebone, B.; Yang, Z.; Brown, C.; Landriault, M.; Peng, X.

    2009-01-01

    This paper reported on a study that used gas chromatography-mass spectrometry (GC-MS) and gas chromatography flame ionization detection (GC-FID) to investigate and characterize the contamination in southern China's Pearl River Delta, with particular reference to contamination from petroleum,n-alkanes, polycyclic aromatic hydrocarbons (PAHs), biomarkers and diamondoid compounds. Forensic analysis of sediments was necessary in order to decode the contamination history and evaluate the contamination level of the aquatic ecosystem. The contamination of the Pearl River Delta sediment was derived from various inputs, including petrogenic, biogenic and pyrogenic sources. However, in addition to identifying PAHs and biomarker terpanes and steranes, the detection of trace diamondoid compounds in the sediments demonstrated that the pollution in the river was derived partially from petroleum sources. Diamondoids are a class of saturated hydrocarbons that consist of three-dimensionally fused cyclohexane rings. They occur naturally in source rocks, crude oils, intermediate petroleum distillates, and finished petroleum products. They are more resistant to biodegradation than most other petroleum compounds such as n-alkanes. As such, they can play an important role in identifying and characterizing petroleum contamination in the environment. It was concluded that the petroleum contamination in the Pearl River Delta is attributed to the mixture of medium to heavy petroleum residues. 31 refs., 6 tabs., 4 figs

  17. Determination of levels of polycyclic aromatic hydrocarbons in soil ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    ABSTRACT: Soil samples contaminated with spent motor engine oil collected from Abakaliki auto-mechanic site were ... Waste oil is a mixture of different chemicals including petroleum hydrocarbons, chlorinated biphenyls, chlorodibenzofurans, additives, decomposition products and heavy metals that come from engine.

  18. Porphyrin-Embedded Silicate Materials for Detection of Hydrocarbon Solvents

    Science.gov (United States)

    2011-01-14

    are those often associated with contamination in areas near petroleum processing and handling sites. BTEX (benzene, toluene, ethylbenzene, xylene ...absorption spectroscopy, quartz crystal microbalance (QCM), and FTIR have been utilized for aromatic hydrocarbon sensing applications based on these...mixture of benzene, toluene, ethylbenzene, xylene ). Aromatic BTEX components possess a mechanism for interaction with the sorbent via π-bond

  19. Bioremediation of hydrocarbon contaminated-oil field drill-cuttings ...

    African Journals Online (AJOL)

    The effectiveness of 2 bacterial isolates (Bacillus subtilis and Pseudomonas aeruginosa) in the restoration of oil-field drill-cuttings contaminated with polycyclic aromatic hydrocarbons (PAHs) was studied. A mixture of 4 kg of the drill-cuttings and 0.67 kg of top-soil were charged into triplicate plastic reactors labeled A1 to A3, ...

  20. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    Although thraustochytrid protists are known to be of widespread occurrence in the sea, their hydrocarbon-degrading abilities have never been investigated. We isolated thraustochytrids from coastal waters and sediments of Goa coast by enriching MPN...

  1. Occurrence and distribution of persistent chlorinated hydrocarbons in the seas around India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    , sediment and biota). It provides the method analysis for determination of the concentration of various chlorinated hydrocarbons. The most striking feature of this article is the delineation of a comprehensive map of the residue levels of various...

  2. Simultaneous separation and determination of hydrocarbons and organochlorine compounds by using a two-step microcolumn.

    Science.gov (United States)

    Rodriguez, O M; Desideri, P G; Lepri, L; Checchini, L

    1991-08-30

    The simultaneous separation and determination of a mixture of hydrocarbons and organochlorine compounds was successfully carried out by using sorption chromatography on a two-step microcolumn of silica and aluminium oxide for their fractionation, and a dual detector system. In addition to the separation and identification of hydrocarbons and heterocompounds containing nitrogen, oxygen and sulphur atoms, separation and identification of chlorinated hydrocarbons (dichlorobenzenes, p-chlorotoluene, hexachlorobutadiene, 1,2,4-trichlorobenzene and 2-chloronaphthalene), pesticides (chlorpicrin, aldrin, lindane, alpha- and beta-benzene hexachloride (BHC), endrin, dieldrin, endosulphan, methoxychlor) and herbicides (propanil, dichlobenil, trifluralin, difolatan) were achieved in mixtures containing polychlorinated biphenyl, strobane and chlordane.

  3. Superlattice configurations in linear chain hydrocarbon binary mixtures

    Indian Academy of Sciences (India)

    Unknown

    number of samples. PBV thanks Prof. Ramana Rao,. EIT, Mainafe, Eritrea Ms Marta Asmara University/. Library, Eritea and Mr Asmamaw Molla Debub. University, Dilla, Ethiopia for cooperation. References. 1. Shashikanth P B and Prasad P B V 1999 Bull. Mater. Sci. 22 65. 2. Shashikanth P B and Prasad P B V 2001 Cryst.

  4. Modeling Hydrodynamic State of Oil and Gas Condensate Mixture in a Pipeline

    Directory of Open Access Journals (Sweden)

    Dudin Sergey

    2016-01-01

    Based on the developed model a calculation method was obtained which is used to analyze hydrodynamic state and composition of hydrocarbon mixture in each ith section of the pipeline when temperature-pressure and hydraulic conditions change.

  5. Gas adsorption and gas mixture separations using mixed-ligand MOF material

    Science.gov (United States)

    Hupp, Joseph T [Northfield, IL; Mulfort, Karen L [Chicago, IL; Snurr, Randall Q [Evanston, IL; Bae, Youn-Sang [Evanston, IL

    2011-01-04

    A method of separating a mixture of carbon dioxiode and hydrocarbon gas using a mixed-ligand, metal-organic framework (MOF) material having metal ions coordinated to carboxylate ligands and pyridyl ligands.

  6. Residue processing

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, W.; Rank, V.

    1942-10-15

    In the first stage of coal hydrogenation, the liquid phase, light and heavy oils were produced; the latter containing the nonliquefied parts of the coal, the coal ash, and the catalyst substances. It was the problem of residue processing to extract from these so-called let-down oils that which could be used as pasting oils for the coal. The object was to obtain a maximum oil extraction and a complete removal of the solids, because of the latter were returned to the process they would needlessly burden the reaction space. Separation of solids in residue processing could be accomplished by filtration, centrifugation, extraction, distillation, or low-temperature carbonization (L.T.C.). Filtration or centrifugation was most suitable since a maximum oil yield could be expected from it, since only a small portion of the let-down oil contained in the filtration or centrifugation residue had to be thermally treated. The most satisfactory centrifuge at this time was the Laval, which delivered liquid centrifuge residue and centrifuge oil continuously. By comparison, the semi-continuous centrifuges delivered plastic residues which were difficult to handle. Various apparatus such as the spiral screw kiln and the ball kiln were used for low-temperature carbonization of centrifuge residues. Both were based on the idea of carbonization in thin layers. Efforts were also being made to produce electrode carbon and briquette binder as by-products of the liquid coal phase.

  7. Improved ZIF-8 membrane: Effect of activation procedure and determination of diffusivities of light hydrocarbons

    KAUST Repository

    Pan, Yichang

    2015-06-23

    Zeolitic imidazolate framework ZIF-8 has shown great potential for effective separation of hydrocarbon mixtures based on its intrinsic ultramicroporous feature. In order to explore the permeation and diffusion properties of hydrocarbons through ZIF-8 membrane, high-quality ZIF-8 membranes with a separation factor of ~90 for propylene/propane are successfully prepared via optimizing the activation processes. Single-component permeation data for hydrocarbons (C1–C4) through the improved ZIF-8 membrane are measured and analyzed by Maxwell-Stefan (MS) model to get the transport diffusivities of these hydrocarbons. The diffusivity values of hydrocarbon compare well with those obtained by other experimental techniques. Binary mixture permeation also can be well predicted through single-component adsorption parameters.

  8. Characterization of Petroleum Hydrocarbon Decomposing Fungi Isolated from Mangrove Rhizosphere

    Directory of Open Access Journals (Sweden)

    Nuni Gofar

    2011-01-01

    Full Text Available The research was done to obtain the isolates of soil borne fungi isolated from mangrove rhizosphere which were capable of degrading petroleum hydrocarbon compounds. The soil samples were collected from South Sumatra mangrove forest which was contaminated by petroleum. The isolates obtained were selected based on their ability to survive, to grow and to degrade polycyclic aromatic hydrocarbons in medium containing petroleum residue. There were 3 isolates of soil borne hydrocarbonoclastic fungi which were able to degrade petroleum in vitro. The 3 isolates were identified as Aspergillus fumigates, A. parasiticus, and Chrysonilia sitophila. C. sitophila was the best isolate to decrease total petroleum hydrocarbon (TPH from medium containing 5-20% petroleum residue.

  9. Polycyclic aromatic hydrocarbons in municipal waste ashes from ...

    African Journals Online (AJOL)

    The levels of isolated polycyclic aromatic hydrocarbons (PAH) in ash residues of wastes from some major waste dumps in Lagos, Nigeria, were determined. The total amounts of the PAH in the ashes were in the range of 0.06 – 0.4 mg/g. The ash from the waste dump that contains the highest level also displayed greatest ...

  10. A GC-system for the analysis of residual geothermal gases

    Science.gov (United States)

    Sheppard, D.S.; Truesdell, A.H.

    1985-01-01

    The gases evolved from geothermal fields, after condensation of H2O, CO2, H2S and NH3 in caustic solution, contain He, H2, Ar, O2, N2, CH4 and higher hydrocarbons. The analysis for the major components in these residual gas mixtures can be achieved by use of two simple gas chromatographs in parallel, and using 5A?? molecular sieve. The separation of He and H2 to baseline is achieved by using low temperatures (30??C) coupled with a relatively long column; and the difficult separation of Ar and O2 is achieved by use of a cryogenically cooled column. The use of switching valves to backflush and bypass columns ensures that a minimum time for analysis can be achieved whilst retaining baseline separations of the He/H2 and Ar/O2 pairs. ?? 1985 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.

  11. Separation and effect of residual moisture in liquid phase adsorption of xylene on y zeolites

    Directory of Open Access Journals (Sweden)

    P. Lahot

    2014-06-01

    Full Text Available The separation of p-xylene and m-xylene from C8 aromatic hydrocarbon feed using Y zeolites is investigated. Effect of residual moisture on p-xylene adsorption on BaY was measured in order to optimize the activation temperature of the adsorbent. The results show that with an increase in temperature the moisture on the adsorbent decreases. An optimum loading of moisture is required for adsorption of xylene on the adsorbents. The Everett equation is used to determine the adsorption capacity and selectivity. It has been found that the adsorbents best suited for the separation of p-xylene, m-xylene, o-xylene and ethyl benzene from the mixture of C8 aromatics are NaY, NaY, BaY and KY, respectively. The XRD results show that the crystallinity of the adsorbent decreases upon exchanging the zeolites to K+ and Ba2+ ions.

  12. Reappraisal of hydrocarbon biomarkers in Archean rocks.

    Science.gov (United States)

    French, Katherine L; Hallmann, Christian; Hope, Janet M; Schoon, Petra L; Zumberge, J Alex; Hoshino, Yosuke; Peters, Carl A; George, Simon C; Love, Gordon D; Brocks, Jochen J; Buick, Roger; Summons, Roger E

    2015-05-12

    Hopanes and steranes found in Archean rocks have been presented as key evidence supporting the early rise of oxygenic photosynthesis and eukaryotes, but the syngeneity of these hydrocarbon biomarkers is controversial. To resolve this debate, we performed a multilaboratory study of new cores from the Pilbara Craton, Australia, that were drilled and sampled using unprecedented hydrocarbon-clean protocols. Hopanes and steranes in rock extracts and hydropyrolysates from these new cores were typically at or below our femtogram detection limit, but when they were detectable, they had total hopane (rock) and total sterane (rock) concentrations comparable to those measured in blanks and negative control samples. In contrast, hopanes and steranes measured in the exteriors of conventionally drilled and curated rocks of stratigraphic equivalence reach concentrations of 389.5 pg per gram of rock and 1,039 pg per gram of rock, respectively. Polycyclic aromatic hydrocarbons and diamondoids, which exceed blank concentrations, exhibit individual concentrations up to 80 ng per gram of rock in rock extracts and up to 1,000 ng per gram of rock in hydropyrolysates from the ultraclean cores. These results demonstrate that previously studied Archean samples host mixtures of biomarker contaminants and indigenous overmature hydrocarbons. Therefore, existing lipid biomarker evidence cannot be invoked to support the emergence of oxygenic photosynthesis and eukaryotes by ∼ 2.7 billion years ago. Although suitable Proterozoic rocks exist, no currently known Archean strata lie within the appropriate thermal maturity window for syngenetic hydrocarbon biomarker preservation, so future exploration for Archean biomarkers should screen for rocks with milder thermal histories.

  13. CO2 Removal from Multi-component Gas Mixtures Utilizing Spiral-Wound Asymmetric Membranes

    International Nuclear Information System (INIS)

    Said, W.B.; Fahmy, M.F.M.; Gad, F.K.; EI-Aleem, G.A.

    2004-01-01

    A systematic procedure and a computer program have been developed for simulating the performance of a spiral-wound gas permeate for the CO 2 removal from natural gas and other hydrocarbon streams. The simulation program is based on the approximate multi-component model derived by Qi and Henson(l), in addition to the membrane parameters achieved from the binary simulation program(2) (permeability and selectivity). Applying the multi-component program on the same data used by Qi and Henson to evaluate the deviation of the approximate model from the basic transport model, showing results more accurate than those of the approximate model, and are very close to those of the basic transport model, while requiring significantly less than 1 % of the computation time. The program was successfully applied on the data of Salam gas plant membrane unit at Khalda Petroleum Company, Egypt, for the separation of CO 2 from hydrocarbons in an eight-component mixture to estimate the stage cut, residue, and permeate compositions, and gave results matched with the actual Gas Chromatography Analysis measured by the lab

  14. Detonation velocity in poorly mixed gas mixtures

    Science.gov (United States)

    Prokhorov, E. S.

    2017-10-01

    The technique for computation of the average velocity of plane detonation wave front in poorly mixed mixture of gaseous hydrocarbon fuel and oxygen is proposed. Here it is assumed that along the direction of detonation propagation the chemical composition of the mixture has periodic fluctuations caused, for example, by layered stratification of gas charge. The technique is based on the analysis of functional dependence of ideal (Chapman-Jouget) detonation velocity on mole fraction (with respect to molar concentration) of the fuel. It is shown that the average velocity of detonation can be significantly (by more than 10%) less than the velocity of ideal detonation. The dependence that permits to estimate the degree of mixing of gas mixture basing on the measurements of average detonation velocity is established.

  15. Análise microestrutural de misturas cerâmicas de grês porcelanato com adição de chamote de telhas cerâmicas Microstructural analysis of porcelain stoneware tile mixture with the addition of roof tile residue

    Directory of Open Access Journals (Sweden)

    M. M. de Melo

    2009-12-01

    tradicionais, como feldspato e talco, exigidas na fabricação de grês porcelanato.Aiming at reducing environmental impacts, ceramic industries have worked towards adapting their production methods as well as looking into reusing and recycling their own products. The roof tile industry, despite constant development, still produces large volumes of rejected material, as a consequence of faulty processing, especially during firing. Units depicting signs of overfiring, cracking and distortion, as well as geometry and colour non-uniformities are often discarded with no environmental concern. In addition to that, discarded products have negative economic effects considering the energy, raw materials and working hours used in the fabrication of products that do not go to market. Often, defective roof tiles account for 20% of the monthly production of the ceramic industries. On the other hand, such discarded roof tiles can be reused in the production of new ceramic products, including those with higher added value, such as stoneware tiles. To that end, it is essential to assess the effect of the addition of these ceramic residues in the ceramic mixtures traditionally used to produce stoneware tiles. The present study aimed at investigating the microstructural development of stoneware tile mixtures containing roof tile residues. Contents of 10%, 20% and 30% of residue were added to two different ceramic mixtures. Three firing temperatures were studied, i.e., 1150 ºC, 1200 ºC and 1250 ºC. The heating rate was set to 10 ºC/min. Samples with or without residue were sintered and had their microstructure, water absorption and apparent porosity characterized. The addition of tile roof residue reduced the water absorption of both mixtures studied. By adding 30% residue to mixture 2 and firing at 1250 ºC, it was possible to reduce its water absorption below 0,5%, typical of stoneware tiles. Due to its mineralogical composition, the residue studied can be useful in reducing the large

  16. Quantitative Hydrocarbon Surface Analysis

    Science.gov (United States)

    Douglas, Vonnie M.

    2000-01-01

    The elimination of ozone depleting substances, such as carbon tetrachloride, has resulted in the use of new analytical techniques for cleanliness verification and contamination sampling. The last remaining application at Rocketdyne which required a replacement technique was the quantitative analysis of hydrocarbons by infrared spectrometry. This application, which previously utilized carbon tetrachloride, was successfully modified using the SOC-400, a compact portable FTIR manufactured by Surface Optics Corporation. This instrument can quantitatively measure and identify hydrocarbons from solvent flush of hardware as well as directly analyze the surface of metallic components without the use of ozone depleting chemicals. Several sampling accessories are utilized to perform analysis for various applications.

  17. Residual risk

    African Journals Online (AJOL)

    ing the residual risk of transmission of HIV by blood transfusion. An epidemiological approach assumed that all HIV infections detected serologically in first-time donors were pre-existing or prevalent infections, and that all infections detected in repeat blood donors were new or incident infections. During 1986 - 1987,0,012%.

  18. Microbial degradation of polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Volkering, F.; Breure, A.M.; Andel, J.G. van

    1992-01-01

    Polycyclic aromatic hydrocarbons (PAH) are hazardous compounds originating from oil, tar, creosote, or from incomplete combustion of fossil fuels. Application of biotechnological techniques for remediation of polluted soils from PAH demonstrated that the high molecular compounds are degraded very slowly, and that the residual concentration of PAH often is too high to permit application of the treated soil. Investigations were started to establish process parameters for optimal biodegradation of PAH. The aim is to achieve a relation between the physical properties of PAH and the biodegradation kinetics in different matrices, in order to identify applicability of biotechnological cleanup methods for waste streams and polluted soil. (orig.) [de

  19. THE EFFECTS OF EQUIVALENCE RATIO ON THE FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND SOOT IN PREMIXED ETHANE FLAMES. (R825412)

    Science.gov (United States)

    AbstractThe formation of polycyclic aromatic hydrocarbons (PAH) and soot has been investigated in atmospheric-pressure, laminar, ethane/oxygen/argon premixed flames as a function of mixture equivalence ratio. Mole fraction profiles of major products, trace aromatics, ...

  20. TRANSPORT PROPERTIES FOR REFRIGERANT MIXTURES

    Directory of Open Access Journals (Sweden)

    V. Geller

    2014-06-01

    Full Text Available A set of models to predict viscosity and thermal conductivity of refrigerant mixtures is developed. A general model for viscosity and thermal conductivity use the three contributions sum form (the dilute-gas terms, the residual terms, and the liquid terms. The corresponding states model is recommended to predict the dense gas transport properties over a range of reduced density from 0 to 2. It is shown that the RHS model provides the most reliable results for the saturated-liquid and the compressed-liquid transport properties over a range of given temperatures from 0,5 to 0,95.

  1. Composition of carbonization residues

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer; Leonhardt

    1943-11-30

    This report gave a record of the composition of several samples of residues from carbonization of various hydrogenation residue from processing some type of coal or tar in the Bergius process. These included Silesian bituminous coal processed at 600 atm. with iron catalyst, in one case to produce gasoline and middle oil and in another case to produce heavy oil excess, Scholven coal processed at 250 atm. with tin oxalate and chlorine catalyst, Bruex tar processed in a 10-liter oven using iron catalyst, and a pitch mixture from Welheim processed in a 10-liter over using iron catalyst. The values gathered were compared with a few corresponding values estimated for Boehlen tar and Gelsenberg coal based on several assumptions outlined in the report. The data recorded included percentage of ash in the dry residue and percentage of carbon, hydrogen, oxygen, nitrogen, chlorine, total sulfur, and volatile sulfur. The percentage of ash varied from 21.43% in the case of Bruex tar to 53.15% in the case of one of the Silesian coals. Percentage of carbon varied from 44.0% in the case of Scholven coal to 78.03% in the case of Bruex tar. Percentage of total sulfur varied from 2.28% for Bruex tar to a recorded 5.65% for one of the Silesian coals and an estimated 6% for Boehlen tar. 1 table.

  2. Catalyst for hydrocarbon conversion

    International Nuclear Information System (INIS)

    Duhaut, P.; Miquel, J.

    1975-01-01

    A description is given for a catalyst and process for hydrocarbon conversions, e.g., reforming. The catalyst contains an alumina carrier, platinum, iridium, at least one metal selected from uranium, vanadium, and gallium, and optionally halogen in the form of metal halide of one of the aforesaid components. (U.S.)

  3. EUV photochemical production of unsaturated hydrocarbons: implications to EUV photochemistry in Titan and Jovian planets.

    Science.gov (United States)

    Imanaka, Hiroshi; Smith, Mark A

    2009-10-22

    The EUV photochemistry of methane is one of the dominant chemical processes in the upper atmospheres of Titan and Jovian planets. The dilution of CH(4) with N(2) significantly changes the subsequent hydrocarbon chemistry initiated by EUV photoionization. At wavelengths below 80 nm, the presence of the dominant N(2) species in a N(2)/CH(4) gas mixture (=95/5) selectively enhances the formation of unsaturated hydrocarbons, such as benzene and toluene, while pure CH(4) gas leads to a wide mixture of saturated/unsaturated hydrocarbon species. This enhanced formation of unsaturated hydrocarbons is most likely initiated by the generation of CH(3)(+) via a dissociative charge-transfer reaction between N(2)(+) and CH(4). This mechanism was further confirmed with the dilution of CH(4) with Ar, which shows similarly enhanced formation of unsaturated species from an Ar/CH(4) (=95/5) gas mixture. In contrast, the depleted generation of unsaturated species from a H(2)/CH(4) gas mixture (=95/5) suggests that the CH(5)(+) ion generated via a proton-transfer reaction is not an important precursor in the production of complex unsaturated hydrocarbons. Therefore, it is the dissociative charge-transfer reaction of CH(4) that initiates the formation of unsaturated complex hydrocarbons through production of C(2)H(5)(+) with subsequent dissociative recombination. Implications regarding photochemistry in the upper atmospheres of Titan and the Jovian planets are discussed.

  4. Optimal mixture experiments

    CERN Document Server

    Sinha, B K; Pal, Manisha; Das, P

    2014-01-01

    The book dwells mainly on the optimality aspects of mixture designs. As mixture models are a special case of regression models, a general discussion on regression designs has been presented, which includes topics like continuous designs, de la Garza phenomenon, Loewner order domination, Equivalence theorems for different optimality criteria and standard optimality results for single variable polynomial regression and multivariate linear and quadratic regression models. This is followed by a review of the available literature on estimation of parameters in mixture models. Based on recent research findings, the volume also introduces optimal mixture designs for estimation of optimum mixing proportions in different mixture models, which include Scheffé’s quadratic model, Darroch-Waller model, log- contrast model, mixture-amount models, random coefficient models and multi-response model.  Robust mixture designs and mixture designs in blocks have been also reviewed. Moreover, some applications of mixture desig...

  5. Residual basins

    International Nuclear Information System (INIS)

    D'Elboux, C.V.; Paiva, I.B.

    1980-01-01

    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author) [pt

  6. Metabolic responses of Rhodococcus erythropolis PR4 grown on diesel oil and various hydrocarbons.

    Science.gov (United States)

    Laczi, Krisztián; Kis, Ágnes; Horváth, Balázs; Maróti, Gergely; Hegedüs, Botond; Perei, Katalin; Rákhely, Gábor

    2015-11-01

    Rhodococcus erythropolis PR4 is able to degrade diesel oil, normal-, iso- and cycloparaffins and aromatic compounds. The complete DNA content of the strain was previously sequenced and numerous oxygenase genes were identified. In order to identify the key elements participating in biodegradation of various hydrocarbons, we performed a comparative whole transcriptome analysis of cells grown on hexadecane, diesel oil and acetate. The transcriptomic data for the most prominent genes were validated by RT-qPCR. The expression of two genes coding for alkane-1-monooxygenase enzymes was highly upregulated in the presence of hydrocarbon substrates. The transcription of eight phylogenetically diverse cytochrome P450 (cyp) genes was upregulated in the presence of diesel oil. The transcript levels of various oxygenase genes were determined in cells grown in an artificial mixture, containing hexadecane, cycloparaffin and aromatic compounds and six cyp genes were induced by this hydrocarbon mixture. Five of them were not upregulated by linear and branched hydrocarbons. The expression of fatty acid synthase I genes was downregulated by hydrocarbon substrates, indicating the utilization of external alkanes for fatty acid synthesis. Moreover, the transcription of genes involved in siderophore synthesis, iron transport and exopolysaccharide biosynthesis was also upregulated, indicating their important role in hydrocarbon metabolism. Based on the results, complex metabolic response profiles were established for cells grown on various hydrocarbons. Our results represent a functional annotation of a rhodococcal genome, provide deeper insight into molecular events in diesel/hydrocarbon utilization and suggest novel target genes for environmental monitoring projects.

  7. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  8. Biogeochemistry of Halogenated Hydrocarbons

    Science.gov (United States)

    Adriaens, P.; Gruden, C.; McCormick, M. L.

    2003-12-01

    Halogenated hydrocarbons originate from both natural and industrial sources. Whereas direct anthropogenic emissions to the atmosphere and biosphere are often easy to assess, particularly when they are tied to major industrial activities, the attribution of emissions to other human activities (e.g., biomass burning), diffuse sources (e.g., atmospheric discharge, run off), and natural production (e.g., soils, fungi, algae, microorganisms) are difficult to quantify. The widespread occurrence of both alkyl and aryl halides in groundwater, surface water, soils, and various trophic food chains, even those not affected by known point sources, suggests a substantial biogeochemical cycling of these compounds (Wania and Mackay, 1996; Adriaens et al., 1999; Gruden et al., 2003). The transport and reactive fate mechanisms controlling their reactivity are compounded by the differences in sources of alkyl-, aryl-, and complex organic halides, and the largely unknown impact of biogenic processes, such as enzymatically mediated halogenation of organic matter, fungal production of halogenated hydrocarbons, and microbial or abiotic transformation reactions (e.g., Asplund and Grimvall, 1991; Gribble, 1996; Watling and Harper, 1998; Oberg, 2002). The largest source may be the natural halogenation processes in the terrestrial environment, as the quantities detected often exceed the amount that can be explained by human activities in the surrounding areas ( Oberg, 1998). Since biogeochemical processes result in the distribution of a wide range of halogenated hydrocarbon profiles, altered chemical structures, and isomer distributions in natural systems, source apportionment (or environmental forensics) can often only be resolved using multivariate statistical methods (e.g., Goovaerts, 1998; Barabas et al., 2003; Murphy and Morrison, 2002).This chapter will describe the widespread occurrence of halogenated hydrocarbons, interpret their distribution and biogeochemical cycling in light of

  9. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  10. Pressurized thermal and hydrothermal decomposition of algae, wood chip residue, and grape marc: A comparative study

    International Nuclear Information System (INIS)

    Subagyono, Dirgarini J.N.; Marshall, Marc; Jackson, W. Roy; Chaffee, Alan L.

    2015-01-01

    Pressurized thermal decomposition of two marine algae, Pinus radiata chip residue and grape marc using high temperature, high pressure reactions has been studied. The yields and composition of the products obtained from liquefactions under CO of a mixture of biomass and H 2 O (with or without catalyst) were compared with products from liquefaction of dry biomass under N 2 , at different temperatures, gas pressures and for CO runs, water to biomass ratios. Thermochemical reactions of algae produced significantly higher dichloromethane solubles and generally higher product yields to oil and asphaltene than Pinus radiata and grape marc under the reaction conditions used. Furthermore, the biofuels derived from algae contained significant concentrations of aliphatic hydrocarbons as opposed to those from radiata pine and grape marc which were richer in aromatic compounds. The possibility of air transport fuel production from algae thus appears to have considerable advantages over that from radiata pine and grape marc. - Highlights: • Liquefaction of algae gave more oil than that of Pinus radiata and grape marc. • Reactions under CO/H 2 O produced higher yields of oil than N 2 . • Water to biomass ratio had little effect on the yields. • Bio-oil from algae contained substantial amounts of aliphatic hydrocarbons. • Pinus radiata oil was low in N but high in O

  11. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  12. Bioremediation of severely weathered hydrocarbons: is it possible?

    International Nuclear Information System (INIS)

    Gallego, J. R.; Villa, R.; Sierra, C.; Sotres, A.; Pelaez, A. I.; Sanchez, J.

    2009-01-01

    Weathering processes of spilled hydrocarbons promote a reduced biodegradability of petroleum compounds mixtures, and consequently bioremediation techniques are often ruled out within the selection of suitable remediation approaches. This is truly relevant wherever old spills at abandoned industrial sites have to be remediated. However it is well known most of the remaining fractions and individual compounds of weathered oil are still biodegradable, although at slow rates than alkanes or no and two-ring aromatics. (Author)

  13. RESIDUAL RISK ASSESSMENTS - RESIDUAL RISK ...

    Science.gov (United States)

    This source category previously subjected to a technology-based standard will be examined to determine if health or ecological risks are significant enough to warrant further regulation for Coke Ovens. These assesments utilize existing models and data bases to examine the multi-media and multi-pollutant impacts of air toxics emissions on human health and the environment. Details on the assessment process and methodologies can be found in EPA's Residual Risk Report to Congress issued in March of 1999 (see web site). To assess the health risks imposed by air toxics emissions from Coke Ovens to determine if control technology standards previously established are adequately protecting public health.

  14. Heterogeneous OH oxidation of motor oil particles causes selective depletion of branched and less cyclic hydrocarbons.

    Science.gov (United States)

    Isaacman, Gabriel; Chan, Arthur W H; Nah, Theodora; Worton, David R; Ruehl, Chris R; Wilson, Kevin R; Goldstein, Allen H

    2012-10-02

    Motor oil serves as a useful model system for atmospheric oxidation of hydrocarbon mixtures typical of anthropogenic atmospheric particulate matter, but its complexity often prevents comprehensive chemical speciation. In this work we fully characterize this formerly "unresolved complex mixture" at the molecular level using recently developed soft ionization gas chromatography techniques. Nucleated motor oil particles are oxidized in a flow tube reactor to investigate the relative reaction rates of observed hydrocarbon classes: alkanes, cycloalkanes, bicycloalkanes, tricycloalkanes, and steranes. Oxidation of hydrocarbons in a complex aerosol is found to be efficient, with approximately three-quarters (0.72 ± 0.06) of OH collisions yielding a reaction. Reaction rates of individual hydrocarbons are structurally dependent: compared to normal alkanes, reaction rates increased by 20-50% with branching, while rates decreased ∼20% per nonaromatic ring present. These differences in rates are expected to alter particle composition as a function of oxidation, with depletion of branched and enrichment of cyclic hydrocarbons. Due to this expected shift toward ring-opening reactions heterogeneous oxidation of the unreacted hydrocarbon mixture is less likely to proceed through fragmentation pathways in more oxidized particles. Based on the observed oxidation-induced changes in composition, isomer-resolved analysis has potential utility for determining the photochemical age of atmospheric particulate matter with respect to heterogeneous oxidation.

  15. High atmosphere–ocean exchange of semivolatile aromatic hydrocarbons

    KAUST Repository

    González-Gaya, Belén

    2016-05-16

    Polycyclic aromatic hydrocarbons, and other semivolatile aromatic-like compounds, are an important and ubiquitous fraction of organic matter in the environment. The occurrence of semivolatile aromatic hydrocarbons is due to anthropogenic sources such as incomplete combustion of fossil fuels or oil spills, and other biogenic sources. However, their global transport, fate and relevance for the carbon cycle have been poorly assessed, especially in terms of fluxes. Here we report a global assessment of the occurrence and atmosphere-ocean fluxes of 64 polycyclic aromatic hydrocarbons analysed in paired atmospheric and seawater samples from the tropical and subtropical Atlantic, Pacific and Indian oceans. The global atmospheric input of polycyclic aromatic hydrocarbons to the global ocean is estimated at 0.09 Tg per month, four times greater than the input from the Deepwater Horizon spill. Moreover, the environmental concentrations of total semivolatile aromatic-like compounds were 10 2 -10 3 times higher than those of the targeted polycyclic aromatic hydrocarbons, with a relevant contribution of an aromatic unresolved complex mixture. These concentrations drive a large global deposition of carbon, estimated at 400 Tg C yr -1, around 15% of the oceanic CO2 uptake. © 2016 Macmillan Publishers Limited.

  16. Residual nilpotence and residual solubility of groups

    International Nuclear Information System (INIS)

    Mikhailov, R V

    2005-01-01

    The properties of the residual nilpotence and the residual solubility of groups are studied. The main objects under investigation are the class of residually nilpotent groups such that each central extension of these groups is also residually nilpotent and the class of residually soluble groups such that each Abelian extension of these groups is residually soluble. Various examples of groups not belonging to these classes are constructed by homological methods and methods of the theory of modules over group rings. Several applications of the theory under consideration are presented and problems concerning the residual nilpotence of one-relator groups are considered.

  17. INCORPORAÇÃO DE RESÍDUOS VEGETAIS E SEUS EFEITOS SOBRE AS CARACTERÍSTICAS FÍSICO-MECÂNICAS DE MISTURAS DE SOLO-CIMENTO PARA FINS DE CONSTRUÇÃO RURAL PLANT RESIDUES INCORPORATION EFFECTS ON PHYSICAL AND MECHANICAL CHARACTERISTICS OF SOIL-CEMENT MIXTURES FOR AGRICULTURAL BUILDINGS PURPOSES

    Directory of Open Access Journals (Sweden)

    Marcos Fernandes Oliveira

    2007-12-01

    Full Text Available

    O presente trabalho teve como objetivo avaliar o efeito da adição da casca de arroz e da casca da semente do capim braquiária, sobre as propriedades físico-mecânicas de misturas de solo-cimento e conseqüente análise de sua viabilidade técnica com vistas à fabricação de materiais de construção alternativos para fins rurais. Para tal, os resíduos foram triturados, peneirados e tratados em solução de cal e o solo submetido aos ensaios de caracterização segundo normas brasileiras. Os resíduos foram adicionados em substituição ao cimento, variando os teores de cimento e de resíduo vegetal desde 100% de cimento e 0% de resíduo, até 60% de cimento e 40% de resíduo. Posteriormente foram moldados corpos-de-prova cilíndricos que foram submetidos aos ensaios de compressão simples, aos sete, 28 e 56 dias, e de capacidade de absorção de água, aos sete dias da moldagem. Após análise dos resultados, pôde-se concluir que as misturas obtidas a partir da substituição parcial do cimento por 10% de resíduos mostram-se viáveis como matéria-prima na fabricação de elementos construtivos não estruturais, tais como, blocos e tijolos prensados, destinados às construções e instalações rurais.

    PALAVRAS-CHAVE: Solo-cimento, resíduos vegetais, construções rurais.

    The aim of this research was to evaluate the effect of rice and Brachiaria brizantha husks on physical and mechanical properties of soil-cement mixtures and, consequently, to analyse their technical feasibility to manufacture alternative building materials for agricultural purposes. Husks were ground, sieved, and treated in lime solution and soil submitted to characterisation tests according to Brazilian standards. The plant residues were added in substitution to the cement. The cement content and

  18. Efeito da palha e da mistura atrazine e metolachlor no controle de plantas daninhas na cultura do milho, em sistema de plantio direto Effect of corn plant residue and mixture of atrazine plus metolachlor on the weeds control in no-till corn system

    Directory of Open Access Journals (Sweden)

    Maurílio Fernandes de Oliveira

    2001-01-01

    Full Text Available O objetivo deste trabalho foi estudar o efeito de níveis de palha de milho e da mistura formulada atrazine e metolachlor no controle de plantas daninhas na cultura de milho, em sistema de plantio direto. O ensaio foi realizado num Latossolo Vermelho distrófico, argiloso, fase cerrado, sendo a dessecação do mato feita com glyphosate, 15 dias antes do plantio. O delineamento experimental utilizado foi o de blocos ao acaso, com parcelas subdivididas e com três repetições. Antes do plantio do milho, distribuíram-se cinco níveis de palha de milho (0, 3, 6, 9 e 12 tha-1, nas parcelas, de modo uniforme. Nas subparcelas, após o plantio, foram considerados dois tratamentos referentes a herbicida: ausência de herbicida ou a dose de 6,0 Lha-1 de atrazine, e metolachlor (1.200+ 1.800gha-1. Avaliou-se o número das plantas daninhas, por espécie, aos 26 e 41 dias após o plantio. O número total de plantas daninhas foi reduzido significativamente pelos níveis de palha, independentemente da presença do herbicida e da época de avaliação. O herbicida não apresentou efeito significativo na primeira época de avaliação; entretanto, na segunda, a redução no número total de plantas daninhas foi de, aproximadamente, 53% em relação às parcelas que não o receberam. A população total de planta daninha foi significativamente superior na segunda avaliação, na ausência do herbicida. Na presença do herbicida, não houve diferença significativa na população total de invasoras entre as duas épocas de avaliação.The objective of this work was to study the effect of corn plant residue and mixture of atrazine plus metolachlor on weed control in no-till corn system. This experiment was performed in an Oxisol, and the weed desiccation was done using glyphosate, 15 days before planting. The experimental design was a randomized block, with three replications. Before corn planting, five levels of corn plant residues (0, 3, 6, 9 e 12tha-1 were

  19. Biodegradation studies of oil sludge containing high hydrocarbons concentration

    International Nuclear Information System (INIS)

    Olguin-Lora, P.; Munoz-Colunga, A.; Castorena-Cortes, G.; Roldan-Carrillo, T.; Quej Ake, L.; Reyes-Avila, J.; Zapata-Penasco, I.; Marin-Cruz, J.

    2009-01-01

    Oil industry has a significant impact on environment due to the emission of, dust, gases, waste water and solids generated during oil production all the way to basic petrochemical product manufacturing stages. the aim of this work was to evaluate the biodegradation of sludge containing high hydrocarbon concentration originated by a petroleum facility. A sludge sampling was done at the oil residuals pool (ORP) on a gas processing center. (Author)

  20. Hydrocarbons: source of energy

    International Nuclear Information System (INIS)

    Imarisio, G.; Frias, M.; Bemtgen, J.M.

    1989-01-01

    Hydrocarbons are at present the single most important source of energy, since they are the most versatile and widely used. It is expected that their importance will extend well into the next century and therefore it is essential to provide for all those improvements which will extend their availability and usefulness. The sub-programme ''Optimization of the production and utilization of hydrocarbons'' (within the Non-Nuclear Energy R and D Programme of the European Communities) is pursuing a number of R and D topics aimed at the above-mentioned results. It is implemented by means of shared-cost R and D contracts. At this first Seminar held in Lyon (France) from 21-23 September, 1988, all contractors of the sub-programme presented the state of progress of their R and D projects. These proceedings comprise all the papers presented at the Seminar. The section on oilfield exploration includes a report of work on the interpretation of nuclear logs by means of mathematical models. (author)

  1. A numerical study of laminar flames propagating in stratified mixtures

    Science.gov (United States)

    Zhang, Jiacheng

    (CTh) is shown to be a parameter that determines the effect of extra thermal diffusion by mixture stratification on flame propagation. Smaller values reflect less impact of stratification. For the cases considered, the values of CTh are quite small. This work suggests that employing the laminar flame speed from a homogeneous mixture to approximate the flame speed (and flame structure) in thermally and compositionally stratified mixtures is reasonable for hydrocarbon/air and hydrogen/air mixtures.

  2. Pyrochlore catalysts for hydrocarbon fuel reforming

    Science.gov (United States)

    Berry, David A.; Shekhawat, Dushyant; Haynes, Daniel; Smith, Mark; Spivey, James J.

    2012-08-14

    A method of catalytically reforming a reactant gas mixture using a pyrochlore catalyst material comprised of one or more pyrochlores having the composition A2B2-y-zB'yB"zO7-.DELTA., where y>0 and z.gtoreq.0. Distribution of catalytically active metals throughout the structure at the B site creates an active and well dispersed metal locked into place in the crystal structure. This greatly reduces the metal sintering that typically occurs on supported catalysts used in reforming reactions, and reduces deactivation by sulfur and carbon. Further, oxygen mobility may also be enhanced by elemental exchange of promoters at sites in the pyrochlore. The pyrochlore catalyst material may be utilized in catalytic reforming reactions for the conversion of hydrocarbon fuels into synthesis gas (H2+CO) for fuel cells, among other uses.

  3. Hydrocarbon vapor diffusion in intact core sleeves

    International Nuclear Information System (INIS)

    Ostendorf, D.W.; Moyer, E.E.; Yuefeng Xie; Rajan, R.V.

    1993-01-01

    The diffusion of 2,2,4-trimethylpentane (TMP) and 2,2,5-trimethylhexane (TMH) vapors out of residually contaminated sandy soil from the US Environmental Protection Agency (EPA) field research site at Traverse City, Michigan, was measured and modeled. The headspace of an intact core sleeve sample was swept with nitrogen gas to simulate the diffusive release of hydrocarbon vapors from residual aviation gasoline in and immediately above the capillary fringe to a soil-venting air flow in the unsaturated zone. The resulting steady-state profile was modeled using existing diffusivity and air porosity estimates in a balance of diffusive flux and a first order source term. The source strength, which was calibrated with the observed flux of 2,2,4-TMP leaving the sleeve, varied with the residual gasoline remaining in the core, but was independent of the headspace sweep flow rate. This finding suggested that lower soil-venting air flow rates were in principle as effective as higher air flow rates in venting LNAPL vapors from contaminated soils. The saturated vapor concentration ratio of 2,2,4-TMP to 2,2,5-TMH decreased from 6.6 to 3.5 over the duration of the experiments in an expression of distillation effects. The vertical profile model was tested against sample port data in four separate experiments for both species, yielding mean errors ranging from 0 to -24% in magnitude

  4. Hydrocarbon Receptor Pathway in Dogs

    NARCIS (Netherlands)

    Steenbeek, F.G. van; Spee, B.; Penning, L.C.; Kummeling, A.; Gils, I.H.M.; Grinwis, G.C.M.; Leenen, D. van; Holstege, F.C.P.; Vos-Loohuis, M.; Rothuizen, J.; Leegwater, P.A.J.

    The aryl hydrocarbon receptor (AHR) mediates biological responses to toxic chemicals. An unexpected role for AHR in vascularization was suggested when mice lacking AHR displayed impaired closure of the ductus venosus after birth, as did knockout mice for aryl hydrocarbon receptor interacting

  5. Limitations of the toxic equivalency factor (TEF) approach for risk assessment of halogenated aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Safe, S. [Texas A and M Univ., College Station, TX (United States). Dept. of Veterinary Physiology and Pharmacology

    1995-12-31

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and related halogenated aromatic hydrocarbons (HAHs) are present as complex mixtures of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) in most environmental matrices. Risk management of these mixtures utilize the toxic equivalency factor (TEF) approach in which the TCDD (dioxin) or toxic equivalents of a mixture is a summation of the congener concentration (Ci) times TEF{sub i} (potency relative to TCDD) where. TEQ{sub mixture} = {Sigma}[Cil] {times} TEF{sub i}. TEQs are determined only for those HAHs which are aryl hydrocarbon (Ah) receptor agonists and this approach assumes that the toxic or biochemical effects of individual compounds in a mixture are additive. Several in vivo and in vitro laboratory and field studies with different HAH mixtures have been utilized to validate the TEF approach. For some responses, the calculated toxicities of PCDD/PCDF and PCB mixtures predict the observed toxic potencies. However, for fetal cleft palate and immunotoxicity in mice, nonadditive (antagonistic) responses are observed using complex PCB mixtures or binary mixtures containing an Ah receptor agonist with 2,2{prime},4,4{prime},5,5{prime}-hexachlorobiphenyl (PCB153). The potential interactive effects of PCBs and other dietary Ah receptor antagonist suggest that the TEF approach for risk management of HAHs requires further refinement and should be used selectively.

  6. Petroleum hydrocarbon concentrations in eight mollusc species along Tamilnadu coast, Bay of Bengal, India.

    Science.gov (United States)

    Veerasingam, S; Venkatachalapathy, R; Sudhakar, S; Raja, P; Rajeswari, V

    2011-01-01

    Eight mollusc species and sediment samples collected from three different stations along Tamilnadu coast, Bay of Bengal, India were analysed for the levels of petroleum hydrocarbons to elucidate the status of the petroleum residues in mollusc meant for human consumption. The concentrations of petroleum hydrocarbons in sediments along Tamilnadu coast varied from 5.04-25.5 microg/g dw (dry weight). High concentration of petroleum hydrocarbons in the sediment of Uppanar estuary (25.5 +/- 1.45 microg/g dw) was perhaps land and marine based anthropogenic sources of this region. The petroleum hydrocarbon residues in eight mollusc species collected from Uppanar, Vellar and Coleroon estuaries varied between 2.44-6.04 microg/g ww (wet weight). Although the concentration of petroleum hydrocarbons in sediment of the Uppanar region was markedly higher than the background, the petroleum hydrocarbon residues in mollusc collected from Uppanar estuary did not suggest bioaccumulation. The results signified that industrial growth has affected the aquatic environments and regular monitoring will help to adopt stringent pollution control measures for better management of the aquatic region.

  7. Mixture of residual fish hydrolysate and fish extract hydrolysate to ...

    African Journals Online (AJOL)

    Bacillus licheniformis 6346 activated in nutrient broth-starch was inoculated to a locally formulated solid medium (paddy husk, rice flour, (NH4)2SO4, cuttle fish powder, murate potash, table salt, triple super phosphate, sesame oil, coconut oil and tap water) and the highest -amylase activity was obtained on day 5 (1075 U g ...

  8. Joint Bayesian analysis of forensic mixtures.

    Science.gov (United States)

    Pascali, Vince L; Merigioli, Sara

    2012-12-01

    Evaluation of series of PCR experiments referring to the same evidence is not infrequent in a forensic casework. This situation is met when 'series of results in mixture' (EPGs produced by reiterating PCR experiments over the same DNA mixture extract) have to be interpreted or when 'potentially related traces' (mixtures that can have contributors in common) require a combined interpretation. In these cases, there can be uncertainty on the genotype assignment, since: (a) more than one genotype combination fall under the same peak profile; (b) PCR preferential amplification alters pre-PCR allelic proportions; (c) other, more unpredictable technical problems (dropouts/dropins, etc.) take place. The uncertainty in the genotype assignment is in most cases addressed by empirical methods (selection of just one particular profile; extraction of consensual or composite profiles) that disregard part of the evidence. Genotype assignment should conversely take advantage from a joint Bayesian analysis (JBA) of all STRs peak areas generated at each experiment. This is the typical case of Bayesian analysis in which adoption of object-oriented Bayesian networks (OOBNs) could be highly helpful. Starting from experimentally designed mixtures, we created typical examples of 'series of results in mixture' of 'potentially related traces'. JBA was some administered to the whole peak area evidence, by specifically tailored OOBNs models, which enabled genotype assignment reflecting all the available evidence. Examples of a residual ambiguity in the genotype assignment came to light at assumed genotypes with partially overlapping alleles (for example: AB+AC→ABC). In the 'series of results in mixture', this uncertainty was in part refractory to the joint evaluation. Ambiguity was conversely dissipated at the 'potentially related' trace example, where the ABC allelic scheme at the first trace was interpreted together with other unambiguous combinations (ABCD; AB) at the related trace. We

  9. Thermodynamic study of (anthracene + phenanthrene) solid state mixtures.

    Science.gov (United States)

    Rice, James W; Fu, Jinxia; Sandström, Emma; Ditto, Jenna C; Suuberg, Eric M

    2015-11-01

    Polycyclic aromatic hydrocarbons (PAH) are common components of many materials, such as petroleum and various types of tars. They are generally present in mixtures, occurring both naturally and as byproducts of fuel processing operations. It is important to understand the thermodynamic properties of such mixtures in order to understand better and predict their behavior ( i.e. , fate and transport) in the environment and in industrial operations. To characterize better the thermodynamic behavior of PAH mixtures, the phase behavior of a binary (anthracene + phenanthrene) system was studied by differential scanning calorimetry, X-ray diffraction, and the Knudsen effusion technique. Mixtures of (anthracene + phenanthrene) exhibit non-ideal mixture behavior. They form a lower-melting, phenanthrene-rich phase with an initial melting temperature of 372 K (identical to the melting temperature of pure phenanthrene) and a vapor pressure of roughly ln P /Pa = -2.38. The phenanthrene-rich phase coexists with an anthracene-rich phase when the mole fraction of phenanthrene ( x P ) in the mixture is less than or equal to 0.80. Mixtures initially at x P = 0.90 consist entirely of the phenanthrene-rich phase and sublime at nearly constant vapor pressure and composition, consistent with azeotrope-like behavior. Quasi-azeotropy was also observed for very high-content anthracene mixtures (2.5 < x P < 5) indicating that anthracene may accommodate very low levels of phenanthrene in its crystal structure.

  10. Treating hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Scott, R.; MacIvor, W.

    1869-09-01

    The treatment of hydrocarbon oils, such as coal or shale oils, paraffin oils, and petroleum, either in the crude or more or less refined state has the object of reducing the specific gravity and otherwise improving the qualities of such oils. The oil to be treated is put into any ordinary still and distilled. The vapor escaping during the distillation is passed through one or more heating vessels or chambers and exposed to the heat necessary to produce the change. The heating vessels or chambers may be made of metal, clay, or any other material adapted to endure heat, and they may be made of any desired form, or they may be constituted of a coil of metal pipes or a series of tubes such as are used for heating air for blast furnaces.

  11. An intention-activation account of residual switch costs

    NARCIS (Netherlands)

    De Jong, R; Monsell, S; Driver, J

    2000-01-01

    Residual switch costs are performance costs associated with a shift of task that persist even when there is ample time to prepare in advance for the new task. I present a mixture-model approach for evaluating the contributions of two possible causes of residual switch costs: (1) failures to take

  12. Decarboxylation of fatty acids with triruthenium dodecacarbonyl: Influence of the compound structure and analysis of the product mixtures

    Science.gov (United States)

    Recently, the decarboxylation of oleic acid (9(Z)-octadecenoic acid) catalyzed by triruthenium dodecacarbonyl, Ru3(CO)12, to give a mixture of heptadecenes with concomitant formation of other hydrocarbons, heptadecane and C17 alkylbenzenes, was reported. The product mixture, consisting of about 77% ...

  13. Perception of trigeminal mixtures.

    Science.gov (United States)

    Filiou, Renée-Pier; Lepore, Franco; Bryant, Bruce; Lundström, Johan N; Frasnelli, Johannes

    2015-01-01

    The trigeminal system is a chemical sense allowing for the perception of chemosensory information in our environment. However, contrary to smell and taste, we lack a thorough understanding of the trigeminal processing of mixtures. We, therefore, investigated trigeminal perception using mixtures of 3 relatively receptor-specific agonists together with one control odor in different proportions to determine basic perceptual dimensions of trigeminal perception. We found that 4 main dimensions were linked to trigeminal perception: sensations of intensity, warmth, coldness, and pain. We subsequently investigated perception of binary mixtures of trigeminal stimuli by means of these 4 perceptual dimensions using different concentrations of a cooling stimulus (eucalyptol) mixed with a stimulus that evokes warmth perception (cinnamaldehyde). To determine if sensory interactions are mainly of central or peripheral origin, we presented stimuli in a physical "mixture" or as a "combination" presented separately to individual nostrils. Results showed that mixtures generally yielded higher ratings than combinations on the trigeminal dimensions "intensity," "warm," and "painful," whereas combinations yielded higher ratings than mixtures on the trigeminal dimension "cold." These results suggest dimension-specific interactions in the perception of trigeminal mixtures, which may be explained by particular interactions that may take place on peripheral or central levels. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Identifying Mixtures of Mixtures Using Bayesian Estimation

    Science.gov (United States)

    Malsiner-Walli, Gertraud; Frühwirth-Schnatter, Sylvia; Grün, Bettina

    2017-01-01

    ABSTRACT The use of a finite mixture of normal distributions in model-based clustering allows us to capture non-Gaussian data clusters. However, identifying the clusters from the normal components is challenging and in general either achieved by imposing constraints on the model or by using post-processing procedures. Within the Bayesian framework, we propose a different approach based on sparse finite mixtures to achieve identifiability. We specify a hierarchical prior, where the hyperparameters are carefully selected such that they are reflective of the cluster structure aimed at. In addition, this prior allows us to estimate the model using standard MCMC sampling methods. In combination with a post-processing approach which resolves the label switching issue and results in an identified model, our approach allows us to simultaneously (1) determine the number of clusters, (2) flexibly approximate the cluster distributions in a semiparametric way using finite mixtures of normals and (3) identify cluster-specific parameters and classify observations. The proposed approach is illustrated in two simulation studies and on benchmark datasets. Supplementary materials for this article are available online. PMID:28626349

  15. MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS

    International Nuclear Information System (INIS)

    Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare; Zonca, Alberto

    2013-01-01

    We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproduce the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 × 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.

  16. Conversion of Biomass-Derived Furans into Hydrocarbon Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Moens, L.; Johnson, D. K.

    2013-01-01

    One of the most studied chemical transformations of carbohydrates is their thermocatalytic dehydration to form furans. Cellulose-derived glucose is thereby converted into 5-hydroxymethylfurfuraldehyde (5-HMF), while the hemicellulose-derived pentoses (e.g., xylose, arabinose) form furfuraldehyde. Our objective is to identify new pathways to convert furfuryl alcohol into a mixture of aliphatic hydrocarbons that can be used as drop-in fuels for diesel (C10-20) and jet fuel (C9-16) blends. Furfuryl alcohol is produced commercially through hydrogenation of furfuraldehyde that is derived from hemicellulose-derived pentoses via acid-catalyzed dehydration. The steps that we are currently pursuing to convert furfuryl alcohol into hydrocarbons are 1) oligomerization of furfuryl alcohol to form dimers (C10) and trimers (C15), and 2) hydrotreatment of the dimers and trimers to produce a mixture of linear hydrocarbons with carbon chain lengths in the range of diesel and jet fuels. This presentation will discuss our progress in the development of this pathway.

  17. SEPARATION OF FLUID MIXTURES

    Science.gov (United States)

    Lipscomb, R.; Craig, A.; Labrow, S.; Dunn, J.F.

    1958-10-28

    An apparatus is presented for separating gaseous mixtures by selectively freezing a constituent of the mixture and subsequently separating the frozen gas. The gas mixture is passed through a cylinder fltted with a cooling jacket, causing one gas to freeze on the walls of the cylinder. A set of scraper blades are provided in the interior of the cyllnder, and as the blades oscillate, the frozen gas is scraped to the bottom of the cylinder. Means are provided for the frozen material to pass into a heating chamber where it is vaporized and the product gas collected.

  18. Predicting flammability of gas mixtures containing volatile organic compounds

    International Nuclear Information System (INIS)

    Liekhus, K.

    1997-01-01

    One requirement regarding the transportation of transuranic (TRU) radioactive waste containers currently limits the total concentration of potentially flammable volatile organic compounds (VOCs) and flammable gases in the headspace of the waste container. Typical VOCs observed in the drums include aromatic hydrocarbons, ketones, alcohols, cyclohexane, as well as chlorinated hydrocarbons (alkanes and alkenes). Flammable gases, such as hydrogen and methane, may be generated in the containers by radiation-induced decomposition (radiolysis) of water and hydrocarbon waste forms. An experimental program was initiated to identify an accurate means for predicting flammability for gas mixtures containing one or more of the following species: hydrogen, carbon tetrachloride, 1,2-dichloroethane, toluene, or 2-butanone. The lower flammability limits (LFL) of gas mixtures containing equimolar quantity for each species were determined in a 19-liter laboratory flammability chamber using a strong spark ignition source. The group factor contribution method was determined to be more accurate than the LeChatelier method for estimating the LFL for these gas mixtures

  19. Iterative Mixture Component Pruning Algorithm for Gaussian Mixture PHD Filter

    Directory of Open Access Journals (Sweden)

    Xiaoxi Yan

    2014-01-01

    Full Text Available As far as the increasing number of mixture components in the Gaussian mixture PHD filter is concerned, an iterative mixture component pruning algorithm is proposed. The pruning algorithm is based on maximizing the posterior probability density of the mixture weights. The entropy distribution of the mixture weights is adopted as the prior distribution of mixture component parameters. The iterative update formulations of the mixture weights are derived by Lagrange multiplier and Lambert W function. Mixture components, whose weights become negative during iterative procedure, are pruned by setting corresponding mixture weights to zeros. In addition, multiple mixture components with similar parameters describing the same PHD peak can be merged into one mixture component in the algorithm. Simulation results show that the proposed iterative mixture component pruning algorithm is superior to the typical pruning algorithm based on thresholds.

  20. Pyrolysis of fibre residues with plastic contamination from a paper recycling mill: Energy recoveries

    International Nuclear Information System (INIS)

    Brown, Logan Jeremy; Collard, François-Xavier; Görgens, Johann

    2017-01-01

    Highlights: • Pyrolysis of fibre-plastics residues from paper recycling mill into fuel products. • Product with remarkable energy content up to 42.8 MJ/kg. • Influence of temperature on the product yields and fuel properties. • Effect of plastic composition on product properties. - Abstract: Pyrolysis is a promising technology for the production of marketable energy products from waste mixtures, as it decomposes heterogeneous material into homogenous fuel products. This research assessed the ability of slow pyrolysis to convert three waste streams, composed of fibre residues contaminated with different plastic mixtures, into char and tarry phase products at three different temperatures (300, 425 and 550 °C). The products were characterised in terms of mass yield, higher heating value (HHV) and gross energy conversion (EC). Significant amounts of hydrocarbon plastics in the feed materials increased the calorific values of the char (up to 32.9 MJ/kg) and tarry phase (up to 42.8 MJ/kg) products, comparable to high volatile bituminous A coal and diesel respectively. For all three waste streams converted at 300 °C, the majority of the energy in the feedstock was recovered in the char product (>80%), while deoxygenation of fibre component resulted in char with increased calorific value (up to 31.6 MJ/kg) being produced. Pyrolysis at 425 °C for two of the waste streams containing significant amounts of plastic produced both a valuable char and tarry phase, which resulted in an EC greater than 74%. Full conversion of plastic at 550 °C increased the tarry phase yield but dramatically decreased the char HHV. The influence of temperature on product yield and HHV was discussed based on the pyrolysis mechanisms and in relation to the plastic composition of the waste streams.

  1. Conversion of Pentose-Derived Furans into Hydrocarbon Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Moens, L.; Johnson, D. K.

    2012-01-01

    We are interested in the conversion of biomass-derived hemicellulose into hydrocarbon molecules that can be used in the formulation of 'drop-in' fuels such as gasoline (C5-12), diesel (C10-20) and jet fuel (C9-16). Our focus lies on the use of furfuryl alcohol as a starting material since that is already produced commercially from hemicellulose-derived pentoses. The steps required to convert the latter into hydrocarbons are 1) oligomerization of furfuryl alcohol to form dimers (C10) and trimers (C15), and 2) hydrotreatment of the dimers and trimers to produce a mixture of linear hydrocarbons with carbon chain lengths in the range of diesel and jet fuels. However, furfuryl alcohol readily polymerizes to form resins in the presence of an acid catalyst, and the exothermic oligomerization must be carried out under reaction control. This presentation will discuss our progress in the development of this sugar-to-hydrocarbon pathway.

  2. Formaldehyde, methanol and hydrocarbon emissions from methanol-fueled cars

    International Nuclear Information System (INIS)

    Williams, R.L.; Lipari, F.; Potter, R.A.

    1990-01-01

    Exhaust and evaporative emissions tests were conducted on several methanol- and gasoline-fueled vehicles. Separate samples for chromatographic analysis of formaldehyde, methanol, and individual hydrocarbons were collected in each of the three phases of the driving cycle and in each of the two portions of the evaporative emissions test. One vehicle, equipped with an experimental variable-fuel engine, was tested using methanol/gasoline fuel mixtures of 100, 85, 50, 15, and 0 percent methanol. Combustion-generated hydrocarbons were lowest using methanol fuel, and increased several-fold as the gasoline fraction was increased. Gasoline components in the exhaust increased from zero as the gasoline fraction of the fuel was increased. On the other hand, formaldehyde emissions were several times higher using methanol fuel than they were using gasoline. A dedicated methanol car and the variable-fuel car gave similar emissions patterns when they both were tested using methanol fuel. The organic-carbon composition of the exhaust was 85-90 percent methanol, 5-7 percent formaldehyde, and 3-9 percent hydrocarbons. Several cars that were tested using gasoline emitted similar distributions of hydrocarbons, even through the vehicles represented a broad range of current and developmental engine families and emissions control systems

  3. In situ observation of self-assembled hydrocarbon Fischer-Tropsch products on a cobalt catalyst

    NARCIS (Netherlands)

    Navarro, V.; Spronsen, M.A. van; Frenken, J.W.M.

    2016-01-01

    Fischer-Tropsch synthesis is a heterogeneous catalytic reaction that creates approximately 2% of the world's fuel. It involves the synthesis of linear hydrocarbon molecules from a gaseous mixture of carbon monoxide and hydrogen at high pressures (from a few to tens of bars) and high temperatures

  4. Calculation of Interfacial Tensions of Hydrocarbon-water Systems under Reservoir Conditions

    DEFF Research Database (Denmark)

    Zuo, You-Xiang; Stenby, Erling Halfdan

    1998-01-01

    Assuming that the number densities of each component in a mixture are linearly distributed across the interface between the coexisting vapor-liquid or liquid-liquid phases, we developed in this research work a linear-gradient-theory (LGT) model for computing the interfacial tension of hydrocarbon......-brine systems. The new model was tested on a number of hydrocarbon-water/brine mixtures and two crude oil-water systems under reservoir conditions. The results show good agreement between the predicted and the experimental interfacial tension data.......Assuming that the number densities of each component in a mixture are linearly distributed across the interface between the coexisting vapor-liquid or liquid-liquid phases, we developed in this research work a linear-gradient-theory (LGT) model for computing the interfacial tension of hydrocarbon-water...... mixtures on the basis of the SRK equation of state. With this model, it is unnecessary to solve the time-consuming density-profile equations of the gradient-theory model. In addition, a correlation was developed for representing the effect of electrolytes on the interfacial tension of hydrocarbon...

  5. Calculation of Interfacial Tensions of Hydrocarbon-water Systems under Reservoir Conditions

    DEFF Research Database (Denmark)

    Zuo, You-Xiang; Stenby, Erling Halfdan

    1998-01-01

    Assuming that the number densities of each component in a mixture are linearly distributed across the interface between the coexisting vapor-liquid or liquid-liquid phases, we developed in this research work a linear-gradient-theory (LGT) model for computing the interfacial tension of hydrocarbon......-brine systems. The new model was tested on a number of hydrocarbon-water/brine mixtures and two crude oil-water systems under reservoir conditions. The results show good agreement between the predicted and the experimental interfacial tension data.......Assuming that the number densities of each component in a mixture are linearly distributed across the interface between the coexisting vapor-liquid or liquid-liquid phases, we developed in this research work a linear-gradient-theory (LGT) model for computing the interfacial tension of hydrocarbon......-water mixtures on the basis of the SRK equation of state. With this model, it is unnecessary to solve the time-consuming density-profile equations of the gradient-theory model. In addition, a correlation was developed for representing the effect of electrolytes on the interfacial tension of hydrocarbon...

  6. Use of Residual Solids from Pulp and Paper Mills for Enhancing Strength and Durability of Ready-Mixed Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Tarun R. Naik; Yoon-moon Chun; Rudolph N. Kraus

    2003-09-18

    This research was conducted to establish mixture proportioning and production technologies for ready-mixed concrete containing pulp and paper mill residual solids and to study technical, economical, and performance benefits of using the residual solids in the concrete. Fibrous residuals generated from pulp and paper mills were used, and concrete mixture proportions and productions technologies were first optimized under controlled laboratory conditions. Based on the mixture proportions established in the laboratory, prototype field concrete mixtures were manufactured at a ready-mixed concrete plant. Afterward, a field construction demonstration was held to demonstrate the production and placement of structural-grade cold-weather-resistant concrete containing residual solids.

  7. Environmental Remediation: Removal of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nkansah, Marian Asantewah

    2012-11-15

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous persistent semi-volatile organic compounds. They are contaminants that are resistant to degradation and can remain in the environment for long periods due to their high degree of conjugation, and aromaticity. PAHs are present in industrial effluents as products of incomplete combustion processes of organic compounds. Petroleum, coal and shale oil contain extremely complex mixtures of these PAHs, and their transport and refining process can also result in the release of PAHs. It is therefore prudent that such effluents are treated before discharge into the environment. In this project, different approaches to the treatment of PAHs have been investigated. Hydrous pyrolysis has been explored as a potential technique for degrading PAHs in water using anthracene as a model compound. The experiments were performed under different conditions of temperature, substrate, redox systems and durations. The conditions include oxidising systems comprising pure water, hydrogen peroxide and Nafion-SiO2 solid catalyst in water; and reducing systems of formic acid and formic acid / Nafion-SiO2 / Pd-C catalysts to assess a range of reactivities. Products observed in GCMS analysis of the extract from the water phase include anthrone, anthraquinone, xanthone and multiple hydro-anthracene derivatives (Paper I). In addition a modified version of the Nafion-SiO2 solid catalyst in water oxidising system was tested; and reducing systems of formic acid and formic acid / Nafion-SiO2 / Pd-C catalysts were adopted for the conversion of a mixture of anthracene, fluorene and fluoranthene. The rate of conversion in the mixture was high as compared to that of only anthracene (Paper II). Also the use of LECA (Lightweight expanded clay aggregates) as an adsorbent (Paper III) for PAHs (phenanthrene, fluoranthene and pyrene) removal from water has been.(Author)

  8. Growth of hydrocarbon utilizing microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Mavinkurve, S.

    Two isolates from marine mud having broad spectrum hydrocarbon utilizing profile were identified as Arthrobacter simplex and Candida tropicalis.Both the organisms grew exponentially on crude oil. The cell yield of the organisms was influenced...

  9. Predicting hydrocarbon release from soil

    International Nuclear Information System (INIS)

    Poppendieck, D.; Loehr, R.C.

    2002-01-01

    'Full text:' The remediation of hazardous chemicals from soils can be a lengthy and costly process. As a result, recent regulatory initiatives have focused on risk-based corrective action (RBCA) approaches. Such approaches attempt to identify the amount of chemical that can be left at a site with contaminated soil and still be protective of human health and the environment. For hydrocarbons in soils to pose risk to human heath and the environment, the hydrocarbons must be released from the soil and accessible to microorganisms, earthworms, or other higher level organisms. The sorption of hydrocarbons to soil can reduce the availability of the hydrocarbon to receptors. Typically in soils and sediments, there is an initial fast release of a hydrocarbon from the soil to the aqueous phase followed by a slower release of the remaining hydrocarbon to the aqueous phase. The rate and extent of slow release can influence aqueous hydrocarbon concentrations and the fate and transport of hydrocarbons in the subsurface. Once the fast fraction of the chemical has been removed from the soil, the remaining fraction of a chemical may desorb at a rate that natural mechanisms can attenuate the released hydrocarbon. Hence, active remediation may be needed only until the fast fraction has been removed. However, the fast fraction is a soil and chemical specific parameter. This presentation will present a tier I type protocol that has been developed to quickly estimate the fraction of hydrocarbons that are readily released from the soil matrix to the aqueous phase. Previous research in our laboratory and elsewhere has used long-term desorption (four months) studies to determine the readily released fraction. This research shows that a single short-term (less than two weeks) batch extraction procedure provides a good estimate of the fast released fraction derived from long-term experiments. This procedure can be used as a tool to rapidly evaluate the release and bioavailability of

  10. LIQUID HYDROCARBON FUEL CELL DEVELOPMENT.

    Science.gov (United States)

    A compound anode consists of a reforming catalyst bed in direct contact with a palladium-silver fuel cell anode. The objective of this study was to...prove the feasibility of operating a compound anode fuel cell on a liquid hydrocarbon and to define the important parameters that influence cell...performance. Both reformer and fuel cell tests were conducted with various liquid hydrocarbon fuels. Included in this report is a description of the

  11. Hydrocarbon removal with constructed wetlands

    OpenAIRE

    Eke, Paul Emeka

    2008-01-01

    Wetlands have long played a significant role as natural purification systems, and have been effectively used to treat domestic, agricultural and industrial wastewater. However, very little is known about the biochemical processes involved, and the use of constructed treatment wetlands in the removal of petroleum aromatic hydrocarbons from produced and/or processed water. Wastewaters from the oil industry contain aromatic hydrocarbons such as benzene, toluene, ethylbenzene and x...

  12. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  13. Enhancement of in situ Remediation of Hydrocarbon Contaminated Soil

    Energy Technology Data Exchange (ETDEWEB)

    Palmroth, M.

    2006-07-01

    oxidation of contaminants and by integrating the process to biological treatment, in which the formed degradation products can be biodegraded. Phytoremediation was used to remove fresh and aged petroleum hydrocarbons from soil, and modified FentonAEs reaction combined with biodegradation was used to remove aged creosote oil from soil. The effects of hydrocarbon aging, different plant species and soil amendments on the removal efficiency were studied in phytoremediation experiments. Lab-scale experiments were made with fresh diesel fuel, and a field study was made with aged hydrocarbons deriving from diesel fuel and lubricants. The used plant species were pine, poplar, a grass mixture and a legume mixture. The experiments with modified Fenton's treatment were carried out in soil columns, to which concentrated H{sub 2}O{sub 2} was added simulating in situ injection. Iron was not added since the soil was rich in iron. After FentonAEs treatment, the soil was incubated in serum bottles to determine the effects on bioavailability of PAHs by modified FentonAEs oxidation and to simulate the potential of intrinsic remediation. In addition to hydrocarbon analyses, the effects of both methods on soil microbial activities and toxicity were determined. In the presence of white clover and green pea, pine or poplar, 89 to 98 % of diesel fuel was removed, whereas the presence of grasses did not increase diesel fuel removal compared to treatment without plants, where up to 86 % of diesel fuel was removed. When diesel was applied to the trees for a second time, reduction in one month was 9 to 25 % higher than what was achieved after first month of first application. During the four growing season study with soil contaminated with aged hydrocarbon contaminants, the presence of vegetation did not increase hydrocarbon removal in unfertilised soil. Vegetation cover was denser in amended soil than in unfertilised soil. The addition of compost or NPK fertiliser enhanced hydrocarbon removal

  14. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

    Venezuela is an important player in the energy world, because of its hydrocarbons reserves. The process for calculating oil and associated gas reserves is described bearing in mind that 90% of the gas reserves of Venezuela are associated to oil. Likewise, an analysis is made of the oil reserves figures from 1975 to 2003. Reference is also made to inconsistencies found by international experts and the explanations offered in this respect by the Ministry of Energy and Petroleum (MENPET) and Petroleos de Venezuela (PDVSA) regarding the changes that took place in the 1980s. In turn, Hubbert's Law is explained to determine peak production of conventional oil that a reservoir or field will reach, as well as its relationship with remaining reserves. Emphasis is placed on the interest of the United Nations on this topic. The reserves of associated gas are presented along with their relationship with the different crude oils that are produced and with injected gas, as well as with respect to the possible changes that would take place in the latter if oil reserves are revised. Some recommendations are submitted so that the MENPET starts preparing the pertinent policies ruling reserves. (auth)

  15. Sequestration of CO2 in Mixtures of Bauxite and Saline Waste Water

    Energy Technology Data Exchange (ETDEWEB)

    Dilmore, R.M.; Soong, Y.; Griffith, C.; Allen, D.E.; Hedges, S.W.; Frommell, E.A.; Fu, J.K.; Dobbs, C.L.; Zhu, C.

    2007-05-01

    Batch and semi-batch experiments were conducted to assess feasibility of utilizing mixtures of caustic bauxite residue slurry and produced brine from the Oriskany sandstone formation to sequester CO2 • Bauxite residue/brine mixture of 90/10 by volume sequestered 9.5 g of CO2 per liter of mixture (100 psig of CO2 at 20 ºC) • Carbon trapping is accomplished primarily through solubilization • Solution of the product mixture was neutralized following carbonation • Flow-through carbonation at 25 ºC and 1 atm. demonstrates that carbonation rates are acceptable for proposed process applications

  16. Some Results from Studies of Microwave Discharges in Liquid Heavy Hydrocarbons

    Science.gov (United States)

    Averin, K. A.; Lebedev, Yu. A.; Shakhatov, V. A.

    2018-01-01

    Some results from studies of microwave discharges in heavy hydrocarbons are presented. Microwave energy was introduced into liquid hydrocarbon via a coaxial line. The pressure above the liquid surface was equal to the atmospheric pressure. The discharge was ignited in a mixture of argon and hydrocarbon vapor. Argon was supplied through a channel in the central conductor of the coaxial line. The emission spectra of discharges in different liquid hydrocarbons were studied. It is shown that the emission spectra mainly consist of sequences of Swan bands, while radiation of other plasma components is on the noise level. Spectra of plasma emission are presented for discharges in liquid n-heptane, nefras, and C-9 oil used to produce chemical fibers. The rotational (gas) and vibrational temperatures are determined by processing the observed spectra.

  17. Two-step processing of oil shale to linear hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, O.L.; Ryzhov, A.N.; Latypova, D.Zh.; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry; Avakyan, T.A. [Gubkin Russian State University of Oil and Gas, Moscow (Russian Federation)

    2013-11-01

    Thermal and catalytic steam reforming of oil shale mined from Leningrad and Kashpir deposits was studied. Experiments were performed in fixed bed reactor by varying temperature and steam flow rate. Data obtained were approximated by empirical formulas containing some parameters calculated by least-squares method. Thus predicting amount of hydrogen, carbon monoxide and methane in producer gas is possible for given particular kind of oil shale, temperature and steam flow rate. Adding Ni catalyst enriches hydrogen and depletes CO content in effluent gas at low gasification temperatures. Modeling gas simulating steam reforming gases (H{sub 2}, CO, CO{sub 2}, and N{sub 2} mixture) was tested in hydrocarbon synthesis over Co-containing supported catalyst. Selectivity of CO conversion into C{sub 5+} hydrocarbons reaches 84% while selectivity to methane is 7%. Molecular weight distribution of synthesized alkanes obeys Anderson-Schulz-Flory equation and chain growth probability 0.84. (orig.)

  18. Degradation of ¹³C-labeled pyrene in soil-compost mixtures and fertilized soil.

    Science.gov (United States)

    Adam, Iris K U; Miltner, Anja; Kästner, Matthias

    2015-11-01

    Polycyclic aromatic hydrocarbons (PAH) are toxic pollutants widely distributed in the environment due to natural and anthropogenic processes. In order to mitigate tar oil contaminations with PAH, research on improving bioremediation approaches, which are sometimes inefficient, is needed. However, the knowledge on the fate of PAH-derived carbon and the microbial degraders in particular in compost-supplemented soils is still limited. Here we show the PAH carbon turnover mass balance in microcosms with soil-compost mixtures or in farmyard fertilized soil using [(13)C6]-pyrene as a model PAH. Complete pyrene degradation of 100 mg/kg of soil was observed in all supplemented microcosms within 3 to 5 months, and the residual (13)C was mainly found as carbon converted to microbial biomass. Long-term fertilization of soil with farmyard manure resulted in pyrene removal efficiency similar to compost addition, although with a much longer lag phase, higher mineralization, and lower carbon incorporation into the biomass. Organic amendments either as long-term manure fertilization or as compost amendment thus play a key role in increasing the PAH-degrading potential of the soil microbial community. Phospholipid fatty acid stable isotope probing (PLFA-SIP) was used to trace the carbon within the microbial population and the amount of biomass formed from pyrene degradation. The results demonstrate that complex microbial degrader consortia rather than the expected single key players are responsible for PAH degradation in organic-amended soil.

  19. New Insight into the Kinetics of Deep Liquid Hydrocarbon Cracking and Its Significance

    Directory of Open Access Journals (Sweden)

    Wenzhi Zhao

    2017-01-01

    Full Text Available The deep marine natural gas accumulations in China are mainly derived from the cracking of liquid hydrocarbons with different occurrence states. Besides accumulated oil in reservoir, the dispersed liquid hydrocarbon in and outside source also is important source for cracking gas generation or relayed gas generation in deep formations. In this study, nonisothermal gold tube pyrolysis and numerical calculations as well as geochemical analysis were conducted to ascertain the expulsion efficiency of source rocks and the kinetics for oil cracking. By determination of light liquid hydrocarbons and numerical calculations, it is concluded that the residual bitumen or hydrocarbons within source rocks can occupy about 50 wt.% of total oil generated at oil generation peak. This implies that considerable amounts of natural gas can be derived from residual hydrocarbon cracking and contribute significantly to the accumulation of shale gas. Based on pyrolysis experiments and kinetic calculations, we established a model for the cracking of oil and its different components. In addition, a quantitative gas generation model was also established to address the contribution of the cracking of residual oil and expulsed oil for natural gas accumulations in deep formations. These models may provide us with guidance for gas resource evaluation and future gas exploration in deep formations.

  20. Bioavailability assessment and environmental fate of polycyclic aromatic hydrocarbons in biostimulated creosote-contaminated soil.

    Science.gov (United States)

    Sabaté, Jordi; Viñas, Marc; Solanas, Anna M

    2006-06-01

    When hydrocarbon-contaminated soil is subjected to bioremediation technology, hydrocarbon depletion is typically marked by an initially rapid reduction rate. This rate decreases over time and frequently a residual concentration remains in the soil. This kinetic has been attributed primarily to the enrichment of more recalcitrant fractions, as well as to the lack of resting hydrocarbon bioavailability. Thus, at the end of the bioremediation process, a part of the residual hydrocarbon soil concentration represents the non-bioavailable fraction, which is difficult to degrade by microbial populations and which poses a minor hazard. Therefore, determination of the bioavailable fraction in a bioremediation project represents both an estimation of the maximum level of achievable biodegradation, as well as an additional indication of the environmental health hazard. In the present study, aged creosote-contaminated soil was subjected to biostimulation processes, and the bioavailable fraction for several target polycyclic aromatic hydrocarbons (PAHs) was calculated using a mild extraction with cyclodextrines. The amount of PAH extracted corresponded to the desorbing fraction and can be regarded as the bioavailable fraction. The non-desorbing fraction data obtained from this procedure were compared to the remaining PAH concentrations following bioremediation treatment of soil microcosms. These results permitted the establishment of a theoretical biodegradation limit based on the desorbing fraction. In addition, neither accumulation of intermediate metabolites, nor the formation of bound-residues or reduced acute toxicity was observed.

  1. Temperature-dependent mid-IR absorption spectra of gaseous hydrocarbons

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  2. Broadly tunable mid-infrared VECSEL for multiple components hydrocarbon gas sensing

    Science.gov (United States)

    Rey, J. M.; Fill, M.; Felder, F.; Sigrist, M. W.

    2014-12-01

    A new sensing platform to simultaneously identify and quantify volatile C1 to C4 alkanes in multi-component gas mixtures is presented. This setup is based on an optically pumped, broadly tunable mid-infrared vertical-external-cavity surface-emitting laser (VECSEL) developed for gas detection. The lead-chalcogenide VECSEL is the key component of the presented optical sensor. The potential of the proposed sensing setup is illustrated by experimental absorption spectra obtained from various mixtures of volatile hydrocarbons and water vapor. The sensor has a sub-ppm limit of detection for each targeted alkane in a hydrocarbon gas mixture even in the presence of a high water vapor content.

  3. Evaluación de las propiedades mecánicas de una mezcla densa en caliente modificada con un desecho de polietileno de baja densidad (PEBD Mechanical properties evaluation of a dense hot asphalt mixture modified with a residue of low density polyethylene (LDPE

    Directory of Open Access Journals (Sweden)

    Hugo Rondón Quintana

    2010-04-01

    Full Text Available El artículo presenta los resultados experimentales de ensayar una mezcla asfáltica densa en caliente tipo MDC-2 (acorde con las especificaciones del Instituto Nacional de Vías - INVIAS, 2007 modificada con un desecho de polietileno de baja densidad (PEBD. Para la evaluación del comportamiento de las mezclas asfálticas convencionales (sin aditivo y modificadas se realizaron ensayos Marshall, módulo dinámico, deformación permanente y resistencia a fatiga. Las mezclas fueron elaboradas con un cemento asfáltico (CA producido en Colombia tipo CA 80-100. Al CA con y sin aditivo se realizaron ensayos de caracterización de asfaltos como penetración y punto de ablandamiento. La modificación de las mezclas se realizó por vía húmeda. Las mezclas modificadas con desecho de PEBD experimentan mayor rigidez (bajo carga monotónica y cíclica y resistencia a la deformación permanente en comparación con las convencionales. Sin embargo la resistencia a fatiga de las mezclas convencionales disminuye cuando se adiciona PEBD al CA. Adicionalmente el CA modificado presenta mayor resistencia a la penetración, mayor punto de ablandamiento y menor susceptibilidad térmica a fluir que el convencional.Laboratory tests were used to evaluate the effect on the mechanical properties of a hot asphalt mix (MDC-2 as per INVIAS, 2007 specifications due to the addition by wet way of a residue of low density polyethylene (LDPE. The strength under monotonic load, resilient modulus, rutting and fatigue strength were evaluated. Asphalt cement (AC AC 80-100 was used from Colombia. The results show that the monotonic and cyclic mechanical strength evaluated were higher for the mixes modified with LDPE compared with mixtures with asphalts without additives. However, the mixes modified with LDPE undergo less fatigue strength. Additionally, characterization tests were conducted on asphalt cement with and without additive. The LDPE produces higher penetration resistance

  4. Chemometric comparison of polychlorinated biphenyl residues and toxicologically active polychlorinated biphenyl congeners in the eggs of Forster's Terns (Sterna fosteri)

    Science.gov (United States)

    Schwartz, Ted R.; Stalling, David L.

    1991-01-01

    The separation and characterization of complex mixtures of polychlorinated biphenyls (PCBs) is approached from the perspective of a problem in chemometrics. A technique for quantitative determination of PCB congeners is described as well as an enrichment technique designed to isolate only those congener residues which induce mixed aryl hydrocarbon hydroxylase enzyme activity. A congener-specific procedure is utilized for the determination of PCBs in whichn-alkyl trichloroacetates are used as retention index marker compounds. Retention indices are reproducible in the range of ±0.05 to ±0.7 depending on the specific congener. A laboratory data base system developed to aid in the editing and quantitation of data generated from capillary gas chromatography was employed to quantitate chromatographic data. Data base management was provided by computer programs written in VAX-DSM (Digital Standard MUMPS) for the VAX-DEC (Digital Equipment Corp.) family of computers.In the chemometric evaluation of these complex chromatographic profiles, data are viewed from a single analysis as a point in multi-dimensional space. Principal Components Analysis was used to obtain a representation of the data in a lower dimensional space. Two-and three-dimensional proections based on sample scores from the principal components models were used to visualize the behavior of Aroclor® mixtures. These models can be used to determine if new sample profiles may be represented by Aroclor profiles. Concentrations of individual congeners of a given chlorine substitution may be summed to form homologue concentration. However, the use of homologue concentrations in classification studies with environmental samples can lead to erroneous conclusions about sample similarity. Chemometric applications are discussed for evaluation of Aroclor mixture analysis and compositional description of environmental residues of PCBs in eggs of Forster's terns (Sterna fosteri) collected from colonies near Lake Poygan

  5. Verifying reciprocal relations for experimental diffusion coefficients in multicomponent mixtures

    DEFF Research Database (Denmark)

    Medvedev, Oleg; Shapiro, Alexander

    2003-01-01

    into Onsager coefficients and a subsequent symmetry check make it possible to evaluate different thermodynamic models with regard to their possibility of being used for prediction of the transport properties. We performed several checks of this kind for ternary mixtures of hydrocarbons and alcohols, where......The goal of the present study is to verify the agreement of the available data on diffusion in ternary mixtures with the theoretical requirement of linear non-equilibrium thermodynamics consisting in symmetry of the matrix of the phenomenological coefficients. A common set of measured diffusion...... diffusion coefficients into Onsager coefficients for a non-ideal mixture involves derivatives of the chemical potentials and, thus, should be based on a certain thermodynamic model (cubic equation of state (EoS), an activity coefficient model, etc.). Transformation of the Fickian diffusion coefficients...

  6. Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in sludge organic matter pools as a driving force of their fate during anaerobic digestion.

    Science.gov (United States)

    Aemig, Quentin; Chéron, Claire; Delgenès, Nadine; Jimenez, Julie; Houot, Sabine; Steyer, Jean-Philippe; Patureau, Dominique

    2016-02-01

    The fate of organic matter during anaerobic digestion of sewage sludge was studied in batch systems thanks to a sequential chemical fractionation of the particulate phase coupled to fluorescence spectroscopy. Polycyclic Aromatic Hydrocarbons (PAHs) distribution within the organic pools was characterized from their analysis in the residual fraction after each extraction. Both methods were combined to understand the link between PAHs presence in organic pools and their spectral characterization after extraction. Two batch systems (sludge and inoculum mixture) were set up to study the impact of PAHs spiking on their fate and distribution. The sequential fractionation allowed us to extract and characterize about 50% of total Chemical Oxygen Demand. Moreover, fluorescence spectroscopy helped us to understand the organic pools evolution: the most easily extracted pools composed of protein-like molecules were highly degraded meaning that chemical accessibility mimics the bioaccessibility to degrading microorganisms. PAHs were present in all pools of organic matter but native PAHs were mainly present in low accessible (hardly extractable) fractions and during anaerobic digestion, they accumulated in the non-accessible (non extractable) fraction. Spiked PAHs were more dissipated during anaerobic digestion since spiking made them present in more accessible fractions. During the anaerobic digestion, contrary to native PAHs, spiked ones relocated toward less accessible organic fractions confirming the ageing phenomenon. PCA analysis showed that, in spiked mixture, PAHs presence in organic pools is linked to both PAHs physical-chemical properties and quality/quantity of the associated organic pools. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Mixtures Estimation and Applications

    CERN Document Server

    Mengersen, Kerrie; Titterington, Mike

    2011-01-01

    This book uses the EM (expectation maximization) algorithm to simultaneously estimate the missing data and unknown parameter(s) associated with a data set. The parameters describe the component distributions of the mixture; the distributions may be continuous or discrete. The editors provide a complete account of the applications, mathematical structure and statistical analysis of finite mixture distributions along with MCMC computational methods, together with a range of detailed discussions covering the applications of the methods and features chapters from the leading experts on the subject

  8. Syntrophic biodegradation of hydrocarbon contaminants.

    Science.gov (United States)

    Gieg, Lisa M; Fowler, S Jane; Berdugo-Clavijo, Carolina

    2014-06-01

    Anaerobic environments are crucial to global carbon cycling wherein the microbial metabolism of organic matter occurs under a variety of redox conditions. In many anaerobic ecosystems, syntrophy plays a key role wherein microbial species must cooperate, essentially as a single catalytic unit, to metabolize substrates in a mutually beneficial manner. Hydrocarbon-contaminated environments such as groundwater aquifers are typically anaerobic, and often methanogenic. Syntrophic processes are needed to biodegrade hydrocarbons to methane, and recent studies suggest that syntrophic hydrocarbon metabolism can also occur in the presence of electron acceptors. The elucidation of key features of syntrophic processes in defined co-cultures has benefited greatly from advances in 'omics' based tools. Such tools, along with approaches like stable isotope probing, are now being used to monitor carbon flow within an increasing number of hydrocarbon-degrading consortia to pinpoint the key microbial players involved in the degradative pathways. The metagenomic sequencing of hydrocarbon-utilizing consortia should help to further identify key syntrophic features and define microbial interactions in these complex communities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Model-based experimental design for assessing effects of mixtures of chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Baas, Jan, E-mail: jan.baas@falw.vu.n [Vrije Universiteit of Amsterdam, Dept of Theoretical Biology, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Stefanowicz, Anna M., E-mail: anna.stefanowicz@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Klimek, Beata, E-mail: beata.klimek@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Laskowski, Ryszard, E-mail: ryszard.laskowski@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Kooijman, Sebastiaan A.L.M., E-mail: bas@bio.vu.n [Vrije Universiteit of Amsterdam, Dept of Theoretical Biology, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)

    2010-01-15

    We exposed flour beetles (Tribolium castaneum) to a mixture of four poly aromatic hydrocarbons (PAHs). The experimental setup was chosen such that the emphasis was on assessing partial effects. We interpreted the effects of the mixture by a process-based model, with a threshold concentration for effects on survival. The behavior of the threshold concentration was one of the key features of this research. We showed that the threshold concentration is shared by toxicants with the same mode of action, which gives a mechanistic explanation for the observation that toxic effects in mixtures may occur in concentration ranges where the individual components do not show effects. Our approach gives reliable predictions of partial effects on survival and allows for a reduction of experimental effort in assessing effects of mixtures, extrapolations to other mixtures, other points in time, or in a wider perspective to other organisms. - We show a mechanistic approach to assess effects of mixtures in low concentrations.

  10. Laboratory studies of the properties of in-situ burn residues: chemical composition of residues

    International Nuclear Information System (INIS)

    Trudel, B.K.; Buist, I.A.; Schatzke, D.; Aurand, D.

    1996-01-01

    The chemical composition of the residue from small-scale burns of thick oil slicks was studied. The objective was to describe the changes in chemical composition in oils burning on water and to determine how these changes were influenced by the condition of the burn. Small-scale test burns involved burning 40-cm diameter pools of oil on water. A range of eight oil types including seven crude oils and an automotive diesel were burned. For each oil, slicks of fresh oil of three different thicknesses were tested. Two of the oils were tested before and after weathering. Results showed that the composition of the residue differed greatly from the parent oil. Asphaltenes, high-boiling-point aromatics and resins remained concentrated in the burn residue. The burning of slicks appeared to remove most of the lower-molecular weight aromatic hydrocarbons which included the more toxic and more bioavailable components of the crude oils. 11 refs., 6 tabs

  11. utilization of ensiled metabolizable mixture of cassava peel and caged

    African Journals Online (AJOL)

    Toluwande

    2011-09-05

    Sep 5, 2011 ... component of farm animal feed has been documented [8, 9]. Therefore, this investigation was carried out to study the response of broiler chicken to fermented mixture of cassava peel and caged layers' manure (obtained as farm residue or waste) and fed as a component of energy source in the feed.

  12. I-optimal mixture designs

    OpenAIRE

    GOOS, Peter; JONES, Bradley; SYAFITRI, Utami

    2013-01-01

    In mixture experiments, the factors under study are proportions of the ingredients of a mixture. The special nature of the factors in a mixture experiment necessitates specific types of regression models, and specific types of experimental designs. Although mixture experiments usually are intended to predict the response(s) for all possible formulations of the mixture and to identify optimal proportions for each of the ingredients, little research has been done concerning their I-optimal desi...

  13. X-ray excited optical luminescence of polynuclear aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Oestreich, G.J.

    1979-05-01

    X-ray excited optical luminescence (XEOL) coupled with time resolved spectroscopy was employed to analyze polynuclear aromatic hydrocarbons (PAH) in n-alkane solvents at 10 K. A pulsed XEOL system which was designed around minicomputer control of a medical x-ray unit was developed. Computer software which generated variable width x-ray pulses, monitored timing reference pulses, controlled data acquisition, and analyzed data was written. Phosphorescence decay constants of several PAHs were determined. Synthetic mixtures of zone refined PAHs were prepared and time resolved with the pulsed XEOL technique. Analytical results obtained from the five component mixtures of PAHs at the part per million level were tabulated. Systematic improvements and further development of the pulsed XEOL method were considered.

  14. Mixtures of chemical pollutants at European legislation safety concentrations: how safe are they?

    DEFF Research Database (Denmark)

    Carvalho, Raquel N.; Arukwe, Augustine; Ait-Aissa, Selim

    2014-01-01

    , polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic...

  15. Modelling of phase equilibria of glycol ethers mixtures using an association model

    DEFF Research Database (Denmark)

    Garrido, Nuno M.; Folas, Georgios; Kontogeorgis, Georgios

    2008-01-01

    Vapor-liquid and liquid-liquid equilibria of glycol ethers (surfactant) mixtures with hydrocarbons, polar compounds and water are calculated using an association model, the Cubic-Plus-Association Equation of State. Parameters are estimated for several non-ionic surfactants of the polyoxyethylene...

  16. Study utilization of extractable petroleum hydrocarbons biodegradation waste as the main material for making solid fuels

    Science.gov (United States)

    Hendrianie, Nuniek; Juliastuti, Sri Rachmania; Ar-rosyidah, Fanny Husna; Rochman, Hilal Abdur

    2017-05-01

    Nowadays the existence of energy sources of oil and was limited. Therefore, it was important to searching for new innovations of renewable energy sources by utilizing the waste into a source of energy. On the other hand, the process of extractable petroleum hydrocarbons biodegradation generated sludge that had calorific value and untapped. Because of the need for alternative sources of energy innovation with the concept of zero waste and the fuel potential from extractable petroleum hydrocarbons biodegradation waste, so it was necessary to study the use of extractable petroleum hydrocarbons biodegradation waste as the main material for making solid fuel. In addition, sawdust is a waste that had a great quantities and also had a high calorific value to be mixed with extractable petroleum hydrocarbons biodegradation waste. The purpose of this study was to determine the characteristics of the extractable petroleum hydrocarbons biodegradation waste and to determine the potential and a combination of a mixture of extractable petroleum hydrocarbons biodegradation waste and sawdust which has the best calorific value. The variables of this study was the composition of the waste and sawdust as follows 1:1; 1:3; and 3:1 (mass of sawdust : mass of waste) and time of sawdust carbonization was 10, 15 and 20 minutes. Sawdust was carbonized to get the high heating value. The characteristic of main material and fuel analysis performed with proximate analysis. While the calorific value analysis was performed with a bomb calorimeter. From the research, it was known that extractable petroleum hydrocarbons biodegradation waste had a moisture content of 3.06%; volatile matter 19.98%; ash content of 0.56%; fixed carbon content of 76.4% and a calorific value of 717 cal/gram. And a mixture that had the highest calorific value (4286.5 cal/gram) achieved in comparison sawdust : waste (3:1) by carbonization of sawdust for 20 minutes.

  17. Temperature-dependent mid-IR absorption spectra of gaseous hydrocarbons

    Science.gov (United States)

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

    2007-10-01

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

  18. New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes

    International Nuclear Information System (INIS)

    Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X.; Wang, S.

    2014-01-01

    Hydrocarbons have high thermodynamic performances, belong to the group of natural refrigerants, and they are the main components in mixture Joule-Thomson low temperature refrigerators (MJTR). New evaluations of nucleate boiling contribution and nucleate boiling suppression factor in flow boiling heat transfer have been proposed for hydrocarbons. A forced convection heat transfer enhancement factor correlation incorporating liquid velocity has also been proposed. In addition, the comparisons of the new model and other classic models were made to evaluate its accuracy in heat transfer prediction

  19. Oil-shale gasification for obtaining of gas for synthesis of aliphatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Strizhakova, Yu. [Samara State Univ. (Russian Federation); Avakyan, T.; Lapidus, A.L. [I.M. Gubkin Russian State Univ. of Oil and Gas, Moscow (Russian Federation)

    2011-07-01

    Nowadays, the problem of qualified usage of solid fossil fuels as raw materials for obtaining of motor fuels and chemical products is becoming increasingly important. Gasification with further processing of gaseous products is a one of possible ways of their use. Production of synthesis gas with H{sub 2}/CO ratio equal 2 is possible by gasification of oil-shale. This gas is converted into the mixture of hydrocarbons over cobalt catalyst at temperature from 160 to 210 C at atmospheric pressure. The hydrocarbons can be used as motor, including diesel, or reactive fuel. (orig.)

  20. Biodegradation of hydrocarbon remnants by biological activators in the presence of INIPOL EAP 22

    International Nuclear Information System (INIS)

    Bergueiro, J. R.; Luengo, M. C.; Socias, S.; Perez, F.; Laseca, D.; Perez-Navarro, A.; Morales, N.

    1997-01-01

    Degradation of highly weathered hydrocarbon mixtures resulting from an accidental spill in an oil refinery was studied, using BIOLEN IG 30 as the degradation agent microorganism, and INIPOL EAP 22 as the biodegradation accelerator. Results show that BIOLEN IG 30 is able to degrade highly weathered hydrocarbons at 20 degrees C, in the presence of INIPOL EAP 22. BIOLEN IG 30 is also able to degrade the total ionic and anionic dispersants in FINASOL OSR 51 (a dispersant), even in the absence of a biodegradation accelerator. 10 refs., 7 tabs., 3 figs

  1. Thermodiffusion in Multicomponent Mixtures Thermodynamic, Algebraic, and Neuro-Computing Models

    CERN Document Server

    Srinivasan, Seshasai

    2013-01-01

    Thermodiffusion in Multicomponent Mixtures presents the computational approaches that are employed in the study of thermodiffusion in various types of mixtures, namely, hydrocarbons, polymers, water-alcohol, molten metals, and so forth. We present a detailed formalism of these methods that are based on non-equilibrium thermodynamics or algebraic correlations or principles of the artificial neural network. The book will serve as single complete reference to understand the theoretical derivations of thermodiffusion models and its application to different types of multi-component mixtures. An exhaustive discussion of these is used to give a complete perspective of the principles and the key factors that govern the thermodiffusion process.

  2. Sugarcane rice residue biochars and their applications

    Science.gov (United States)

    Wang, J. J.

    2014-12-01

    Sugarcane production in U.S. involves either pre-harvest burning or after-harvest burning of the residue. Approximately 70-90% of the dry matter of harvested sugarcane trash is lost through open field burning. This practice has caused considerable concerns over air quality and soil sustainability. We propose an alternative conservation approach to convert the sugarcane residue to biochar and used as soil amendment to conserve carbon and potentially improve soil fertility. In this study, fundamental properties of biochars made from sugarcane residue along with rice residues were tested for agronomic and environmental benefits. Sugarcane and rice harvest residues and milling processing byproducts bagasse and rice husk were converted to biochars at different pyrolysis temperatures and characterized. In general, sugarcane leave biochar contained more P, K, Ca and Mg than sugarcane bagasse biochar. Rice straw biochar had more S, K Ca but less P than rice husk biochar. Both biochars had higher available fraction of total P than that of total K. Sugarcane leave biochar converted at 450oC was dominated with various lignin derived phenols as well as non-specific aromatic compounds whereas bagasse biochar was with both lignin derived phenol and poly aromatic hydrocarbon (PAH). Rice straw char was dominated with non-specific aromatic compounds. At 750oC, charred material was dominated with aromatic ethers while losing the aromatic C=C structures. These molecular and surface property differences likely contributed to the difference in water holding capacities observed with these biochars. On the other hand, rice straw biochars produced at different pyrolysis temperatures had no significant effect on rice germination. Soils treated with sugarcane leave/trash biochar significantly enhanced sugarcane growth especially the root length. Treating soil with either sugarcane leave or bagasse char also enhanced soil adsorption capacity of atrazine; a common herbicide used in sugarcane

  3. Federal Environmental Regulations Impacting Hydrocarbon Exploration, Drilling, and Production Operations

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Herbert B.; Johnson, William I.

    1999-04-27

    Waste handling and disposal from hydrocarbon exploration, drilling, and production are regulated by the US Environmental Protection Agency (EPA) through federal and state regulations and/or through implementation of federal regulations. Some wastes generated in these operations are exempt under the Resource Conservation and Recovery Act (RCRA) but are not exempt under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), Superfund Amendments and Reauthorization Act (SARA), and other federal environmental laws. Exempt wastes remain exempt only if they are not mixed with hazardous wastes or hazardous substances. Once mixture occurs, the waste must be disposed as a hazardous material in an approved hazardous waste disposal facility. Before the Clean Air Act as amended in 1990, air emissions from production, storage, steam generation, and compression facilities associated with hydrocarbon exploration, drilling, and production industry were not regulated. A critical proposed regulatory change which will significantly effect Class II injection wells for disposal of produced brine and injection for enhanced oil recovery is imminent. Federal regulations affecting hydrocarbon exploration, drilling and production, proposed EPA regulatory changes, and a recent significant US Court of Appeals decision are covered in this report. It appears that this industry will, in the future, fall under more stringent environmental regulations leading to increased costs for operators.

  4. Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

    KAUST Repository

    Jjunju, Fred Paul Mark

    2013-07-01

    Characterization of the various petroleum constituents (hydronaphthalenes, thiophenes, alkyl substituted benzenes, pyridines, fluorenes, and polycyclic aromatic hydrocarbons) was achieved under ambient conditions without sample preparation by desorption atmospheric pressure chemical ionization (DAPCI). Conditions were chosen for the DAPCI experiments to control whether ionization was by proton or electron transfer. The protonated molecule [M+H]+ and the hydride abstracted [MH]+ form were observed when using an inert gas, typically nitrogen, to direct a lightly ionized plasma generated by corona discharge onto the sample surface in air. The abundant water cluster ions generated in this experiment react with condensed-phase functionalized hydrocarbon model compounds and their mixtures at or near the sample surface. On the other hand, when naphthalene was doped into the DAPCI gas stream, its radical cation served as a charge exchange reagent, yielding molecular radical cations (M+) of the hydrocarbons. This mode of sample ionization provided mass spectra with better signal/noise ratios and without unwanted side-products. It also extended the applicability of DAPCI to petroleum constituents which could not be analyzed through proton transfer (e.g., higher molecular PAHs such as chrysene). The thermochemistry governing the individual ionization processes is discussed and a desorption/ionization mechanism is inferred. © 2012 Elsevier B.V.

  5. Effective viscosity of confined hydrocarbons

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V.N.; Persson, B.N.J.

    2012-01-01

    We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity ηeff for nanometer-thin films depends linearly on the logarithm of the shear rate: log ηeff=C-nlog γ̇, where...

  6. Formulating liquid hydrocarbon fuels for SOFCs

    Science.gov (United States)

    Saunders, G. J.; Preece, J.; Kendall, K.

    The injection of liquid hydrocarbons directly into an SOFC system is considered for application to hybrid vehicles. The main problem is carbon deposition on the nickel anode when molecules such as ethanol or iso-octane are injected directly. Such carbon deposition has been studied using a microtubular SOFC with a mass spectrometer analysing the product gases to investigate the reaction sequence and also to investigate the deposited carbon by temperature programmed oxidation (TPO). The results show that only two liquids could be injected directly onto nickel cermet anodes without serious carbon blockage, methanol and methanoic acid. Even then, TPO experiments revealed deposition of small amounts of carbon which could be prevented by small additions of air or water to the fuel. Gasoline type molecules like iso-octane killed the SOFC in about 30 min operation, with about 90% of the molecular carbon being deposited on the nickel cermet anode. However, certain mixtures of iso-octane, water, alcohol and surfactant were found to produce beneficial results with remarkably low carbon deposition, less than 1% of the molecular carbon appearing on the anode. Such formulations had octane numbers appropriate to internal combustion engine operation.

  7. Porphyrins Fused with Unactivated Polycyclic Aromatic Hydrocarbons

    KAUST Repository

    Diev, Vyacheslav V.

    2012-01-06

    A systematic study of the preparation of porphyrins with extended conjugation by meso,β-fusion with polycyclic aromatic hydrocarbons (PAHs) is reported. The meso-positions of 5,15-unsubstituted porphyrins were readily functionalized with PAHs. Ring fusion using standard Scholl reaction conditions (FeCl 3, dichloromethane) occurs for perylene-substituted porphyrins to give a porphyrin β,meso annulated with perylene rings (0.7:1 ratio of syn and anti isomers). The naphthalene, pyrene, and coronene derivatives do not react under Scholl conditions but are fused using thermal cyclodehydrogenation at high temperatures, giving mixtures of syn and anti isomers of the meso,β-fused porphyrins. For pyrenyl-substituted porphyrins, a thermal method gives synthetically acceptable yields (>30%). Absorption spectra of the fused porphyrins undergo a progressive bathochromic shift in a series of naphthyl (λ max = 730 nm), coronenyl (λ max = 780 nm), pyrenyl (λ max = 815 nm), and perylenyl (λ max = 900 nm) annulated porphyrins. Despite being conjugated with unsubstituted fused PAHs, the β,meso-fused porphyrins are more soluble and processable than the parent nonfused precursors. Pyrenyl-fused porphyrins exhibit strong fluorescence in the near-infrared (NIR) spectral region, with a progressive improvement in luminescent efficiency (up to 13% with λ max = 829 nm) with increasing degree of fusion. Fused pyrenyl-porphyrins have been used as broadband absorption donor materials in photovoltaic cells, leading to devices that show comparatively high photovoltaic efficiencies. © 2011 American Chemical Society.

  8. Study of volumetric properties (PVT) of mixtures made of light hydrocarbons (C1-C4), carbon dioxide and hydrogen sulfide - Experimental measurements through a vibrating tube densimeter and modelling; Etude des proprietes volumetriques (PVT) d'hydrocarbures legers (C1-C4), du dioxyde de carbone et de l'hydrogene sulfure. Mesures par densimetrie a tube vibrant et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Rivollet, F.

    2005-12-15

    Various pollutant contents (i.e. carbon dioxide, hydrogen sulphide or other sulphur products) are found in produced oils. These latter must undergo a number of transformations and purifications. The design and dimensioning of the corresponding units can well be optimized only if one has reliable and accurate data about phase equilibria and volumetric properties and of course reliable and accurate modeling. This work was devoted partly to measurements of volumetric properties on three binary mixtures (ethane - hydrogen sulphide, ethane - propane and carbon dioxide - hydrogen sulphide). These measurements were carried out using equipment, comprising a vibrating tube densimeter (Paar, model DMA 512 P), which was especially designed and built for this work. The binary mixtures were studied in the 253 to 363 K temperature range from at pressures up to either 20 or 40 MPa. Two calibration methods of the vibrating tube were used: the FPMC method (Forced Path Mechanical Calibration) described in the literature and an original method containing neural network, developed herein. The study undertaken about the modeling of volumetric properties made it possible to highlight the inadequacy of the traditional use of cubic equations of state to represent simultaneously volumetric properties and phase equilibria. Among the equations of state investigated, a close attention however was paid to cubic equations of state because of their very great use in the oil field. A new tool was found to adapt cubic equations of state to the simultaneous and satisfactory representation of volumetric properties and phase equilibria. It concerns the coupling of the cubic Redlich-Kwong-Soave equation of state with volume correction through a neural network. This new model was tested successfully, it makes it possible to benefit from the existing work of representation of phase equilibria (mixing rules and interaction coefficients) while improving calculation of the volumetric data.

  9. Co-acclimation of bacterial communities under stresses of hydrocarbons with different structures

    Science.gov (United States)

    Wang, Hui; Wang, Bin; Dong, Wenwen; Hu, Xiaoke

    2016-01-01

    Crude oil is a complex mixture of hydrocarbons with different structures; its components vary in bioavailability and toxicity. It is important to understand how bacterial communities response to different hydrocarbons and their co-acclimation in the process of degradation. In this study, microcosms with the addition of structurally different hydrocarbons were setup to investigate the successions of bacterial communities and the interactions between different bacterial taxa. Hydrocarbons were effectively degraded in all microcosms after 40 days. High-throughput sequencing offered a great quantity of data for analyzing successions of bacterial communities. The results indicated that the bacterial communities responded dramatically different to various hydrocarbons. KEGG database and PICRUSt were applied to predict functions of individual bacterial taxa and networks were constructed to analyze co-acclimations between functional bacterial groups. Almost all functional genes catalyzing degradation of different hydrocarbons were predicted in bacterial communities. Most of bacterial taxa were believed to conduct biodegradation processes via interactions with each other. This study addressed a few investigated area of bacterial community responses to structurally different organic pollutants and their co-acclimation and interactions in the process of biodegradation. The study could provide useful information to guide the bioremediation of crude oil pollution. PMID:27698451

  10. Mixture based outlier filtration

    Czech Academy of Sciences Publication Activity Database

    Pecherková, Pavla; Nagy, Ivan

    2006-01-01

    Roč. 46, č. 2 (2006), s. 30-35 ISSN 1210-2709 R&D Projects: GA MŠk 1M0572; GA MDS 1F43A/003/120 Institutional research plan: CEZ:AV0Z10750506 Keywords : data filtration * system modelling * mixture models Subject RIV: BD - Theory of Information http://library.utia.cas.cz/prace/20060165.pdf

  11. Mechanical reliability analysis of tubes intended for hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nahal, Mourad; Khelif, Rabia [Badji Mokhtar University, Annaba (Algeria)

    2013-02-15

    Reliability analysis constitutes an essential phase in any study concerning reliability. Many industrialists evaluate and improve the reliability of their products during the development cycle - from design to startup (design, manufacture, and exploitation) - to develop their knowledge on cost/reliability ratio and to control sources of failure. In this study, we obtain results for hardness, tensile, and hydrostatic tests carried out on steel tubes for transporting hydrocarbons followed by statistical analysis. Results obtained allow us to conduct a reliability study based on resistance request. Thus, index of reliability is calculated and the importance of the variables related to the tube is presented. Reliability-based assessment of residual stress effects is applied to underground pipelines under a roadway, with and without active corrosion. Residual stress has been found to greatly increase probability of failure, especially in the early stages of pipe lifetime.

  12. Small angle neutron scattering study on short and long chain phosphatidylcholine mixture in trehalose solution

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiroshi [Department of Physics, Gunma University, Maebashi, Gunma (Japan)

    2001-03-01

    Trehalose protects cells and proteins against various stresses due to low temperatures or dryness. In order to clarify the molecular mechanism of cryoprotective function of trehalose, we have studied the interaction between trehalose and phosphatidylcholine (PC) which is a main lipid component of cell membranes. In this study, the structural change of a binary PC mixture by the presence of trehalose was investigated by means of small angle neutron scattering. The PC binary mixture studied contains dihexanoyl-PC (diC{sub 6}PC) and dihexadecy-PC (DHPC). The former has short hydrocarbon chains and the latter has long hydrocarbon chains. The scattering profiles from the DHPC/diC{sub 6}PC mixture were changed, depending on trehalose concentrations. This change can be interpreted as suggesting that the presence of trehalose reduces the interfacial area between water and PCs. (author)

  13. Integrating biodegradation and electroosmosis for the enhanced removal of polycyclic aromatic hydrocarbons from creosote-polluted soils.

    Science.gov (United States)

    Niqui-Arroyo, José-Luis; Ortega-Calvo, José-Julio

    2007-01-01

    This paper presents a hybrid technology of soil remediation based on the integration of biodegradation and electroosmosis. We employed soils with different texture (clay soil and loamy sand) containing a mixture of polycyclic aromatic hydrocarbons (PAH) present in creosote, and inoculation with a representative soil bacterium able to degrade fluorene, phenanthrene, fluoranthene, pyrene, anthracene, and benzo[a]pyrene. Two different modes of treatment were prospected: (i) inducing in soil the simultaneous occurrence of biodegradation and electroosmosis in the presence of a biodegradable surfactant, and (ii) treating the soils sequentially with electrokinetics and bioremediation. Losses of PAH due to simultaneous biodegradation and electroosmosis (induced by a continuous electric field) were significantly higher than in control cells that contained the surfactant but no biological activity or no current. The method was especially successful with loamy sand. For example, benzo[a]pyrene decreased its concentration by 50% after 7 d, whereas 22 and 17% of the compound had disappeared as a result of electrokinetic flushing and bioremediation alone, respectively. The use of periodical changes in polarity and current pulses increased by 16% in the removal of total PAH and in up to 30% of specific compounds, including benzo[a]pyrene. With the aim of reaching lower residual levels through bioremediation, an electrokinetic pretreatment was also evaluated as a way to mobilize the less bioaccessible fraction of PAH. Residual concentrations of total biodegradable PAH, remaining after bioremediation in soil slurries, were twofold lower in electrokinetically pretreated soils than in untreated soils. The results indicate that biodegradation and electroosmosis can be successfully integrated to promote the removal of PAH from soil.

  14. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

    2013-03-01

    This technology pathway case investigates the upgrading of woody biomass derived synthesis gas (syngas) to hydrocarbon biofuels. While this specific discussion focuses on the conversion of syngas via a methanol intermediate to hydrocarbon blendstocks, there are a number of alternative conversion routes for production of hydrocarbons through a wide array of intermediates from syngas. Future work will also consider the variations to this pathway to determine the most economically viable and lowest risk conversion route. Technical barriers and key research needs have been identified that should be pursued for the syngas-to-hydrocarbon pathway to be competitive with petroleum-derived gasoline-, diesel- and jet-range hydrocarbon blendstocks.

  15. Methods for deactivating copper in hydrocarbon fluids

    Energy Technology Data Exchange (ETDEWEB)

    Roling, P.V.; Niu, J.H.Y.; Reid, D.K.

    1988-06-07

    This patent describes a method of inhibiting the formation of free radicals in a hydrocarbon medium by deactivating a metallic species selected from the group consisting of Cu, Fe, CO, Ni, V, Cr, and Mn contained in the hydrocarbon medium, wherein in the absence of the deactivating the metallic species would initiate formation of free radicals in the hydrocarbon medium in turn leading to decomposition of the hydrocarbon medium. The method comprises inhibiting the formation of free radicals by adding to the hydrocarbon medium, which already contains the metal species, an effective amount to deactivate the metallic species of an effective Mannich product formed by reaction of reactants (A), (B), and (C).

  16. The use of gaseous fuels mixtures for SI engines propulsion

    Science.gov (United States)

    Flekiewicz, M.; Kubica, G.

    2016-09-01

    Paper presents results of SI engine tests, carried on for different gaseous fuels. Carried out analysis made it possible to define correlation between fuel composition and engine operating parameters. Tests covered various gaseous mixtures: of methane and hydrogen and LPG with DME featuring different shares. The first group, considered as low carbon content fuels can be characterized by low CO2 emissions. Flammability of hydrogen added in those mixtures realizes the function of combustion process activator. That is why hydrogen addition improves the energy conversion by about 3%. The second group of fuels is constituted by LPG and DME mixtures. DME mixes perfectly with LPG, and differently than in case of other hydrocarbon fuels consists also of oxygen makes the stoichiometric mixture less oxygen demanding. In case of this fuel an improvement in engine volumetric and overall engine efficiency has been noticed, when compared to LPG. For the 11% DME share in the mixture an improvement of 2% in the efficiency has been noticed. During the tests standard CNG/LPG feeding systems have been used, what underlines utility value of the research. The stand tests results have been followed by combustion process simulation including exhaust forming and charge exchange.

  17. Separating Underdetermined Convolutive Speech Mixtures

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Wang, DeLiang; Larsen, Jan

    2006-01-01

    a method for underdetermined blind source separation of convolutive mixtures. The proposed framework is applicable for separation of instantaneous as well as convolutive speech mixtures. It is possible to iteratively extract each speech signal from the mixture by combining blind source separation...

  18. Mixtures of truncated basis functions

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre; Rumí, Rafael

    2012-01-01

    In this paper we propose a framework, called mixtures of truncated basis functions (MoTBFs), for representing general hybrid Bayesian networks. The proposed framework generalizes both the mixture of truncated exponentials (MTEs) framework and the mixture of polynomials (MoPs) framework. Similar...

  19. The natural petroleum hydrocarbon background in subtidal sediments of Prince William Sound, Alaska

    International Nuclear Information System (INIS)

    Page, D.S.; Boehm, P.D.; Douglas, G.S.; Bence, A.E.

    1993-01-01

    A natural regional petroleum hydrocarbon background has been identified in the subtidal sediments of Prince William Sound. This hydrocarbon background, which is readily distinguished from Exxon Valdez spill oil by advanced hydrocarbon fingerprinting methods, is derived from petroleum seeps in the eastern Gulf of Alaska. The Alaska Coastal Current carries fine-grained sediments and associated hydrocarbons into the Sound where they are deposited. This activity has been ongoing for the past 160 years and probably for many thousands of years. Results of a stratified random study (SRS) of nearshore subtidal sediments conducted in 1990 and a fixed site study conducted in 1989, 1990, and 1991 show that this background is significant even in shallow water (3--30 m) and that it is a general phenomenon of the Sound. Polycyclic aromatic hydrocarbon (PAH) mixing model calculations show that, where present in nearshore subtidal sediments, residues of Exxon Valdez spill oil form a small increment on the natural background. The recognition of pre-existing natural and anthropogenic hydrocarbon backgrounds in a spill area is a fundamentally important component of natural resource damage assessment

  20. Analysis of petroleum hydrocarbons in soil from view of bioremediation process

    International Nuclear Information System (INIS)

    Mracnova, R.; Sojak, L.; Kubinec, R.; Kraus, A.; Eszenyiova, A.; Ostrovsky, I.

    2002-01-01

    The pollution of the environment by petroleum hydrocarbons is the most often pollution of them all. Nevertheless, hydrocarbons present in environment can be not only of petroleum or anthropogenic origin, but of biogenic as well. Typically the hydrocarbons are presented in the environment as very complex mixtures of individual compounds with very different chemical structure, wide range of the boiling points (∼800 0 C) as well as with the wide range of the number of carbon atoms. Immediately they are spread in any environmental matrix the complex physical, chemical and biochemical reactions start. A lot of methods have been developed and new are permanently in progress for the monitoring and control of petroleum hydrocarbons contamination and/or soils bioremediation. Generally, all methods by whose the hydrocarbons contaminants are determined in GC-FID system do not satisfied recommendations for enough accurate and precise results. Hyphenation of capillary gas chromatography and mass selective detector operated in the selective ion monitoring mode essentially allows detailed specification of non-polar extractable hydrocarbons. Isoprenoid alkanes, alkylhomologues of aromatic hydrocarbons and polycyclic alkanes hopanes-like were investigated as markers for recognition of petroleum and biogenic contamination. C 30 17α(H)21β(H)-hopane (C 30 -hopane) seems to be a suitable marker to identify hydrocarbons origin, to determine composting rates for nonpolar extractable compounds and to calculate real content of non-polar extractable compounds in final composting status on the assumption that the contamination is of mineral oil type. This is the survey into the results obtained in this field published in the literature as well as reached in our laboratory. (author)

  1. Upgrading of syngas hydrotreated fractionated oxidized bio-oil to transportation grade hydrocarbons

    International Nuclear Information System (INIS)

    Luo, Yan; Hassan, El Barbary; Guda, Vamshi; Wijayapala, Rangana; Steele, Philip H.

    2016-01-01

    Highlights: • Hydrotreating of fractionated oxidized bio-oil with syngas was feasible. • Hydrocarbon properties were similar with all syngas H 2 /CO molar ratios except viscosity. • Syngas with H 2 /CO molar ratio of (4:6) produced the highest hydrocarbon yield. • The produced hydrocarbons were in the range of gasoline, jet fuel and diesel boiling points. - Abstract: Fast pyrolysis bio-oils have the potential to replace a part of transportation fuels obtained from fossil. Bio-oil can be successfully upgraded into stable hydrocarbons (gasoline, jet fuel and diesel) through a two-stage hydrodeoxygenation process. Consumption large amount of expensive hydrogen during this process is the major hurdle for commercialization of this technology. Applying syngas in the hydrotreating step can significantly reduce the cost of the whole process and make it competitive. In this study, four different models of syngas with different H 2 concentrations (H 2 /CO molar ratios = 2:8, 4:6, 6:4 and 8:2) were used for the 1st-stage hydrotreating step of oxidized fractionated bio-oil (OFB). The 2nd-stage hydrocracking step was performed on the produced organic liquid products (OLPs) by using pure H 2 gas. The effect of syngas H 2 concentrations on the yields and properties of OLPs and the 2nd-stage hydrocarbons (HCs) was investigated. Physical and chemical properties of the 2nd-stage hydrocarbons were similar regardless syngas H 2 content, with the exception of the viscosity. Syngas with H 2 /CO molar ratio of 4:6 gave significantly highest HCs yield (24.8 wt.%) based on the OFB. Simulated distillation analysis proved that all 2nd-stage hydrocarbons were mixture from a wide range boiling point fuels. These results also indicated that the successful 1st-stage syngas hydrotreating step was having the potential to produce different hydrocarbons.

  2. Direct assessment of cumulative aryl hydrocarbon receptor agonist activity in sera from experimentally exposed mice and environmentally exposed humans

    DEFF Research Database (Denmark)

    Schlezinger, Jennifer J; Bernard, Pamela L; Haas, Amelia

    2010-01-01

    BACKGROUND: Aryl hydrocarbon receptor (AhR) ligands adversely affect many biological processes. However, assessment of the significance of human exposures is hampered by an incomplete understanding of how complex mixtures affect AhR activation/inactivation. OBJECTIVES: These studies used biologic...

  3. Field trapping of subsurface vapor phase petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Moyer, E.E.; Ostendorf, D.W.; Kampbell, D.H.; Xie, Y.

    1994-01-01

    Soil gas samples from intact soil cores were collected on adsorbents at a field site, then thermally desorbed and analyzed by laboratory gas chromatography (GC). Vertical concentration profiles of predominant vapor phase petroleum hydrocarbons under ambient conditions were obtained for the zone directly above the capillary fringe. Water and residual phase weathered aviation gasoline were present in this region of the profile. The sampling, trapping, and GC methodology was effective in most respects. Reproducibility, trapping, and desorption efficiency were generally satisfactory, and different sorbent tubes gave similar results. A minor shortcoming of the method occurred with the most volatile compound, 2,3-dimethylbutane, which was poorly retained during several weeks of storage time and was also poorly desorbed. Vapor phase concentrations of predominant hydrocarbon compounds all increased with depth at one sampling location. At a more highly contaminated location, concentrations of highly volatile compounds increased with depth while concentrations of less volatile compounds remained constant or decreased, possibly indicating distillation effects. Scatter in the data was attributed to heterogeneities in water and residual phase distribution

  4. Separation of C2 hydrocarbons from methane in a microporous metal-organic framework

    Science.gov (United States)

    Tang, Fu-Shun; Lin, Rui-Biao; Lin, Rong-Guang; Zhao, John Cong-Gui; Chen, Banglin

    2018-02-01

    The recovery of C2 hydrocarbons including acetylene, ethylene and ethane is challenging but important for natural gas upgrading. The separation of C2 hydrocarbons over methane was demonstrated here by using a microporous metal-organic framework [Zn3(OH)2(SDB)2] (H2SDB = 4,4'-sulfonyldibenzoic acid) consisting narrow one-dimensional pore channels. Gas sorption experiments revealed that this MOF material showed considerable uptake capacity for C2H2, C2H4 and C2H6 under ambient conditions, while its capacity for CH4 was very low. High selectivity from IAST calculations for C2H2/CH4, C2H4/CH4 and C2H6/CH4 binary mixtures demonstrated that this MOF material were promising for efficiently separating important separation of C2 hydrocarbons from methane in natural gas processing.

  5. A bacteriophage system for screening and study of biologically active polycyclic aromatic hydrocarbons and related compounds.

    Science.gov (United States)

    Hsu, W T; Harvey, R G; Lin, E J; Weiss, S B

    1977-01-01

    The usefulness of bacterial viruses for detecting substances that are potentially carcinogenic is reexamined as a model system for screening biologically active polycyclic aromatic hydrocarbons. A modification of the original assay procedure allows one to distinguish between aromatics that can modify the biological activity of infectious nucleic acids directly and those polycyclic aromatic hydrocarbons that require metabolic activation by Escherichia coli enzymes. The effect of chemical modification of several different polycyclic aromatic hydrocarbons, with respect to their biological activity in the phage assay system, is described. Among the 31 different compounds examined, (+/-)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide was the most potent inhibitor of infectious phage nucleic acid. The (+) and (-) isomers of the above racemic mixture did not differ significantly in their capacity to inhibit phage replication. PMID:323848

  6. Hydrocarbon Rocket Technology Impact Forecasting

    Science.gov (United States)

    Stuber, Eric; Prasadh, Nishant; Edwards, Stephen; Mavris, Dimitri N.

    2012-01-01

    Ever since the Apollo program ended, the development of launch propulsion systems in the US has fallen drastically, with only two new booster engine developments, the SSME and the RS-68, occurring in the past few decades.1 In recent years, however, there has been an increased interest in pursuing more effective launch propulsion technologies in the U.S., exemplified by the NASA Office of the Chief Technologist s inclusion of Launch Propulsion Systems as the first technological area in the Space Technology Roadmaps2. One area of particular interest to both government agencies and commercial entities has been the development of hydrocarbon engines; NASA and the Air Force Research Lab3 have expressed interest in the use of hydrocarbon fuels for their respective SLS Booster and Reusable Booster System concepts, and two major commercially-developed launch vehicles SpaceX s Falcon 9 and Orbital Sciences Antares feature engines that use RP-1 kerosene fuel. Compared to engines powered by liquid hydrogen, hydrocarbon-fueled engines have a greater propellant density (usually resulting in a lighter overall engine), produce greater propulsive force, possess easier fuel handling and loading, and for reusable vehicle concepts can provide a shorter turnaround time between launches. These benefits suggest that a hydrocarbon-fueled launch vehicle would allow for a cheap and frequent means of access to space.1 However, the time and money required for the development of a new engine still presents a major challenge. Long and costly design, development, testing and evaluation (DDT&E) programs underscore the importance of identifying critical technologies and prioritizing investment efforts. Trade studies must be performed on engine concepts examining the affordability, operability, and reliability of each concept, and quantifying the impacts of proposed technologies. These studies can be performed through use of the Technology Impact Forecasting (TIF) method. The Technology Impact

  7. Catalytic method for synthesizing hydrocarbons

    Science.gov (United States)

    Sapienza, R.S.; Sansone, M.J.; Slegeir, W.A.R.

    A method for synthesizing hydrocarbons from carbon monoxide and hydrogen by contacting said gases with a slurry of a catalyst composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants.

  8. Deep desulfurization of hydrocarbon fuels

    Science.gov (United States)

    Song, Chunshan [State College, PA; Ma, Xiaoliang [State College, PA; Sprague, Michael J [Calgary, CA; Subramani, Velu [State College, PA

    2012-04-17

    The invention relates to processes for reducing the sulfur content in hydrocarbon fuels such as gasoline, diesel fuel and jet fuel. The invention provides a method and materials for producing ultra low sulfur content transportation fuels for motor vehicles as well as for applications such as fuel cells. The materials and method of the invention may be used at ambient or elevated temperatures and at ambient or elevated pressures without the need for hydrogen.

  9. Residual gas analysis

    International Nuclear Information System (INIS)

    Berecz, I.

    1982-01-01

    Determination of the residual gas composition in vacuum systems by a special mass spectrometric method was presented. The quadrupole mass spectrometer (QMS) and its application in thin film technology was discussed. Results, partial pressure versus time curves as well as the line spectra of the residual gases in case of the vaporization of a Ti-Pd-Au alloy were demonstrated together with the possible construction schemes of QMS residual gas analysers. (Sz.J.)

  10. Abnormal pressure in hydrocarbon environments

    Science.gov (United States)

    Law, B.E.; Spencer, C.W.

    1998-01-01

    Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

  11. Source rock hydrocarbons. Present status

    International Nuclear Information System (INIS)

    Vially, R.; Maisonnier, G.; Rouaud, T.

    2013-01-01

    This report first presents the characteristics of conventional oil and gas system, and the classification of liquid and gaseous non conventional hydrocarbons, with the peculiar case of coal-bed methane. The authors then describe how source rock hydrocarbons are produced: production of shale oils and gases (horizontal drilling, hydraulic fracturing, exploitation) and of coal-bed methane and coal mine methane. In the next part, they address and discuss the environmental impact of source rock hydrocarbon production: installation footprint, water resource management, drilling fluids, fracturing fluids composition, toxicity and recycling, air pollution, induced seismicity, pollutions from other exploitation and production activities. They propose an overview of the exploitation and production of source rock gas, coal-bed gas and other non conventional gases in the world. They describe the current development and discuss their economic impacts: world oil context and trends in the USA, in Canada and other countries, impacts on the North American market, on the world oil industry, on refining industries, on the world oil balance. They analyse the economic impacts of non conventional gases: development potential, stakes for the world gas trade, consequence for gas prices, development opportunities for oil companies and for the transport sector, impact on CO 2 emissions, macro-economic impact in the case of the USA

  12. Petroleum hydrocarbon concentrations in ten commercial fish species along Tamilnadu coast, Bay of Bengal, India.

    Science.gov (United States)

    Veerasingam, S; Venkatachalapathy, R; Raja, P; Sudhakar, S; Rajeswari, V; Asanulla, R Mohamed; Mohan, R; Sutharsan, P

    2011-05-01

    The aim of the present study was to evaluate the distribution of petroleum hydrocarbons in ten commercial fish species and water samples in three estuaries along Tamilnadu coast, Bay of Bengal, India. Fish and water samples collected from Tamilnadu coast, India, were extracted and analyzed for petroleum hydrocarbons by ultraviolet fluorescence (UVF) spectroscopy. The petroleum hydrocarbon concentration (PHC) in coastal waters and fish species varied between 2.28 and 14.02 μg/l and 0.52 and 2.05 μg/g, respectively. The highest PHC concentration was obtained in Uppanar estuarine waters (14.02 ± 0.83) and the lowest was observed in Vellar estuarine waters (2.28 ± 0.25). Among the ten fish species, Sardinella longiceps have high PHC concentration from all the locations. This study suggests that S. longiceps can be used as a good biological indicator for petroleum hydrocarbon pollution in water. The concentration of petroleum hydrocarbons in coastal waters along Tamilnadu coast is markedly higher than that in the background, but there is no evidence for its increase in fish of this region. From a public health point, petroleum hydrocarbon residue levels in all fish samples analyzed in this study are considerably lower than the hazardous levels. At present, as Tamilnadu coastal area is in a rapid development stage of new harbour, chemical industries, power plants, oil exploration and other large-scale industries, further assessment of petroleum hydrocarbons and the various hydrodynamic conditions acting in the region are to be studied in detail and continuous pollution monitoring studies should be conducted for improving the aquatic environment. The results will also be useful for pollution monitoring program along the coastal region and also to check the levels of petroleum hydrocarbons.

  13. Modelling fate and effects of toxicologically relevant hydrocarbon fractions following hypothetical oil spills in a marine environment

    International Nuclear Information System (INIS)

    St-Amand, A.; Mazzocco, P.; Stephenson, M.

    2009-01-01

    Numerical oil spill models have generally focused on the transport and fate of oil following a spill through processes such as advection, evaporation, spreading dissolution, dispersion, emulsification, biodegradation and sedimentation. These models provide information regarding the trajectory, location and size of the oil slick, as well as the location where the slick will touch shorelines. The models normally treat the spilled hydrocarbon as a single product or group of representative compounds which is not very useful in evaluating toxicological risks to aquatic biota. For that reason, Stantec developed a model that simultaneously evaluates the likely fate and co-toxicity of toxicologically relevant hydrocarbon compounds and fractions in water following an oil spill in a marine environment. Compounds currently considered in the model include polycyclic aromatic hydrocarbons, volatile organic compounds, BTEX compounds, (benzene, toluene, ethylbenzene, xylenes) and the Canada-Wide Standard hydrocarbon fractions. The fate of these hydrocarbons in the marine environment was simulated using a mass-balance compartment approach in which specific states of the oil and relevant environmental media were considered. At each time step following the hydrocarbon release, the model updated physical properties such as the density and viscosity of the spilled mixtures. When predicting the fate of the mixture, environmental conditions such as wind speed and wave height were taken into account to determine whether droplets of the spilled product remained entrained in the water column or if they resurfaced and possibly emulsified. Two hypothetical spill scenarios were investigated based on assumed spill volumes, assumed product compositions representing a distilled product and crude oil, and assumed environmental and meteorological conditions. The key outputs of the model were the dissolved concentrations of toxicologically relevant hydrocarbon compounds and fractions in the water

  14. Separation of gas mixtures

    International Nuclear Information System (INIS)

    1981-01-01

    Apparatus is described for the separation of a gaseous plasma mixture into components in some of which the original concentration of a specific ion has been greatly increased or decreased, comprising: a source for converting the gaseous mixture into a train of plasma packets; an open-ended vessel with a main section and at least one branch section, adapted to enclose along predetermined tracks the original plasma packets in the main section, and the separated plasma components in the branch sections; drive means for generating travelling magnetic waves along the predetermined tracks with the magnetic flux vector of the waves transverse to each of the tracks; and means for maintaining phase coherence between the plasma packets and the magnetic waves at a value needed for accelerating the components of the packets to different velocities and in such different directions that the plasma of each packet is divided into distinctly separate packets in some of which the original concentration of a specific ion has been greatly increased or decreased, and which plasma packets are collected from the branch sections of the vessels. (author)

  15. Polycyclic aromatic hydrocarbons and the Oak Ridge National Laboratory's experimental coal program: minimizing the hazards

    Energy Technology Data Exchange (ETDEWEB)

    Forrester, R.C. III; Cochran, H.D.; Bolton, N.E.

    1977-01-01

    Many processing techniques for the liquefaction or gasification of coal are being developed at the Oak Ridge National Laboratory and elsewhere. Although different in many other respects, all coal conversion processes produce a liquid effluent comprising a complex mixture of hydrocarbons. Such mixtures invariably contain significant amounts of polycyclic, aromatic compounds, some of which are known to be highly active carcinogens. The underlying philosophy that has been adopted for the protection of personnel involved in experimental coal processing operations is defined, and procedures that have been instituted to govern the conduct of such experimental work and handling of associated coal-derived liquids are detailed.

  16. International comparison of a hydrocarbon gas standard at the picomol per mol level.

    Science.gov (United States)

    Rhoderick, George C; Duewer, David L; Apel, Eric; Baldan, Annarita; Hall, Bradley; Harling, Alice; Helmig, Detlev; Heo, Gwi Suk; Hueber, Jacques; Kim, Mi Eon; Kim, Yong Doo; Miller, Ben; Montzka, Steve; Riemer, Daniel

    2014-03-04

    Studies of climate change increasingly recognize the diverse influences of hydrocarbons in the atmosphere, including roles in particulates and ozone formation. Measurements of key nonmethane hydrocarbons (NMHCs) suggest atmospheric mole fractions ranging from low picomoles per mol (ppt) to nanomoles per mol (ppb), depending on location and compound. To accurately establish mole fraction trends and to relate measurement records from many laboratories and researchers, it is essential to have accurate, stable, calibration standards. In February of 2008, the National Institute of Standards and Technology (NIST) developed and reported on picomoles per mol standards containing 18 nonmethane hydrocarbon compounds covering the mole fraction range of 60 picomoles per mol to 230 picomoles per mol. The stability of these gas mixtures was only characterized over a short time period (2 to 3 months). NIST recently prepared a suite of primary standard gas mixtures by gravimetric dilution to ascertain the stability of the 2008 picomoles per mol NMHC standards suite. The data from this recent chromatographic intercomparison of the 2008 to the 2011 suites confirm a much longer stability of almost 5 years for 15 of the 18 hydrocarbons; the double-bonded alkenes of propene, isobutene, and 1-pentene showed instability, in line with previous publications. The agreement between the gravimetric values from preparation and the analytical mole fractions determined from regression illustrate the internal consistency of the suite within ±2 pmol/mol. However, results for several of the compounds reflect stability problems for the three double-bonded hydrocarbons. An international intercomparison on one of the 2008 standards has also been completed. Participants included National Metrology Institutes, United States government laboratories, and academic laboratories. In general, results for this intercomparison agree to within about ±5% with the gravimetric mole fractions of the hydrocarbons.

  17. Hydrocarbon Reserves: Abundance or Scarcity

    International Nuclear Information System (INIS)

    2005-01-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

  18. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may

  19. Research of Deformation of Clay Soil Mixtures Mixtures

    OpenAIRE

    Romas Girkontas; Tadas Tamošiūnas; Andrius Savickas

    2014-01-01

    The aim of this article is to determine clay soils and clay soils mixtures deformations during drying. Experiments consisted from: a) clay and clay mixtures bridges (height ~ 0,30 m, span ~ 1,00 m); b) tiles of clay and clay, sand and straw (height, length, wide); c) cylinders of clay; clay and straw; clay, straw and sand (diameter; height). According to the findings recommendations for clay and clay mixtures drying technology application were presented. During the experiment clay bridge bear...

  20. Retention efficiencies of halogenated and non-halogenated hydrocarbons in selected wetland ecosystem in Lake Victoria Basin

    Directory of Open Access Journals (Sweden)

    Shadrack Mule

    2015-06-01

    Full Text Available The determination of retention efficiencies of halogenated and non-halogenated hydrocarbon in selected wetland ecosystems in Lake Victoria basin was carried out. Qualitative and quantitative determination of the presence of residual hydrocarbons in Kigwal/Kimondi, Nyando and Nzoia wetland ecosystems using Gas Chromatography - Mass Spectrometer (GC-MS instrument indicated the presence of residual organochlorines, organophosphorus, carbamates and synthetic pyrethroid hydrocarbons in water, sediment and plant materials. In order to compare the retention efficiencies of the wetlands, the wetland ecosystems were divided into three different sections, namely: inlet, mid and outlet. Calculations of mass balances of residual halogenated and non-halogenated hydrocarbons at the respective sections was done taking into account the partition of the studied compounds in samples of water, sediments and papyrus reed plant materials and analyzed using validated Gas Chromatography - Mass Spectrometer (GC-MS method. From the analysis, several residual hydrocarbons namely: bendiocarb, benzene hexachloride (BHC, carbaryl, cypermethrin, decis, deltamethrin, diazinon, dieldrin, DDT, DDD, DDE, malathion, propoxur, sumithion, 5-phenylrhodanine, 1,3,5-trichlorobenzene, 1-(2-phenoxybenzylhydrazine were detected and quantified. The levels of the selected residual hydrocarbons in water samples were used to calculate the retention efficiencies of a specific hydrocarbon and the values recorded. Generally, River Nyando wetland recorded mean percentage retention efficiencies of 76 and 94% for dry and rainy seasons respectively; Kigwal/Kimondi wetland had seasonal mean percentage retention efficiencies of 63 to 78%. River Nzoia also had calculated seasonal mean percentage retention efficiencies of between 56 to 88%. Dry season had lower mean percentages retention efficiencies as compared to rainy season in the three wetlands of interest during the period of study. The study

  1. Agricultural pesticide residues

    International Nuclear Information System (INIS)

    Fuehr, F.

    1984-01-01

    The utilization of tracer techniques in the study of agricultural pesticide residues is reviewed under the following headings: lysimeter experiments, micro-ecosystems, translocation in soil, degradation of pesticides in soil, biological availability of soil-applied substances, bound residues in the soil, use of macro- and microautography, double and triple labelling, use of tracer labelling in animal experiments. (U.K.)

  2. Concomitant variables in finite mixture models

    NARCIS (Netherlands)

    Wedel, M

    The standard mixture model, the concomitant variable mixture model, the mixture regression model and the concomitant variable mixture regression model all enable simultaneous identification and description of groups of observations. This study reviews the different ways in which dependencies among

  3. Calculation Method to Determine the Group Composition of Vacuum Distillate with High Content of Saturated Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Nazarova Galina

    2016-01-01

    Full Text Available Calculation method to determine the group composition of the heavy fraction of vacuum distillate with high content of saturated hydrocarbons, obtained by vacuum distillation of the residue from the West Siberian oil with subsequent hydrotreating, are given in this research. The method is built on the basis of calculation the physico-chemical characteristics and the group composition of vacuum distillate according to the fractional composition and density considering with high content of saturated hydrocarbons in the fraction. Calculation method allows to determine the content of paraffinic, naphthenic, aromatic hydrocarbons and the resins in vacuum distillate with high accuracy and can be used in refineries for rapid determination of the group composition of vacuum distillate.

  4. Mutagenicity of complex mixtures

    International Nuclear Information System (INIS)

    Pelroy, R.A.

    1985-01-01

    The effect of coal-derived complex chemical mixtures on the mutagenicity of 6-aminochrysene (6-AC) was determined with Salmonella typhimurium TA98. Previous results suggested that the mutagenic potency of 6-AC for TA98 in the standard microsomal activation (Ames) assay increased if it was presented to the cells mixed with high-boiling coal liquids (CL) from the solvent refined coal (SRC) process. In this year's work, the apparent mutational synergism of CL and 6-AC was independently verified in a fluctuation bioassay which allowed quantitation of mutational frequencies and cell viability. The results of this assay system were similar to those in the Ames assay. Moreover, the fluctation assay revealed that mutagenesis and cellular toxicity induced by 6-AC were both strongly enhanced if 6-AC was presented to the cells mixed in a high-boiling CL. 4 figures

  5. Preservation properties for the discrete mean residual life ordering

    Directory of Open Access Journals (Sweden)

    Abdulhakim Al-Babtain

    2015-04-01

    Full Text Available The purpose of this paper is to prove several preservation properties of stochastic comparisons based on the discrete mean residual life ordering d-MRL under the reliability operations of convolutions, mixtures. Fi…nally we introduce a discrete renewal process application

  6. PESTICIDE RESIDUES IN THE WATER AND FISH (LAGOON ...

    African Journals Online (AJOL)

    Liquid-liquid and liquid-solid extraction technique was employed to extract pesticide residues in water and fish samples, respectively, using 1:1 (v/v) ethyl acetate/dichloromethane mixture before being analyzed by gas chromatography. The highest level of pesticide contaminations was recorded in the Chemu lagoon as ...

  7. Methods for deactivating iron in hydrocarbon fluids

    Energy Technology Data Exchange (ETDEWEB)

    Roling, P.V.; Niu, J.H.Y.

    1989-11-28

    This patent describes a method of deactivating an iron species disposed in a hydrocarbon medium wherein the absence of the deactivating the metal would initiate decomposition of the hydrocarbon medium. The method comprises: adding to the hydrocarbon medium an effective amount of a Mannich reaction product formed by reaction of reactants A, B, and C; wherein A comprises an alkyl substituted phenol; B comprises of polyoxyalkylenediamine; and C comprises an aldehyde.

  8. Fate of polynuclear aromatic hydrocarbons in soil

    International Nuclear Information System (INIS)

    Bulman, T.L.; Lesage, S.; Fowlie, P.; Webber, M.D.

    1987-01-01

    A study was performed on the persistence of selected polynuclear aromatic hydrocarbons (PAH's) in soil. Two incubation studies were performed. In the first, a mixture of eight PAH's were added to unacclimated soil at levels of 5 and 50 mg/kg and the concentrations were monitored with time. In the second, C 14 -labelled benzo(a)pyrene or anthracene was added to soil incubated in biometer flasks. Microbial degradation, physical and chemical degradation, volatilization and binding were assessed as mechanisms affecting benzo(a)pyrene and anthracene in soil. The disappearance of PAH's appeared to be related to molecular weight, water solubility, volatility and adsorptivity to soil. The loss during this initial period approximated first order kinetics, in some cases following a lag period. The remaining 2-6% of the added PAH's, however, was lost at a much reduced rate. With the 50 mg/kg level of application, reduced rates of disappearance in later stages resulted in levels five to ten times the background concentration which persisted throughout the 400 days. Degradation of phenanthrene, anthracene, fluoranthene and pyrene at the 5 mg/kg application rate, however, resulted in concentrations close to background levels within 400 days. Either a model other than first order or a combination of two models was required to adequately describe the loss of 99% of the added PAH's. The mechanisms leading to a decrease in PAH concentration, identified through the use of C 14 labelling, were predominantly volatilization and adsorption to soil solids for anthracene and adsorption to soil solids for benzo(a)pyrene. Microbial transformation of benzo(a)pyrene was minimal. 17 refs., 10 figs., 4 tabs

  9. Distribution, partitioning and sources of polycyclic aromatic hydrocarbons in the water-SPM-sediment system of Lake Chaohu, China

    DEFF Research Database (Denmark)

    Qin, Ning; He, Wei; Kong, Xiang-Zhen

    2014-01-01

    The residual levels of polycyclic aromatic hydrocarbons (PAHs) in the water, suspended particular matter (SPM) and sediment from Lake Chaohu were measured with a gas chromatograph-mass spectrometer (GC-MS). The spatial-temporal distributions and the SPM-water partition of PAHs and their influenci...

  10. High Molecular Weight Petrogenic and Pyrogenic Hydrocarbons in Aquatic Environments

    Science.gov (United States)

    Abrajano, T. A., Jr.; Yan, B.; O'Malley, V.

    2003-12-01

    the extensive geochemical and analytical framework that was meticulously built by petroleum geochemists over the years (e.g., Tissot and Welte, 1984; Peters et al., 1992; Peters and Moldowan, 1993; Engel and Macko, 1993; Moldowan et al., 1995; Wang et al., 1999; Faksness et al., 2002).Hydrocarbon compounds present in petroleum or pyrolysis by-products can be classified based on their composition, molecular weight, organic structure, or some combination of these criteria. For example, a report of the Committee on Intrinsic Remediation of the US NRC classified organic contaminants into HMW hydrocarbons, low molecular weight (LMW) hydrocarbons, oxygenated hydrocarbons, halogenated aliphatics, halogenated aromatics, and nitroaromatics (NRC, 2000). Hydrocarbons are compounds comprised exclusively of carbon and hydrogen and they are by far the dominant components of crude oil, processed petroleum hydrocarbons (gasoline, diesel, kerosene, fuel oil, and lubricating oil), coal tar, creosote, dyestuff, and pyrolysis waste products. These hydrocarbons often occur as mixtures of a diverse group of compounds whose behavior in near-surface environments is governed by their chemical structure and composition, the geochemical conditions and media of their release, and biological factors, primarily microbial metabolism, controlling their transformation and degradation.Hydrocarbons comprise from 50% to 99% of compounds present in refined and unrefined oil, and compounds containing other elements such as oxygen, nitrogen, and sulfur are present in relatively smaller proportions. Hydrocarbon compounds have carbons joined together as single C - C bonds (i.e., alkanes), double or triple C=C bonds (i.e., alkenes or olefins), or via an aromatic ring system with resonating electronic structure (i.e., aromatics). Alkanes, also called paraffins, are the dominant component of crude oil, with the carbon chain forming either straight (n-alkanes), branched (iso-alkanes), or cyclic (naphthenes

  11. Effect of biochar on the fate of volatile petroleum hydrocarbons in an aerobic sandy soil

    Science.gov (United States)

    Bushnaf, Khaled M.; Puricelli, Sara; Saponaro, Sabrina; Werner, David

    2011-11-01

    Biochar addition to soil is currently being investigated as a novel technology to remediate polluted sites. A critical consideration is the impact of biochar on the intrinsic microbial pollutant degradation, in particular at sites polluted with a mixture of readily biodegradable and more persistent organic pollutants. We therefore studied the impact of biochar (2% on dry weight basis) on the fate of volatile petroleum hydrocarbons in an aerobic sandy soil with batch and column studies. The soil-water partitioning coefficient, K d, was enhanced in the biochar-amended soil up to a factor 36, and petroleum hydrocarbon vapor migration was retarded accordingly. Despite increased sorption, in particular of monoaromatic hydrocarbons, the overall microbial respiration was comparable in the biochar-amended and unamended soil. This was due to more rapid biodegradation of linear, cyclic and branched alkanes in the biochar amended soil. We concluded that the total petroleum hydrocarbon degradation rate was controlled by a factor other than substrate availability and the reduced availability of monoaromatic hydrocarbons in the biochar amended soil led to greater biodegradation of the other petroleum compounds.

  12. Decomposition and hydrocarbon growth processes for esters in non-premixed flames.

    Science.gov (United States)

    Schwartz, William R; McEnally, Charles S; Pfefferle, Lisa D

    2006-06-01

    Biomass fuels are a promising renewable energy source, and so, the mechanisms that may produce toxic oxygenated byproducts and aromatic hydrocarbons from oxygenated hydrocarbons are of interest. Esters have the form R-(C=O)-O-R' and are components of biodiesel fuels. The five specific esters studied here are isomers of C5H10O2. The experiments were performed in atmospheric pressure coflowing methane/air non-premixed flames. A series of flames were generated by separately doping the fuel mixture with 5,000 ppm of each ester. This concentration is sufficiently large to produce measurable changes in intermediate hydrocarbon concentrations, yet small enough to not disturb the overall flame structure. Since the overall structure is not perturbed, the measured changes in the intermediate hydrocarbons can be directly attributed to the reactions of the esters. Analysis of these changes reveals that unimolecular six-centered dissociation is the primary decomposition pathway for the three esters with molecular arrangements capable of undergoing that mechanism. The remaining two esters exhibited decomposition rates and products that are consistent with simple fission as the dominant decomposition mechanism, though we do not exclude other pathways from playing a significant role in their decomposition. All of the esters produce aromatic hydrocarbons at higher rates than the undoped fuel, and the molecular arrangement of the ester isomers plays a role in the degree of aromatic formation. Isomer variations also influence the type and quantity of toxic oxygenates that are produced in the flames.

  13. Testing the efficiency of extraction of incurred residues from soil with optimized multi-residue method.

    Science.gov (United States)

    Suszter, Gabriella K; Ambrus, Árpád

    2017-08-03

    The reproducibility of extraction of residues from spiked soil samples and from soils containing incurred residues was tested with 14 C-labeled test compounds of different physical-chemical properties. Nearly 100% of the compounds added to the sample before extraction could be recovered with an average reproducibility relative standard deviation (CV) of 5.4%. The additional steps of the determination process (cleanup, evaporation, etc.) contributed to the major part of the variability of the results (CV = 10-20%). The incurred residues were most efficiently extracted with acetone for 30 min followed by the mixture of acetone/ethyl acetate 1:1 for additional 30 min. However, they could only be recovered at various extent (64-90% of total residues), underlying the importance of testing the efficiency of extraction. The residues were identified and quantified by gas chromatography applying thermionic detector. The performance parameters of the method complied with the international method validation guidelines, and they proved to be robust and suitable for determination of pesticide residues in soils of widely different physical-chemical properties.

  14. Interfacial tensions of binary mixtures of ethanol with octane, decane, dodecane, and tetradecane

    International Nuclear Information System (INIS)

    Mejia, Andres; Cartes, Marcela; Segura, Hugo

    2011-01-01

    Highlights: → Experimental interfacial tensions in binary mixtures with aneotropic behavior. → Experimental interfacial tensions for ethanol + hydrocarbon mixtures. → Aneotropic displacement in ethanol mixtures. - Abstract: This contribution is devoted to the experimental characterization of interfacial tensions of a representative group of binary mixtures pertaining to the (ethanol + linear hydrocarbon) series (i.e. octane, decane, dodecane, and tetradecane). Experimental measurements were isothermically performed using a maximum differential bubble pressure technique, which was applied over the whole mole fraction range and over the temperature range 298.15 K < T/K < 318.15 K. Experimental results show that the interfacial tensions of (ethanol + octane or decane) negatively deviate from the linear behavior and that sharp minimum points on concentration, or aneotropes, are observed for each isotherm. The interfacial tensions of (ethanol + dodecane or tetradecane), in turn, are characterized by combined deviations from the linear behavior, and inflecting behavior observed on concentration for each isotherm. The experimental evidence also shows that these latter mixtures are close to exhibit aneotropy. For the case of (ethanol + octane or decane) mixtures, aneotropy was clearly induced by the similarity of the interfacial tension values of the constituents. The inflecting behavior of the interfacial tensions of (ethanol + dodecane or tetradecane), in turn, was observed in the vicinity of the coordinates of the critical point of these mixtures, thus pointing to the fact that the quasi-aneotropic singularity that affects these mixtures was provoked by the proximity of an immiscibility gap of the liquid phase. Finally, the experimental data of interfacial tensions were smoothed with the Scott-Myers expansion, from which it is possible to conclude that the observed aneotropic concentrations weakly depend on temperature for all the analyzed mixtures.

  15. Demetallization of hydrocarbon containing feed streams

    International Nuclear Information System (INIS)

    Kukes, S.G.; Hawley, G.R.

    1986-01-01

    This patent describes how metals contained in a hydrocarbon containing feed stream are removed by contacting the hydrocarbon containing feed stream under suitable demetallization conditions with hydrogen and a catalyst composition comprising zirconium phosphate, cobalt phosphate and iron phosphate. The life and activity of the catalyst composition may be increased by introducing a decomposable metal compound selected from the group consisting of the metals of Group V-B, Group VI-B, Group VII-B and Group VIII of the Periodic Table into the hydrocarbon containing feed stream prior to contacting the hydrocarbon containing feed stream with the catalyst composition

  16. Detection of hydrocarbons in irradiated foods

    International Nuclear Information System (INIS)

    Miyahara, Makoto; Maitani, Tamio; Saito, Akiko; Kamimura, Tomomi; Nagasawa, Taeko; Kobayashi, Yasuo; Ito, Hitoshi

    2003-01-01

    The hydrocarbon method for the detection of irradiated foods is now recognized as the international technique. This method is based on radiolysis of fatty acids in food to give hydrocarbons. In order to expand this technique's application, ten foods (butter, cheese, chicken, pork, beef, tuna, dry shrimp, avocado, papaya, and mango) were irradiated in the range from 0.5 to 10 kGy and the hydrocarbons in them were detected. Recoveries of the hydrocarbons from most foods were acceptable (38-128%). Some hydrocarbons were found in non-irradiated foods, particularly, in butter, cheese, tuna, and shrimp. Seven irradiated foods, butter, cheese, chicken, beef, pork, tuna, dry shrimp, and avocado were detectable at their practical doses by measuring the appropriate marker hydrocarbons. In most case, marker hydrocarbon will be 1,7-hexadecadiene. However, the marker hydrocarbons produced only in irradiated foods varied from food to food; therefore, it is necessary to check a specific irradiated food for marker hydrocarbons. On the other hand, two irradiated foods (papaya and mango which were irradiated at their practical doses) were difficult to distinguish from non-irradiated foods using this method. (author)

  17. Detection of hydrocarbons in irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Makoto; Maitani, Tamio [National Inst. of Health Sciences, Tokyo (Japan); Saito, Akiko; Kamimura, Tomomi; Nagasawa, Taeko [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Allied Health Sciences; Kobayashi, Yasuo; Ito, Hitoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Establishment

    2003-06-01

    The hydrocarbon method for the detection of irradiated foods is now recognized as the international technique. This method is based on radiolysis of fatty acids in food to give hydrocarbons. In order to expand this technique's application, ten foods (butter, cheese, chicken, pork, beef, tuna, dry shrimp, avocado, papaya, and mango) were irradiated in the range from 0.5 to 10 kGy and the hydrocarbons in them were detected. Recoveries of the hydrocarbons from most foods were acceptable (38-128%). Some hydrocarbons were found in non-irradiated foods, particularly, in butter, cheese, tuna, and shrimp. Seven irradiated foods, butter, cheese, chicken, beef, pork, tuna, dry shrimp, and avocado were detectable at their practical doses by measuring the appropriate marker hydrocarbons. In most case, marker hydrocarbon will be 1,7-hexadecadiene. However, the marker hydrocarbons produced only in irradiated foods varied from food to food; therefore, it is necessary to check a specific irradiated food for marker hydrocarbons. On the other hand, two irradiated foods (papaya and mango which were irradiated at their practical doses) were difficult to distinguish from non-irradiated foods using this method. (author)

  18. Hydrocarbon-degrading sulfate-reducing bacteria in marine hydrocarbon seep sediments

    OpenAIRE

    Kleindienst, Sara

    2012-01-01

    Microorganisms are key players in our biosphere because of their ability to degrade various organic compounds including a wide range of hydrocarbons. At marine hydrocarbon seeps, more than 90% of sulfate reduction (SR) is potentially coupled to non-methane hydrocarbon oxidation. Several hydrocarbon-degrading sulfate-reducing bacteria (SRB) were enriched or isolated from marine sediments. However, in situ active SRB remained largely unknown. In the present thesis, the global distribution and a...

  19. Chemical data quantify Deepwater Horizon hydrocarbon flow rate and environmental distribution.

    Science.gov (United States)

    Ryerson, Thomas B; Camilli, Richard; Kessler, John D; Kujawinski, Elizabeth B; Reddy, Christopher M; Valentine, David L; Atlas, Elliot; Blake, Donald R; de Gouw, Joost; Meinardi, Simone; Parrish, David D; Peischl, Jeff; Seewald, Jeffrey S; Warneke, Carsten

    2012-12-11

    Detailed airborne, surface, and subsurface chemical measurements, primarily obtained in May and June 2010, are used to quantify initial hydrocarbon compositions along different transport pathways (i.e., in deep subsurface plumes, in the initial surface slick, and in the atmosphere) during the Deepwater Horizon oil spill. Atmospheric measurements are consistent with a limited area of surfacing oil, with implications for leaked hydrocarbon mass transport and oil drop size distributions. The chemical data further suggest relatively little variation in leaking hydrocarbon composition over time. Although readily soluble hydrocarbons made up ∼25% of the leaking mixture by mass, subsurface chemical data show these compounds made up ∼69% of the deep plume mass; only ∼31% of the deep plume mass was initially transported in the form of trapped oil droplets. Mass flows along individual transport pathways are also derived from atmospheric and subsurface chemical data. Subsurface hydrocarbon composition, dissolved oxygen, and dispersant data are used to assess release of hydrocarbons from the leaking well. We use the chemical measurements to estimate that (7.8 ± 1.9) × 10(6) kg of hydrocarbons leaked on June 10, 2010, directly accounting for roughly three-quarters of the total leaked mass on that day. The average environmental release rate of (10.1 ± 2.0) × 10(6) kg/d derived using atmospheric and subsurface chemical data agrees within uncertainties with the official average leak rate of (10.2 ± 1.0) × 10(6) kg/d derived using physical and optical methods.

  20. Handling of Solid Residues

    International Nuclear Information System (INIS)

    Medina Bermudez, Clara Ines

    1999-01-01

    The topic of solid residues is specifically of great interest and concern for the authorities, institutions and community that identify in them a true threat against the human health and the atmosphere in the related with the aesthetic deterioration of the urban centers and of the natural landscape; in the proliferation of vectorial transmitters of illnesses and the effect on the biodiversity. Inside the wide spectrum of topics that they keep relationship with the environmental protection, the inadequate handling of solid residues and residues dangerous squatter an important line in the definition of political and practical environmentally sustainable. The industrial development and the population's growth have originated a continuous increase in the production of solid residues; of equal it forms, their composition day after day is more heterogeneous. The base for the good handling includes the appropriate intervention of the different stages of an integral administration of residues, which include the separation in the source, the gathering, the handling, the use, treatment, final disposition and the institutional organization of the administration. The topic of the dangerous residues generates more expectation. These residues understand from those of pathogen type that are generated in the establishments of health that of hospital attention, until those of combustible, inflammable type, explosive, radio-active, volatile, corrosive, reagent or toxic, associated to numerous industrial processes, common in our countries in development

  1. Neurotoxicity of Metal Mixtures.

    Science.gov (United States)

    Andrade, V M; Aschner, M; Marreilha Dos Santos, A P

    2017-01-01

    Metals are the oldest toxins known to humans. Metals differ from other toxic substances in that they are neither created nor destroyed by humans (Casarett and Doull's, Toxicology: the basic science of poisons, 8th edn. McGraw-Hill, London, 2013). Metals are of great importance in our daily life and their frequent use makes their omnipresence and a constant source of human exposure. Metals such as arsenic [As], lead [Pb], mercury [Hg], aluminum [Al] and cadmium [Cd] do not have any specific role in an organism and can be toxic even at low levels. The Substance Priority List of Agency for Toxic Substances and Disease Registry (ATSDR) ranked substances based on a combination of their frequency, toxicity, and potential for human exposure. In this list, As, Pb, Hg, and Cd occupy the first, second, third, and seventh positions, respectively (ATSDR, Priority list of hazardous substances. U.S. Department of Health and Human Services, Public Health Service, Atlanta, 2016). Besides existing individually, these metals are also (or mainly) found as mixtures in various parts of the ecosystem (Cobbina SJ, Chen Y, Zhou Z, Wub X, Feng W, Wang W, Mao G, Xu H, Zhang Z, Wua X, Yang L, Chemosphere 132:79-86, 2015). Interactions among components of a mixture may change toxicokinetics and toxicodynamics (Spurgeon DJ, Jones OAH, Dorne J-L, Svendsen C, Swain S, Stürzenbaum SR, Sci Total Environ 408:3725-3734, 2010) and may result in greater (synergistic) toxicity (Lister LJ, Svendsen C, Wright J, Hooper HL, Spurgeon DJ, Environ Int 37:663-670, 2011). This is particularly worrisome when the components of the mixture individually attack the same organs. On the other hand, metals such as manganese [Mn], iron [Fe], copper [Cu], and zinc [Zn] are essential metals, and their presence in the body below or above homeostatic levels can also lead to disease states (Annangi B, Bonassi S, Marcos R, Hernández A, Mutat Res 770(Pt A):140-161, 2016). Pb, As, Cd, and Hg can induce Fe, Cu, and Zn

  2. Wetting and evaporation of binary mixture drops.

    Science.gov (United States)

    Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

    2008-09-11

    Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

  3. Lindane and propoxur residues in cocoa from Central region of Ghana

    African Journals Online (AJOL)

    Lindane and propoxur residue levels in cocoa samples taken from the Central Region of Ghana were determined. Propoxur and Lindane residues in cocoa were extracted by continuous soxhlet extraction with a 1:1 v/v acetone-chloroform and acetone-hexane (20:80 v/v) mixture for propoxur and lindane respectively for 12 ...

  4. Methanogenic degradation of petroleum hydrocarbons in subsurface environments remediation, heavy oil formation, and energy recovery.

    Science.gov (United States)

    Gray, N D; Sherry, A; Hubert, C; Dolfing, J; Head, I M

    2010-01-01

    Hydrocarbons are common constituents of surface, shallow, and deep-subsurface environments. Under anaerobic conditions, hydrocarbons can be degraded to methane by methanogenic microbial consortia. This degradation process is widespread in the geosphere. In comparison with other anaerobic processes, methanogenic hydrocarbon degradation is more sustainable over geological time scales because replenishment of an exogenous electron acceptor is not required. As a consequence, this process has been responsible for the formation of the world's vast deposits of heavy oil, which far exceed conventional oil assets such as those found in the Middle East. Methanogenic degradation is also a potentially important component of attenuation in hydrocarbon contamination plumes. Studies of the organisms, syntrophic partnerships, mechanisms, and geochemical signatures associated with methanogenic hydrocarbon degradation have identified common themes and diagnostic markers for this process in the subsurface. These studies have also identified the potential to engineer methanogenic processes to enhance the recovery of energy assets as biogenic methane from residual oils stranded in petroleum systems. Copyright 2010 Elsevier Inc. All rights reserved.

  5. Impact of hydrocarbon biodegradation on low frequency electrical properties of unconsolidated sediments

    Science.gov (United States)

    Abdel Aal, Gamal Zidan

    The influence of biodegradation processes and subsequent physicochemical changes on the low frequency electrical properties (e.g., real and imaginary conductivity) of unconsolidated sediments was investigated in laboratory sand columns and core sediments retrieved from a hydrocarbon contaminated site. The low frequency electrical measurements were conducted using induced polarization (IP) method in the frequency range 0.1--1000 Hz. Biological, geochemical, isotopic analyses, scanning electron microscopy images and surface area measurements were conducted to help in the interpretation of the low frequency electrical measurements. In a laboratory column experiment, the biotic column (nutrient, dissolved diesel and bacteria) showed (a) temporal increase in the real, imaginary, and surface conductivity, and (b) temporal decrease in the formation factor. The abiotic columns (nutrient; and nutrient and dissolved diesel) showed no significant changes. Increase in microbial population numbers, decrease in organic carbon source, nitrate, and sulfate and increase in dissolved inorganic carbon and fluid conductivity were indicative of microbial activity in the biotic column. IP results of core sediments retrieved from the field showed that the magnitude of IP response (e.g., imaginary conductivity) for hydrocarbon contaminated sediments undergoing biodegradation was relatively higher compared to uncontaminated sediments. More specifically, samples from within the smear zone at the site and contaminated with residual hydrocarbon showed a relatively higher magnitude in the IP parameters (e.g., imaginary conductivity) compared to dissolved phase contaminated samples. Previous microbiological study at the site showed a high percentage of oil degrading microorganisms within the smear zone. Further, a laboratory column experiment was conducted to investigate the variations in the temporal changes of IP magnitudes associated with different phases of hydrocarbon contamination

  6. Hydrocarbon production with nuclear explosives

    International Nuclear Information System (INIS)

    Wade Watkins, J.

    1970-01-01

    The tremendous energy of nuclear explosives and the small dimensions of the explosive package make an ideal combination for drill-hole explosive emplacement in deep, thick hydrocarbon deposits. Potential applications exist in fracturing low permeability natural-gas and petroleum formations for stimulating production, fracturing oil shale to permit in situ retorting, and creating storage chimneys for natural gas, liquefied petroleum gas, petroleum, petroleum products, helium, and other fluids. Calculations show, for example, that less than 100 shots per year would be needed to stabilize the natural gas reserves to production ratio. Under the Government-industry Plowshare program, two experiments, Projects Gasbuggy and Rulison, were conducted to stimulate natural gas production from low-permeability formations. Incomplete information indicates that both were technically successful. Potential problems associated with the use of nuclear explosives for underground engineering applications are radioactive contamination, maximum yield limitations, high costs of detonating contained nuclear explosives, and adverse public opinion. Results at Project Gasbuggy and other considerations indicated that the problem of radioactive contamination was about as predicted and not an insurmountable one. Also, it was demonstrated that shots at adequate depths could be detonated without appreciable damage to existing surface and subsurface buildings, natural features, and equipment. However, costs must be reduced and the public must be better informed before these techniques can be widely used in field operations. On the basis of present knowledge, the potential of nuclear-explosive stimulation of hydrocarbon production appears good. Additional field experiments will be required to adequately explore that potential. (author)

  7. Total organic carbon, an important tool in a holistic approach to hydrocarbon source fingerprinting

    International Nuclear Information System (INIS)

    Boehm, P.D.; Burns, W.A.; Page, D.S.; Bence, A.E.; Mankiewicz, P.J.; Brown, J.S.; Douglas, G.S.

    2002-01-01

    Total organic carbon (TOC) was used to verify the consistency of source allocation results for the natural petrogenic hydrocarbon background of the northern Gulf of Alaska and Prince William Sound where the Exxon Valdez oil spill occurred in 1998. The samples used in the study were either pre-spill sediments or from the seafloor outside the spill path. It is assumed that the natural petrogenic hydrocarbon background in the area comes from either seep oil residues and shale erosion including erosion from petroleum source rock shales, or from coals including those of the Bering River coalfields. The objective of this study was to use the TOC calculations to discriminate between the two very different sources. TOC can constrain the contributions of specific sources and rule out incorrect source allocations, particularly when inputs are dominated by fossil organic carbon. The benthic sediments used in this study showed excellent agreement between measured TOC and calculated TOC from hydrocarbon fingerprint matches of polycyclic aromatic hydrocarbons (PAH) and chemical biomarkers. TOC and fingerprint matches confirmed that TOC sources were properly identified. The matches quantify the hydrocarbon contributions of different sources to the benthic sediments and the degree of hydrocarbon winnowing by waves and currents. It was concluded that the natural petrogenic hydrocarbon background in the sediments in the area comes from eroding Tertiary shales and oil seeps along the northern Gulf of Alaska coast. Thermally mature area coals are excluded from being important contributors to the background at Prince William Sound because of their high TOC content. 26 refs., 4 figs

  8. Advanced oxygen-hydrocarbon Earth-to-orbit propulsion

    Science.gov (United States)

    Obrien, C. J.

    1981-01-01

    Liquid oxygen/hydrocarbon (LO2/HC) rocket engine cycles for a surface to orbit transportation system were evaluated. A consistent engine system data base is established for defining advantages and disadvantages, system performance and operating limits, engine parametric data, and technology requirements for candidate engine systems. Preliminary comparisons of the engine cycles utilizing delivered specific impulse values are presented. Methane and propane staged combustion cycles are the highest LO2/HC performers. The hydrogen cooled LO2/methane dual throat engine was found to be the highest performing. Technology needs identified in the study include: high temperature turbines; oxidizer-rich preburners; LO2, methane, and propane cooling; methane and propane fuel-rich preburners; the HC fuel turbopump; and application of advanced composite materials to the engine system. Parametric sensitivity analysis data are displayed which show the effect of variations in engine thrust, mixture ratio, chamber pressure, area ratio, cycle life, and turbine inlet temperature on specific impulse and engine weight.

  9. Exposure to polycyclic aromatic hydrocarbons with special focus on cancer

    Directory of Open Access Journals (Sweden)

    Thamaraiselvan Rengarajan

    2015-03-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are a group of compounds consisting of two or more fused aromatic rings. Most of them are formed during incomplete combustion of organic materials such as wood and fossil fuels, petroleum products, and coal. The composition of PAH mixtures varies with the source and is also affected by selective weathering effects in the environment. PAHs are ubiquitous pollutants frequently found in a variety of environments such as fresh water and marine sediments, the atmosphere, and ice. Due to their widespread distribution, the environmental pollution due to PAHs has aroused global concern. Many PAHs and their epoxides are highly toxic, mutagenic and/or carcinogenic to microorganisms as well as to higher forms of life including humans. The main aim of this review is to provide contemporary information on PAH sources, route of exposure, worldwide emission rate, and adverse effects on humans, especially with reference to cancer.

  10. Pyrochlore-type catalysts for the reforming of hydrocarbon fuels

    Science.gov (United States)

    Berry, David A [Morgantown, WV; Shekhawat, Dushyant [Morgantown, WV; Haynes, Daniel [Morgantown, WV; Smith, Mark [Morgantown, WV; Spivey, James J [Baton Rouge, LA

    2012-03-13

    A method of catalytically reforming a reactant gas mixture using a pyrochlore catalyst material comprised of one or more pyrochlores having the composition A.sub.2-w-xA'.sub.wA''.sub.xB.sub.2-y-zB'.sub.yB''.sub.zO.sub.7-.DELTA.. Distribution of catalytically active metals throughout the structure at the B site creates an active and well dispersed metal locked into place in the crystal structure. This greatly reduces the metal sintering that typically occurs on supported catalysts used in reforming reactions, and reduces deactivation by sulfur and carbon. Further, oxygen mobility may also be enhanced by elemental exchange of promoters at sites in the pyrochlore. The pyrochlore catalyst material may be utilized in catalytic reforming reactions for the conversion of hydrocarbon fuels into synthesis gas (H.sub.2+CO) for fuel cells, among other uses.

  11. [Residual neuromuscular blockade].

    Science.gov (United States)

    Fuchs-Buder, T; Schmartz, D

    2017-06-01

    Even small degrees of residual neuromuscular blockade, i. e. a train-of-four (TOF) ratio >0.6, may lead to clinically relevant consequences for the patient. Especially upper airway integrity and the ability to swallow may still be markedly impaired. Moreover, increasing evidence suggests that residual neuromuscular blockade may affect postoperative outcome of patients. The incidence of these small degrees of residual blockade is relatively high and may persist for more than 90 min after a single intubating dose of an intermediately acting neuromuscular blocking agent, such as rocuronium and atracurium. Both neuromuscular monitoring and pharmacological reversal are key elements for the prevention of postoperative residual blockade.

  12. TENORM: Wastewater Treatment Residuals

    Science.gov (United States)

    Water and wastes which have been discharged into municipal sewers are treated at wastewater treatment plants. These may contain trace amounts of both man-made and naturally occurring radionuclides which can accumulate in the treatment plant and residuals.

  13. Easy and flexible mixture distributions

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Mabit, Stefan L.

    2013-01-01

    We propose a method to generate flexible mixture distributions that are useful for estimating models such as the mixed logit model using simulation. The method is easy to implement, yet it can approximate essentially any mixture distribution. We test it with good results in a simulation study...

  14. Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons

    Science.gov (United States)

    Zecevic, Jovana; Vanbutsele, Gina; de Jong, Krijn P.; Martens, Johan A.

    2015-12-01

    The ability to control nanoscale features precisely is increasingly being exploited to develop and improve monofunctional catalysts. Striking effects might also be expected in the case of bifunctional catalysts, which are important in the hydrocracking of fossil and renewable hydrocarbon sources to provide high-quality diesel fuel. Such bifunctional hydrocracking catalysts contain metal sites and acid sites, and for more than 50 years the so-called intimacy criterion has dictated the maximum distance between the two types of site, beyond which catalytic activity decreases. A lack of synthesis and material-characterization methods with nanometre precision has long prevented in-depth exploration of the intimacy criterion, which has often been interpreted simply as ‘the closer the better’ for positioning metal and acid sites. Here we show for a bifunctional catalyst—comprising an intimate mixture of zeolite Y and alumina binder, and with platinum metal controllably deposited on either the zeolite or the binder—that closest proximity between metal and zeolite acid sites can be detrimental. Specifically, the selectivity when cracking large hydrocarbon feedstock molecules for high-quality diesel production is optimized with the catalyst that contains platinum on the binder, that is, with a nanoscale rather than closest intimacy of the metal and acid sites. Thus, cracking of the large and complex hydrocarbon molecules that are typically derived from alternative sources, such as gas-to-liquid technology, vegetable oil or algal oil, should benefit especially from bifunctional catalysts that avoid locating platinum on the zeolite (the traditionally assumed optimal location). More generally, we anticipate that the ability demonstrated here to spatially organize different active sites at the nanoscale will benefit the further development and optimization of the emerging generation of multifunctional catalysts.

  15. Residuation in orthomodular lattices

    Directory of Open Access Journals (Sweden)

    Chajda Ivan

    2017-04-01

    Full Text Available We show that every idempotent weakly divisible residuated lattice satisfying the double negation law can be transformed into an orthomodular lattice. The converse holds if adjointness is replaced by conditional adjointness. Moreover, we show that every positive right residuated lattice satisfying the double negation law and two further simple identities can be converted into an orthomodular lattice. In this case, also the converse statement is true and the corresponence is nearly one-to-one.

  16. Catalytic copyrolysis of cork oak and bio-oil distillation residue

    Science.gov (United States)

    Lee, Yejin; Oh, Daejun; Kim, Young-Min; Jae, Jungho; Jung, Sang-Chul; Jeon, Jong-Ki; Kim, Sang Chai; Park, Young-Kwon

    2018-01-01

    The atmospheric distillation residue (ADR) of cork oak (CO) pyrolysis oil was used as the co-feeding material for the catalytic pyrolysis of CO over HZSM-5 catalysts to improve the formation of aromatic hydrocarbons. Although the non-catalytic copyrolysis of CO and ADR did not improve the formation of aromatic hydrocarbons, the catalytic copyrolysis of CO and ADR promoted the synergistic formation of aromatic hydrocarbons. HZSM-5(30), having a lower SiO2/Al2O3(30), showed better performance for the formation of aromatic hydrocarbons than HZSM-5(80) because of its higher acidity. The catalytic copyrolysis of CO and ADR also decreased the formation of coke. The largest quantity of aromatic hydrocarbons was obtained from the catalytic copyrolysis of CO and ADR over HZSM-5 (30) at 600 °C, whereas the lowest coke yield was achieved at 700 °C. When the catalyst to sample ratio was increased from 2:1 to 5:1, the synergistic formation of aromatic hydrocarbons was limited, resulting in a lower experimental yield of aromatic hydrocarbons than the theoretical yield. A lower coke yield was also achieved at a high catalyst to sample ratio (5:1).

  17. Contribution to radiolysis study of liquid hydrocarbons

    International Nuclear Information System (INIS)

    Rimbaud, Michel.

    1978-01-01

    This work deals with radiolysis of liquid hydrocarbons. First, the radiochemical yields of various products are correlated with the theoretical bond energies, for some hydrocarbons. Several values of scavenging parameter αsub(S) are calculated and the methods for these determinations are criticized. In the last part, we present a new method for the calculation of electron scavenging rate constants [fr

  18. Identification and Characterisation of Major Hydrocarbons in ...

    African Journals Online (AJOL)

    Identification and Characterisation of Major Hydrocarbons in Thermally Degraded Low Density Polyethylene Films. ... There were alkanes, alkenes, halogenated alkanes, and very few aromatics in the liquid product and, the hydrocarbons were observed to range between C10 - C27. The FTIR and GC-MS results show the ...

  19. hydrocarbons biodegradation and evidence of mixed petroleum ...

    African Journals Online (AJOL)

    DJFLEX

    mode (EI) at 70Ev ionisation energy and scanned from 50 to 650 dalton. 3.0 Result and discussion. 3.1 n-alkanes and Isoprenoid Hydrocarbons. The concentrations (mgkg-1) ..... community in the Yellowish geothermal environment. Nature 434, 1000-1014. Cross River System. HYDROCARBONS BIODEGRADATION AND ...

  20. Occurrence and growth potentials of hydrocarbon degrading ...

    African Journals Online (AJOL)

    Hydrocarbon degraders identified as Acinetobacter, Flavobacterium, and Micrococcus were obtained. Most of the organisms grew well on diesel. Pseudomonas sp. grew luxuriantly on diesel and kerosene while Bacillus sp. did not grow on kerosene. Optimal growth on the hydrocarbon occurred between the 8th and 14th ...

  1. Interactions of Cyclic Hydrocarbons with Biological Membranes

    NARCIS (Netherlands)

    SIKKEMA, J; DEBONT, JAM; POOLMAN, B

    1994-01-01

    Many cyclic hydrocarbons, e.g. aromatics, cycloalkanes, and terpenes, are toxic to microorganisms. The primary site of the toxic action is probably the cytoplasmic membrane, but the mechanism of the toxicity is still poorly understood. The effects of cyclic hydrocarbons were studied in liposomes

  2. Versatility of hydrocarbon production in cyanobacteria.

    Science.gov (United States)

    Xie, Min; Wang, Weihua; Zhang, Weiwen; Chen, Lei; Lu, Xuefeng

    2017-02-01

    Cyanobacteria are photosynthetic microorganisms using solar energy, H 2 O, and CO 2 as the primary inputs. Compared to plants and eukaryotic microalgae, cyanobacteria are easier to be genetically engineered and possess higher growth rate. Extensive genomic information and well-established genetic platform make cyanobacteria good candidates to build efficient biosynthetic pathways for biofuels and chemicals by genetic engineering. Hydrocarbons are a family of compounds consisting entirely of hydrogen and carbon. Structural diversity of the hydrocarbon family is enabled by variation in chain length, degree of saturation, and rearrangements of the carbon skeleton. The diversified hydrocarbons can be used as valuable chemicals in the field of food, fuels, pharmaceuticals, nutrition, and cosmetics. Hydrocarbon biosynthesis is ubiquitous in bacteria, yeasts, fungi, plants, and insects. A wide variety of pathways for the hydrocarbon biosynthesis have been identified in recent years. Cyanobacteria may be superior chassis for hydrocabon production in a photosynthetic manner. A diversity of hydrocarbons including ethylene, alkanes, alkenes, and terpenes can be produced by cyanobacteria. Metabolic engineering and synthetic biology strategies can be employed to improve hydrocarbon production in cyanobacteria. This review mainly summarizes versatility and perspectives of hydrocarbon production in cyanobacteria.

  3. Palynofacies characterization for hydrocarbon source rock ...

    Indian Academy of Sciences (India)

    This paper deals with the hydrocarbon source rock evaluation of the Subathu Formation exposed at. Marhighat on Sarahan–Narag road in Sirmaur district of Himachal Pradesh. Hydrocarbon potential of these sediments is estimated on the basis of palynofacies analysis and thermal alteration index (TAI) values based on the ...

  4. Bioavailability and bioaccessibility of petroleum hydrocarbons in contaminated site soils

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, G.; Angell, R.; Strive, E.; Ma, W. [Stantec Consulting Ltd., Surrey, BC (Canada)

    2010-07-01

    Although the bioavailability and/or bioaccessibility of contaminants in soil can be measured by various ecological receptors, the methods that are suitable for metals do not necessarily work well for petroleum hydrocarbons (PHCs). In this study, several biological and chemical methods were used at various PHC contaminated sites to find the most fitting method for different soil types in terms of predicting the biological responses of organisms as measured by standard single species toxicity tests. Organisms such as plants, earthworms, and collembolan were exposed to soils with different PHC concentrations. Multiple endpoints were then measured to evaluate the biological responses. The exposure concentrations for the 4 CCME hydrocarbon fractions were measured using hexane:acetone extraction as well as extractions with cyclodextrin, and a mixture of enzymes to simulate the gastro-intestinal fluid of an earthworm. The estimated exposure concentrations depended on the extraction method. The study showed that existing methodologies must be modified in order to better estimate the biological effect of PHCs in soil. Comparative data was presented and discussed along with proposed methodological modifications.

  5. Bioavailability and bioaccessibility of petroleum hydrocarbons in contaminated site soils

    International Nuclear Information System (INIS)

    Stephenson, G.; Angell, R.; Strive, E.; Ma, W.

    2010-01-01

    Although the bioavailability and/or bioaccessibility of contaminants in soil can be measured by various ecological receptors, the methods that are suitable for metals do not necessarily work well for petroleum hydrocarbons (PHCs). In this study, several biological and chemical methods were used at various PHC contaminated sites to find the most fitting method for different soil types in terms of predicting the biological responses of organisms as measured by standard single species toxicity tests. Organisms such as plants, earthworms, and collembolan were exposed to soils with different PHC concentrations. Multiple endpoints were then measured to evaluate the biological responses. The exposure concentrations for the 4 CCME hydrocarbon fractions were measured using hexane:acetone extraction as well as extractions with cyclodextrin, and a mixture of enzymes to simulate the gastro-intestinal fluid of an earthworm. The estimated exposure concentrations depended on the extraction method. The study showed that existing methodologies must be modified in order to better estimate the biological effect of PHCs in soil. Comparative data was presented and discussed along with proposed methodological modifications.

  6. Adsorption of volatile hydrocarbons in iron polysulfide chalcogels

    KAUST Repository

    Ahmed, Ejaz

    2014-11-01

    We report the synthesis, characterization and possible applications of three new metal-chalcogenide aerogels KFe3Co3S 21, KFe3Y3S22 and KFe 3Eu3S22. Metal acetates react with the alkali metal polychalcogenides in formamide/water mixture to form extended polymeric frameworks that exhibit gelation phenomena. Amorphous aerogels obtained after supercritical CO2 drying have BET surface area from 461 to 573 m 2/g. Electron microscopy images and nitrogen adsorption measurements showed that pore sizes are found in micro (below 2 nm), meso (2-50 nm), and macro (above 50 nm) porous regions. These chalcogels possess optical bandgaps in the range of 1.55-2.70 eV. These aerogels have been studied for the adsorption of volatile hydrocarbons and gases. A much higher adsorption of toluene in comparison with cyclohexane and cyclopentane vapors have been observed. The adsorption capacities of the three volatile hydrocarbons are found in the following order: toluene > cyclohexane > cyclopentane. It has been observed that high selectivity in adsorption is feasible with high-surface-area metal chalcogenides. Similarly, almost an eight to ten times increase in adsorption selectivity towards CO2 over H2/CH4 was observed in the aerogels. Moreover, reversible ion-exchange properties for K+/Cs+ ions have also been demonstrated. © 2014 Elsevier Inc. All rights reserved.

  7. Characterization of Hospital Residuals

    International Nuclear Information System (INIS)

    Blanco Meza, A.; Bonilla Jimenez, S.

    1997-01-01

    The main objective of this investigation is the characterization of the solid residuals. A description of the handling of the liquid and gassy waste generated in hospitals is also given, identifying the source where they originate. To achieve the proposed objective the work was divided in three stages: The first one was the planning and the coordination with each hospital center, in this way, to determine the schedule of gathering of the waste can be possible. In the second stage a fieldwork was made; it consisted in gathering the quantitative and qualitative information of the general state of the handling of residuals. In the third and last stage, the information previously obtained was organized to express the results as the production rate per day by bed, generation of solid residuals for sampled services, type of solid residuals and density of the same ones. With the obtained results, approaches are settled down to either determine design parameters for final disposition whether for incineration, trituration, sanitary filler or recycling of some materials, and storage politics of the solid residuals that allow to determine the gathering frequency. The study concludes that it is necessary to improve the conditions of the residuals handling in some aspects, to provide the cleaning personnel of the equipment for gathering disposition and of security, minimum to carry out this work efficiently, and to maintain a control of all the dangerous waste, like sharp or polluted materials. In this way, an appreciable reduction is guaranteed in the impact on the atmosphere. (Author) [es

  8. Assessment of mixture toxicity of copper, cadmium, and phenanthrenequinone to the marine bacterium Vibrio fischeri.

    Science.gov (United States)

    Wang, Wenxi; Lampi, Mark A; Huang, Xiao-Dong; Gerhardt, Karen; Dixon, D George; Greenberg, Bruce M

    2009-04-01

    Transition metals and polycyclic aromatic hydrocarbons (PAHs) are cocontaminants at many sites. Contaminants in mixtures are known to interact with biological systems in ways that can greatly alter the toxicity of individual compounds. The toxicities (individually and as mixtures) of copper (Cu), a redox-active metal; cadmium (Cd), a nonredox active metal; and phenanthrenequinone (PHQ), a redox-active oxygenated PAH, were examined using the bioluminescent bacterium Vibrio fischeri. We found that the cotoxicity of Cu/PHQ was dependent on the ratio of concentrations of each chemical in the mixture. Different interaction types (synergism, antagonism, and additivity) were observed with different combinations of these toxicants. The interaction types changed from antagonism at a low Cu to PHQ ratio (1:4), to additive at an intermediate Cu to PHQ ratio (2:3), to synergistic at higher Cu to PHQ ratios (3:2 and 4:1). In contrast to Cu/PHQ mixtures, the cotoxicity of Cd/PHQ did not change at different mixture ratios and was found for the most part to be additive. For the individual chemicals and their mixtures, reactive oxygen species (ROS) production was observed in V. fischeri, suggesting that individual and mixture toxicity of Cu, Cd, and PHQ to V. fischeri involves ROS-related mechanisms. This study shows that mixture ratios can alter individual chemical toxicity, and should be taken into account in risk assessment. Copyright 2008 Wiley Periodicals, Inc.

  9. R-O-C N species produced by ion irradiation of ice mixtures : Comparison with astronomical observations

    NARCIS (Netherlands)

    Palumbo, ME; Strazzulla, G; Pendleton, YJ; Tielens, AGGM

    2000-01-01

    We have investigated the effects induced by ion bombardment of mixtures containing nitrogen-bearing compounds at low temperatures. The results show the formation of a band at 2080 cm(-1) in binary mixtures, NH(3):CH(4) and N(2):CH(4), which we attribute to HCN embedded in the organic residue formed

  10. Radon in groundwater contaminated by dissolved hydrocarbons in Santa Bárbara d'Oeste, São Paulo State, Brazil.

    Science.gov (United States)

    Galhardi, J A; Bonotto, D M

    2012-10-01

    This investigation reported the (222)Rn activity concentration and dissolved hydrocarbon content in groundwater collected in three gas stations where occurred tanks leaks, in Santa Barbara d'Oeste, São Paulo State, Brazil. The results indicated a tendency of correlation between the radon and BTEX, suggesting that the presence of dissolved hydrocarbons increase the radon concentration in water, due to the preferential partition at this phase. The radiometric data are useful for the detection of residual contamination and dissolved hydrocarbon plumes in groundwater, reinforcing the findings of previous studies held elsewhere. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Microbial degradation of total petroleum hydrocarbons in crude oil: a field-scale study at the low-land rainforest of Ecuador.

    Science.gov (United States)

    Maddela, Naga Raju; Scalvenzi, Laura; Venkateswarlu, Kadiyala

    2017-10-01

    A field-level feasibility study was conducted to determine total petroleum hydrocarbon (TPH)-degrading potential of two bacterial strains, Bacillus thuringiensis B3 and B. cereus B6, and two fungi, Geomyces pannorum HR and Geomyces sp. strain HV, all soil isolates obtained from an oil field located in north-east region of Ecuador. Crude oil-treated soil samples contained in wooden boxes received a mixture of all the four microorganisms and were incubated for 90 days in an open low-land area of Amazon rainforest. The percent removal of TPHs in soil samples that received the mixed microbial inoculum was 87.45, indicating the great potential of the soil isolates in field-scale removal of crude oil. The TPHs-degrading efficiency was verified by determining the toxicity of residues, remained in soil after biodegradation, toward viability of Artemia salina or seed germination and plant growth of cowpea. Our results clearly suggest that the selected soil isolates of bacteria and fungi could be effectively used for large-scale bioremediation of sites contaminated with crude oil.

  12. Private sector perspectives on hydrocarbon contamination

    International Nuclear Information System (INIS)

    Hills, J.J.

    1991-01-01

    In order to effectively resolve a problem, one should attempt to gain a comprehensive understanding of all facets of the problem. With regard to hydrocarbon contamination, it is essential for regulators, consultants, attorneys, bankers, business owners, and others involved with this issue to develop a comprehensive understanding of the major perspectives associated with hydrocarbon contamination in order to address and effectively resolve the specific hydrocarbon contamination issues these groups are, or will be, facing. The purpose of this paper is to identify the hydrocarbon contamination issues from private and public sector perspectives. In doing so, the author hopes to present another important perspective that will provide those involved with hydrocarbon contamination a more complete picture of the scope of the problem

  13. Apparatus for recovery of liquid hydrocarbon

    International Nuclear Information System (INIS)

    Lamphere, D.A.; Bowles, D.F.

    1993-01-01

    A pump unit is described for recovery of liquid hydrocarbon from a body of liquid with a hydrocarbon/water interface, comprising a pump with a pump intake, and a linear probe, fixed in relation to said pump intake, and oriented to extend perpendicularly to said hydrocarbon/water interface and through said hydrocarbon/water interface, when in use, said probe including antenna means for generating an electromagnetic signal and electrical driving means for driving said antenna means, said driving means including signaling means for generating a signal indicative of the linear location of said hydrocarbon/water interface relative to said pump intake, wherein said linear probe includes a linearly extending electrically conductive member comprising said antenna means, a non-conductive coating on said conductive member, and means for electrically driving said conductive member with a low frequency electrical signal

  14. Nonlinearity of bituminous mixtures

    Science.gov (United States)

    Mangiafico, S.; Babadopulos, L. F. A. L.; Sauzéat, C.; Di Benedetto, H.

    2018-02-01

    This paper presents an experimental characterization of the strain dependency of the complex modulus of bituminous mixtures for strain amplitude levels lower than about 110 μm/m. A series of strain amplitude sweep tests are performed at different temperatures (8, 10, 12 and 14°C) and frequencies (0.3, 1, 3 and 10 Hz), during which complex modulus is monitored. For each combination of temperature and frequency, four maximum strain amplitudes are targeted (50, 75, 100 and 110 μm/m). For each of them, two series of 50 loading cycles are applied, respectively at decreasing and increasing strain amplitudes. Before each decreasing strain sweep and after each increasing strain sweep, 5 cycles are performed at constant maximum targeted strain amplitude. Experimental results show that the behavior of the studied material is strain dependent. The norm of the complex modulus decreases and phase angle increases with strain amplitude. Results are presented in Black and Cole-Cole plots, where characteristic directions of nonlinearity can be identified. Both the effects of nonlinearity in terms of the complex modulus variation and of the direction of nonlinearity in Black space seem to validate the time-temperature superposition principle with the same shift factors as for linear viscoelasticity. The comparison between results obtained during increasing and decreasing strain sweeps suggests the existence of another phenomenon occurring during cyclic loading, which appears to systematically induce a decrease of the norm of the complex modulus and an increase of the phase angle, regardless of the type of the strain sweep (increasing or decreasing).

  15. IDENTIFICATION OF SOME CARCINOGENIC POLYCYCLIC AROMATIC HYDROCARBONS IN BANGLADESHI VEHICLES EXHAUST TAR BY GAS CHROMATOGRAPHY-MASS SPECTROPHOTOMETER

    Directory of Open Access Journals (Sweden)

    M. Amzad Hossain

    2010-06-01

    Full Text Available A more sensitive GC-MS method has been established for the determination of some carcinogenic polycyclic aromatic hydrocarbons (PAHs in vehicles exhaust tar samples. The tar samples were extracted using dichloromethane (DMC: n-hexane solvent mixture. A multi-layer clean-up (silica gel/sodium sulphate column was used, followed by glass fiber filter (GFF paper. The method was successfully applied to determine a number of PAHs present in exhaust tar sample of different vehicles of the Atomic Energy Centre, Dhaka, Bangladesh.   Keywords: Carcinogenic polycyclic aromatic hydrocarbons, vehicles tar samples, identification, GC-MS/MS

  16. Hydrocarbon separations in a metal-organic framework with open iron(II) coordination sites.

    Science.gov (United States)

    Bloch, Eric D; Queen, Wendy L; Krishna, Rajamani; Zadrozny, Joseph M; Brown, Craig M; Long, Jeffrey R

    2012-03-30

    The energy costs associated with large-scale industrial separation of light hydrocarbons by cryogenic distillation could potentially be lowered through development of selective solid adsorbents that operate at higher temperatures. Here, the metal-organic framework Fe(2)(dobdc) (dobdc(4-) : 2,5-dioxido-1,4-benzenedicarboxylate) is demonstrated to exhibit excellent performance characteristics for separation of ethylene/ethane and propylene/propane mixtures at 318 kelvin. Breakthrough data obtained for these mixtures provide experimental validation of simulations, which in turn predict high selectivities and capacities of this material for the fractionation of methane/ethane/ethylene/acetylene mixtures, removal of acetylene impurities from ethylene, and membrane-based olefin/paraffin separations. Neutron powder diffraction data confirm a side-on coordination of acetylene, ethylene, and propylene at the iron(II) centers, while also providing solid-state structural characterization of the much weaker interactions of ethane and propane with the metal.

  17. Significance of Microbiology in Porous Hydrocarbon Related Systems

    KAUST Repository

    Augsburger, Nicolas

    2017-07-01

    This thesis explores bio-mediated processes in geotechnical and petroleum engineering. Worldwide energy consumption is rapidly increasing as the world population and per-capita consumption rises. The US Energy Information Agency (EIA) predicts that hydrocarbons will remain the primary energy source to satisfy the surging energy demands in the near future. The three topics described in detail in this document aim to link microbiology with geotechnical engineering and the petroleum industry. Microorganisms have the potential to exploit residual hydrocarbons in depleted reservoirs in a technique known as microbial enhanced oil recovery, MEOR. The potential of biosurfactants was analyzed in detail with a literature review. Biosurfactant production is the most accepted MEOR technique, and has been successfully implemented in over 700 field cases. Temperature is the main limiting factor for these techniques. The dissolution of carbonates by microorganisms was investigated experimentally. We designed a simple, economical, and robust procedure to monitor diffusion through porous media. This technique determined the diffusion coefficient of H+ in 1.5% agar, 1.122 x 10-5 cm2 sec-1, by using bromothymol blue as a pH indicator and image processing. This robust technique allows for manipulation of the composition of the agar to identify the effect of specific compounds on diffusion. The Red Sea consists of multiple seeps; the nearby sediments are telltales of deeper hydrocarbon systems. Microbial communities associated with the sediments function as in-situ sensors that provide information about the presence of carbon sources, metabolites, and the remediation potential. Sediments seeps in the Red Sea revealed different levels of bioactivity. The more active seeps, from the southern site in the Red Sea, indicated larger pore sizes, higher levels of carbon, and bioactivity with both bacteria and archaeal species present.

  18. A strategy for aromatic hydrocarbon bioremediation under anaerobic conditions and the impacts of ethanol: A microcosm study

    Science.gov (United States)

    Chen, Yu Dao; Barker, James F.; Gui, Lai

    2008-02-01

    -reducing conditions. This study suggests that addition of excess ferric iron combined with limited nitrate has promise for in situ bioremediation of BTEX and TMB in the Borden aquifer and possibly for other sites contaminated by hydrocarbons. This study is the first to report 1,2,3-TMB biodegradation under strictly anaerobic condition. With the addition of 500 mg/L ethanol but without EA addition, ethanol and its main intermediate, acetate, were quickly biodegraded within 41 d with methane as a major product. Ethanol initially present at 5000 mg/L without EA addition declined slowly with the persistence of unidentified volatile fatty acids, likely propionate and butyrate, but less methane. In contrast, all ethanol disappeared with repeated additions of either nitrate or ferric iron, but acetate and unidentified intermediates persisted under iron-enhanced conditions. With the addition of 500 mg/L ethanol and nitrate, only minor toluene biodegradation was observed under denitrifying conditions and only after ethanol and acetate were utilized. The higher ethanol concentration (5000 mg/L) essentially shut down BTEX biodegradation likely due to high EA demand provided by ethanol and its intermediates. The negative findings for anaerobic BTEX biodegradation in the presence of ethanol and/or its biodegradation products are in contrast to recent research reported by Da Silva et al. [Da Silva, M.L.B., Ruiz-Aguilar, G.M.L., Alvarez, P.J.J., 2005. Enhanced anaerobic biodegradation of BTEX-ethanol mixtures in aquifer columns amended with sulfate, chelated ferric iron or nitrate. Biodegradation. 16, 105-114]. Our results suggest that the apparent conservation of high residual labile carbon as biodegradation products such as acetate makes natural attenuation of aromatics less effective, and makes subsequent addition of EAs to promote in situ BTEX biodegradation problematic.

  19. Catalytic cracking of non-edible sunflower oil over ZSM-5 for hydrocarbon bio-jet fuel.

    Science.gov (United States)

    Zhao, Xianhui; Wei, Lin; Julson, James; Qiao, Qiquan; Dubey, Ashish; Anderson, Gary

    2015-03-25

    Non-edible sunflower oils that were extracted from sunflower residual wastes were catalytically cracked over a ZSM-5 catalyst in a fixed-bed reactor at three different reaction temperatures: 450°C, 500°C and 550°C. The catalyst was characterized using XRD, FT-IR, BET and SEM. Characterizations of the upgraded sunflower oils, hydrocarbon fuels, distillation residues and non-condensable gases were carried out. The effect of the reaction temperature on the yield and quality of liquid products was discussed. The results showed that the reaction temperature affected the hydrocarbon fuel yield but had a minor influence on its properties. The highest conversion efficiency from sunflower oils to hydrocarbon fuels was 30.1%, which was obtained at 550°C. The reaction temperature affected the component content of the non-condensable gases. The non-condensable gases generated at 550°C contained the highest content of light hydrocarbons (C1-C5), CO, CO2 and H2. Compared to raw sunflower oils, the properties of hydrocarbon fuels including the dynamic viscosity, pH, moisture content, density, oxygen content and heating value were improved. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Management of NORM Residues

    International Nuclear Information System (INIS)

    2013-06-01

    The IAEA attaches great importance to the dissemination of information that can assist Member States in the development, implementation, maintenance and continuous improvement of systems, programmes and activities that support the nuclear fuel cycle and nuclear applications, and that address the legacy of past practices and accidents. However, radioactive residues are found not only in nuclear fuel cycle activities, but also in a range of other industrial activities, including: - Mining and milling of metalliferous and non-metallic ores; - Production of non-nuclear fuels, including coal, oil and gas; - Extraction and purification of water (e.g. in the generation of geothermal energy, as drinking and industrial process water; in paper and pulp manufacturing processes); - Production of industrial minerals, including phosphate, clay and building materials; - Use of radionuclides, such as thorium, for properties other than their radioactivity. Naturally occurring radioactive material (NORM) may lead to exposures at some stage of these processes and in the use or reuse of products, residues or wastes. Several IAEA publications address NORM issues with a special focus on some of the more relevant industrial operations. This publication attempts to provide guidance on managing residues arising from different NORM type industries, and on pertinent residue management strategies and technologies, to help Member States gain perspectives on the management of NORM residues

  1. Hydrocarbon pollution from marinas in estuarine sediments

    Science.gov (United States)

    Voudrias, Evangelos A.; Smith, Craig L.

    1986-03-01

    A measure of the impact of marinas on three Eastern Virginia estuarine creeks was obtained by a study of hydrocarbons in their sediments. Two of the creeks support considerable marine activity, including pleasure boat marinas, boat repair facilities, and commercial fishing operations. The third creek, which served as a control, is seldom used by boats, and is surrounded by marsh and woodland. Sediments from the creeks with marinas contained significantly higher levels of both aromatic and aliphatic hydrocarbons than did the control. Differences in the concentrations of certain oil-pollution indicators, such as the 17α,21β-hopane homologs and phytane, and low molecular weight aromatic hydrocarbons, are indicative of light petroleum fractions. Most of the aromatic hydrocarbons from all creeks, however, appear to have a pyrogenic origin. Although hydrocarbons from three probable origins (petroleum, pyrogenesis, and recent biosynthesis) were detected in all locations, the petroleum-derived and pyrogenic hydrocarbons were of only minor importance relative to the biogenic hydrocarbons in the control creek.

  2. Thermal signature measurements for ammonium nitrate/fuel mixtures by laser heating

    Energy Technology Data Exchange (ETDEWEB)

    Nazarian, Ashot; Presser, Cary, E-mail: cpresser@nist.gov

    2016-01-10

    Highlights: • LDTR is a useful diagnostic for characterizing AN/fuel mixture thermochemical behavior. • Each AN/fuel mixture thermal signature was different. • AN/fuel mixture signature features were defined by the individual constituents. • Baseline signatures changed after an experiment. - Abstract: Measurements were carried out to obtain thermal signatures of several ammonium nitrate/fuel (ANF) mixtures, using a laser-heating technique referred to as the laser-driven thermal reactor (LDTR). The mixtures were ammonium nitrate (AN)/kerosene, AN/ethylene glycol, AN/paraffin wax, AN/petroleum jelly, AN/confectioner's sugar, AN/cellulose (tissue paper), nitromethane/cellulose, nitrobenzene/cellulose, AN/cellulose/nitromethane, AN/cellulose/nitrobenzene. These mixtures were also compared with AN/nitromethane and AN/diesel fuel oil, obtained from an earlier investigation. Thermograms for the mixtures, as well as individual constituents, were compared to better understand how sample thermal signature changes with mixture composition. This is the first step in development of a thermal-signature database, to be used along with other signature databases, to improve identification of energetic substances of unknown composition. The results indicated that each individual thermal signature was associated unambiguously with a particular mixture composition. The signature features of a particular mixture were shaped by the individual constituent signatures. It was also uncovered that the baseline signature was modified after an experiment due to coating of unreacted residue on the substrate surface and a change in the reactor sphere oxide layer. Thus, care was required to pre-oxidize the sphere prior to an experiment. A minimum sample mass (which was dependent on composition) was required to detect the signature characteristics. Increased laser power served to magnify signal strength while preserving the signature features. For the mixtures examined, the thermal

  3. MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS

    Energy Technology Data Exchange (ETDEWEB)

    Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare [INAF-Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, I-09012 Capoterra (Italy); Zonca, Alberto, E-mail: gmulas@oa-cagliari.inaf.it, E-mail: silvia@oa-cagliari.inaf.it, E-mail: ccp@oa-cagliari.inaf.it, E-mail: azonca@oa-cagliari.inaf.it [Dipartimento di Fisica, Universita di Cagliari, Strada Prov.le Monserrato-Sestu Km 0.700, I-09042 Monserrato (Italy)

    2013-07-01

    We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproduce the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 Multiplication-Sign 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.

  4. Effects of hydrocarbon contamination on ozone generation with dielectric barrier discharges

    Science.gov (United States)

    Lopez, Jose L.; Vezzu, Guido; Freilich, Alfred; Paolini, Bernhard

    2013-08-01

    The increasing usage of the feed gases of lower grade liquid oxygen (LOX) containing higher levels of trace hydrocarbon impurities in dielectric barrier discharge (DBD) for ozone generation requires a better understanding of the kinetics of the by-product formation resulting from reactions involving these hydrocarbon impurities. As a case study of hydrocarbon impurities, the kinetics of CH4 conversion in DBDs and the subsequent HNO3 formation were investigated by means of gas-phase plasma diagnostics, supported by detailed process modeling, and extensive in-situ and ex-situ by-product analysis. The by-products formation in the plasma with the presence of CH4, were found to differ significantly in oxygen-fed generators as compared to generators fed with oxygen/nitrogen mixtures. The amount of HNO3 formed depends on the concentration of NOx formed in the plasma and the amount of CH4 that is converted, but not on the O3 concentration. In the present work we have investigated CH4 concentrations of up to 1.95 wt% of the feed gas. The rate of deterioration of the overall ozone generator performance was found to be affected by the concentration of nitrogen in the oxygen/nitrogen mixture.

  5. Residual-stress measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ezeilo, A.N.; Webster, G.A. [Imperial College, London (United Kingdom); Webster, P.J. [Salford Univ. (United Kingdom)

    1997-04-01

    Because neutrons can penetrate distances of up to 50 mm in most engineering materials, this makes them unique for establishing residual-stress distributions non-destructively. D1A is particularly suited for through-surface measurements as it does not suffer from instrumental surface aberrations commonly found on multidetector instruments, while D20 is best for fast internal-strain scanning. Two examples for residual-stress measurements in a shot-peened material, and in a weld are presented to demonstrate the attractive features of both instruments. (author).

  6. Using supercritical fluids to refine hydrocarbons

    Science.gov (United States)

    Yarbro, Stephen Lee

    2015-06-09

    A system and method for reactively refining hydrocarbons, such as heavy oils with API gravities of less than 20 degrees and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure, using a selected fluid at supercritical conditions. A reaction portion of the system and method delivers lightweight, volatile hydrocarbons to an associated contacting unit which operates in mixed subcritical/supercritical or supercritical modes. Using thermal diffusion, multiphase contact, or a momentum generating pressure gradient, the contacting unit separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques.

  7. Process for recovery of liquid hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Millar, J.F.; Cockshott, J.E.

    1978-04-11

    Methane is recovered as a gas for discharge to a pipeline from a gas stream containing methane and heavier hydrocarbons, principally ethane and propane. Separation is accomplished by condensing the heavier hydrocarbons and distilling the methane therefrom. A liquid product (LPG) comprising the heavier hydrocarbons is subsequently recovered and transferred to storage. Prior to being discharged to a pipeline, the recovered methane gas is compressed and in undergoing compression the gas is heated. The heat content of the gas is employed to reboil the refrigerant in an absorption refrigeration unit. The refrigeration unit is used to cool the LPG prior to its storage.

  8. The offshore hydrocarbon releases (HCR) database

    International Nuclear Information System (INIS)

    Bruce, R.A.P.

    1995-01-01

    Following Cullen Recommendation 39 which states that: ''The regulatory body should be responsible for maintaining a database with regard to hydrocarbon leaks, spills, and ignitions in the Industry and for the benefit of Industry'', HSE Offshore Safety Division (HSE-OSD) has now been operating the Hydrocarbon Releases (HCR) Database for approximately 3 years. This paper deals with the reporting of Offshore Hydrocarbon Releases, the setting up of the HCR Database, the collection of associated equipment population data, and the main features and benefits of the database, including discussion on the latest output information. (author)

  9. Waste Plastic Converting into Hydrocarbon Fuel Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Moinuddin; Mamunor Rashid, Mohammad; Molla, Mohammad

    2010-09-15

    The increased demand and high prices for energy sources are driving efforts to convert organic compounds into useful hydrocarbon fuels. Although much of this work has focused on biomass, there are strong benefits to deriving fuels from waste plastic material. Natural State Research Inc. (NSR) has invented a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbon of liquid fuel (patent pending). The method and principle of the production / process will be discussed. Initial tests with several widely used polymers indicate a high potential for commercialization.

  10. Reduced chemical kinetic model of detonation combustion of one- and multi-fuel gaseous mixtures with air

    Science.gov (United States)

    Fomin, P. A.

    2018-03-01

    Two-step approximate models of chemical kinetics of detonation combustion of (i) one hydrocarbon fuel CnHm (for example, methane, propane, cyclohexane etc.) and (ii) multi-fuel gaseous mixtures (∑aiCniHmi) (for example, mixture of methane and propane, synthesis gas, benzene and kerosene) are presented for the first time. The models can be used for any stoichiometry, including fuel/fuels-rich mixtures, when reaction products contain molecules of carbon. Owing to the simplicity and high accuracy, the models can be used in multi-dimensional numerical calculations of detonation waves in corresponding gaseous mixtures. The models are in consistent with the second law of thermodynamics and Le Chatelier's principle. Constants of the models have a clear physical meaning. The models can be used for calculation thermodynamic parameters of the mixture in a state of chemical equilibrium.

  11. Evaluation of superpave mixtures containing hydrated lime.

    Science.gov (United States)

    2013-07-01

    The use of hydrated lime in Hot-Mix Asphalt (HMA) mixtures can reduce permanent deformation, long-term aging, and moisture : susceptibility of mixtures. In addition, hydrated lime increases the stiffness and fatigue resistance of mixtures. This study...

  12. Performance evaluation of Louisiana superpave mixtures.

    Science.gov (United States)

    2008-12-01

    This report documents the performance of Louisiana Superpave mixtures through laboratory mechanistic tests, mixture : volumetric properties, gradation analysis, and early field performance. Thirty Superpave mixtures were evaluated in this : study. Fo...

  13. Genotoxicity of complex mixtures: CHO cell mutagenicity assay

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, M.E.; Samuel, J.E.

    1985-02-01

    A Chinese hamster ovary (CHO) mammalian cell assay was used to evaluate the genotoxicity of complex mixtures (synthetic fuels). The genotoxicity (mutagenic potency) of the mixtures increased as the temperature of their boiling range increased. Most of the genotoxicity in the 750/sup 0/F+ boiling-range materials was associated with the neutral polycyclic aromatic hydrocarbon (PAH) fractions. Chemical analysis data indicate that the PAH fractions of high-boiling coal liquids contain a number of known chemical carcinogens, including five- and six-ring polyaromatics (e.g., benzo(a)pyrene) as well as four- and five-ring alkyl-substituted PAH (e.g., methylchrysene and dimethylbenzanthracenes); concentrations are a function of boiling point (bp). In vitro genotoxicity was also detected in fractions of nitrogen-containing polyaromatic compounds, as well as in those with aliphatics of hydroxy-containing PAH. Mutagenic activity of some fractions was detectable in the CHO assay in the absence of an exogenous metabolic activation system; in some instances, addition of exogenous enzymes and cofactors inhibited expression of the direct-acting mutagenic potential of the fraction. These data indicate that the organic matrix of the chemical fraction determines whether, and to what degree, various mutagens are expressed in the CHO assay. Therefore, the results of biological assays of these mixtures must be correlated with chemical analyses for proper interpretation of these data. 29 references, 16 figures, 4 tables.

  14. Bioassay-based risk assessment of complex mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, K.C.; Safe, S.H. [Texas A& M Univ., Houston, TX (United States); Randerath, K.; Randerath, E. [College Station and Baylor College of Medicine, Houston, TX (United States)

    1994-12-31

    To compare the standard chemical-based risk assessment with in vitro genotoxicity assays, two complex environmental mixtures from a wood preserving site were analyzed in the Salmonella/microsome and E. coli prophage induction assays. Using GC/MS, sample 003 was found to contain relatively low levels of polycyclic aromatic hydrocarbons (PNAs) and elevated levels of polychlorinated dibenzo-p-dioxins (PCDDs), while sample 005 had higher levels of PNAs and relatively low levels of PCDDs. The complex mixtures were sequentially extracted with methylene chloride and methanol for analysis in Salmonella, or extracted with 1:1 hexane: acetone mixture for analysis in the prophage induction assay. At a dose of 1.0 mg/plate in Salmonella strain TA98 with metabolic activation, the methanol extract of sample 003 induced 197 net revertants, while sample 005 induced 436 net revertants. In the prophage induction assay, with activation, the hexane:acetone extract of sample 003 induced a fold increase that was slightly lower than that observed with sample 005. The estimated incremental carcinogenic risk for dermal adsorption and ingestion was 1.5E-3 for sample 003, while for sample 005 the estimated risk was 1.5E-2. Thus, the sample which induced the maximum response in both bioassays also had the highest estimated cancer risk. However, the frequency of PNA-DNA adducts in both skin and liver tissues was appreciably higher with sample 005 than with sample 003.

  15. Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico.

    Science.gov (United States)

    Romero, Isabel C; Schwing, Patrick T; Brooks, Gregg R; Larson, Rebekka A; Hastings, David W; Ellis, Greg; Goddard, Ethan A; Hollander, David J

    2015-01-01

    The Deepwater Horizon (DWH) spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM) over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000-1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals) in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC), aliphatic, polycyclic aromatic hydrocarbon (PAHs), and biomarker (hopanes, steranes, diasteranes) compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1) sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material), and 2) advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related) variability in the DeSoto Canyon, NE of the DWH wellhead.

  16. Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    Isabel C Romero

    Full Text Available The Deepwater Horizon (DWH spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000-1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC, aliphatic, polycyclic aromatic hydrocarbon (PAHs, and biomarker (hopanes, steranes, diasteranes compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1 sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material, and 2 advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related variability in the DeSoto Canyon, NE of the DWH wellhead.

  17. Solution Approach for a Mathematical Model Developed for Membrane Separation of a Gas Hydrocarbon Mixture

    Science.gov (United States)

    Boroujeni, Mahdi K.; Goodarzi, F.

    2011-09-01

    In present study, a special mathematical model for membrane separation processes was studied. Mathematical model was developed for propylene/propane system and was solved using finite difference solution approach. In this study, membrane length is shared into a number of nodes and required equations are written for each node, separately. Also, golden section method was used for suitable step size selection. It is prescience that the results accuracy and calculation time, depend on number of meshes. Therefore 20 meshes were obtained as an optimum number. The effect of pressure drop equation on solution procedure of the model was also investigated and it was found that the pressure drop equation has a negligible effect on it.

  18. Formation of chemical compounds from irradiated mixtures of aromatic hydrocarbons and nitrogen oxides

    NARCIS (Netherlands)

    Besemer, A.C.

    1982-01-01

    The paper describes the analysis of products of the photochemical degradation of toluene and toluene-14C in smog chamber experiments. Compounds identified included methylglyoxal, possibly the recently postulated butenedial and other carbonyl compounds. The main product of photochemical degradation

  19. Radiation aging studies of CO2 hydrocarbon mixtures for the SLD drift chamber

    International Nuclear Information System (INIS)

    Venuti, J.P.; Chadwick, G.B.

    1988-10-01

    The SLD drift chamber requires a 'slow' drifting gas and low diffusion to allow wave form digitization. CO 2 provides this but requires an admixture of a quencher to provide more gain. A test chamber with an 8 sense wire cell, such as will appear in the final chamber, was exposed to an x-ray tube while containing a variety of binary admixtures of Co 2 : 8% isobutane, 8% ethane, and 2% isopropanol. It was determined that adding small fractions of water (≤0.66%) or isopropanol (1--2%) to the Co 2 : 8% ethane, or 8% isobutane extended the useful life of the chamber so that integrated charge collections of /approximately/1 C/cm are permissible. Results and discussions are presented. 10 refs., 7 figs., 1 tab

  20. Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

    Science.gov (United States)

    Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are not. Thus, we examined the mutagenicity in Salmonella TA100 of photochemical atmospheres generated in a steady-state a...

  1. Interfacial interactions and mass transfer at the interfacial region of bituminous hydrocarbon mixtures

    NARCIS (Netherlands)

    Van Lent, D.Q.

    2014-01-01

    The adhesion between bitumen and aggregate is a complex process with numerous of variables. To improve the understanding of the bond between bitumen and aggregates in road applications, this research focuses on preferential adsorption, which is one aspect of bitumen-aggregate adhesion. The main

  2. Isothermal P-V-T Measurements on Gas Hydrocarbon Mixtures Using a Vibrating Tube Apparatus

    Czech Academy of Sciences Publication Activity Database

    Čapla, L.; Buryan, P.; Jedelský, J.; Rottner, M.; Linek, Jan

    2002-01-01

    Roč. 34, č. 5 (2002), s. 657-667 ISSN 0021-9614 Institutional research plan: CEZ:AV0Z4072921 Keywords : density * equation of state * high pressure Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.000, year: 2002

  3. Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

    Data.gov (United States)

    U.S. Environmental Protection Agency — Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are...

  4. Evaluation of hydrocarbons level and identification of indigenous ...

    African Journals Online (AJOL)

    The parameters analyzed over an experimental period of 60 days were; total heterotrophic bacteria (THB), hydrocarbon utilizing bacteria (HUB), total petroleum hydrocarbon (TPH), polyaromatic hydrocarbon (PAH) and total hydrocarbon content (THC). The total heterotrophic bacterial count (THB) ranges from 1.36 x 106 ...

  5. Hydrocarbons from ethanol using [Fe,Al]ZSM-5 zeolites obtained by direct synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes Machado, Nadia Regina Camargo; Calsavara, Valmir [Departamento de Engenharia Quimica, Universidade Estadual de Maringa, Av. Colombo, 5790, CEP 87020-900, Maringa, Parana (Brazil); Astrath, Nelson Guilherme Castelli; Neto, Antonio Medina; Baesso, Mauro Luciano [Departamento de Fisica, Universidade Estadual de Maringa, Av. Colombo, 5790, CEP 87020-900, Maringa, Parana (Brazil)

    2006-09-01

    The search for new energy sources has impulsed hydrocarbon production from methanol and ethanol over ZSM-5 zeolites. Iron incorporation by different methods has led to a variety of chemical applications. Thus, hydrocarbon production from ethanol was evaluated using a [Fe,Al]ZSM-5 zeolite which was synthesized without nitrogenated templates, using ethanol and crystallization seeds and partially substituting iron for aluminium in the reaction mixture. Characterization was done by X-ray diffraction (XRD), Fourier-transform infra-red spectroscopy (FTIR), temperature programmed reduction (TPR), temperature programmed desorption of ammonia (TPD), nitrogen adsorption, electron paramagnetic resonance (EPR) and photoacoustic spectroscopies. Iron content in the synthesized samples varied from 0.02 to 1.82%. The obtained samples were used for the ethanol transformation, producing hydrocarbons from ethene to aromatics. Maximum production of liquid hydrocarbons was achieved with the zeolite with 0.5% iron. The procedure for obtaining the acid form of the zeolites, involving ammonium exchange and calcinations, has changed the iron species, probably with extraction from the structure, migration and agglomeration. (author)

  6. Forest residues in cattle feed

    Directory of Open Access Journals (Sweden)

    João Elzeário Castelo Branco Iapichini

    2012-12-01

    amount of 1% over the live weight + 10% of intake. The results of the first phase of the research, for steers supplemented in pasture, showed good acceptability and consumption in the three levels of substitution, with an average of 3.0 kg of concentrate per head. No rejection was observed for consumption of the mixture, as well as any physiological negative / change and clinical levels tested The pine cone (strobilus without the pine nuts (seeds was obtained as a residue of genetically improved seed collection. Likely source of tannins and fiber, dried and triturated pine cones can contribute to lower production costs due to the substitution of an ingredient in feed formulation, as an aid in control of internal parasites and also in the possible mitigation of methane gas production, resulting from digestion of ruminants, one of the gases responsible for the greenhouse effect. The potential use of pine cone as an ingredient in replacement of roughage and concentrate in the diet of ruminants qualifies as a new source of revenue in pine forestry activity, since no such product currently has no commercial value timber and its accumulation along the dried leaves among the trees, increase the risk of forest fires. Finally, these technological and social innovations result in remarkable potential to leverage Regional Programs Sustainable Development.

  7. Composition of carbonization residues

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer; Leonhardt

    1943-11-27

    This report compared the composition of samples from Wesseling and Leuna. In each case the sample was a residue from carbonization of the residues from hydrogenation of the brown coal processed at the plant. The composition was given in terms of volatile components, fixed carbon, ash, water, carbon, hydrogen, oxygen, nitrogen, volatile sulfur, and total sulfur. The result of carbonization was given in terms of (ash and) coke, tar, water, gas and losses, and bitumen. The composition of the ash was given in terms of silicon dioxide, ferric oxide, aluminum oxide, calcium oxide, magnesium oxide, potassium and sodium oxides, sulfur trioxide, phosphorus pentoxide, chlorine, and titanium oxide. The most important difference between the properties of the two samples was that the residue from Wesseling only contained 4% oil, whereas that from Leuna had about 26% oil. Taking into account the total amount of residue processed yearly, the report noted that better carbonization at Leuna could save 20,000 metric tons/year of oil. Some other comparisons of data included about 33% volatiles at Leuna vs. about 22% at Wesseling, about 5 1/2% sulfur at Leuna vs. about 6 1/2% at Leuna, but about 57% ash for both. Composition of the ash differed quite a bit between the two. 1 table.

  8. Designing with residual materials

    NARCIS (Netherlands)

    Walhout, W.; Wever, R.; Blom, E.; Addink-Dölle, L.; Tempelman, E.

    2013-01-01

    Many entrepreneurial businesses have attempted to create value based on the residual material streams of third parties. Based on ‘waste’ materials they designed products, around which they built their company. Such activities have the potential to yield sustainable products. Many of such companies

  9. The Fate of Hydrocarbon Pollution in Kebnekaise, Arctic Sweden

    Science.gov (United States)

    Rosqvist, G. N.; Jarjso, J.; Clason, C.; Jansson, P.; Karlin, T.

    2013-12-01

    A C-130J-30 Super Hercules plane crashed into the west-facing wall of the Kebnekaise mountain (2103 m), Arctic Sweden, on March 15th 2012. When starting from Evenes, Narvik, Norway, the aircraft had 14100 l fuel, 50 l hydraulic oil and 170 l motor oil onboard. Best estimates are that at least 12 000 l of fuel was sprayed over the mountain most of which was buried together with the wreck in a huge snow avalanche that was triggered by the impact in a NW facing cirque on Rabots glacier between ca 1600 and 2000 m. Fuel decontamination was not possible because of the extreme impact site conditions. The Hercules airplane was fueled with JET A-1 which is a hydrocarbon product in the Kerosene/Jet Fuel category consisting of sweetened kerosene and hydrotreated light distillates. The major components of all 'kerosene's' are branched- and straight-chain paraffins and naphthenes (cycloparaffins or cycloalkanes), which normally account for 70% by volume. Aromatic hydrocarbons, such as alkyl benzenes (single ring) and alkylnaphthalenes (double ring) do not exceed 25 % by volume of kerosene. The fuel also contains polycyclic aromatic hydrocarbons (PAH), but in very small volumes compared to the major components. The physical and chemical properties of each component (or block) of the hydrocarbon mixture influence its migration rate and fate. Some components of the fuel will volatilize, some are soluble in water but the vast majority are non-soluble. Although the solubility of these so called Light Nonaqueous Phase Liquids (LNAPL) in water is small they are highly toxic. We need to consider transport of the soluble components of the LNAPL in the melt-water, and transport of the non-soluble components with the melt-water system. Transport and storage can occur through and in snow (or firn), crevasses, and cavities on, in or under the glacier. Storage in, and contamination of, basal sediments, located below the glacier, or pro-glacial sediments, in front of the glacier are also

  10. Determining Biodegradation Kinetics of Hydrocarbons at Low Concentrations: Covering 5 and 9 Orders of Magnitude of Kow and Kaw

    DEFF Research Database (Denmark)

    Birch, Heidi; Høst Hammershøj, Rikke; Mayer, Philipp

    2018-01-01

    A partitioning-based experimental platform was developed and applied to determine primary biodegradation kinetics of 53 hydrocarbons at ng/L to μg/L concentrations covering C8-C20, 11 structural classes, and several orders of magnitude in hydrophobicity and volatility: (1) Passive dosing from...... a loaded silicone donor was used to set the concentration of each hydrocarbon in mixture stock solutions; (2) these solutions were combined with environmental water samples in gastight auto sampler vials for 1-100 days incubation, and (3) automated solid phase microextraction (SPME) coupled to GC......-MS was applied directly on these test systems for measuring primary biodegradation relative to abiotic controls. First order biodegradation kinetics were obtained for 40 hydrocarbons in activated sludge filtrate, 18 in seawater, and 21 in lake water. Water phase half-lives in seawater and lake water were poorly...

  11. Evaluation of Synthetic Hydrocarbon Instrument Bearing Oils

    National Research Council Canada - National Science Library

    Rebuck, Neal

    1982-01-01

    The work reported herein resulted from the testing of three viscosity grade synthetic hydrocarbon oils to determine their suitability as replacements for Specification MIL-L-83176 superrefined mineral oils...

  12. Gravity observations for hydrocarbon reservoir monitoring

    NARCIS (Netherlands)

    Glegola, M.A.

    2013-01-01

    In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The

  13. Informative document halogenated hydrocarbon-containing waste

    NARCIS (Netherlands)

    Verhagen H

    1992-01-01

    This "Informative document halogenated hydrocarbon-containing waste" forms part of a series of "Informative documents waste materials". These documents are conducted by RIVM on the instructions of the Directorate General for the Environment, Waste Materials Directorate, in

  14. Hydrocarbon Leak Detection Sensor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT is proposing the development of a sensor to detect the presence of hydrocarbons in turbopump Inter-Propellant Seals (IPS). The purpose of the IPS is to prevent...

  15. Using microorganisms to aid in hydrocarbon degradation

    International Nuclear Information System (INIS)

    Black, W.; Zamora, J.

    1993-01-01

    Aliphatic hydrocarbons are threatening the potable water supply and the aquatic ecosystem. Given the right microbial inhabitant(s), a large portion of these aliphatic hydrocarbons could be biodegraded before reaching the water supply. The authors' purpose is to isolate possible oil-degrading organisms. Soil samples were taken from hydrocarbon-laden soils at petroleum terminals, a petroleum refinery waste-treatment facility, a sewage-treatment plant grease collector, a site of previous bioremediation, and various other places. Some isolates known to be good degraders were obtained from culture collection services. These samples were plated on a 10w-30 multigrade motor oil solid medium to screen for aliphatic hydrocarbon degraders. The degrading organisms were isolated, identified, and tested (CO 2 evolution, BOD, and COD) to determine the most efficient degrader(s). Thirty-seven organisms were tested, and the most efficient degraders were Serratia marcescens, Escherichia coli, and Enterobacter agglomerans

  16. Using microorganisms to aid in hydrocarbon degradation

    Energy Technology Data Exchange (ETDEWEB)

    Black, W.; Zamora, J. (Middle Tennessee State Univ., Murfreesboro (United States))

    1993-04-01

    Aliphatic hydrocarbons are threatening the potable water supply and the aquatic ecosystem. Given the right microbial inhabitant(s), a large portion of these aliphatic hydrocarbons could be biodegraded before reaching the water supply. The authors' purpose is to isolate possible oil-degrading organisms. Soil samples were taken from hydrocarbon-laden soils at petroleum terminals, a petroleum refinery waste-treatment facility, a sewage-treatment plant grease collector, a site of previous bioremediation, and various other places. Some isolates known to be good degraders were obtained from culture collection services. These samples were plated on a 10w-30 multigrade motor oil solid medium to screen for aliphatic hydrocarbon degraders. The degrading organisms were isolated, identified, and tested (CO[sub 2] evolution, BOD, and COD) to determine the most efficient degrader(s). Thirty-seven organisms were tested, and the most efficient degraders were Serratia marcescens, Escherichia coli, and Enterobacter agglomerans.

  17. Molecular characterization of autochthonous hydrocarbon utilizing ...

    African Journals Online (AJOL)

    Prof. Ogunji

    detoxify organic contaminants has been established as an economical, efficient, versatile and environmentally friendly treatment. ... required to provide informed and quick response to emergent environmental challenges. Therefore the objectives of this ... hydrocarbon pollutants in the environment. Materials and Methods.

  18. cyclic -perimeter hydrocarbon ruthenium complexes bearing ...

    Indian Academy of Sciences (India)

    - cyclic -perimeter hydrocarbon ruthenium complexes bearing functionalized pyridyl diketones: Isolation of complexes with 2-N∩O and 4-N∩O bonding modes of ligands. Saphidabha L Nongbri Babulal Das Mohan Rao Kollipara.

  19. Determination of carcinogenic polycyclic aromatic hydrocarbons ...

    African Journals Online (AJOL)

    Determination of carcinogenic polycyclic aromatic hydrocarbons (pahs), anthracene in different variety of fish samples in the Bangsai river of Bangladesh. F Yeasmin, SMM Rahman, S Rana, KJ Fatema, MA Hossain ...

  20. Observation of the Dissolution from Residual Phase Multicomponent Nonaqueous Phase Liquids

    Science.gov (United States)

    Brahma, P. P.; Harmon, T. C.

    2001-05-01

    Nonaqueous phase liquid (NAPL) subsurface contaminants (e.g., fuels, solvents) are typically complex mixtures. This work examines the impact of intra-NAPL diffusion and mixture nonideality on dissolution from multicomponent NAPL mixtures through a computational and experimental approach. Downstream concentrations are observed during the controlled dissolution of three-component residual NAPL in a three-dimensional model aquifer. These results, when compared to single-component residual NAPL results, are used to identify (1) if and when intra-NAPL interactions contribute significantly to the overall dissolution process, and (2) the role that factors, such as length scale, hydrodynamic conditions, and/or mixture ideality, play in determining (1). Model ternary mixtures were chosen to represent a range of ideality based on UNIFAC-estimated activity coefficients. In this case, tetrachloroethene (PCE), trichloroethene (TCE), and 1,1,1-trichloroethane (TCA) were selected as the ideal mixture. The mixture of PCE, TCE, and octanol was shown to exhibit significant deviations from ideality and selected to represent a nonideal mixture. Experimental results for the two mixtures are compared to each other and to analogous results from pure PCE dissolution experiments. The experimental results are further interpreted using a three-dimensional transport model subject to a boundary concentration history calculated using a ternary intra-NAPL diffusion/dissolution submodel. The combined experimental and computational findings are used to delineate conditions for which a detailed physical-chemical description of NAPL dissolution is warranted and those for which a simplified description will suffice.

  1. Nonparametric e-Mixture Estimation.

    Science.gov (United States)

    Takano, Ken; Hino, Hideitsu; Akaho, Shotaro; Murata, Noboru

    2016-12-01

    This study considers the common situation in data analysis when there are few observations of the distribution of interest or the target distribution, while abundant observations are available from auxiliary distributions. In this situation, it is natural to compensate for the lack of data from the target distribution by using data sets from these auxiliary distributions-in other words, approximating the target distribution in a subspace spanned by a set of auxiliary distributions. Mixture modeling is one of the simplest ways to integrate information from the target and auxiliary distributions in order to express the target distribution as accurately as possible. There are two typical mixtures in the context of information geometry: the [Formula: see text]- and [Formula: see text]-mixtures. The [Formula: see text]-mixture is applied in a variety of research fields because of the presence of the well-known expectation-maximazation algorithm for parameter estimation, whereas the [Formula: see text]-mixture is rarely used because of its difficulty of estimation, particularly for nonparametric models. The [Formula: see text]-mixture, however, is a well-tempered distribution that satisfies the principle of maximum entropy. To model a target distribution with scarce observations accurately, this letter proposes a novel framework for a nonparametric modeling of the [Formula: see text]-mixture and a geometrically inspired estimation algorithm. As numerical examples of the proposed framework, a transfer learning setup is considered. The experimental results show that this framework works well for three types of synthetic data sets, as well as an EEG real-world data set.

  2. Hydrocarbon fractions. Aromatic determination by mass spectrometry

    International Nuclear Information System (INIS)

    Anon.

    Analysis of hydrocarbon fractions by mass spectrometry using low energy electrons, for determination of aromatic hydrocarbons repartition, suitable for fraction with the following properties: boiling point up to 320 0 C, whithout olefine, sulfur content up to 0.1 per cent, boiling range up to 100 0 C, if the final temperature is 200 0 C, and up to 50 0 C, if over 200 0 C [fr

  3. Artificial Hydrocarbon Networks Fuzzy Inference System

    OpenAIRE

    Ponce, Hiram; Ponce, Pedro; Molina, Arturo

    2013-01-01

    This paper presents a novel fuzzy inference model based on artificial hydrocarbon networks, a computational algorithm for modeling problems based on chemical hydrocarbon compounds. In particular, the proposed fuzzy-molecular inference model (FIM-model) uses molecular units of information to partition the output space in the defuzzification step. Moreover, these molecules are linguistic units that can be partially understandable due to the organized structure of the topology and metadata param...

  4. The future of oil and hydrocarbon man

    CERN Document Server

    Campbell, Colin

    1999-01-01

    Man appeared on the planet about four million years ago, and by 1850 numbered about one billion Ten came Hydrocarbon man. World population has since increased six-fold. After the oil price shocks of the 1970s, people asked "when will production peak?". It is not easy to answer this question because of the very poor database. Reserves and the many different hydrocarbon categories are poorly defined, reporting practices are ambiguous, revisions are not backdated...

  5. Formation of hydrocarbons by bacteria and algae

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T.G.

    1980-12-01

    A literature review has been performed summarizing studies on hydrocarbon synthesis by microorganisms. Certain algal and bacterial species produce hydrocarbons in large quantities, 70 to 80% of dry cell mass, when in a controlled environment. The nutritional requirements of these organisms are simple: CO/sub 2/ and mineral salts. The studies were initiated to determine whether or not microorganisms played a role in petroleum formation. 90 references. (DMC)

  6. Hydrocarbon pollution and monitorin in Augusta Bay

    Energy Technology Data Exchange (ETDEWEB)

    Crisafi, E.; De Domenico, L.; Puglisi, A. [Consiglio Nazionale delle Ricerche, Messina (Italy). Thallasographic Inst.; Magazzu`, G. [Lecce, Univ. (Italy). Biology Dept.

    1995-12-31

    Surveys in the coastal waters of Sicily (Augusta Bay) were carried out between 1900 and 1991 in order to assess the level of the hydrocarbon - pollution. Results show that helicopter tele-survey is an optimal technique for monitoring polycyclic aromatic hydrocarbons (PAH). High PAH concentrations, due to the discharge of sewage and industrial effluents, as well as shipping activity, were found in the area.

  7. Zeolitic catalytic conversion of alcohols to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2018-04-10

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  8. Zeolitic catalytic conversion of alochols to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2017-01-03

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  9. Birds and polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Albers, P.H.

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.

  10. Polycyclic hydrocarbons - occurrence and determination

    International Nuclear Information System (INIS)

    Drzewicz, P.

    2007-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a special group of atmospheric contaminants included in the persistent toxic substances (PTS) and also in the volatile organic compounds (VOC) groups. PAHs are present in the atmosphere and their origin can be due to anthropogenic activities. The main source of emission of PAH is the combustion of fossil fuels. Their specific characteristics, high volatility, mutagenic and carcinogenic power, easily transportable for long distances with the wind, make them important contaminants despite of the fact that they are present at very low concentrations. The report provides a review of main analytical methods applied in the determination of PAH in air. Special attention was devoted to heterocyclic PAH which contain one or more heteroatom (sulphur, oxygen, nitrogen) in the multiple-fused ring. The presence of heterocyclic PAH requires very complex, laborious and long lasting sample separation methods before analysis. In some cases, application of different temperature programs in gas chromatography allows to determine PAH and heterocyclic PAH in gaseous samples without sample pretreatment. Gas chromatography methods for the determination of PAH and heterocyclic PAH in the gas from combustion of light heating oil has been optimized. (author) [pl

  11. Monitoring of microbial hydrocarbon remediation in the soil

    OpenAIRE

    Chikere, Chioma Blaise; Okpokwasili, Gideon Chijioke; Chikere, Blaise Ositadinma

    2011-01-01

    Bioremediation of hydrocarbon pollutants is advantageous owing to the cost-effectiveness of the technology and the ubiquity of hydrocarbon-degrading microorganisms in the soil. Soil microbial diversity is affected by hydrocarbon perturbation, thus selective enrichment of hydrocarbon utilizers occurs. Hydrocarbons interact with the soil matrix and soil microorganisms determining the fate of the contaminants relative to their chemical nature and microbial degradative capabilities, respectively....

  12. Applications of electrochemically-modulated liquid chromatography (EMLC): Separations of aromatic amino acids and polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Li [Iowa State Univ., Ames, IA (United States)

    1998-03-27

    The research in this thesis explores the separation capabilities of a new technique termed electrochemically-modulated liquid chromatography (EMLC). The thesis begins with a general introduction section which provides a literature review of this technique as well as a brief background discussion of the two research projects in each of the next two chapters. The two papers which follow investigate the application of EMLC to the separation of a mixture of aromatic amino acids and of a mixture of polycyclic aromatic hydrocarbons (PAHs). The last section presents general conclusions and summarizes the thesis. References are compiled in the reference section of each chapter. The two papers have been removed for separate processing.

  13. Distribution of pesticide residues in soil and uncertainty of sampling.

    Science.gov (United States)

    Suszter, Gabriela K; Ambrus, Árpád

    2017-08-03

    Pesticide residues were determined in about 120 soil cores taken randomly from the top 15 cm layer of two sunflower fields about 30 days after preemergence herbicide treatments. Samples were extracted with acetone-ethyl acetate mixture and the residues were determined with GC-TSD. Residues of dimethenamid, pendimethalin, and prometryn ranged from 0.005 to 2.97 mg/kg. Their relative standard deviations (CV) were between 0.66 and 1.13. The relative frequency distributions of residues in soil cores were very similar to those observed in root and tuber vegetables grown in pesticide treated soils. Based on all available information, a typical CV of 1.00 was estimated for pesticide residues in primary soil samples (soil cores). The corresponding expectable relative uncertainty of sampling is 20% when composite samples of size 25 are taken. To obtain a reliable estimate of the average residues in the top 15 cm layer of soil of a field up to 8 independent replicate random samples should be taken. To obtain better estimate of the actual residue level of the sampled filed would be marginal if larger number of samples were taken.

  14. GammaProteobacteria as a potential bioindicator of a multiple contamination by polycyclic aromatic hydrocarbons (PAHs) in agricultural soils

    International Nuclear Information System (INIS)

    Niepceron, Maïté; Martin-Laurent, Fabrice; Crampon, Marc; Portet-Koltalo, Florence; Akpa-Vinceslas, Marthe; Legras, Marc; Bru, David; Bureau, Fabrice; Bodilis, Josselin

    2013-01-01

    The impact of a multiple contamination by polycyclic aromatic hydrocarbons (PAHs) was studied on permanent grassland soil, historically presenting low contamination (i.e. less than 1 mg kg −1 ). Soil microcosms were spiked at 300 mg kg −1 with either single or a mixture of seven PAHs. While total dissipation of the phenanthrene was reached in under 90 days, only 60% of the PAH mixture were dissipated after 90 days. Interestingly, after 30 days, the abundance of the GammaProteobacteria class (assessed by qPCR) become significantly higher in microcosms spiked with the PAH mixture. In addition, the specific abundance of the cultivable Pseudomonas spp., which belong to the GammaProteobacteria class, increased earlier and transiently (after 8 days) in the microcosms spiked with the PAH mixture. Consequently, we propose to use the GammaProteobacteria as a bioindicator to detect the impact on the bacterial community of a multiple contamination by PAHs in agricultural soils. -- The abundance of the GammaProteobacteria class increases significantly in response to a spiking by a polycyclic aromatic hydrocarbon mixture

  15. Hydrogen production by reforming of liquid hydrocarbons in a membrane reactor for portable power generation-Experimental studies

    Science.gov (United States)

    Damle, Ashok S.

    One of the most promising technologies for lightweight, compact, portable power generation is proton exchange membrane (PEM) fuel cells. PEM fuel cells, however, require a source of pure hydrogen. Steam reforming of hydrocarbons in an integrated membrane reactor has potential to provide pure hydrogen in a compact system. Continuous separation of product hydrogen from the reforming gas mixture is expected to increase the yield of hydrogen significantly as predicted by model simulations. In the laboratory-scale experimental studies reported here steam reforming of liquid hydrocarbon fuels, butane, methanol and Clearlite ® was conducted to produce pure hydrogen in a single step membrane reformer using commercially available Pd-Ag foil membranes and reforming/WGS catalysts. All of the experimental results demonstrated increase in hydrocarbon conversion due to hydrogen separation when compared with the hydrocarbon conversion without any hydrogen separation. Increase in hydrogen recovery was also shown to result in corresponding increase in hydrocarbon conversion in these studies demonstrating the basic concept. The experiments also provided insight into the effect of individual variables such as pressure, temperature, gas space velocity, and steam to carbon ratio. Steam reforming of butane was found to be limited by reaction kinetics for the experimental conditions used: catalysts used, average gas space velocity, and the reactor characteristics of surface area to volume ratio. Steam reforming of methanol in the presence of only WGS catalyst on the other hand indicated that the membrane reactor performance was limited by membrane permeation, especially at lower temperatures and lower feed pressures due to slower reconstitution of CO and H 2 into methane thus maintaining high hydrogen partial pressures in the reacting gas mixture. The limited amount of data collected with steam reforming of Clearlite ® indicated very good match between theoretical predictions and

  16. Hydrocarbon contamination of coastal sediments from the Sfax area (Tunisia), Mediterranean Sea.

    Science.gov (United States)

    Louati, A; Elleuch, B; Kallel, M; Saliot, A; Dagaut, J; Oudot, J

    2001-06-01

    The coastal area off the city of Sfax (730,000 inhabitants), well-known for fisheries and industrial activities, receives high inputs of organic matter mostly anthropogenic. Eighteen stations were selected in the vicinity of the direct discharge of industrial sewage effluents in the sea in order to study the spatial distribution of the organic contamination. Surface sediments sampled in the shallow shelf were analysed for hydrocarbons by Fourier transform infrared spectroscopy, gas chromatography and gas chromatography/mass spectrometry. Total hydrocarbon distributions revealed high contamination as compared to other coastal Mediterranean sites, with an average concentration of 1865 ppm/dry weight sediment. Gas chromatographic distribution patterns, values of unresolved mixture/n-alkane ratio and distributions of steranes and hopanes confirmed a petroleum contamination of the Arabian light crude oil type. Biogenic compounds were also identified with a series of short-chain carbon-numbered n-alkenes in the carbon range 16-24.

  17. Distribution and sources of aliphatic hydrocarbons in surface sediments of Sergipe River estuarine system.

    Science.gov (United States)

    Lima, Manoel B; Feitosa, Elaine A; Emídio, Elissandro S; Dórea, Haroldo S; Alexandre, Marcelo R

    2012-08-01

    The assessment of aliphatic hydrocarbons was performed in the Sergipe River estuarine system, northeastern Brazil. Aliphatic hydrocarbons concentration ranged from 9.9 ug g⁻¹ up to 30.8 ug g⁻¹ of dry sediment. The carbon preference index (CPI, based on nC₂₄ to nC₃₄ range), indicated predominance of petrogenic input in two of the sites analyzed (P4 and P5). The unresolved complex mixture (UCM) was found to be present in seven of the nine sites sampled (except for P4 and P5). Overall, the results of this work suggest that there is a mix of organic matter sources to the sediment. Although the coast of Sergipe has an intense off shore petroleum exploration and the Sergipe River crosses the entire city of Aracaju, the capital city of Sergipe, non-significant anthropogenic fingerprint was assessed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Polycyclic aromatic hydrocarbons affect survival and development of common snapping turtle (Chelydra serpentina) embryos and hatchlings

    International Nuclear Information System (INIS)

    Van Meter, Robin J.; Spotila, James R.; Avery, Harold W.

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds found in the John Heinz National Wildlife Refuge in Philadelphia, Pennsylvania. We assessed the impact of PAHs and crude oil on snapping turtle development and behavior by exposing snapping turtle eggs from the Refuge and from three clean reference sites to individual PAHs or a crude oil mixture at stage 9 of embryonic development. Exposure to PAHs had a significant effect on survival rates in embryos from one clean reference site, but not in embryos from the other sites. There was a positive linear relationship between level of exposure to PAHs and severity of deformities in embryos collected from two of the clean reference sites. Neither righting response nor upper temperature tolerance (critical thermal maximum, CTM) of snapping turtle hatchlings with no or minor deformities was significantly affected by exposure to PAHs. - Exposure to polycyclic aromatic hydrocarbons on the egg reduces survival of snapping turtle embryos and causes developmental abnormalities

  19. Studies concerning thermodynamics and kinetics of the absorption of halogenated hydrocarbons relevant to environment

    International Nuclear Information System (INIS)

    Weisweiler, W.; Eidam, K.; Winterbauer, H.

    1993-07-01

    In the context of the research project the scrubbing of air contaminated by peculiar volatile organic compounds was investigated using the absorption technique by means of high boiling organics as washing liquids. Eight chlorinated hydrocarbons well known from technical processes were chosen to be representative for the volatile organic compounds. Eleven absorption media were selected on the basis of their physical properties. For the determination of the solubility data of the absorption media due to chlorinated hydrocarbons, nitrogen as well as a mixture of nitrogen and oxygen were used as carrier gas. The influence of the dipole moment of the absorption media on the amount of solubility - expressed as enrichment factor - was studied, too. Concerning the technical application, the thermostability and the stability against diluted inorganic acids were studied as well. (orig.). 56 figs., 8 tabs., 63 refs [de

  20. Study of the elimination on palladium three-way catalysts of the different unburnt hydrocarbons types contained in automobiles exhaust gases; Etude de l`elimination sur catalyseurs trois-voies a base de palladium des differentes categories d`hydrocarbures imbrules presentes dans les gaz d`echappement automobiles

    Energy Technology Data Exchange (ETDEWEB)

    Amon-Meziere, I.

    1996-04-22

    This work was done about a study of behaviour of automotive three-way catalyst containing palladium. In particularly the conversion of many hydrocarbons and oxygenate compounds was studied either alone or mixed. The temperature range of reaction, the influence of the hydrocarbon nature on his conversion, the effect of thermal ageing of catalyst and the effect of dioxide sulfur on the hydrocarbon oxidation was clarified. We have showed the different reaction who were done at the time of different pollutant conversion (CO, NO and one HC) and the influence of different species present in a real exhaust gas on the catalytic oxidation of propane and propane has been checked. We have concluded that the presence of the other species in the gas mixture did not modify very much the activities of the catalyst toward hydrocarbon conversion under stoichiometric conditions, that the slow step of hydrocarbon oxidation is the absorption of molecule and that under oxidizing conditions propane conversion was effected by oxygen. Then we have evaluated our palladium/rhodium three-way catalyst as regards its effectiveness in the catalytic oxidation of different hydrocarbon species and oxygenated compounds taken individually. Two categories of hydrocarbons can also distinguished: first the short chain alkanes and then the long chain alkanes and the other hydrocarbons. We have showed the inhibiting effect of hydrocarbons as concerns CO oxidation and NO reduction. And the study of hydrocarbons mixtures has showed an inhibiting effect of one hydrocarbon on the oxidation of the hydrocarbons in few cases. The study of behaviour of the ageing catalyst containing palladium has showed an important decrease of its effectiveness who can be explained by the decrease of active site number. Some ppm of sulfur dioxide in gas mixture resulted in its inhibiting effect of all species conversion. (author) 74 refs.