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Sample records for hydrocarbon molecules heavier

  1. Monte Carlo properties of the hydrocarbon chains of phospholipid molecules

    Science.gov (United States)

    Zhurkin, D. V.; Rabinovich, A. L.

    2015-02-01

    Properties of 65 chain hydrocarbon molecules in the unperturbed state are investigated using the Monte Carlo method at temperatures of 293, 303, and 313 K. Chains with the general structure CH3-(CH2) a -(CH=CH-CH2) d -(CH2) b -CH3 are considered. The number of carbon atoms in a skeleton N = 16, 18, 20, and 22; the number of cis-double bonds d = 0, 1, ..., 6. Conformations are generated with continuous varying of the angles of internal rotation around simple C-C bonds in the range of 0°-360°, the interdependence of each three angles along the chain is allowed for, and essential sampling is performed. Different properties of molecules are considered: the average maximum projections of hydrocarbon chains on their main axes of inertia, average squares of the radii of inertia, and relative fluctuations in the squares of the radii of inertia. The dependence of the calculated characteristics on the structural parameters of the chains is investigated.

  2. Energetics and electronic structure of nanoscale rotors consisting of triptycene and hydrocarbon molecules

    Science.gov (United States)

    Akiba, Miki; Okada, Susumu

    2017-10-01

    Using the density functional theory with generalized gradient approximation, we studied the energetics and electronic structures of nanoscale rotors consisting of tryptycene and hydrocarbon molecules with respect to their mutual orientation. Energy barriers for the rotational motion of an attached hydrocarbon molecule range from 40 to 200 meV, depending on the attached molecular species and arrangements. The electronic structure of the nanoscale molecular rotors does not depend on the rotational angle of the attached hydrocarbon molecules.

  3. Electron spectroscopy of selected atmospheric molecules and hydrocarbons

    Science.gov (United States)

    Davies, Julia Ann

    The thesis presents experimental results obtained by electron impact energy-loss spectroscopy. Differential oscillator strengths (DOS) of selected atmospheric molecules and hydrocarbons and vibrational excitation cross sections of ozone are measured. A critical comparison with earlier experiments and theory (where it exists) is made. The thesis is arranged in seven chapters. The first discusses molecular structure, spectroscopy and electron-molecule scattering as is relevant to the scope of this thesis. The next two chapters describe the experimental apparatus used. A high resolution electron spectrometer produces an electron beam (˜10 nA) incident upon the molecular target. Scattered electrons of selected energy-loss and scattering angle are detected by the spectrometer providing a total apparatus resolution of ˜50 meV. The vacuum system, gas inlet system and power supplies are also discussed. Chapters 4, 5 and 6 contain the main results obtained during postgraduate studies. DOS of selected atmospheric molecules (O2, N2, N2O, CO and CO2) are presented and critically compared with previous optical and synchrotron studies. Good agreement between results validates the experimental apparatus and techniques used in this work. A detailed study of the DOS of small alkanes (CH4, C2H6, C3H8 and C4H10) and small alkenes (C2H4, C3H6 and C4H8) shows similarities and trends in these series. DOS of ozone, O3, are also measured and the vibrational excitation of ozone is investigated as a function of scattering angle (40° ≤ theta ≤ 120°) and inccident energy (3 eVmolecule of importance in ozone chemistry. Suggestions for future work, such as an investigation into the effects of temperature on DOS spectra for atmospheric molecules, are also presented.

  4. Anharmonicity and infrared bands of Polycyclic Aromatic Hydrocarbon (PAH) molecules

    Science.gov (United States)

    Petrignani, Annemieke; Maltseva, Elena; Candian, Alessandra; Mackie, Cameron; Huang, Xinchuan; Lee, Timothy J.; Tielens, Alexander; Oomens, Jos; Buma, Wybren Jan

    2015-08-01

    We present a systematic laboratory study of the CH stretching region in Polycyclic Aromatic Hydrocarbon (PAH) molecules of different shapes and sizes to investigate anharmonic behaviour and address the reliability of the never-validated but universally accepted scaling factors employed in astronomical PAH models. At the same time, new anharmonic theoretical quantum chemistry studies have been performed with the software program Spectro using our experimental data as benchmark. We performed mass and conformational-resolved, high-resolution spectroscopy of cold (~10K) linear and compact PAH molecules starting with naphthalene (C10H8) in the 3-µm CH stretching region. Surprisingly, the measured infrared spectra show many more strong modes than expected. Measurements of the deuterated counterparts demonstrate that these bands are the result of Fermi Resonances. First comparisons with harmonic and anharmonic DFT calculations using Gaussian 09 show that both approximations are not able to reproduce in detail the observed molecular reality. The improved anharmonic calculations performed with Spectro now include the effects of Fermi resonances and have been applied to PAHs for the first time. The analysis of the experimental data is greatly aided by these new theoretical quantum chemistry studies. Preliminary assignments are presented, aided by comparison between the observed rotational contour and the symmetry of candidate bands.

  5. Magnetic molecules derived from hydrogenation of Polycyclic Aromatic Hydrocarbons

    CERN Document Server

    Vergés, J A; Louis, E; Pastor-Abia, L; SanFabian, E

    2008-01-01

    Present routes to produce magnetic organic-based materials adopt a common strategy: the use of magnetic species (atoms, polyradicals, etc.) as building blocks. We explore an alternative approach which consists of selective hydrogenation of Polycyclic Aromatic Hydrocarbons. Self-Consistent-Field (SCF) (Hartree-Fock and DFT) and multi-configurational (CISD and MCSCF) calculations on coronene and corannulene, both hexa-hydrogenated, show that the formation of stable high spin species is possible. The spin of the ground states is discussed in terms of the Hund rule and Lieb's theorem for bipartite lattices (alternant hydrocarbons in this case). This proposal opens a new door to magnetism in the organic world.

  6. Additivity rule for electron scattering on hydrocarbon molecules--considering two different shielding effects

    Institute of Scientific and Technical Information of China (English)

    Sun Jin-Feng; Du Chao-Ling; Shi De-Heng; Liu Yu-Fang

    2004-01-01

    Considering the overlapping among atoms in the molecule and the not full transparency of the molecule by electron,we propose a new formulation of the additivity rule (AR). Here the new AR is employed to calculate the total cross sections (TCS) for electron scattering on hydrocarbon molecules C2H2, C2H4, C2H6, and C3H8 over an incident energy range of 10-2000eV. The results are compared with the experimental data and other available theoretical calculations.This gives good agreement.

  7. Multifractal analysis of slacken surface in hydrocarbon molecules through fuel additives

    Directory of Open Access Journals (Sweden)

    G. Arockia Prabakar

    2014-09-01

    Full Text Available This paper investigates the effect of organic fuel additives (Bio-Glycerol on fuel savings, emission reduction and extend engine life. Using this enzyme, a motor cycle is tested five times. The test report shows the reduction in the release of carbon monoxide (CO and hydrocarbon upto 60%. The use of organic fuel additives in diesel vehicles for different periods of time reveals the reduction in air pollution by 55%. Finally, we have experimented scanning electron microscope (SEM test for organic fuel additives with biodiesel. The SEM image shows the existence of molecules of hydrocarbons. The analysis elucidated the complex morphology of molecules of hydrocarbons in fuel additives with biodiesel. The hydrocarbon molecules are slackened and irregular as it refers to the fractal form. SEM Photograph images are analyzed by multifractal analysis. MFA (multifractal analysis is carried out according to the method of moments, i.e., the probability distribution is estimated for moments which differ from -150

  8. Infrared spectra of protonated polycyclic aromatic hydrocarbon molecules: Azulene

    Science.gov (United States)

    Zhao, Dawei; Langer, Judith; Oomens, Jos; Dopfer, Otto

    2009-11-01

    The infrared (IR) spectrum of protonated azulene (AzuH+, C10H9+) has been measured in the fingerprint range (600-1800 cm-1) by means of IR multiple photon dissociation (IRMPD) spectroscopy in a Fourier transform ion cyclotron resonance mass spectrometer equipped with an electrospray ionization source using a free electron laser. The potential energy surface of AzuH+ has been characterized at the B3LYP/6-311G∗∗ level in order to determine the global and local minima and the corresponding transition states for interconversion. The energies of the local and global minima, the dissociation energies for the lowest-energy fragmentation pathways, and the proton affinity have been evaluated at the CBS-QB3 level. Comparison with calculated linear IR absorption spectra supports the assignment of the IRMPD spectrum to C4-protonated AzuH+, the most stable of the six distinguishable C-protonated AzuH+ isomers. Comparison between Azu and C4-AzuH+ reveals the effects of protonation on the geometry, vibrational properties, and the charge distribution of these fundamental aromatic molecules. Calculations at the MP2 level indicate that this technique is not suitable to predict reliable IR spectra for this type of carbocations even for relatively large basis sets. The IRMPD spectrum of protonated azulene is compared to that of isomeric protonated naphthalene and to an astronomical spectrum of the unidentified IR emission bands.

  9. About the Results of the Destruction of the Molecules of Liquid Hydrocarbons in the Field of Acoustic Cavitation

    OpenAIRE

    2016-01-01

    Analysis was conducted of fractional composition of hydrocarbon fuel. It is found that the excitation of cavitation in the fuel leads to a change of its fractional composition. This result can be explained by the destruction of liquid hydrocarbon molecules under high intensity of the unsteady pressure field

  10. Inclusion of poly-aromatic hydrocarbon (PAH) molecules in a functionalized layered double hydroxide

    Indian Academy of Sciences (India)

    L Mohanambe; S Vasudevan

    2006-01-01

    The internal surface of an Mg-Al layered double hydroxide has been functionalized by anchoring carboxy-methyl derivatized -cyclodextrin cavities to the gallery walls. Neutral polyaromatic hydrocarbon (PAH) molecules have been included within the functionalized solid by driving the hydrophobic aromatic molecules from a polar solvent into the less polar interior of the anchored cyclodextrin cavities by a partitioning process. The optical (absorption and emission) properties of the PAH molecules included within the functionalized Mg-Al layered double hydroxide solid are similar to that of dilute solutions of the PAH in non-polar solvents. The unique feature of these hybrid materials is that they are thermally stable over a wide temperature range with their emission properties practically unaltered.

  11. Energetics and Electronic Structures of Carbon Nanotubes Encapsulating Polycyclic Aromatic Hydrocarbon Molecules

    Science.gov (United States)

    Kigure, Shota; Iizumi, Yoko; Okazaki, Toshiya; Okada, Susumu

    2014-12-01

    We report total-energy electronic structure calculations that provide energetics of the encapsulation of polycyclic aromatic hydrocarbon (PAH) molecules coronene, sumanene, and corannulene into carbon nanotubes (CNTs) and electronic structures of the resulting carbon hybrid structures. Our calculations elucidate that the encapsulation of these PAHs into CNTs is an exothermic reaction for nanotubes with indexes of (16,0), (17,0), and (18,0) or thicker for coronene, sumanene, and corannulene molecules, respectively, and that the energy gain upon encapsulation is up to 1 eV per molecule. We also find that the stacking arrangement of encapsulated PAH molecules depends on the molecular species and inner spacing of the CNTs: coronene is tilted to the CNT axis in its stable conformation, sumanene is stacked normal to the CNT axis, and corannulene is randomly arranged along the CNT axis. The electron states of the PAH-CNT hybrids depend on both the space inside the CNTs and the tilting angle of the PAH molecules with respect to the CNTs, leading to substantial hybridization between π states of the PAH molecules and CNTs.

  12. Discovery of Blue Luminescence in the Red Rectangle: Possible Fluorescence from Neutral Polycyclic Aromatic Hydrocarbon Molecules?

    CERN Document Server

    Vijh, U P; Gordon, K D

    2004-01-01

    Here we report our discovery of a band of blue luminescence (BL) in the Red Rectangle (RR) nebula. This enigmatic proto-planetary nebula is also one of the brightest known sources of extended red emission as well as of unidentified infra-red (UIR) band emissions. The spectrum of this newly discovered BL is most likely fluorescence from small neutral polycyclic aromatic hydrocarbon (PAH) molecules. PAH molecules are thought to be widely present in many interstellar and circumstellar environments in our galaxy as well as in other galaxies, and are considered likely carriers of the UIR-band emission. However, no specific PAH molecule has yet been identified in a source outside the solar system, as the set of mid-infra-red emission features attributed to these molecules between the wavelengths of 3.3 micron and 16.4 micron is largely insensitive to molecular sizes. In contrast, near-UV/blue fluorescence of PAHs is more specific as to size, structure, and charge state of a PAH molecule. If the carriers of this nea...

  13. Electron impact total and ionization cross-sections for some hydrocarbon molecules and radicals

    Energy Technology Data Exchange (ETDEWEB)

    Vinodkumar, M. [Open Univ., Dept. of Physics and Astronomy, Milton Keynes MK (United Kingdom); Vinodkumar, M. [VP and RPTP Science College, Vallabh Vidyanagar, Gujarat (India); Joshipura, K.N.; Limbachiya, C.G. [Sardar Patel Univ., Dept. of Physics, Vallabh Vidyanagar, Gujarat (India); Limbachiya, C.G. [PS Science College, Kadi (N.G.), Gujarat (India); Antony, B.K. [Massachusetts Lowell Univ., Dept. of Environmental, Earth and Atmospheric Sciences, Lowell, MA (United States)

    2006-01-15

    Electron impact total (50 to 2000 eV) and ionization (threshold to 2000 eV) cross-sections are calculated using the SCOP (spherical complex optical potential) and CSP-ic (complex scattering potential-ionization contribution) methods for the hydrocarbon molecules (CH{sub 4}, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}, C{sub 3}H{sub 4}, C{sub 3}H{sub 6} and C{sub 3}H{sub 8}) and radicals (CH{sub x} (x=1-3)). Present method has already been tested successfully to other plasma molecules and radicals. Our results exhibited in this paper show good agreement with experimental results where available. For the radical species, we have presently done a first estimate of the total cross-sections. (authors)

  14. Hydrocarbons in the ISM: Their Evolution and the Grain-to-Molecule Transition

    Science.gov (United States)

    Jones, Anthony P.

    The evolution of hydrocarbon grains in the ISM is determined, principally, by the effects of photo-processing (annealing) which lead to a progressive loss of hydrogen from the structure and an associated 'graphitisation' of the material. Eventually this 'graphitisation' results in a low-density, highly aromatic material that can disaggregate into its aromatic-rich molecular components. These changes are followed through the use of an extended random covalent network (RCN) model for the hydrocarbon structure. This type of 'top down' process could be a significant source of the large molecular infrared band carriers in photon dominated regions. On the basis of this simple model there should thus be a relationship between the small grain and large molecule infrared emission bands across, and within, astrophysical boundaries such as photo-dissociation regions. 1. Introduction Carbon is the most abundant dust-forming element in the ISM and a large fraction of this carbon is in the form of grains comprised, principally, of hydrocarbon materials, including those where the hydrogen content is minimal. Interstellar hydrocarbon grains include: graphite, hydrogenated amorphous aliphatic and/or aromatic hydrocarbons (a-C, a-C:H) and (nano)diamond. These hydrocarbon dusts play a pivotal role in determining, amongst other things, the interstellar extinction, the dust thermal emission and the photo-electric heating of the gas in the ISM. 2. Hydrocarbon grains in the ISM Hydrocarbon grains are formed in the circumstellar shells around C-rich evolved stars, in supernova ejecta and also in the ISM itself via accretion and solid-state chemistry. The physical and chemical properties of hydrocarbon grains are indeed complex and vary in response to the ambient conditions (density, temperature, radiation field, ...). For example they can undergo both chemical and physical processing (growth and changes in chemical composition through accretion and reaction, erosion via inertial or chemi

  15. C-C stretching Raman spectra and stabilities of hydrocarbon molecules in natural gas hydrates: a quantum chemical study.

    Science.gov (United States)

    Liu, Yuan; Ojamäe, Lars

    2014-12-11

    The presence of specific hydrocarbon gas molecules in various types of water cavities in natural gas hydrates (NGHs) are governed by the relative stabilities of these encapsulated guest molecule-water cavity combinations. Using molecular quantum chemical dispersion-corrected hybrid density functional computations, the interaction (ΔE(host--guest)) and cohesive energies (ΔE(coh)), enthalpies, and Gibbs free energies for the complexes of host water cages and hydrocarbon guest molecules are calculated at the ωB97X-D/6-311++G(2d,2p) level of theory. The zero-point energy effect of ΔE(host-guest) and ΔE(coh) is found to be quite substantial. The energetically optimal host-guest combinations for seven hydrocarbon gas molecules (CH4, C2H6, C3H6, C3H8, C4H8, i-C4H10, and n-C4H10) and various water cavities (D, ID, T, P, H, and I) in NGHs are found to be CH4@D, C2H6@T, C3H6@T, C3H8@T, C4H8@T/P/H, i-C4H10@H, and n-C4H10@H, as the largest cohesive energy magnitudes will be obtained with these host-guest combinations. The stabilities of various water cavities enclosing hydrocarbon molecules are evaluated from the computed cohesive Gibbs free energies: CH4 prefers to be trapped in a ID cage; C2H6 prefer T cages; C3H6 and C3H8 prefer T and H cages; C4H8 and i-C4H10 prefer H cages; and n-C4H10 prefer I cages. The vibrational frequencies and Raman intensities of the C-C stretching vibrational modes for these seven hydrocarbon molecules enclosed in each water cavity are computed. A blue shift results after the guest molecule is trapped from gas phase into various water cages due to the host-guest interactions between the water cage and hydrocarbon molecule. The frequency shifts to the red as the radius of water cages increases. The model calculations support the view that C-C stretching vibrations of hydrocarbon molecules in the water cavities can be used as a tool to identify the types of crystal phases and guest molecules in NGHs.

  16. Dissociative photoionization of polycyclic aromatic hydrocarbon molecules carrying an ethynyl group

    CERN Document Server

    Rouillé, Gaël; Fulvio, Daniele; Jäger, Cornelia; Henning, Thomas; Garcia, Gustavo A; Tang, Xiao-Feng; Nahon, Laurent

    2015-01-01

    The life cycle of the population of interstellar polycyclic aromatic hydrocarbon (PAH) molecules depends partly on the photostability of the individual species. We have studied the dissociative photoionization of two ethynyl-substituted PAH species, namely, 9-ethynylphenanthrene and 1-ethynylpyrene. Their adiabatic ionization energy and the appearance energy of fragment ions have been measured with the photoelectron photoion coincidence (PEPICO) spectroscopy technique. The adiabatic ionization energy has been found at 7.84 +/- 0.02 eV for 9-ethynylphenanthrene and at 7.41 +/- 0.02 eV for 1-ethynylpyrene. These values are similar to those determined for the corresponding non-substituted PAH molecules phenanthrene and pyrene. The appearance energy of the fragment ion indicative of the loss of a H atom following photoionization is also similar for either ethynyl-substituted PAH molecule and its non-substituted counterpart. The measurements are used to estimate the critical energy for the loss of a H atom by the ...

  17. Small hydrocarbon molecules in cloud-forming Brown Dwarf and giant gas planet atmospheres

    CERN Document Server

    Bilger, Camille; Helling, Christiane

    2013-01-01

    We study the abundances of complex carbon-bearing molecules in the oxygen-rich dust- forming atmospheres of Brown Dwarfs and giant gas planets. The inner atmospheric re- gions that form the inner boundary for thermochemical gas-phase models are investigated. Results from Drift-phoenix atmosphere simulations, which include the feedback of phase- non-equilibrium dust cloud formation on the atmospheric structure and the gas-phase abun- dances, are utilised. The resulting element depletion leads to a shift in the carbon-to-oxygen ratio such that several hydrocarbon molecules and cyanopolycyanopolyynene molecules can be present. An increase in surface gravity and/or a decrease in metallicity support the increase in the partial pressures of these species. CO, CO2, CH4, and HCN contain the largest fraction of carbon. In the upper atmosphere of low-metallicity objects, more carbon is contained in C4H than in CO, and also CH3 and C2H2 play an increasingly important role as carbon-sink. We determine chemical relaxation...

  18. Thermal control of sequential on-surface transformation of a hydrocarbon molecule on a copper surface

    Science.gov (United States)

    Kawai, Shigeki; Haapasilta, Ville; Lindner, Benjamin D.; Tahara, Kazukuni; Spijker, Peter; Buitendijk, Jeroen A.; Pawlak, Rémy; Meier, Tobias; Tobe, Yoshito; Foster, Adam S.; Meyer, Ernst

    2016-09-01

    On-surface chemical reactions hold the potential for manufacturing nanoscale structures directly onto surfaces by linking carbon atoms in a single-step reaction. To fabricate more complex and functionalized structures, the control of the on-surface chemical reactions must be developed significantly. Here, we present a thermally controlled sequential three-step chemical transformation of a hydrocarbon molecule on a Cu(111) surface. With a combination of high-resolution atomic force microscopy and first-principles computations, we investigate the transformation process in step-by-step detail from the initial structure to the final product via two intermediate states. The results demonstrate that surfaces can be used as catalysing templates to obtain compounds, which cannot easily be synthesized by solution chemistry.

  19. Gas-phase Reactions of Polycyclic Aromatic Hydrocarbon Anions with Molecules of Interstellar Relevance

    Science.gov (United States)

    Demarais, Nicholas J.; Yang, Zhibo; Martinez, Oscar; Wehres, Nadine; Snow, Theodore P.; Bierbaum, Veronica M.

    2012-02-01

    We have studied reactions of small dehydrogenated polycyclic aromatic hydrocarbon anions with neutral species of interstellar relevance. Reaction rate constants are measured at 300 K for the reactions of phenide (C6H- 5), naphthalenide (C10H- 7), and anthracenide (C14H- 9) with atomic H, H2, and D2 using a flowing afterglow-selected ion flow tube instrument. Reaction rate constants of phenide with neutral molecules (CO, O2, CO2, N2O, C2H2, CH3OH, CH3CN, (CH3)2CO, CH3CHO, CH3Cl, and (CH3CH2)2O) are also measured under the same conditions. Experimental measurements are accompanied by ab initio calculations to provide insight into reaction pathways and enthalpies. Our measured reaction rate constants should prove useful in the modeling of astrophysical environments, particularly when applied to dense regions of the interstellar and circumstellar medium.

  20. Interface formation between hydrocarbon ring molecules and III-V semiconductor surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Passmann, Regina

    2008-08-15

    In this work a systematical study to investigate the adsorption structures of small hydrocarbon ring shaped molecules on III-V semiconductor surfaces with Photo-Emission Spectroscopy (PES), Reflectance Anisotropy Spectroscopy (RAS), Scanning Tunneling Microscopy (STM) as well as Low Electron Energy Diffraction (LEED) was performed. To investigate the influence of the surface structure in detail the surface dimer configuration to the adsorption process of organic molecules GaAs(001) surfaces, the c(4 x 4), the (2 x 4) and the (4 x 2) have been investigated as well as the adsorption of cyclopentene on the InP(001)(2 x 4) reconstructed surface. In the direct comparison it is shown that cyclopentene bonds to the InP(001)(2 x 4) surface via a cycloaddition like reaction. During this adsorption the double bond splits which is in contrast to the adsorption of cyclopentene on the GaAs(001) surfaces. Therefrom it is concluded that the surface geometry has an influence on the resulting adsorption structure. In order to investigate the influence of the intra-molecular double bonds, cyclopentene (one double bond), 1,4-cyclohexadiene (two double bonds) and benzene (three double bonds) were used for the characterization of the interface formation. With the investigations on the GaAs(001) reconstructed surfaces it was shown that a dependency of the bonding configuration on the intra-molecular double bonds exists. During the adsorption of cyclopentene no evidence was found that the double bond has to be involved in the interface formation while during the adsorption of 1,4-cyclohexadiene and benzene the double bonds are involved. Furthermore it was found that a bonding to As atoms of the surface is more likely than a bonding to Ga atoms. (orig.)

  1. Geometrical constraint on stacking of polycyclic aromatic hydrocarbon molecules encapsulated in a single-walled carbon nanotube.

    Science.gov (United States)

    Mouri, K; Shintani, K

    2016-11-16

    The stacking morphologies of polycyclic aromatic hydrocarbon (PAH) molecules encapsulated in a single-walled carbon nanotube (SWCNT) are investigated by using a molecular-dynamics (MD) method. The encapsulating SWCNTs are of twenty different diameters. For coronene molecules, both conjugate-gradient (CG) energy minimization of the stacked molecules in a SWCNT and dynamics simulation (DS) of encapsulation of the molecules in a SWCNT are performed; while for sumanene molecules, only DS of encapsulation of the molecules in a SWCNT is performed. The tilt angles and intermolecular distances are calculated from the final configurations via CG and DS. On the assumption that the morphologies of the molecules in a SWCNT are determined by the geometrical constraint condition, semi-analytical formulas for the dependence of the tilt angles of the molecules on the SWCNT diameter are derived. These formulas are expressed in terms of the inverse functions of cosine the arguments of which are linear functions of the SWCNT diameter, and successfully agree with the simulation data. Accordingly, they are useful for controlling the tilt angles of the PAH molecules encapsulated in a SWCNT by adjusting the SWCNT diameter. It is also revealed that the stacking geometry of sumanene molecules with small tilt angles in a SWCNT is consistent with that of a sumanene dimer in a free space which Karunarathna and Saebo (Struct. Chem., 2014, 25, 1831) obtained using ab-initio calculations.

  2. Dispersion and fall out of heavier particles

    DEFF Research Database (Denmark)

    Astrup, Poul

    2016-01-01

    they may like gasses and aerosols be transported more or less far by the wind. The present paper focuses on the growth of plumes of such particles larger and heavier than aerosols and transported by the wind. Implementation in existing decision support puff dispersion programs requires a parameterization...... of this growth, and two reasonable describing parameterizations have been found, one in the literature, one proposed here, and both are compared to experimental work found in the literature. The parameterization from the literature has been implemented in the dispersion program RIMPUFF, which has subsequently...... shown that the effect on fall out to a large extent overrules the effect on the dispersion of such particles....

  3. Analysis of the magnetically induced current density of molecules consisting of annelated aromatic and antiaromatic hydrocarbon rings.

    Science.gov (United States)

    Sundholm, Dage; Berger, Raphael J F; Fliegl, Heike

    2016-06-21

    Magnetically induced current susceptibilities and current pathways have been calculated for molecules consisting of two pentalene groups annelated with a benzene (1) or naphthalene (2) moiety. Current strength susceptibilities have been obtained by numerically integrating separately the diatropic and paratropic contributions to the current flow passing planes through chosen bonds of the molecules. The current density calculations provide novel and unambiguous current pathways for the unusual molecules with annelated aromatic and antiaromatic hydrocarbon moieties. The calculations show that the benzene and naphthalene moieties annelated with two pentalene units as in molecules 1 and 2, respectively, are unexpectedly antiaromatic sustaining only a local paratropic ring current around the ring, whereas a weak diatropic current flows around the C-H moiety of the benzene ring. For 1 and 2, the individual five-membered rings of the pentalenes are antiaromatic and a slightly weaker semilocal paratropic current flows around the two pentalene rings. Molecules 1 and 2 do not sustain any net global ring current. The naphthalene moiety of the molecule consisting of a naphthalene annelated with two pentalene units (3) does not sustain any strong ring current that is typical for naphthalene. Instead, half of the diatropic current passing the naphthalene moiety forms a zig-zag pattern along the C-C bonds of the naphthalene moiety that are not shared with the pentalene moieties and one third of the current continues around the whole molecule partially cancelling the very strong paratropic semilocal ring current of the pentalenes. For molecule 3, the pentalene moieties and the individual five-membered rings of the pentalenes are more antiaromatic than for 1 and 2. The calculated current patterns elucidate why the compounds with formally [4n + 2] π-electrons have unusual aromatic properties violating the Hückel π-electron count rule. The current density calculations also provide

  4. Absolute fragmentation cross sections in atom-molecule collisions: Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.; Gatchell, M.; Stockett, M. H.; Alexander, J. D.; Schmidt, H. T.; Cederquist, H.; Zettergren, H., E-mail: henning@fysik.su.se [Department of Physics, Stockholm University, S-106 91 Stockholm (Sweden); Zhang, Y. [Department of Mathematics, Faculty of Physics, M. V. Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Rousseau, P.; Maclot, S.; Delaunay, R.; Adoui, L. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen Cedex 05 (France); Université de Caen Basse-Normandie, Esplanade de la Paix, F-14032 Caen (France); Domaracka, A.; Huber, B. A. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen Cedex 05 (France); Schlathölter, T. [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)

    2014-06-14

    We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH{sup +}) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections (including statistical fragmentation) for 110 eV PAH/PAH{sup +} + He collisions, and show that they compare well with experimental results. We demonstrate that non-statistical fragmentation becomes dominant for large PAHs and that it yields highly reactive fragments forming strong covalent bonds with atoms (H and N) and molecules (C{sub 6}H{sub 5}). Thus nonstatistical fragmentation may be an effective initial step in the formation of, e.g., Polycyclic Aromatic Nitrogen Heterocycles (PANHs). This relates to recent discussions on the evolution of PAHNs in space and the reactivities of defect graphene structures.

  5. Ionization of Polycyclic Aromatic Hydrocarbon Molecules around the Herbig Ae/Be environment

    OpenAIRE

    Sakon, Itsuki; Okamoto, Yoshiko K.; Kataza, Hirokazu; Onaka, Takashi; Kaneda, Hidehiro; Honda, Mitsuhiko

    2007-01-01

    We present the results of mid-infrared N-band spectroscopy of the Herbig Ae/Be system MWC1080 using the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on board the 8m Subaru Telescope. The MWC1080 has a geometry such that the diffuse nebulous structures surround the central Herbig B0 type star. We focus on the properties of polycyclic aromatic hydrocarbons (PAHs) and PAH-like species, which are thought to be the carriers of the unidentified infrared (UIR) bands in such environments. A s...

  6. Electron correlations and two-photon states in polycyclic aromatic hydrocarbon molecules: A peculiar role of geometry

    Energy Technology Data Exchange (ETDEWEB)

    Aryanpour, Karan [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); Shukla, Alok [Department of Physics, Indian Institute of Technology, Powai, Mumbai 400076 (India); Mazumdar, Sumit [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States)

    2014-03-14

    We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene, and circumcoronene, all possessing D{sub 6h} point group symmetry versus ovalene with D{sub 2h} symmetry, within the Pariser-Parr-Pople model of interacting π-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitatively different from single-particle descriptions. More remarkably, a peculiar role of molecular geometry is found. The consequence of electron correlations is far stronger for ovalene, where the lowest spin-singlet two-photon state is a quantum superposition of pairs of lowest spin triplet states, as in the linear polyenes. The same is not true for D{sub 6h} group hydrocarbons. Our work indicates significant covalent character, in valence bond language, of the ground state, the lowest spin triplet state and a few of the lowest two-photon states in D{sub 2h} ovalene but not in those with D{sub 6h} symmetry.

  7. Electron correlations and two-photon states in polycyclic aromatic hydrocarbon molecules: A peculiar role of geometry

    Science.gov (United States)

    Aryanpour, Karan; Shukla, Alok; Mazumdar, Sumit

    2014-03-01

    We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene, and circumcoronene, all possessing D6h point group symmetry versus ovalene with D2h symmetry, within the Pariser-Parr-Pople model of interacting π-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitatively different from single-particle descriptions. More remarkably, a peculiar role of molecular geometry is found. The consequence of electron correlations is far stronger for ovalene, where the lowest spin-singlet two-photon state is a quantum superposition of pairs of lowest spin triplet states, as in the linear polyenes. The same is not true for D6h group hydrocarbons. Our work indicates significant covalent character, in valence bond language, of the ground state, the lowest spin triplet state and a few of the lowest two-photon states in D2h ovalene but not in those with D6h symmetry.

  8. Structure and binding in crystals of cage-like molecules: hexamine and platonic hydrocarbons

    CERN Document Server

    Berland, Kristian; 10.1063/1.3366652

    2010-01-01

    In this paper, we show that first-principle calculations using a van der Waals density functional (vdW-DF), [Phys. Rev. Lett. $\\mathbf{92}$, 246401 (2004)] permits determination of molecular crystal structure. We study the crystal structures of hexamine and the platonic hydrocarbons (cubane and dodecahedrane). The calculated lattice parameters and cohesion energy agree well with experiments. Further, we examine the asymptotic accounts of the van der Waals forces by comparing full vdW-DF with asymptotic atom-based pair potentials extracted from vdW-DF. The character of the binding differ in the two cases, with vdW-DF giving a significant enhancement at intermediate and relevant binding separations. We analyze consequences of this result for methods such as DFT-D, and question DFT-D's transferability over the full range of separations.

  9. Ionization of Polycyclic Aromatic Hydrocarbon Molecules around the Herbig Ae/be ENVIRONMENT*

    Science.gov (United States)

    Sakon, Itsuki; Onaka, Takashi; Okamoto, Yoshiko K.; Kataza, Hirokazu; Kaneda, Hidehiro; Honda, Mitsuhiko

    We present the results of mid-infrared N-band spectroscopy of the Herbig Ae/Be system MWC1080 using the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on board the 8 m Subaru Telescope. The MWC1080 has a geometry such that the diffuse nebulous structures surround the central Herbig B0 type star. We focus on the properties of polycyclic aromatic hydrocarbons (PAHs) and PAH-like species, which are thought to be the carriers of the unidentified infrared (UIR) bands in such environments. A series of UIR bands at 8.6, 11.0, 11.2, and 12.7 μm is detected throughout the system and we find a clear increase in the UIR 11.0 μm/11.2 μm ratio in the vicinity of the central star. Since the UIR 11.0 μm feature is attributed to a solo-CH out-of-plane wagging mode of cationic PAHs while the UIR 11.2 μm feature to a solo-CH out-of-plane bending mode of neutral PAHs, the large 11.0 μm/11.2 μm ratio directly indicates a promotion of the ionization of PAHs near the central star.

  10. Ionization of Polycyclic Aromatic Hydrocarbon Molecules around the Herbig Ae/Be Environment

    Science.gov (United States)

    Sakon, Itsuki; Onaka, Takashi; Okamoto, Yoshiko K.; Kataza, Hirokazu; Kaneda, Hidehiro; Honda, Mitsuhiko

    We present the results of mid-infrared N-band spectroscopy of the Herbig Ae/Be system MWC1080 using the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on board the 8 m Subaru Telescope. The MWC1080 has a geometry such that the diffuse nebulous structures surround the central Herbig B0 type star. We focus on the properties of polycyclic aromatic hydrocarbons (PAHs) and PAH-like species, which are thought to be the carriers of the unidentified infrared (UIR) bands in such environments. A series of UIR bands at 8.6, 11.0, 11.2, and 12.7 μm is detected throughout the system and we find a clear increase in the UIR 11.0 μm/11.2 μm ratio in the vicinity of the central star. Since the UIR 11.0 μm feature is attributed to a solo-CH out-of-plane wagging mode of cationic PAHs while the UIR 11.2 μm feature to a solo-CH out-of-plane bending mode of neutral PAHs, the large 11.0 μm/11.2 μm ratio directly indicates a promotion of the ionization of PAHs near the central star.

  11. New limits on heavier electroweakinos and their LHC signatures

    Science.gov (United States)

    Datta, Amitava; Ganguly, Nabanita; Poddar, Sujoy

    2016-12-01

    We investigate the heavier electroweakino sectors in several versions of the MSSM, which has not been explored so far in the light of the LHC data, and obtain new bounds using the ATLAS Run I constraints in the 3 l +E̸T channel. We also venture beyond the trilepton events and predict several novel multilepton +E̸T signatures of these electroweakinos which may show up during LHC Run II before the next long shutdown. These signals can potentially distinguish between various models with nondecoupled heavier electroweakinos and the much studied ones with decoupled heavier electroweakinos.

  12. Finite temperature infrared spectroscopy of polycyclic aromatic hydrocarbon molecules: Path-integral molecular dynamics

    Science.gov (United States)

    Calvo, F.; Parneix, P.; Van-Oanh, N.-T.

    2010-03-01

    The vibrational spectra of the naphthalene, pyrene, and coronene molecules have been computed in the 0-3500 cm-1 infrared range using classical and quantum molecular dynamics simulations based on a dedicated tight-binding potential energy surface. The ring-polymer molecular dynamics (RPMD) and partially adiabatic centroid molecular dynamics (CMD) methods have been employed to account for quantum nuclear effects. The contributions of quantum delocalization to the line shift and broadening are significant in the entire spectral range and of comparable magnitude as pure thermal effects. While the two methods generally produce similar results, the CMD method may converge slower at low temperature with increasing Trotter discretization number. However, and contrary to the CMD method, the RPMD approach suffers from serious resonance problems at high frequencies and low temperatures.

  13. Average American 15 Pounds Heavier Than 20 Years Ago

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160233.html Average American 15 Pounds Heavier Than 20 Years Ago ... since the late 1980s and early 1990s, the average American has put on 15 or more additional ...

  14. Mantle hydrocarbons: abiotic or biotic?

    Science.gov (United States)

    Sugisaki, R; Mimura, K

    1994-06-01

    Analyses of 227 rocks from fifty localities throughout the world showed that mantle derived rocks such as tectonized peridotites in ophiolite sequences (tectonites) arid peridotite xenoliths in alkali basalts contain heavier hydrocarbons (n-alkanes), whereas igneous rocks produced by magmas such as gabbro arid granite lack them. The occurrence of hydrocarbons indicates that they were not derived either from laboratory contamination or from held contamination; these compounds found in the mantle-derived rocks are called here "mantle hydrocarbons." The existence of hydrocarbons correlates with petrogenesis. For example, peridotite cumulates produced by magmatic differentiation lack hydrocarbons whereas peridotite xenoliths derived from the mantle contain them. Gas chromatographic-mass spectrometric records of the mantle hydrocarbons resemble those of aliphatics in meteorites and in petroleum. Features of the hydrocarbons are that (a) the mantle hydrocarbons reside mainly along grain boundaries and in fluid inclusions of minerals; (b) heavier isoprenoids such as pristane and phytane are present; and (c) delta 13C of the mantle hydrocarbons is uniform (about -27%). Possible origins for the mantle hydrocarbons are as follows. (1) They were in organically synthesized by Fischer-Tropsch type reaction in the mantle. (2) They were delivered by meteorites and comets to the early Earth. (3) They were recycled by subduction. The mantle hydrocarbons in the cases of (1) and (2) are abiogenic and those in (3) are mainly biogenic. It appears that hydrocarbons may survive high pressures and temperatures in the mantle, but they are decomposed into lighter hydrocarbon gases such as CH4 at lower pressures when magmas intrude into the crust; consequently, peridotite cumulates do not contain heavier hydrocarbons but possess hydrocarbon gases up to C4H10.

  15. Absolute fragmentation cross sections in atom-molecule collisions : Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

    NARCIS (Netherlands)

    Chen, T.; Gatchell, M.; Stockett, M. H.; Alexander, J. D.; Zhang, Y.; Rousseau, P.; Domaracka, A.; Maclot, S.; Delaunay, R.; Adoui, L.; Huber, B. A.; Schlathölter, T.; Schmidt, H. T.; Cederquist, H.; Zettergren, H.

    2014-01-01

    We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH+) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections

  16. New observational constraints on hydrocarbon chemistry in Saturn's upper atmosphere

    Science.gov (United States)

    Koskinen, Tommi; Moses, Julianne I.; West, Robert; Guerlet, Sandrine; Jouchoux, Alain

    2016-10-01

    Until now there have been only a few observations of hydrocarbons and photochemical haze in the region where they are produced in Saturn's upper atmosphere. We present new results on hydrocarbon abundances and atmospheric structure based on more than 40 stellar occultations observed by the Cassini/UVIS instrument that we have combined with results from Cassini/CIRS to generate full atmosphere structure models. In addition to detecting CH4, C2H2, C2H4 and C2H6, we detect benzene (C6H6) in UVIS occultations that probe different latitudes and present the first vertical abundance profiles for this species in its production region. Benzene is the simplest ring polyaromatic hydrocarbon (PAH) and a stepping stone to the formation of more complex molecules that are believed to form stratospheric haze. Our calculations show that the observed abundances of benzene can be explained by solar-driven ion chemistry that is enhanced by high-latitude auroral production at least in the northern spring hemisphere. Condensation of benzene and heavier hydrocarbons is possible in the cold polar night of the southern winter where we detect evidence for high altitude haze. We also report on substantial variability in the CH4 profiles that arise from dynamics and affects the minor hydrocarbon abundances. Our results demonstrate the importance of hydrocarbon ion chemistry and coupled models of chemistry and dynamics for future studies of Saturn's upper atmosphere.

  17. 石油烃分子组成预测研究进展%The research progress of petroleum hydrocarbon molecules prediction

    Institute of Scientific and Technical Information of China (English)

    王佳; 焦国凤; 周祥; 郭锦标

    2014-01-01

    The molecules composition of petroleum hydrocarbon is important data in petroleum refining and processing. According to the bulk properties obtained molecules predicted, it can provide a good reference for the petroleum processing. Summarizes the main method of predicted petroleum hydrocarbon molecules composition, such as Stochastic Reconstruction, Entropy Maximum, Monte Carlo Simulation, Molecular Type Homologous Series, Analyzes the characteristics and shortcomings of these methods, and discusses the direction of development on the future.%石油烃分子组成是目前石油炼制和加工过程中重要数据,通过易得的宏观物性对分子组成进行预测可以为石油加工过程提供良好的参考。对国内外石油烃分子组成的主要预测方法随机重构方法,熵最大化法,蒙特卡洛模拟方法,MTHS矩阵法等方法进行了介绍,对其特点与不足进行了讨论,并对未来的发展方向进行了展望。

  18. Chemical properties of the heavier actinides and transactinides

    Energy Technology Data Exchange (ETDEWEB)

    Hulet, E.K.

    1981-01-01

    The chemical properties of each of the elements 99 (Es) through 105 are reviewed and their properties correlated with the electronic structure expected for 5f and 6d elements. A major feature of the heavier actinides, which differentiates them from the comparable lanthanides, is the increasing stability of the divalent oxidation state with increasing atomic number. The divalent oxidation state first becomes observable in the anhydrous halides of californium and increases in stability through the series to nobelium, where this valency becomes predominant in aqueous solution. In comparison with the analogous 4f electrons, the 5f electrons in the latter part of the series are more tightly bound. Thus, there is a lowering of the 5f energy levels with respect to the Fermi level as the atomic number increases. The metallic state of the heavier actinides has not been investigated except from the viewpoint of the relative volatility among members of the series. In aqueous solutions, ions of these elements behave as a normal trivalent actinides and lanthanides (except for nobelium). Their ionic radii decrease with increasing nuclear charge which is moderated because of increased screening of the outer 6p electrons by the 5f electrons. The actinide series of elements is completed with the element lawrencium (Lr) in which the electronic configuration is 5f/sup 14/7s/sup 2/7p. From Mendeleev's periodicity and Dirac-Fock calculations, the next group of elements is expected to be a d-transition series corresponding to the elements Hf through Hg. The chemical properties of elements 104 and 105 only have been studied and they indeed appear to show the properties expected of eka-Hf and eka-Ta. However, their nuclear lifetimes are so short and so few atoms can be produced that a rich variety of chemical information is probably unobtainable.

  19. Vibronic structure in triatomic molecules: The hydrocarbon flame bands of the formyl radical (HCO). A theoretical study

    Science.gov (United States)

    Serrano-Andrés, Luis; Forsberg, Niclas; Malmqvist, Per-A.˚Ke

    1998-05-01

    A theoretical study of the vibrational structure of the X˜ 2A' ground and B˜ 2A' excited states of the formyl radical, HCO, and its deuterated form, DCO, has been performed. The potential energy surfaces have been computed by means of a multiconfigurational perturbative method, CASPT2. The computed geometries and the harmonic and anharmonic frequencies are successfully compared to the available experimental information. The vibrational intensities of the transition B˜ 2A'↔X˜2A' have been computed both for absorption and emission. The results lead to accurate determinations of several structural parameters and some reassignments of the vibrational transitions of the so-called hydrocarbon flame bands of the formyl radical.

  20. Atomic charge transfer-counter polarization effects determine infrared CH intensities of hydrocarbons: a quantum theory of atoms in molecules model.

    Science.gov (United States)

    Silva, Arnaldo F; Richter, Wagner E; Meneses, Helen G C; Bruns, Roy E

    2014-11-14

    Atomic charge transfer-counter polarization effects determine most of the infrared fundamental CH intensities of simple hydrocarbons, methane, ethylene, ethane, propyne, cyclopropane and allene. The quantum theory of atoms in molecules/charge-charge flux-dipole flux model predicted the values of 30 CH intensities ranging from 0 to 123 km mol(-1) with a root mean square (rms) error of only 4.2 km mol(-1) without including a specific equilibrium atomic charge term. Sums of the contributions from terms involving charge flux and/or dipole flux averaged 20.3 km mol(-1), about ten times larger than the average charge contribution of 2.0 km mol(-1). The only notable exceptions are the CH stretching and bending intensities of acetylene and two of the propyne vibrations for hydrogens bound to sp hybridized carbon atoms. Calculations were carried out at four quantum levels, MP2/6-311++G(3d,3p), MP2/cc-pVTZ, QCISD/6-311++G(3d,3p) and QCISD/cc-pVTZ. The results calculated at the QCISD level are the most accurate among the four with root mean square errors of 4.7 and 5.0 km mol(-1) for the 6-311++G(3d,3p) and cc-pVTZ basis sets. These values are close to the estimated aggregate experimental error of the hydrocarbon intensities, 4.0 km mol(-1). The atomic charge transfer-counter polarization effect is much larger than the charge effect for the results of all four quantum levels. Charge transfer-counter polarization effects are expected to also be important in vibrations of more polar molecules for which equilibrium charge contributions can be large.

  1. Crossed beam investigation of elementary reactions relevant to the formation of polycyclic aromatic hydrocarbon (PAH)-like molecules in extraterrestrial environments

    Science.gov (United States)

    Kaiser, R. I.; Asvany, O.; Lee, Y. T.

    2000-04-01

    The reactions of ground state carbon atoms, C( 3P j), with benzene, C 6H 6, and phenyl radicals, C 6H 5, with methylacetylene, CH 3CCH, were investigated in crossed beam experiments at collision energies of 21.8 and 140 kJ mol -1 to investigate elementary reactions relevant to the formation and chemistry of polycyclic aromatic hydrocarbons (PAHs) in extraterrestrial environments. The C( 3P j) reaction proceeds via complex formation and gives a cyclic, seven-membered C 7H 5 doublet radical plus atomic hydrogen. This pathway has neither an entrance nor exit barrier, and is exothermic. Together with the experimental verification of the carbon versus hydrogen exchange under single collision conditions, the findings have an important impact on the chemistry of aromatic molecules in interstellar clouds and outflow of carbon stars. Even in the coldest molecular clouds ( T=10 K), the benzene molecule can be destroyed upon reaction with carbon atoms, whereas they are resistant toward an attack of oxygen and nitrogen atoms. Since the aromatic benzene unit is ubiquitous in extraterrestrial, PAH-like material, our results suggest that PAHs might react with carbon atoms as well. On the other side, the reaction of C 6H 5 radicals with methylacetylene to form phenylmethylacetylene is direct. Since an entrance barrier inhibits the reaction in cold molecular clouds and in the atmospheres of hydrocarbon rich planets like Jupiter and Saturn and satellites such as Titan, this reaction is expected to play a role in PAH synthesis only in high temperature interstellar environments, such as circumstellar outflows of carbon stars.

  2. Numerical Simulation on Distribution of Products of Typical Hydrocarbon Molecules Pyrolysis%典型烃类分子裂解产物分布数值模拟

    Institute of Scientific and Technical Information of China (English)

    张红梅; 罗殿英; 赵雨波; 南子龙; 邵艳波

    2011-01-01

    利用烃类蒸汽热裂解二维工艺数学模型,选择二维模型原料分子中13种典型烃类分子,通过数学模拟考察烃类分子结构和裂解温度对热裂解产物的影响.结果表明:正构烷烃裂解产物中乙烯收率明显大于异构烷烃,且乙烯收率随着烷烃碳数的增加逐渐增加;异构烷烃裂解产物中丙烯收率大于同碳数的正构烷烃,且丙烯收率随碳数增大而显著减少;异构烷烃裂解生成丁二烯的收率大于其他烷烃;环烷烃中五元环裂解生成乙烯、丙烯和丁二烯(三烯)的收率大于六元环,且随碳数增加而略有增加;各烃类分子裂解生成乙烯和丁二烯的收率随温度的增加而增加,而丙烯的收率随温度的增加而略有降低.%The effects of hydrocarbon structure and pyrolysis temperature on the distribution of products from the pyrolysis of 13 typical hydrocarbon molecules were investigated using the two-dimension mathematical model of hydrocarbon steam pyrolysis. The results showed that the ethylene yield of normal paraffins pyrolysis was significantly higher than that of isoparaffin pyrolysis, and the ethylene yield increased with the increase of carbon number; the propylene yield of isoparaffin pyrolysis was higher than that of normal paraffins pyrolysis, and the propylene yield decreased obviously with the increase of carbon number; the butadiene yield of isoparaffin pyrolysis was higher than that of other paraffins pyrolysis; the total yield of ethylene, propylene and butadiene from the pyrolysis of cycloalkanes with five carbon in the rings was higher than that of cycloalkanes with six carbons in the rings, and increased slightly with the increase of carbon number; With the increase of pyrolysis temperature, the yield of ethylene and butadiene of hydrocarbons pyrolysis increased, while the yield of propylene decreased slightly.

  3. Hydrocarbon Spectral Database

    Science.gov (United States)

    SRD 115 Hydrocarbon Spectral Database (Web, free access)   All of the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported.

  4. Hydrocarbon pneumonia

    Science.gov (United States)

    Pneumonia - hydrocarbon ... Coughing Fever Shortness of breath Smell of a hydrocarbon product on the breath Stupor (decreased level of ... Most children who drink or inhale hydrocarbon products and develop ... hydrocarbons may lead to rapid respiratory failure and death.

  5. The Evolution of Multicomponent Systems at High Pressures: VI. The Thermodynamic Stability of the Hydrogen-Carbon System: The Genesis of Hydrocarbons and the Origin of Petroleum

    CERN Document Server

    Kenney, J F; Bendeliani, N A; Alekseev, V A; Kutcherov, Vladimir G.; Bendeliani, Nikolai A.; Alekseev, Vladimir A.

    2002-01-01

    The spontaneous genesis of hydrocarbons which comprise natural petroleum have been analyzed by chemical thermodynamic stability theory. The constraints imposed upon chemical evolution by the second law of thermodynamics are briefly reviewed; and the effective prohibition of transformation, in the regime of temperatures and pressures characteristic of the near-surface crust of the Earth, of biological molecules into hydrocarbon molecules heavier than methane is recognized. A general, first-principles equation of state has been developed by extending scaled particle theory (SPT) and by using the technique of the factored partition function of the Simplified Perturbed Hard Chain Theory (SPHCT). The chemical potentials, and the respective thermodynamic Affinity, have been calculated for typical components of the hydrogen-carbon (H-C) system over a range pressures between 1-100 kbar, and at temperatures consistent with those of the depths of the Earth at such pressures. The theoretical analyses establish that the ...

  6. The Evolution of Hydrocarbons in Saturn's Northern Storm Region

    Science.gov (United States)

    Bjoraker, Gordon; Hesman, B. E.; Achterberg, R. K.; Romani, P. N.

    2012-01-01

    The massive storm at 40N on Saturn that began in December 2010 has produced significant and lasting effects in the northern hemisphere on temperature and species abundances (Fletcher et aL 2011). The northern storm region was observed on several occasions between March 2011 and April 2012 by Cassini's Composite Infrared Spectrometer (CIRS) at a spectral resolution (0.5/cm) which permits the study of trace species in Saturn's stratosphere. During this time period, stratospheric temperatures in regions referred to as "beacons" (warm regions at specific longitudes at the latitude of the storm) became significantly warmer than pre-storm values of 140K, peaking near 220K, and subsequently cooling. These warm temperatures led to greatly enhanced infrared emission due to C4H2, C3H4, C2H2, and C2H6 in the stratosphere as well as the first detection of C2H4 on Saturn in the thermal infrared (Hesman et al. 2012). Using CH4 as a thermometer of Saturn's stratosphere in the beacon regions, we can derive the mixing ratios of each of these molecules. The most common hydrocarbons (C2H2 and C2H6) serve as dynamical tracers on Saturn and their abundances may constrain vertical motion in the stratosphere. All of these hydrocarbons are products of methane photolysis. Since many of the photochemical reactions that produce heavier hydrocarbons such as C4H2 and C3H4 are temperature sensitive, the beacon region provides a natural laboratory for studying these reactions on Saturn. We will discuss the time evolution of the abundances of each of these hydrocarbons from their pre-storm values, through the period of maximum heating , and during the period of cooling that is taking place in Saturn's stratosphere.

  7. Visualizing lone pairs in compounds containing heavier congeners of the carbon and nitrogen group elements

    Indian Academy of Sciences (India)

    Ram Seshadri

    2001-10-01

    In this mini-review, I discuss some recent work on the stereochemistry and bonding of lone pairs of electrons in divalent compounds of the heavier carbon group elements (SnII, PbII) and in trivalent compounds of the heavier nitrogen group elements (BiIII). Recently developed methods that permit the real-space visualization of bonding patterns on the basis of density functional calculations of electronic structure, reveal details of the nature of selectron lone pairs in compounds of the heavier main group elements - their stereochemistry and their inertness (or lack thereof). An examination of tetragonal 4/ SnO, -PbO and BiOF, and cubic $\\bar{3}$ PbS provides a segue into perovskite phases of technological significance, including ferroelectric PbTiO3 and antiferroelectric/piezoelectric PbZrO3, in both of which the lone pairs on Pb atoms play a pivotal rôle.

  8. Examining Differences between Light and Heavier Smoking Vocational Students: A Pilot Study

    Science.gov (United States)

    de Araujo, Vanessa A.; Loukas, Alexandra; Gottlieb, Nell H.

    2011-01-01

    Objective: To examine differences between light and heavier smoking vocational/technical students in tobacco use, related behaviors, and cessation. Design: Cross-sectional. Setting and Methods: Two hundred and four smokers attending two vocational/technical colleges in east Texas, USA, completed an anonymous survey during a regularly scheduled…

  9. Don't Put Off Weight-Loss Surgery Till You're Heavier

    Science.gov (United States)

    ... news/fullstory_167433.html Don't Put Off Weight-Loss Surgery Till You're Heavier Best results seen ... 2017 WEDNESDAY, July 26, 2017 (HealthDay News) -- Having weight-loss surgery before you become severely obese tends to ...

  10. THERMOCHEMISTRY OF HYDROCARBON RADICALS

    Energy Technology Data Exchange (ETDEWEB)

    Kent M. Ervin, Principal Investigator

    2004-08-17

    Gas phase negative ion chemistry methods are employed to determine enthalpies of formation of hydrocarbon radicals that are important in combustion processes and to investigate the dynamics of ion-molecule reactions. Using guided ion beam tandem mass spectrometry, we measure collisional threshold energies of endoergic proton transfer and hydrogen atom transfer reactions of hydrocarbon molecules with negative reagent ions. The measured reaction threshold energies for proton transfer yield the relative gas phase acidities. In an alternative methodology, competitive collision-induced dissociation of proton-bound ion-molecule complexes provides accurate gas phase acidities relative to a reference acid. Combined with the electron affinity of the R {center_dot} radical, the gas phase acidity yields the RH bond dissociation energy of the corresponding neutral molecule, or equivalently the enthalpy of formation of the R{center_dot} organic radical, using equation: D(R-H) = {Delta}{sub acid}H(RH) + EA(R) - IE(H). The threshold energy for hydrogen abstraction from a hydrocarbon molecule yields its hydrogen atom affinity relative to the reagent anion, providing the RH bond dissociation energy directly. Electronic structure calculations are used to evaluate the possibility of potential energy barriers or dynamical constrictions along the reaction path, and as input for RRKM and phase space theory calculations. In newer experiments, we have measured the product velocity distributions to obtain additional information on the energetics and dynamics of the reactions.

  11. Section i: Thermodynamic Properties of Hydrocarbon Radicals, Peroxy Hydrocarbon and Peroxy Chlorohydrocarbon Molecules and Radicals. Section II. Kinetics and Reaction Mechanisms For: (1) Chloroform Pyrolysis and Oxidation; (2) Benzene and Toluene Oxidation Under Atmospheric Conditions.

    Science.gov (United States)

    Lay, Tsan-Horng

    1995-01-01

    Alkyl radicals are important active intermediates in gas phase photochemistry and combustion reaction systems. With the exception of a limited number of the most elementary radicals, accurate thermodynamic properties of alkyl radicals are either not available or only rough estimations exist. An H atom Bond Increment approach is developed and a data base is derived, for accurately estimating thermodynamic properties (Delta H_{f }^circ298, S ^circ298 and Cp(T)) for generic classes of hydrocarbon radical species. Reactions of alkyl radicals with molecular oxygen are one of the major reaction paths for these radicals in atmospheric photochemistry, oxidation of hydrocarbon liquids and combustion process. Alkyl hydroperoxides are subsequently formed through the alkyl peroxy radicals reactions with varied chemical species present in the reaction system. Thermodynamic properties of the alkyl hydroperoxides and related radicals are therefore frequently required in gas phase modeling and kinetic studies on these systems. The thermodynamic properties of alkyl hydroperoxides, alkyl peroxy radicals and hydroperoxyl-1-ethyl radicals including the species with fluorine and chlorine substituents on the alpha-carbon are evaluated using molecular orbital calculations. Chloroform is used as a model chlorocarbon system with high Cl/H ratio to investigate thermal decomposition processes of chlorocarbons in oxidative and pyrolytic reaction environments. A detailed reaction mechanism is developed to describe the important features of products and reagent loss and is shown to predict the experimental data well. Reaction pathways and rate constants are developed for CCl _3, CCl_2 and rm C_2Cl_3 radical addition to O_2 and combination with O, OH HO_2 and ClO. The reversible addition reaction of OH radical with benzene to form the hydroxyl-2,4-cyclohexadienyl (benzene -OH) adduct and the subsequent reactions of this benzene -OH adduct with O_2 are important initial steps for the

  12. A pictorial Stroop paradigm reveals an alcohol attentional bias in heavier compared to lighter social drinkers.

    Science.gov (United States)

    Bruce, Gillian; Jones, Barry T

    2004-12-01

    The findings obtained with the textual Stroop paradigm, testing for an attentional bias towards alcohol stimuli in heavier compared to lighter social drinkers, are limited in number and inconsistent in outcome. Using a pictorial rather than textual Stroop paradigm for the first time in alcohol research, a significant alcohol attentional bias is reported in heavier social drinkers compared to lighter social drinking controls. According to Cohen's scheme, the signifant effect size is classified as 'large'. The presence of an alcohol attentional bias helps to explain the perpetuation of abusive/dependent consumption and the frequency of post-treatment relapse. In a similar vein, these results add to the evidence that a differential alcohol attentional bias might also be present between two levels of social drinking and, in heavier social drinkers, has the potential to impact on the contents of awareness and the flow of thought towards alcohol. In this respect, it extends the small group of other perceptual-cognitive effects measured in social drinkers (alcohol cue reactions, alcohol associations and alcohol expectancies) that can influence the initiation of consumption in some social drinkers.

  13. Searching heavier Higgs boson via di-Higgs production at LHC Run-2

    Directory of Open Access Journals (Sweden)

    Lan-Chun Lü

    2016-04-01

    Full Text Available The discovery of a light Higgs particle h0(125 GeV opens up new prospect for searching heavier Higgs boson(s at the LHC Run-2, which will unambiguously point to new physics beyond the standard model (SM. We study the detection of a heavier neutral Higgs boson H0 via di-Higgs production channel at the LHC (14 TeV, H0→h0h0→WW⁎γγ. This directly probes the Hhh cubic Higgs interaction, which exists in most extensions of the SM Higgs sector. For the decay products of final states WW⁎, we include both pure leptonic mode WW⁎→ℓν¯ℓ¯ν and semi-leptonic mode WW⁎→qq¯′ℓν. We analyze signals and backgrounds by performing fast detector simulation for the full process pp→H→hh→WW⁎γγ→ℓν¯ℓ¯νγγ and pp→H→hh→WW⁎γγ→ℓνqq¯′γγ, over the mass range MH=250–600 GeV. For generic two-Higgs-doublet models (2HDM, we present the discovery reach of the heavier Higgs boson at the LHC Run-2, and compare it with the current Higgs global fit of the 2HDM parameter space.

  14. Searching heavier Higgs boson via di-Higgs production at LHC Run-2

    Science.gov (United States)

    Lü, Lan-Chun; Du, Chun; Fang, Yaquan; He, Hong-Jian; Zhang, Huijun

    2016-04-01

    The discovery of a light Higgs particle h0 (125 GeV) opens up new prospect for searching heavier Higgs boson(s) at the LHC Run-2, which will unambiguously point to new physics beyond the standard model (SM). We study the detection of a heavier neutral Higgs boson H0 via di-Higgs production channel at the LHC (14 TeV), H0 →h0h0 → WW* γγ. This directly probes the Hhh cubic Higgs interaction, which exists in most extensions of the SM Higgs sector. For the decay products of final states WW*, we include both pure leptonic mode WW* → ℓ ν bar ℓ bar ν and semi-leptonic mode WW* → qqbar‧ ℓν. We analyze signals and backgrounds by performing fast detector simulation for the full process pp → H → hh → WW* γγ → ℓ ν bar ℓ bar νγγ and pp → H → hh → WW* γγ → ℓνqqbar‧ γγ, over the mass range MH = 250- 600 GeV. For generic two-Higgs-doublet models (2HDM), we present the discovery reach of the heavier Higgs boson at the LHC Run-2, and compare it with the current Higgs global fit of the 2HDM parameter space.

  15. Emulsification of hydrocarbons by subsurface bacteria

    Science.gov (United States)

    Francy, D.S.; Thomas, J.M.; Raymond, R.L.; Ward, C.H.

    1991-01-01

    Biosurfactants have potential for use in enhancement of in situ biorestoration by increasing the bioavailability of contaminants. Microorganisms isolated from biostimulated, contaminated and uncontaminated zones at the site of an aviation fuel spill and hydrocarbon-degrading microorganisms isolated from sites contaminated with unleaded gasoline were examined for their abilities to emulsify petroleum hydrocarbons. Emulsifying ability was quantified by a method involving agitation and visual inspection. Biostimulated-zone microbes and hydrocarbon-degrading microorganisms were the best emulsifiers as compared to contaminated and uncontaminated zone microbes. Biostimulation (nutrient and oxygen addition) may have been the dominant factor which selected for and encouraged growth of emulsifiers; exposure to hydrocarbon was also important. Biostimulated microorganisms were better emulsifiers of aviation fuel (the contaminant hydrocarbon) than of heavier hydrocarbon to which they were not previously exposed. By measuring surface tension changes of culture broths, 11 out of 41 emulsifiers tested were identified as possible biosurfactant producers and two isolates produced large surface tension reductions indicating the high probability of biosurfactant production.Biosurfactants have potential for use in enhancement of in situ biorestoration by increasing the bioavailability of contaminants. Microorganisms isolated from biostimulated, contaminated and uncontaminated zones at the site of an aviation fuel spill and hydrocarbon-degrading microorganisms isolated from sites contaminated with unleaded gasoline were examined for their abilities to emulsify petroleum hydrocarbons. Emulsifying ability was quantified by a method involving agitation and visual inspection. Biostimulated-zone microbes and hydrocarbon-degrading microorganisms were the best emulsifiers as compared to contaminated and uncontaminated zone microbes. Biostimulation (nutrient and oxygen addition) may have been

  16. Upgrading light hydrocarbons via tandem catalysis: a dual homogeneous Ta/Ir system for alkane/alkene coupling.

    Science.gov (United States)

    Leitch, David C; Lam, Yan Choi; Labinger, Jay A; Bercaw, John E

    2013-07-17

    Light alkanes and alkenes are abundant but are underutilized as energy carriers because of their high volatility and low energy density. A tandem catalytic approach for the coupling of alkanes and alkenes has been developed in order to upgrade these light hydrocarbons into heavier fuel molecules. This process involves alkane dehydrogenation by a pincer-ligated iridium complex and alkene dimerization by a Cp*TaCl2(alkene) catalyst. These two homogeneous catalysts operate with up to 60/30 cooperative turnovers (Ir/Ta) in the dimerization of 1-hexene/n-heptane, giving C13/C14 products in 40% yield. This dual system can also effect the catalytic dimerization of n-heptane (neohexene as the H2 acceptor) with cooperative turnover numbers of 22/3 (Ir/Ta).

  17. Experimental investigation and modeling of an aircraft Otto engine operating with gasoline and heavier fuels

    Science.gov (United States)

    Saldivar Olague, Jose

    A Continental "O-200" aircraft Otto-cycle engine has been modified to burn diesel fuel. Algebraic models of the different processes of the cycle were developed from basic principles applied to a real engine, and utilized in an algorithm for the simulation of engine performance. The simulation provides a means to investigate the performance of the modified version of the Continental engine for a wide range of operating parameters. The main goals of this study are to increase the range of a particular aircraft by reducing the specific fuel consumption of the engine, and to show that such an engine can burn heavier fuels (such as diesel, kerosene, and jet fuel) instead of gasoline. Such heavier fuels are much less flammable during handling operations making them safer than aviation gasoline and very attractive for use in flight operations from naval vessels. The cycle uses an electric spark to ignite the heavier fuel at low to moderate compression ratios, The stratified charge combustion process is utilized in a pre-chamber where the spray injection of the fuel occurs at a moderate pressure of 1200 psi (8.3 MPa). One advantage of fuel injection into the combustion chamber instead of into the intake port, is that the air-to-fuel ratio can be widely varied---in contrast to the narrower limits of the premixed combustion case used in gasoline engines---in order to obtain very lean combustion. Another benefit is that higher compression ratios can be attained in the modified cycle with heavier fuels. The combination of injection into the chamber for lean combustion, and higher compression ratios allow to limit the peak pressure in the cylinder, and to avoid engine damage. Such high-compression ratios are characteristic of Diesel engines and lead to increase in thermal efficiency without pre-ignition problems. In this experimental investigation, operations with diesel fuel have shown that considerable improvements in the fuel efficiency are possible. The results of

  18. Determination of Polycyclic Aromatic Hydrocarbons In Exhaled Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Moldoveanu SC

    2014-12-01

    Full Text Available The retention by humans of 20 polycyclic aromatic hydrocarbons (PAHs from mainstream cigarette smoke was evaluated. The analysis was done by a new technique using solid phase extraction (SPE for the cleanup and the concenration of PAHs. The new technique has excellent sensitivity and accuracy, which were necessary for the analysis of the very low levels of PAHs present in the exhaled cigarette smoke. The study was done on a common commercial cigarette with 10.6 mg ‘tar’ by U.S. Federal Trade Commission (FTC recommendation. The results were obtained from ten human subjects, each smoking three cigarettes. The exhaled smoke was collected using a vacuum assisted procedure that avoids strain in exhaling. The study showed that the PAHs with a molecular weight lower than about 170 Daltons are retained with high efficiency. The heavier molecules are less retained, but even compounds such as indeno[1,2,3-cd]pyrene, dibenz[a, h]anthracene, and benzoperylene are retained with efficiencies around 50%. The dependence of retention efficiency for PAHs (in % on their octanol-water partition coefficient (LogPow was found to be nonlinear and showed considerable variability for several compounds that have very close LogPow values. Better correlation was obtained between the retention efficiency and PAHs vapor pressure (Log VP.

  19. Spatial fractionation of the dose using neon and heavier ions: A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Peucelle, C.; Martínez-Rovira, I.; Prezado, Y., E-mail: prezado@imnc.in2p3.fr [IMNC-UMR 8165, CNRS Paris 7 and Paris 11 Universities, 15 rue Georges Clemenceau, Orsay Cedex 91406 (France)

    2015-10-15

    Purpose: This work explores a new radiation therapy approach which might trigger a renewed use of neon and heavier ions to treat cancers. These ions were shown to be extremely efficient in radioresistant tumor killing. Unfortunately, the efficient region also extends into the normal tissue in front of the tumor. The strategy the authors propose is to profit from the well-established sparing effect of thin spatially fractionated beams, so that the impact on normal tissues might be minimized while a high tumor control is achieved. The main goal of this work is to provide a proof of concept of this new approach. With that aim, a dosimetric study was carried out as a first step to evaluate the interest of further explorations of this avenue. Methods: The GATE/GEANT4 v.6.1 Monte Carlo simulation platform was employed to simulate arrays of rectangular minibeams (700 μm × 2 cm) of four ions (Ne, Si, Ar, and Fe). The irradiations were performed with a 2 cm-long spread-out Bragg peak centered at 7 cm-depth. Dose distributions in a water phantom were scored considering two minibeams center-to-center distances: 1400 and 3500 μm. Peak and valley doses, peak-to-valley dose ratios (PVDRs), beam penumbras, and relative contribution of nuclear fragments and electromagnetic processes were assessed as figures of merit. In addition, the type and proportion of the secondary nuclear fragments were evaluated in both peak and valley regions. Results: Extremely high PVDR values (>100) and low valley doses were obtained. The higher the atomic number (Z) of the primary ion is, the lower the valleys and the narrower the penumbras. Although the yield of secondary nuclear products increases with Z, the actual dose being deposited by the secondary nuclear fragments in the valleys starts to be the dominant contribution at deeper points, helping in the sparing of proximal normal tissues. Additionally, a wider center-to-center distance leads to a minimized contribution of heavier secondary

  20. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Prof. Ogunji

    hydrocarbon polluted sediments and water .... ecosystem may result in selective increase or decrease in microbial population (Okpokwasili ... been implicated in degradation of hydrocarbons such as crude oil, polyaromatic hydrocarbons and.

  1. Heavier smoking may lead to a relative increase in waist circumference

    DEFF Research Database (Denmark)

    Morris, Richard W; Taylor, Amy E; Fluharty, Meg E

    2015-01-01

    OBJECTIVES: To investigate, using a Mendelian randomisation approach, whether heavier smoking is associated with a range of regional adiposity phenotypes, in particular those related to abdominal adiposity. DESIGN: Mendelian randomisation meta-analyses using a genetic variant (rs16969968/rs1051730...... in the CHRNA5-CHRNA3-CHRNB4 gene region) as a proxy for smoking heaviness, of the associations of smoking heaviness with a range of adiposity phenotypes. PARTICIPANTS: 148,731 current, former and never-smokers of European ancestry aged ≥ 16 years from 29 studies in the consortium for Causal Analysis Research...... circumference, 0.02% (-0.05% to 0.08%) for hip circumference and 0.10% (0.02% to 0.19%) for waist-hip ratio, for each extra minor allele. CONCLUSIONS: For a given BMI, a gene variant associated with increased cigarette consumption was associated with increased waist circumference. Smoking in an effort...

  2. Apparatus for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2013-03-19

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  3. Abiogenic hydrocarbons in commercial gases from the Songliao Basin, China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mecha- nisms and from different sources in nature. It is demonstrated that the biodegradation or thermode- gradation of complex high-molecule sedimentary organic material can form microbial gas or thermogenic gas. The δ 13C1 value ranges from -110‰ to -50‰ for microbial gases but from -50‰ to -35‰ (even heavier) for thermogenic gases. Controlled by the kinetic isotope fractionation, both microbial and thermogenic gases have δ 13C and δ D values characterized by normal distribution, i.e. δ 13C1< δ 13C2< δ 13C3< δ 13C4 and δ DCH4< δ DC2H6< δ DC3H8<δ DC4H10, and by a positive correlation between the δ 13C and δ D values. Simple carbonbearing molecules (CH4, CO and CO2) can form abiogenic alkane gases via polymerization in the abiological chemical process in nature, with δ 13C1 heavier than -30‰. Moreover, controlled by the kinetic isotope fractionation, abiogenic alkane gases are characterized by a reverse distribution of δ 13C values and a normal trend of δ D values, namely δ 13C1> δ 13C2> δ 13C3> δ 13C4 and δ DCH4<δ DC2H6< δ DC3H8< δ DC4H10. The δ 13C values and δ D values are negatively correlated. Natural gases from 26 commercial gas wells distributed in the Xujiaweizi and Yingshan-Miaotaizi faulted depressions in the Songliao Basin, China, show δ13C1 values ranging from -30.5‰ to -16.7‰ with a very narrow δ D range between -203‰―-196‰. These gases are characterized by a reverse distribution of δ 13C values but a normal distribution of δ D values, and a negative correlation between their δ 13C and δ D values, indicating an abiological origin. The present study has revealed that abiogenic hydrocarbons not only exist in nature but also can make significant contribution to commercial gas reserviors. It is estimated that

  4. Graph theory for alternating hydrocarbons with attached ports

    NARCIS (Netherlands)

    Hesselink, Wim H.

    2013-01-01

    Properties of molecules of certain hydrocarbons give rise to difficult questions in graph theory. This paper is primarily devoted to the graph theory, but the physico-chemical motivation, which is somewhat speculative, is also presented. Molecules of unsaturated hydrocarbons exhibit alternating path

  5. Carbene supported dimer of heavier ketenimine analogue with p and si atoms.

    Science.gov (United States)

    Roy, Sudipta; Dittrich, Birger; Mondal, Totan; Koley, Debasis; Stückl, A Claudia; Schwederski, Brigitte; Kaim, Wolfgang; John, Michael; Vasa, Suresh Kumar; Linser, Rasmus; Roesky, Herbert W

    2015-05-20

    A cyclic alkyl(amino) carbene (cAAC) stabilized dimer [(cAAC)Si(P-Tip)]2 (2) (Tip = 2,4,6-triisopropylphenyl) is reported. 2 can be considered as a dimer of the heavier ketenimine (R2C═C═N-R) analogue. The dark-red rod-shaped crystals of 2 were synthesized by reduction of the precursor, cAAC-dichlorosilylene-stabilized phosphinidene (cAAC)SiCl2→P-Tip with sodium napthalenide. The crystals of 2 are storable at room temperature for several months and stable up to 215 °C under an inert atmosphere. X-ray single-crystal diffraction revealed that 2 contains a cyclic nonplanar four-membered SiPSiP ring. Magnetic susceptibility measurements confirmed the singlet spin ground state of 2. Cyclic voltammetry of 2 showed a quasi-reversible one-electron reduction indicating the formation of the corresponding radical anion 2(•-), which was further characterized by EPR measurements in solution. The electronic structure and bonding of 2 and 2(•-) were studied by theoretical calculations. The experimentally obtained data are in good agreement with the calculated values.

  6. Muon transfer from muonic hydrogen to heavier atoms; Transfert de charge muonique

    Energy Technology Data Exchange (ETDEWEB)

    Dupays, A

    2004-06-01

    This work concerns muon transfer from muonic hydrogen to heavier atoms. Recently, a method of measurement of the hyperfine structure of ground-state muonic hydrogen based on the collision energy dependence of the muon transfer rate to oxygen has been proposed. This proposal is based on measurements which where performed at the Paul Scherrer Institute in the early nineties which indicate that the muon transfer from muonic hydrogen to oxygen increases by a factor of 4 going from thermal to 0.12 eV energies. The motivation of our calculations was to confirm this behaviour. To study the collision energy dependence of the muon transfer rate, we have used a time-independent close-coupling method. We have set up an hyperspherical elliptic formalism valid for nonzero total angular momentum which allows accurate computations of state-to-state reactive and charge exchange processes. We have applied this formalism to muon-transfer process to oxygen and neon. The comparison with experimental results is in both cases excellent. Finally, the neon transfer rate dependence with energy suggests to use neon instead of oxygen to perform a measurement of the hyperfine structure of muonic hydrogen. The results of accurate calculations of the muon transfer rates from muonic protium and deuterium atoms to nitrogen, oxygen and neon are also reported. Very good agreement with measured rates is obtained and for the three systems, the isotopic effect is perfectly reproduced. (author)

  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. Volatile hydrocarbons inhibit methanogenic crude oil degradation

    Directory of Open Access Journals (Sweden)

    Angela eSherry

    2014-04-01

    Full Text Available Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene and xylenes were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34 and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 µmol CH4/g sediment/day with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34. For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 µmol CH4/g sediment/day. This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers.

  9. Earlier age of smoking initiation may not predict heavier cigarette consumption in later adolescence.

    Science.gov (United States)

    Morrell, Holly E R; Song, Anna V; Halpern-Felsher, Bonnie L

    2011-09-01

    Previous studies suggest that earlier cigarette smoking initiation in adolescence predicts greater cigarette consumption later in adolescence or adulthood. Results from these studies have been used to inform interventions for adolescent smoking. However, previous studies suffer from several important methodological limitations. The objective of the present study was to address these limitations by longitudinally and prospectively examining whether and how age of initiation of smoking among adolescents predicts cigarette consumption by age 16 or 17. Participants completed an in-class survey every 6 months for 2-3 school years. Participants included 395 adolescents (Mean age=14 years at baseline; 53.2% female) from two public high schools in Northern California (Schools A and B) who completed self-report measures of smoking initiation, number of friends who smoke, and number of whole cigarettes smoked by the final survey time point. Adolescents who were older when they first smoked one whole cigarette were 5.3 to 14.6 times more likely in School A and 2.9 to 4.3 times more likely in School B to have smoked a greater number of cigarettes by age 16 or 17. Results suggested that earlier smoking initiation may not lead to heavier cigarette consumption later in time, as has been previously shown. There may be a period of heightened vulnerability in mid- or late adolescence where smoking experimentation is more likely to lead to greater cigarette consumption. Targeting prevention efforts to adolescents aged 14 to 17 years may further reduce smoking initiation among youth, thus limiting subsequent smoking-related morbidity and mortality in adulthood.

  10. Delays in Admittance-Controlled Haptic Devices Make Simulated Masses Feel Heavier.

    Directory of Open Access Journals (Sweden)

    Irene A Kuling

    Full Text Available In an admittance-controlled haptic device, input forces are used to calculate the movement of the device. Although developers try to minimize delays, there will always be delays between the applied force and the corresponding movement in such systems, which might affect what the user of the device perceives. In this experiment we tested whether these delays in a haptic human-robot interaction influence the perception of mass. In the experiment an admittance-controlled manipulator was used to simulate various masses. In a staircase design subjects had to decide which of two virtual masses was heavier after gently pushing them leftward with the right hand in mid-air (no friction, no gravity. The manipulator responded as quickly as possible or with an additional delay (25 or 50 ms to the forces exerted by the subject on the handle of the haptic device. The perceived mass was ~10% larger for a delay of 25 ms and ~20% larger for a delay of 50 ms. Based on these results, we estimated that the delays that are present in nowadays admittance-controlled haptic devices (up to 20ms will give an increase in perceived mass which is smaller than the Weber fraction for mass (~10% for inertial mass. Additional analyses showed that the subjects' decision on mass when the perceptual differences were small did not correlate with intuitive variables such as force, velocity or a combination of these, nor with any other measured variable, suggesting that subjects did not have a consistent strategy during guessing or used other sources of information, for example the efference copy of their pushes.

  11. Crossed beam reaction of cyano radicals with hydrocarbon molecules. IV. Chemical dynamics of cyanoacetylene (HCCCN; X 1Σ+) formation from reaction of CN(X 2Σ+) with acetylene, C2H2(X 1Σg+)

    Science.gov (United States)

    Huang, L. C. L.; Asvany, O.; Chang, A. H. H.; Balucani, N.; Lin, S. H.; Lee, Y. T.; Kaiser, R. I.; Osamura, Y.

    2000-11-01

    The chemical reaction dynamics to form cyanoacetylene, HCCCN (X 1Σ+), via the radical-neutral reaction of cyano radicals, CN(X 2Σ+;ν=0), with acetylene, C2H2(X 1Σg+), are unraveled in crossed molecular beam experiments at two collision energies of 21.1 and 27.0 kJ mol-1. Laboratory angular distributions and time-of-flight spectra of the HCCCN product are recorded at m/e=51 and 50. Experiments were supplemented by electronic structure calculations on the doublet C3H2N potential energy surface and RRKM investigations. Forward-convolution fitting of the crossed beam data combined with our theoretical investigations shows that the reaction has no entrance barrier and is initiated by an attack of the CN radical to the π electron density of the acetylene molecule to form a doublet cis/trans HCCHCN collision complex on the 2A' surface via indirect reactive scattering dynamics. Here 85% of the collision complexes undergo C-H bond rupture through a tight transition state located 22 kJ mol-1 above the cyanoacetylene, HCCCN (X 1Σ+) and H(2S1/2) products (microchannel 1). To a minor amount (15%) trans HCCHCN shows a 1,2-H shift via a 177 kJ mol-1 barrier to form a doublet H2CCCN radical, which is 46 kJ mol-1 more stable than the initial reaction intermediate (microchannel 2). The H2CCCN complex decomposes via a rather loose exit transition state situated only 7 kJ mol-1 above the reaction products HCCCN (X 1Σ+) and H(2S1/2). In both cases the geometry of the exit transition states is reflected in the observed center-of-mass angular distributions showing a mild forward/sideways peaking. The explicit identification of the cyanoacetylene as the only reaction product represents a solid background for the title reaction to be included in reaction networks modeling the chemistry in dark, molecular clouds, outflow of dying carbon stars, hot molecular cores, as well as the atmosphere of hydrocarbon rich planets and satellites such as the Saturnian moon Titan.

  12. Heterobimetallic coordination polymers involving 3d metal complexes and heavier transition metals cyanometallates

    Energy Technology Data Exchange (ETDEWEB)

    Peresypkina, Eugenia V. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Samsonenko, Denis G. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Vostrikova, Kira E., E-mail: vosk@niic.nsc.ru [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); LMI, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France)

    2015-04-15

    The results of the first steps in the design of coordination polymers based on penta- and heptacyanometallates of heavier d transitions metals are presented. The 2D structure of the coordination polymers: [(Mn(acacen)){sub 2}Ru(NO)(CN){sub 5}]{sub n} and two complexes composed of different cyanorhenates, [Ni(cyclam)]{sub 2}[ReO(OH)(CN){sub 4}](ClO{sub 4}){sub 2}(H{sub 2}O){sub 1.25} and [Cu(cyclam)]{sub 2}[Re(CN){sub 7}](H{sub 2}O){sub 12}, was confirmed by single crystal XRD study, the rhenium oxidation state having been proved by the magnetic measurements. An amorphism of [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2} (M=Ni, Cu) polymers does not allow to define strictly their dimensionality and to model anisotropic magnetic behavior of the compounds. However, with high probability a honey-comb like layer structure could be expected for [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2} complexes, studied in this work, because such an arrangement is the most common among the bimetallic assemblies of hexa- and octacyanometallates with a ratio [M(cyclam)]/[M(CN){sub n}]=3/2. For the first time was prepared and fully characterized a precursor (n-Bu{sub 4}N){sub 2}[Ru(NO)(CN){sub 5}], soluble in organic media. - Graphical abstract: The very first results in the design of 2D coordination polymers based on penta- and heptacyanometallates of 4d and5d transitions metals are presented. - Highlights: • Design of coordination polymers based on penta- and heptacyanometallates. • New Ru and Re cyanide based heterobimetallic coordination complexes. • Hydrolysis and ox/red processes involving [Re(CN){sub 7}]{sup 3+} during crystallization. • High magnetic anisotropy of [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2}(H{sub 2}O){sub n}, M=Cu, Ni, complexes.

  13. The hydrocarbon sphere

    Energy Technology Data Exchange (ETDEWEB)

    Mandev, P.

    1984-01-01

    The hydrocarbon sphere is understood to be the area in which hydrocarbon compounds are available. It is believed that the lower boundary on the hydrocarbon sphere is most probably located at a depth where the predominant temperatures aid in the destruction of hydrocarbons (300 to 400 degrees centigrade). The upper limit on the hydrocarbon sphere obviously occurs at the earth's surface, where hydrocarbons oxidize to H20 and CO2. Within these ranges, the occurrence of the hydrocarbon sphere may vary from the first few hundred meters to 15 kilometers or more. The hydrocarbon sphere is divided into the external (mantle) sphere in which the primary gas, oil and solid hydrocarbon fields are located, and the internal (metamorphic) sphere containing primarily noncommercial accumulations of hydrocarbon gases and solid carbon containing compounds (anthraxilite, shungite, graphite, etc.) based on the nature and scale of hydrocarbon compound concentrations (natural gas, oil, maltha, asphalt, asphaltite, etc.).

  14. A Comprehensive Review of Aliphatic Hydrocarbon Biodegradation by Bacteria.

    Science.gov (United States)

    Abbasian, Firouz; Lockington, Robin; Mallavarapu, Megharaj; Naidu, Ravi

    2015-06-01

    Hydrocarbons are relatively recalcitrant compounds and are classified as high-priority pollutants. However, these compounds are slowly degraded by a large variety of microorganisms. Bacteria are able to degrade aliphatic saturated and unsaturated hydrocarbons via both aerobic and anaerobic pathways. Branched hydrocarbons and cyclic hydrocarbons are also degraded by bacteria. The aerobic bacteria use different types of oxygenases, including monooxygenase, cytochrome-dependent oxygenase and dioxygenase, to insert one or two atoms of oxygen into their targets. Anaerobic bacteria, on the other hand, employ a variety of simple organic and inorganic molecules, including sulphate, nitrate, carbonate and metals, for hydrocarbon oxidation.

  15. Searching Heavier Higgs Boson via $H \\to hh \\to WW^*\\gamma\\gamma$ at LHC Run-2

    CERN Document Server

    Lü, Lan-Chun; Fang, Yaquan; He, Hong-Jian; Zhang, Huijun

    2015-01-01

    The LHC discovery of a light Higgs particle $h^0$ (125GeV) opens up new prospect for searching heavier Higgs boson(s) at the LHC Run-2, which will unambiguously point to new physics beyond the standard model (SM). We study the detection of a heavier neutral Higgs boson $H^0$ via di-Higgs production channel at the LHC (14TeV), $H^0 \\to h^0h^0 \\to WW^*\\gamma\\gamma$. This directly probes the $Hhh$ cubic Higgs interaction, which exists in most extensions of the SM Higgs sector. For the decay products of final states $WW^*$, we include both pure leptonic mode $WW^* \\to \\ell\\bar{\

  16. Prediction of neutral noble gas insertion compounds with heavier pnictides: FNgY (Ng = Kr and Xe; Y = As, Sb and Bi).

    Science.gov (United States)

    Ghosh, Ayan; Manna, Debashree; Ghanty, Tapan K

    2016-04-28

    A novel class of interesting insertion compounds obtained through the insertion of a noble gas atom into the heavier pnictides have been explored by various ab initio quantum chemical techniques. Recently, the first neutral noble gas insertion compounds, FXeY (Y = P, N), were theoretically predicted to be stable; the triplet state was found to be the most stable state, with a high triplet-singlet energy gap, by our group. In this study, we investigated another noble gas inserted compound, FNgY (Ng = Kr and Xe; Y = As, Sb and Bi), with a triplet ground state. Density functional theory (DFT), second order Møller-Plesset perturbation theory (MP2), coupled-cluster theory (CCSD(T)) and multi-reference configuration interaction (MRCI) based techniques have been utilized to investigate the structures, stabilities, harmonic vibrational frequencies, charge distributions and topological properties of these compounds. These predicted species, FNgY (Ng = Kr and Xe; Y = As, Sb and Bi) are found to be energetically stable with respect to all the probable 2-body and 3-body dissociation pathways, except for the 2-body channel leading to the global minimum products (FY + Ng). Nevertheless, the finite barrier height corresponding to the saddle points of the compounds connected to their respective global minima products indicates that these compounds are kinetically stable. The structural parameters, energetics, and charge distribution results as well as atoms-in-molecules (AIM) analysis suggest that these predicted molecules can be best represented as F(-)[(3)NgY](+). Thus, all the aforementioned computed results clearly indicate that it may be possible to experimentally prepare the most stable triplet state of FNgY molecules under cryogenic conditions through a matrix isolation technique.

  17. Raman characteristics of hydrocarbon and hydrocarbon inclusions

    Institute of Scientific and Technical Information of China (English)

    ZHANG Nai; TIAN ZuoJi; LENG YingYing; WANG HuiTong; SONG FuQing; MENG JianHua

    2007-01-01

    The Raman spectrograms of hydrocarbon standard samples show that: (1) the Raman spectrogram of normal paraffin has very strong peaks of methyl and methylene (from 2700 cm-1 to 2970 cm-1); (2)branch methyl has the particular peak of 748 cm-1±; (3) six cyclic has the particular peak of 804 cm-1±; (4)phenyl has two particular peaks of 988 cm-1± and 3058 cm-1± and the 988 cm-1± peak is stronger than the 3058 cm-1± peak; and (5) hexene has three alkenyl spectrum peaks of 1294 cm-1±, 1635 cm-1± and 2996 cm-1±, with the 1635 cm-1± peak being the strongest, showing that the number of carbon in hydrocarbon does not affect its Raman spectrogram, and the hydrocarbon molecular structure and base groups affect its Raman spectrogram, the same hydrocarbons (such as normal paraffin) have the same Raman spectrogram; the types (such as CH4, C2H6, C3H8) and the content of hydrocarbon in oil inclusions are not estimated by their characteristic Raman peaks. According to the Raman spectrograms of hydrocarbon compositions, the Raman spectrogram of hydrocarbon inclusion can be divided into five types: saturated hydrocarbon Raman spectrogram, fluoresce Raman spectrogram, saturated hydrocarbon bitumen Raman spectrogram, bitumen Raman spectrogram, and ethane Raman spectrogram.And according to the characteristics of Raman spectrogram, hydrocarbon inclusions can be divided into five types: saturated hydrocarbon inclusion, less saturated hydrocarbon (oil or gas) inclusion,saturated hydrocarbon bitumen inclusion, bitumen inclusion, and methane water inclusion.

  18. Raman characteristics of hydrocarbon and hydrocarbon inclusions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Raman spectrograms of hydrocarbon standard samples show that: (1) the Raman spectrogram of normal paraffin has very strong peaks of methyl and methylene (from 2700 cm-1 to 2970 cm-1); (2) branch methyl has the particular peak of 748 cm-1±; (3) six cyclic has the particular peak of 804 cm-1±; (4) phenyl has two particular peaks of 988 cm-1± and 3058 cm-1± and the 988 cm-1± peak is stronger than the 3058 cm-1± peak; and (5) hexene has three alkenyl spectrum peaks of 1294 cm-1±, 1635 cm-1± and 2996 cm-1±, with the 1635 cm-1± peak being the strongest, showing that the number of carbon in hy-drocarbon does not affect its Raman spectrogram, and the hydrocarbon molecular structure and base groups affect its Raman spectrogram, the same hydrocarbons (such as normal paraffin) have the same Raman spectrogram; the types (such as CH4, C2H6, C3H8) and the content of hydrocarbon in oil inclu-sions are not estimated by their characteristic Raman peaks. According to the Raman spectrograms of hydrocarbon compositions, the Raman spectrogram of hydrocarbon inclusion can be divided into five types: saturated hydrocarbon Raman spectrogram, fluoresce Raman spectrogram, saturated hydro-carbon bitumen Raman spectrogram, bitumen Raman spectrogram, and ethane Raman spectrogram. And according to the characteristics of Raman spectrogram, hydrocarbon inclusions can be divided into five types: saturated hydrocarbon inclusion, less saturated hydrocarbon (oil or gas) inclusion, saturated hydrocarbon bitumen inclusion, bitumen inclusion, and methane water inclusion.

  19. Performance comparison of autothermal reforming for liquid hydrocarbons, gasoline and diesel for fuel cell applications

    Science.gov (United States)

    Kang, Inyong; Bae, Joongmyeon; Bae, Gyujong

    This paper discusses the reforming of liquid hydrocarbons to produce hydrogen for fuel cell applications, focusing on gasoline and diesel due to their high hydrogen density and well-established infrastructures. Gasoline and diesel are composed of numerous hydrocarbon species including paraffins, olefins, cycloparaffins, and aromatics. We have investigated the reforming characteristics of several representative liquid hydrocarbons. In the case of paraffin reforming, H 2 yield and reforming efficiency were close to thermodynamic equilibrium status (TES), although heavier hydrocarbons required slightly higher temperatures than lighter hydrocarbons. However, the conversion efficiency was much lower for aromatics than paraffins with similar carbon number. We have also investigated the reforming performance of simulated commercial diesel and gasoline using simple synthetic diesel and gasoline compositions. Reforming performances of our formulations were in good agreement with those of commercial fuels. In addition, the reforming of gas to liquid (GTL) resulted in high H 2 yield and reforming efficiency showing promise for possible fuel cell applications.

  20. Phototoxicity of individual polycyclic aromatic hydrocarbons and petroleum to marine invertebrate larvae and juveniles

    Energy Technology Data Exchange (ETDEWEB)

    Pelletier, M.C.; Burgess, R.M.; Ho, K.T.; Kuhn, A.; McKinney, R.A.; Ryba, S.A. [Environmental Protection Agency, Narragansett, RI (United States)

    1997-10-01

    Phototoxicity resulting from photoactivated polycyclic aromatic hydrocarbons (PAHs) has been reported in the literature for a variety of freshwater organisms. The magnitude of increase in PAH toxicity often exceeds a factor of 100. In the marine environment phototoxicity to marine organisms has not been reported for individual or complex mixtures of PAHs. In this study, larvae and juveniles of the bivalve, Mulinia lateralis, and juveniles of the mysid shrimp, Mysidopsis bahia, were exposed to individual known phototoxic PAHs (anthracene, fluoranthene, pyrene), as well as the water-accommodated fractions of several petroleum products (Fuel Oil {number_sign}2, Arabian Light Crude, Prudhoe Bay Crude, Fuel Oil {number_sign}6) containing PAHs. Phototoxicity of individual PAHs was 12 to >50,000 times that of conventional toxicity. Three of the petroleum products demonstrated phototoxicity while the lightest product, Fuel Oil {number_sign}2, was not phototoxic at the concentrations tested. The phototoxicity of petroleum products appears to be dependent on the composition and concentrations of phototoxic PAHs present: lighter oils have fewer multiple aromatic ring, phototoxic compounds while heavier oils have higher levels of these types of molecules. This study shows that phototoxicity can occur in marine waters to marine species. Further, the occurrence of oil in marine waters presents the additional risk of phototoxicity not routinely assessed for during oil spills.

  1. Reversible and irreversible higher-order cycloaddition reactions of polyolefins with a multiple-bonded heavier group 13 alkene analogue: contrasting the behavior of systems with π-π, π-π*, and π-n+ frontier molecular orbital symmetry.

    Science.gov (United States)

    Caputo, Christine A; Guo, Jing-Dong; Nagase, Shigeru; Fettinger, James C; Power, Philip P

    2012-04-25

    The heavier group 13 element alkene analogue, digallene Ar(iPr(4))GaGaAr(iPr(4)) (1) [Ar(iPr(4)) = C(6)H(3)-2,6-(C(6)H(3)-2,6-(i)Pr(2))(2)], has been shown to react readily in [n + 2] (n = 6, 4, 2 + 2) cycloaddition reactions with norbornadiene and quadricyclane, 1,3,5,7-cyclooctatetraene, 1,3-cyclopentadiene, and 1,3,5-cycloheptatriene to afford the heavier element deltacyclane species Ar(iPr(4))Ga(C(7)H(8))GaAr(iPr(4)) (2), pseudoinverse sandwiches Ar(iPr(4))Ga(C(8)H(8))GaAr(iPr(4)) (3, 3(iso)), and polycyclic compounds Ar(iPr(4))Ga(C(5)H(6))GaAr(iPr(4)) (4) and Ar(iPr(4))Ga(C(7)H(8))GaAr(iPr(4)) (5, 5(iso)), respectively, under ambient conditions. These reactions are facile and may be contrasted with other all-carbon versions, which require transition-metal catalysis or forcing conditions (temperature, pressure), or with the reactions of the corresponding heavier group 14 species Ar(iPr(4))EEAr(iPr(4)) (E = Ge, Sn), which give very different product structures. We discuss several mechanistic possibilities, including radical- and non-radical-mediated cyclization pathways. These mechanisms are consistent with the improved energetic accessibility of the LUMO of the heavier group 13 element multiple bond in comparison with that of a simple alkene or alkyne. We show that the calculated frontier molecular orbitals (FMOs) of Ar(iPr(4))GaGaAr(iPr(4)) are of π-π symmetry, allowing this molecule to engage in a wider range of reactions than permitted by the usual π-π* FMOs of C-C π bonds or the π-n(+) FMOs of heavier group 14 alkyne analogues.

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

    Science.gov (United States)

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

    2016-10-18

    The present invention is directed to the one step selective conversion of starch, cellulose, or glucose to molecules containing 7 to 26 contiguous carbon atoms. The invention is also directed to the conversion of those intermediates to saturated hydrocarbons. Such saturated hydrocarbons are useful as, for example, fuels.

  3. Photosynthetic terpene hydrocarbon production for fuels and chemicals

    Science.gov (United States)

    Photosynthetic terpene production[ED1] represents an energy and carbon-efficient route for hydrocarbon fuel production. Diverse terpene structures also provide the potential to produce next-generation 'drop-in' hydrocarbon fuel molecules. However, it is highly challenging to achieve efficient redire...

  4. Learning and perceptual similarity among cuticular hydrocarbons in ants.

    Science.gov (United States)

    Bos, Nick; Dreier, Stephanie; Jørgensen, Charlotte G; Nielsen, John; Guerrieri, Fernando J; d'Ettorre, Patrizia

    2012-01-01

    Nestmate recognition in ants is based on perceived differences in a multi-component blend of hydrocarbons that are present on the insect cuticle. Although supplementation experiments have shown that some classes of hydrocarbons, such as methyl branched alkanes and alkenes, have a salient role in nestmate recognition, there was basically no information available on how ants detect and perceive these molecules. We used a new conditioning procedure to investigate whether individual carpenter ants could associate a given hydrocarbon (linear or methyl-branched alkane) to sugar reward. We then studied perceptual similarity between a hydrocarbon previously associated with sugar and a novel hydrocarbon. Ants learnt all hydrocarbon-reward associations rapidly and with the same efficiency, regardless of the structure of the molecules. Ants could discriminate among a large number of pairs of hydrocarbons, but also generalised. Generalisation depended both on the structure of the molecule and the animal's experience. For linear alkanes, generalisation was observed when the novel molecule was smaller than the conditioned one. Generalisation between pairs of methyl-alkanes was high, while generalisation between hydrocarbons that differed in the presence or absence of a methyl group was low, suggesting that chain length and functional group might be coded independently by the ant olfactory system. Understanding variations in perception of recognition cues in ants is necessary for the general understanding of the mechanisms involved in social recognition processes based on chemical cues.

  5. 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.

  6. Geochemical assessment of light gaseous hydrocarbons in near-surface soils of Kutch–Saurashtra: Implication for hydrocarbon prospects

    Indian Academy of Sciences (India)

    P Lakshmi Srinivasa Rao; T Madhavi; D Srinu; M S Kalpana; D J Patil; A M Dayal

    2013-02-01

    Light hydrocarbons in soil have been used as direct indicators in geochemical hydrocarbon exploration, which remains an unconventional path in the petroleum industry. The occurrence of adsorbed soil gases, methane and heavier homologues were recorded in the near-surface soil samples collected from Kutch–Saurashtra, India. Soil gas alkanes were interpreted to be derived from deep-seated hydrocarbon sources and have migrated to the surface through structural discontinuities. The source of hydrocarbons is assessed to be thermogenic and could have been primarily derived from humic organic matter with partial contribution from sapropelic matter. Gas chromatographic analyses of hydrocarbons desorbed from soil samples through acid extraction technique showed the presence of methane through -butane and the observed concentrations (in ppb) vary from: methane (C1) from 4–291, ethane (C2) from 0–84, propane (C3) from 0–37, i-butane (iC4) from 0–5 and -butane (nC4) from 0–4. Carbon isotopes measured for methane and ethane by GC-C-IRMS, range between −42.9‰ to −13.3‰ (Pee Dee Belemnite – PDB) and −21.2‰ to −12.4‰ (PDB), respectively. The increased occurrence of hydrocarbons in the areas near Anjar of Kutch and the area south to Rajkot of Saurashtra signifies the area potential for oil and gas.

  7. Crossed-beam reaction of carbon atoms with hydrocarbon molecules. V. Chemical dynamics of n-C4H3 formation from reaction of C(3Pj) with allene, H2CCCH2(X 1A1)

    Science.gov (United States)

    Kaiser, R. I.; Mebel, A. M.; Chang, A. H. H.; Lin, S. H.; Lee, Y. T.

    1999-06-01

    The crossed molecular beams technique was employed to investigate the reaction between ground state carbon atoms, C(3Pj), and allene, H2CCCH2(X 1A1), at two averaged collision energies of 19.6 and 38.8 kJ mol-1. Product angular distributions and time-of-flight spectra of C4H3 were recorded. Forward-convolution fitting of the data yields weakly polarized center-of-mass angular flux distributions isotropic at lower, but forward scattered with respect to the carbon beam at a higher collision energy. The maximum translational energy release and the angular distributions combined with ab initio and RRKM calculations are consistent with the formation of the n-C4H3 radical in its electronic ground state. The channel to the i-C4H3 isomer contributes less than 1.5%. Reaction dynamics inferred from the experimental data indicate that the carbon atom attacks the π-orbitals of the allenic carbon-carbon double bond barrierless via a loose, reactant-like transition state located at the centrifugal barrier. The initially formed cyclopropylidene derivative rotates in a plane almost perpendicular to the total angular momentum vector around its C-axis and undergoes ring opening to triplet butatriene. At higher collision energy, the butatriene complex decomposes within 0.6 ps via hydrogen emission to form the n-C4H3 isomer and atomic hydrogen through an exit transition state located 9.2 kJ mol-1 above the products. The explicit identification of the n-C4H3 radical under single collision represents a further example of a carbon-hydrogen exchange in reactions of ground state carbon atoms with unsaturated hydrocarbons. This channel opens a barrierless route to synthesize extremely reactive hydrocarbon radicals in combustion processes, interstellar chemistry, and hydrocarbon-rich atmospheres of Jupiter, Saturn, Titan, as well as Triton.

  8. Policy-Relevant Behaviors Predict Heavier Drinking in Both On and Off Premises and Mediate the Relationship Between Heavier Alcohol Consumption and Age, Gender, and Socioeconomic Status-Analysis from the International Alcohol Control Study.

    Science.gov (United States)

    Casswell, Sally; Huckle, Taisia; Wall, Martin; Parker, Karl

    2016-02-01

    Our goal was to investigate the role of behaviors amenable to policy change in mediating the relationship between alcohol consumption in off and on premises, age, and 2 measures of socioeconomic status (education and income). A cross-sectional general population survey was analyzed by using Bayesian path analysis to understand direct and mediating pathways. A total of 1,900 drinkers (past 6 months), aged 18 to 65 years, living in households with landline phones participated in the study. Measures were as follows: typical quantities of alcohol consumed per occasion, frequency of drinking, both off and on premise; gender, age groups; and years of education, personal income, prices paid, time of purchase, and liking for alcohol advertisements. Later times of purchase predicted larger quantities consumed (on and off premise) and more frequent drinking (on premise only). Younger people and males purchased later, and this mediated their heavier consumption. Lower prices paid predicted larger quantities consumed (on premise) and higher frequency of drinking (off premise). Younger and male respondents paid lower prices, and this mediated larger quantities consumed on premise and more frequent drinking off premise. Less well educated paid lower prices, and this mediated drinking more frequently off premise among this group. Liking for alcohol ads predicted drinking larger quantities and higher frequency both off and on premise. Younger and male respondents reported greater liking for ads, and this mediated their consumption of larger quantities and more frequent drinking both on and off premise. Those with higher income drank larger amounts on premise and more frequently on and off, but there were no mediating effects from the policy-relevant variables. Heavier drinking patterns by young people and those less well educated could be ameliorated by attention to alcohol policy. Copyright © 2016 by the Research Society on Alcoholism.

  9. Partial conversion of hydrocarbons to syngas and hydrogen in volumetric radiation burners as a prospective way to enhance the performance characteristics of power engines

    Science.gov (United States)

    Arutyunov, V. S.; Shmelev, V. M.; Shapovalova, O. V.; Rakhmetov, A. N.; Strekova, L. N.

    2013-03-01

    New type of syngas generator based on the partial conversion of natural gas (methane) or heavier hydrocarbons in volumetric permeable matrix burners in the conditions of locked infrared (IR) radiation is suggested as a high-productive, adaptable, and rather simple way of syngas and hydrogen production for various low-scale applications including enhancing the performance characteristics of power engines.

  10. Saturated versus unsaturated hydrocarbon interactions with carbon nanostructures

    Directory of Open Access Journals (Sweden)

    Deivasigamani eUmadevi

    2014-09-01

    Full Text Available The interactions of various acyclic and cyclic hydrocarbons in both saturated and unsaturated forms with the carbon nanostructures (CNSs have been explored by using density functional theory (DFT calculations. Model systems representing armchair and zigzag carbon nanotubes (CNTs and graphene have been considered to investigate the effect of chirality and curvature of the CNSs towards these interactions. Results of this study reveal contrasting binding nature of the acyclic and cyclic hydrocarbons towards CNSs. While the saturated molecules show stronger binding affinity in acyclic hydrocarbons; the unsaturated molecules exhibit higher binding affinity in cyclic hydrocarbons. In addition, acyclic hydrocarbons exhibit stronger binding affinity towards the CNSs when compared to their corresponding cyclic counterparts. The computed results excellently corroborate the experimental observations. The interaction of hydrocarbons with graphene is more favourable when compared with CNTs. Bader’s theory of atoms in molecules has been invoked to characterize the noncovalent interactions of saturated and unsaturated hydrocarbons. Our results are expected to provide useful insights towards the development of rational strategies for designing complexes with desired noncovalent interaction involving CNSs.

  11. Saturated vs. unsaturated hydrocarbon interactions with carbon nanostructures

    Science.gov (United States)

    Umadevi, Deivasigamani; Sastry, G. Narahari

    2014-01-01

    The interactions of various acyclic and cyclic hydrocarbons in both saturated and unsaturated forms with the carbon nanostructures (CNSs) have been explored by using density functional theory (DFT) calculations. Model systems representing armchair and zigzag carbon nanotubes (CNTs) and graphene have been considered to investigate the effect of chirality and curvature of the CNSs toward these interactions. Results of this study reveal contrasting binding nature of the acyclic and cyclic hydrocarbons toward CNSs. While the saturated molecules show stronger binding affinity in acyclic hydrocarbons; the unsaturated molecules exhibit higher binding affinity in cyclic hydrocarbons. In addition, acyclic hydrocarbons exhibit stronger binding affinity toward the CNSs when compared to their corresponding cyclic counterparts. The computed results excellently corroborate the experimental observations. The interaction of hydrocarbons with graphene is more favorable when compared with CNTs. Bader's theory of atoms in molecules has been invoked to characterize the noncovalent interactions of saturated and unsaturated hydrocarbons. Our results are expected to provide useful insights toward the development of rational strategies for designing complexes with desired noncovalent interaction involving CNSs. PMID:25232539

  12. Saturated versus unsaturated hydrocarbon interactions with carbon nanostructures

    Science.gov (United States)

    Umadevi, Deivasigamani; Sastry, G. Narahari

    2014-09-01

    The interactions of various acyclic and cyclic hydrocarbons in both saturated and unsaturated forms with the carbon nanostructures (CNSs) have been explored by using density functional theory (DFT) calculations. Model systems representing armchair and zigzag carbon nanotubes (CNTs) and graphene have been considered to investigate the effect of chirality and curvature of the CNSs towards these interactions. Results of this study reveal contrasting binding nature of the acyclic and cyclic hydrocarbons towards CNSs. While the saturated molecules show stronger binding affinity in acyclic hydrocarbons; the unsaturated molecules exhibit higher binding affinity in cyclic hydrocarbons. In addition, acyclic hydrocarbons exhibit stronger binding affinity towards the CNSs when compared to their corresponding cyclic counterparts. The computed results excellently corroborate the experimental observations. The interaction of hydrocarbons with graphene is more favourable when compared with CNTs. Bader’s theory of atoms in molecules has been invoked to characterize the noncovalent interactions of saturated and unsaturated hydrocarbons. Our results are expected to provide useful insights towards the development of rational strategies for designing complexes with desired noncovalent interaction involving CNSs.

  13. Big Baby, Heavier Kid?

    Science.gov (United States)

    ... and Human Services. More Health News on Child Nutrition Obesity in Children Recent Health News Related MedlinePlus Health Topics Child Nutrition Obesity in Children About MedlinePlus Site Map FAQs Customer ...

  14. Molecule nanoweaver

    Science.gov (United States)

    Gerald, II; Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2009-03-10

    A method, apparatus, and system for constructing uniform macroscopic films with tailored geometric assemblies of molecules on the nanometer scale. The method, apparatus, and system include providing starting molecules of selected character, applying one or more force fields to the molecules to cause them to order and condense with NMR spectra and images being used to monitor progress in creating the desired geometrical assembly and functionality of molecules that comprise the films.

  15. Comparative investigation of pure and mixed rare gas atoms on coronene molecules.

    Science.gov (United States)

    Rodríguez-Cantano, Rocío; Bartolomei, Massimiliano; Hernández, Marta I; Campos-Martínez, José; González-Lezana, Tomás; Villarreal, Pablo; Pérez de Tudela, Ricardo; Pirani, Fernando; Hernández-Rojas, Javier; Bretón, José

    2017-01-21

    Clusters formed by the combination of rare gas (RG) atoms of He, Ne, Ar, and Kr on coronene have been investigated by means of a basin-hopping algorithm and path integral Monte Carlo calculations at T = 2 K. Energies and geometries have been obtained and the role played by the specific RG-RG and RG-coronene interactions on the final results is analysed in detail. Signatures of diffuse behavior of the He atoms on the surface of the coronene are in contrast with the localization of the heavier species, Ar and Kr. The observed coexistence of various geometries for Ne suggests the motion of the RG atoms on the multi-well potential energy surface landscape offered by the coronene. Therefore, the investigation of different clusters enables a comparative analysis of localized versus non-localized features. Mixed Ar-He-coronene clusters have also been considered and the competition of the RG atoms to occupy the docking sites on the molecule is discussed. All the obtained information is crucial to assess the behavior of coronene, a prototypical polycyclic aromatic hydrocarbon clustering with RG atoms at a temperature close to that of interstellar medium, which arises from the critical balance of the interactions involved.

  16. Artificial Hydrocarbon Networks Fuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Hiram Ponce

    2013-01-01

    Full Text Available 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 parameters involved in artificial hydrocarbon networks. In addition, a position controller for a direct current (DC motor was implemented using the proposed FIM-model in type-1 and type-2 fuzzy inference systems. Experimental results demonstrate that the fuzzy-molecular inference model can be applied as an alternative of type-2 Mamdani’s fuzzy control systems because the set of molecular units can deal with dynamic uncertainties mostly present in real-world control applications.

  17. 木质纤维素基平台化合物催化转化制备液体燃料及燃料添加剂%Catalytic production of liquid hydrocarbon fuels and fuel additives from lignocellulosic platform molecules

    Institute of Scientific and Technical Information of China (English)

    朱晨杰; 杜风光; 应汉杰; 欧阳平凯

    2015-01-01

    随着不可再生的石化资源的不断消耗以及生态环境的不断恶化,可再生资源和能源的开发和利用受到越来越多的重视。木质纤维素是地球上最丰富的可再生生物质资源,蕴藏量和产量巨大,具有广阔的开发利用前景。本文在介绍国内外木质纤维素资源开发利用研究的基础上,结合当今世界生物质能领域的研发现状,分别概述了经由呋喃类化合物及乙酰丙酸等木质纤维素基平台化合物分子,制备液体燃料和燃料添加剂的最新研究进展。在总结归纳合成途径的同时,分析了现阶段面临的主要问题及可能的解决办法,以期能为木质纤维素类生物质能源化利用的研究提供有益的参考与借鉴。%Development and utilization of renewable biomass resources has great significance in easing the energy crisis and reducing environmental pollution. Lignocellulosic biomass is much more concerned due to its abundant reserves, lower cost and fast-growing. In this work some relevant processes for the preparation of liquid hydrocarbon fuels and fuel additives from lignocellulosic platform molecules are discussed and summarized. Catalytic transformation of these platform molecules for the production of liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenation, hydrogenolysis, decarbonylation) with the increase of molecular weightvia C-C coupling reactions (e.g. aldol condensation, hydroxyalkylation, ketonization, oligomerization). Moreover, it is shown that these platform molecules can also be converted into a variety of fuel additives through catalytic transformations that include reduction, esterification, etherification, and acetalization reactions. The catalysts and processes involved in these catalytic routes are intensively discussed, and their existing problems as well as possible solutions are addressed, which may provide insights helpful for

  18. Bioremediation of petroleum hydrocarbons: catabolic genes, microbial communities, and applications.

    Science.gov (United States)

    Fuentes, Sebastián; Méndez, Valentina; Aguila, Patricia; Seeger, Michael

    2014-06-01

    Bioremediation is an environmental sustainable and cost-effective technology for the cleanup of hydrocarbon-polluted soils and coasts. In spite of that longer times are usually required compared with physicochemical strategies, complete degradation of the pollutant can be achieved, and no further confinement of polluted matrix is needed. Microbial aerobic degradation is achieved by the incorporation of molecular oxygen into the inert hydrocarbon molecule and funneling intermediates into central catabolic pathways. Several families of alkane monooxygenases and ring hydroxylating dioxygenases are distributed mainly among Proteobacteria, Actinobacteria, Firmicutes and Fungi strains. Catabolic routes, regulatory networks, and tolerance/resistance mechanisms have been characterized in model hydrocarbon-degrading bacteria to understand and optimize their metabolic capabilities, providing the basis to enhance microbial fitness in order to improve hydrocarbon removal. However, microbial communities taken as a whole play a key role in hydrocarbon pollution events. Microbial community dynamics during biodegradation is crucial for understanding how they respond and adapt to pollution and remediation. Several strategies have been applied worldwide for the recovery of sites contaminated with persistent organic pollutants, such as polycyclic aromatic hydrocarbons and petroleum derivatives. Common strategies include controlling environmental variables (e.g., oxygen availability, hydrocarbon solubility, nutrient balance) and managing hydrocarbon-degrading microorganisms, in order to overcome the rate-limiting factors that slow down hydrocarbon biodegradation.

  19. Characterization of weathered petroleum hydrocarbons during a landfarming bioremediation study

    Directory of Open Access Journals (Sweden)

    Maletić Snežana

    2012-01-01

    Full Text Available Landfarming bioremediation was performed over 2 years on soil heavily polluted with weathered oil and oil derivatives: 23200 mg kg-1 of mineral oil, 35300 mg kg-1 total hydrocarbons, and 8.65 mg kg-1 of total PAHs. During the experiment, mineral oil, total hydrocarbon and PAH concentrations decreased by approximately 53%, 27% and 72%, respectively. A GC/MS-Scan was used to identify the crude oil components that persist after bioremediation treatment of contaminated soil and the metabolites generated during this process. The data shows that in weathered-hydrocarbons contaminated soil, the number of initially detected compounds after the bioremediation process further decreased over a 2 year period, and at the same time several new compounds were observed at the end of experiment. Higher persistence was also shown for heavier n-alkanes and branched alkanes, which could be detected over a longer period of time. The analysis highlights the importance of n-alkanes, their substituted derivatives and polycyclic aromatic hydrocarbons as the most significant pollutants.

  20. Oxygenated Derivatives of Hydrocarbons

    Science.gov (United States)

    For the book entitled “Insect Hydrocarbons: Biology, Biochemistry and Chemical Ecology”, this chapter presents a comprehensive review of the occurrence, structure and function of oxygenated derivatives of hydrocarbons. The book chapter focuses on the occurrence, structural identification and functi...

  1. Abiogenic hydrocarbons in commercial gases from the Songliao Basin, China

    Institute of Scientific and Technical Information of China (English)

    WANG XianBin; WANG LianSheng; LIU ChunXue; YAN Hong; LI LiWu; ZHOU XiaoFeng; WANG YongLi; YANG Hui; WANG Guang; GUO ZhanQian; TUO JinCai; GUO HongYan; LI ZhenXi; ZHUO ShengGuang; JIANG HongLiang; ZENG LongWei; ZHANG MingJie

    2009-01-01

    This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mecha-nisms and from different sources in nature. It is demonstrated that the biodegradation or thermode-gradation of complex high-molecule sedimentary organic material can form microbial gas or ther-mogenic gas. The δ13C1 value ranges from -110‰ to -50‰ for microbial gases but from -51‰ to -35‰ (even heavier) for thermogenic gases. Controlled by the kinetic isotope fractionation, both microbial and thermogenic gases have δ13C and δD values characterized by normal distribution, i.e. δ13C1 δ13C2> δ13C3> δ13C4 and δDCH4<δDC2H6< δDC3H8< δDC4H10. The δ13C values and δD values are negatively correlated. Natural gases from 26 commercial gas wells distributed in the Xujiaweizi and Yingshan-Miaotaizi faulted de-pressions in the Songliao Basin, China, show δ13C1 values ranging from -30.5‰. to -16.7‰, with a very narrow δD range between -203‰--196‰. These gases are characterized by a reverse distribution of δ13C values but a normal distribution of δD values, and a negative correlation between their δ13C and δD values, indicating an abiological origin. The present study has revealed that abiogenic hydrocar-bons not only exist in nature but also can make significant contribution to commercial gas reserviors. It is estimated that the reserve volume of alkane gases with abiogenic characteristics in these 26 gas wells in the Songliao Basin is over 500×108 m3, The prospecting practice in the Songliao Basin has demonstrated that abiogenic alkane gases are of a promising resource, and it provides an example for the investigation of and search for abiogenic commercial natural gases worldwide.

  2. 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.

  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. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  5. Energy additivity in branched and cyclic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Gao, H.; Bader, R.F.W. [McMaster Univ., Hamilton, ON (Canada). Dept. of Chemistry; Cortes-Guzman, F. [Univ. Nacional Autonoma de Mexico, (Mexico). Dept. de Fisicoquimica

    2009-11-15

    This paper reported on a study of the energetic relationships between hydrocarbon molecules and the heats of formation. The quantum theory of atoms in molecules (QTAIM) was used to investigate the degree to which branched hydrocarbons obey a group additivity scheme for energy and populations. The QTAIM defined the properties of the chemical groups. The experimental and theoretical transferability of the methyl and methylene groups of the linear hydrocarbons was also explored. The calculations were performed using a large basis set at the restricted Hartree-Fock and MP2(full) levels of theory. The study also investigated the deviations from additivity, noted for small ring hydrocarbons leading to the definition of strain energy. The QTAIM energies recovered the experimental values. The paper included details regarding the delocalization of the electron density over the surface of the cyclopropane ring, responsible for its homoaromatic properties. The calculations presented in this study satisfied the virial theorem for the atomic definition of energy. The paper discussed the problems associated with the use of the density functional theory (DFT) resulting from its failure to satisfy the virial theorem. 44 refs., 9 tabs., 2 figs.

  6. Surpassing the mass restriction of buffer gas cooling: Cooling of low mass ions by localized heavier atoms

    Science.gov (United States)

    Dutta, Sourav; Sawant, Rahul; Rangwala, S. A.

    2016-05-01

    Cooling of trapped ions has resulted in fascinating science including the realization of some of the most accurate atomic clocks. It has also found widespread application, for example, in mass spectrometry and cold chemistry. Among the different methods for cooling ions, cooling by elastic collisions with ultracold neutral atoms is arguably the most generic. However, in spite of its widespread application, there is confusion with regards the collisional heating/cooling of light ions by heavier neutral atoms. We address the question experimentally and demonstrate, for the first time, cooling of light ions by co-trapped heavy atoms. We show that trapped 39 K+ ions are cooled by localized ultracold neutral 85 Rb atoms. The atom-ion mass ratio (= 2.18) is well beyond any theoretical predictions so far. We further argue that cooling of ions by localized cold atoms is possible for any mass ratio. The result opens up the possibility of reaching the elusive s-wave collision regime in atom-ion collisions. S.D. is supported by DST-INSPIRE Faculty Fellowship, India.

  7. Formation of the Abundance Boundaries of the Heavier Neutron-capture Elements in Metal-poor Stars

    Science.gov (United States)

    Yang, Guochao; Li, Hongjie; Liu, Nian; Zhang, Lu; Cui, Wenyuan; Liang, Yanchun; Niu, Ping; Zhang, Bo

    2017-06-01

    The abundance scatter of heavier r-process elements (Z≥slant 56) relative to Fe ([r/Fe]) in metal-poor stars preserves excellent information of the star formation history and provides important insights into the various situations of the Galactic chemical enrichment. In this respect, the upper and lower boundaries of [r/Fe] could present useful clues for investigating the extreme situations of the star formation history and the early Galactic chemical evolution. In this paper, we investigate the formation of the upper and lower boundaries of [r/Fe] for the gas clouds. We find that, for a cloud from which metal-poor stars formed, the formation of the upper limits of [r/Fe] is mainly due to the pollution from a single main r-process event. For a cloud from which metal-poor stars formed, the formation of the lower limits of [r/Fe] is mainly due to the pollution from a single SN II event that ejects primary Fe.

  8. Rising and boiling of a drop of volatile liquid in a heavier one: application to the LMFBR severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Pigny, Sylvain L.; Coste, Pierre F. [DEN/DER/SSTH, CEA/Grenoble, 38054 Grenoble Cedex 9 (France)

    2005-07-01

    Full text of publication follows: The rising and, simultaneously the boiling, of a droplet of volatile liquid in a heavier one is computation-ally investigated. Our calculations are performed with the help of the SIMMER code, in which a specific DNS algorithm is developed, to represent surface tension between the different media in an explicit way. This is required to represent the physical contact that occurs between two liquids and the vapor from the lighter one, since interfacial heat transfers, and therefore boiling kinetics, merely depend on it. The behavior of the three fluids system is of interest as a key phenomenon related to the transition phase of LMFBR severe accidents, before the formation of a fully developed bubble column. The driven force due to the boiling of steel drops can play a major role in the relocation, and, consequently, the recriticality of UO{sub 2} fuel. The problem is investigated focusing first on analytical experiments, built-up with simulating materials, and for which accurate experimental results are provided. The dependence of results with regard to thermodynamical and physical properties is underlined. This point is of interest in view of some uncertainties in the knowledge of data concerning the materials present in the reactor at high temperature. The pressure level is a key parameter in the accident scenarios: its influence is uppermost on the volumic mass of the gas. It is also outlined. (authors)

  9. Rule-based programming and strategies for automated generation of detailed kinetic models for gas phase combustion of polycyclic hydrocarbon molecules; Programmation par regles et strategies pour la generation automatique de mecanismes de combustion d'hydrocarbures polycycliques

    Energy Technology Data Exchange (ETDEWEB)

    Ibanescu, L.

    2004-06-15

    The primary objective of this thesis is to explore the approach of using rule-based systems and strategies, for a complex problem of chemical kinetic: the automated generation of reaction mechanisms. The chemical reactions are naturally expressed as conditional rewriting rules. The control of the chemical reactions chaining is easy to describe using a strategies language, such as the one of the ELAN system, developed in the Protheo team. The thesis presents the basic concepts of the chemical kinetics, the chemical and computational problems related to the conception and validation of a reaction mechanism, and gives a general structure for the generator of reaction mechanisms called GasEI. Our research focuses on the primary mechanism generator. We give solutions for encoding the chemical species, the reactions and their chaining, and we present the prototype developed in ELAN. The representation of the chemical species uses the notion of molecular graphs, encoded by a term structure called GasEI terms. The chemical reactions are expressed by rewriting rules on molecular graphs, encoded by a set of conditional rewriting rules on GasEI terms. The strategies language of the ELAN system is used to express the reactions chaining in the primary mechanism generator. This approach is illustrated by coding ten generic reactions of the oxidizing pyrolysis. Qualitative chemical validations of the prototype show that our approach gives, for acyclic molecules, the same results as the existing mechanism generators, and for polycyclic molecules produces original results.

  10. Bottom of the heap: having heavier competitors accelerates early-life telomere loss in the European starling, Sturnus vulgaris.

    Science.gov (United States)

    Nettle, Daniel; Monaghan, Pat; Boner, Winnie; Gillespie, Robert; Bateson, Melissa

    2013-01-01

    Early-life adversity is associated with poorer health and survival in adulthood in humans and other animals. One pathway by which early-life environmental stressors could affect the adult phenotype is via effects on telomere dynamics. Several studies have shown that early-life adversity is associated with relatively short telomeres, but these are often cross-sectional and usually correlational in design. Here, we present a novel experimental system for studying the relationship between early-life adversity and telomere dynamics using a wild bird, the European starling (Sturnus vulgaris). We used cross-fostering to experimentally assign sibling chicks to either small or large broods for twelve days of the growth period. We measured telomere length in red blood cells using quantitative PCR near the beginning of the experimental manipulation (4 days old), at the end of the experimental manipulation (15 days old), and once the birds were independent (55 days old). Being in a larger brood slowed growth and retarded wing development and the timing of fledging. We found no evidence that overall brood size affected telomere dynamics. However, the greater the number of competitors above the focal bird in the within-brood size hierarchy, the greater was the telomere loss during the period of the experimental manipulation. The number of competitors below the focal in the hierarchy had no effect. The effect of heavier competitors was still evident when we controlled for the weight of the focal bird at the end of the manipulation, suggesting it was not due to retarded growth per se. Moreover, the impact of early competition on telomeres was still evident at independence, suggesting persistence beyond early life. Our study provides experimental support for the hypothesis that social stress, in this case induced by the presence of a greater number of dominant competitors, accelerates the rate of telomere loss.

  11. Bottom of the heap: having heavier competitors accelerates early-life telomere loss in the European starling, Sturnus vulgaris.

    Directory of Open Access Journals (Sweden)

    Daniel Nettle

    Full Text Available Early-life adversity is associated with poorer health and survival in adulthood in humans and other animals. One pathway by which early-life environmental stressors could affect the adult phenotype is via effects on telomere dynamics. Several studies have shown that early-life adversity is associated with relatively short telomeres, but these are often cross-sectional and usually correlational in design. Here, we present a novel experimental system for studying the relationship between early-life adversity and telomere dynamics using a wild bird, the European starling (Sturnus vulgaris. We used cross-fostering to experimentally assign sibling chicks to either small or large broods for twelve days of the growth period. We measured telomere length in red blood cells using quantitative PCR near the beginning of the experimental manipulation (4 days old, at the end of the experimental manipulation (15 days old, and once the birds were independent (55 days old. Being in a larger brood slowed growth and retarded wing development and the timing of fledging. We found no evidence that overall brood size affected telomere dynamics. However, the greater the number of competitors above the focal bird in the within-brood size hierarchy, the greater was the telomere loss during the period of the experimental manipulation. The number of competitors below the focal in the hierarchy had no effect. The effect of heavier competitors was still evident when we controlled for the weight of the focal bird at the end of the manipulation, suggesting it was not due to retarded growth per se. Moreover, the impact of early competition on telomeres was still evident at independence, suggesting persistence beyond early life. Our study provides experimental support for the hypothesis that social stress, in this case induced by the presence of a greater number of dominant competitors, accelerates the rate of telomere loss.

  12. Detection prospects of light NMSSM Higgs pseudoscalar via cascades of heavier scalars from vector boson fusion and Higgs-strahlung

    Science.gov (United States)

    Bomark, N.-E.; Moretti, S.; Roszkowski, L.

    2016-10-01

    A detection at the large hadron collider of a light Higgs pseudoscalar would, if interpreted in a supersymmetric framework, be a smoking gun signature of non-minimal supersymmetry. In this work in the framework of the next-to-minimal supersymmetric standard model we focus on vector boson fusion and Higgs-strahlung production of heavier scalars that subsequently decay into pairs of light pseudoscalars. We demonstrate that although these channels have in general very limited reach, they are viable for the detection of light pseudoscalars in some parts of parameter space and can serve as an important complementary probe to the dominant gluon-fusion production mode. We also demonstrate that in a Higgs factory these channels may reach sensitivities comparable to or even exceeding the gluon fusion channels at the Large Hadron Collider, thus possibly rendering this our best option to discover a light pseudoscalar. It is also worth mentioning that for the singlet dominated scalar this may be the only way to measure its couplings to gauge bosons. Especially promising are channels where the initial scalar is radiated off a W as these events have relatively high rates and provide substantial background suppression due to leptons from the W. We identify three benchmark points that well represent the above scenarios. Assuming that the masses of the scalars and pseudoscalars are already measured in the gluon-fusion channel, the event kinematics can be further constrained, hence significantly improving detection prospects. This is especially important in the Higgs-strahlung channels with rather heavy scalars, and results in possible detection at 200 fb-1 for the most favoured parts of the parameter space.

  13. Carbon isotope composition of low molecular weight hydrocarbons and monocarboxylic acids from Murchison meteorite

    Science.gov (United States)

    Yuen, G.; Blair, N.; Des Marais, D. J.; Chang, S.

    1984-01-01

    Carbon isotopic compositions have been measured for individual hydrocarbons and monocarboxylic acids from the Murchison meteorite, a C2 carbonaceous chondrite which fell in Australia in 1969. With few exceptions, notably benzene, the volatile products are substantially isotopically heavier than their terrestrial counterparts, signifying their extraterrestrial origin. For both classes of compounds, the ratio of C-13 to C-12 decreases with increasing carbon number in a roughly parallel manner, and each carboxylic acid exhibits a higher isotopic ratio than the hydrocarbon containing the same number of carbon atoms. These trends are consistent with the kinetically controlled synthesis of higher homologues from lower ones. The results suggest the possibility that the production mechanisms for hydrocarbons and carboxylic acids may be similar, and impose constraints on the identity of the reactant species.

  14. 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...

  15. Atkins' molecules

    CERN Document Server

    Atkins, Peters

    2003-01-01

    Originally published in 2003, this is the second edition of a title that was called 'the most beautiful chemistry book ever written'. In it, we see the molecules responsible for the experiences of our everyday life - including fabrics, drugs, plastics, explosives, detergents, fragrances, tastes, and sex. With engaging prose Peter Atkins gives a non-technical account of an incredible range of aspects of the world around us, showing unexpected connections, and giving an insight into how this amazing world can be understood in terms of the atoms and molecules from which it is built. The second edition includes dozens of extra molecules, graphical presentation, and an even more accessible and enthralling account of the molecules themselves.

  16. Enumerating molecules.

    Energy Technology Data Exchange (ETDEWEB)

    Visco, Donald Patrick, Jr. (, . Tennessee Technological University, Cookeville, TN); Faulon, Jean-Loup Michel; Roe, Diana C.

    2004-04-01

    This report is a comprehensive review of the field of molecular enumeration from early isomer counting theories to evolutionary algorithms that design molecules in silico. The core of the review is a detail account on how molecules are counted, enumerated, and sampled. The practical applications of molecular enumeration are also reviewed for chemical information, structure elucidation, molecular design, and combinatorial library design purposes. This review is to appear as a chapter in Reviews in Computational Chemistry volume 21 edited by Kenny B. Lipkowitz.

  17. Atmospheric polycyclic aromatic hydrocarbons in Seoul, Korea

    Science.gov (United States)

    Park, Seung S.; Kim, Young J.; Kang, Chang H.

    Daily particulate- and vapor-phase polycyclic aromatic hydrocarbons (PAH) samples were collected at an urban site in Seoul, Korea, during five intensive sampling campaigns between October 1998 and December 1999. PAH samples collected on quartz fiber filters and PUF plugs were first extracted using dichloromethane with ultrasonication and supercritical fluid extraction methods, respectively, and then analyzed by GC/MSD/SIM. Seasonal trends in atmospheric PAH concentrations in the study area were highly influenced by fossil fuel usage for domestic heating, boundary layer height, and air temperature. The relative benzo[a]pyrene amount and particulate organic to elemental carbon ratio calculated from the measurement results suggested that photo-oxidation is not an important factor in the variation of PAH concentrations during the summer sampling periods. Correlation studies between specific PAH of the individual factors identified by principal component factor analysis and meteorological parameters revealed that both temperature and relative humidity gave greater effects on the semi-volatile PAH, PHEN and FLT, rather than on the heavier PAH, B(b+k)F and BghiP.

  18. COMPUTATIONAL METHODS FOR STUDYING THE INTERACTION BETWEEN POLYCYCLIC AROMATIC HYDROCARBONS AND BIOLOGICAL MACROMOLECULES

    Science.gov (United States)

    Computational Methods for Studying the Interaction between Polycyclic Aromatic Hydrocarbons and Biological Macromolecules .The mechanisms for the processes that result in significant biological activity of PAHs depend on the interaction of these molecules or their metabol...

  19. An Energy Upgrade of REX-ISOLDE to 3.1 MeV/u and Acceleration of Heavier Masses up to $A$=150.

    CERN Multimedia

    Wenander, F J C

    2002-01-01

    With an additional 9-gap resonator, operated at 202.56 MHz, the maximum beam energy of REX-ISOLDE will be increased from 2.2 MeV/u to 3.1 MeV/u. This enlarges considerably the range of mass numbers of projectiles reaching the Coulomb barrier for nuclear reactions. Acceleration of heavier projectiles, however, requires longer charge breeding times leading to smaller pulse repetition rates. Thus EBIS developments aiming at shorter breeding times by using higher electron beam current densities are foreseen. Moreover, longer breeding times require longer accumulation times and larger ion storage capacities in REXTRAP to maintain the beam intensities, which will be reached by using new cooling techniques. Although various optimization steps can be performed with ion sources local to REX-ISOLDE, a commissioning of the modified REX-ISOLDE with ISOLDE beams of heavier masses with 15 shifts is requested.

  20. Density functional calculations on hydrocarbon isodesmic reactions

    Science.gov (United States)

    Fortunelli, Alessandro; Selmi, Massimo

    1994-06-01

    Hartree—Fock, Hartree—Fock-plus-correlation and self-consistent Kohn—Sham calculations are performed on a set of hydrocarbon isodesmic reactions, i.e. reactions among hydrocarbons in which the number and type of carbon—carbon and carbon—hydrogen bonds is conserved. It is found that neither Hartree—Fock nor Kohn—Sham methods correctly predict standard enthalpies, Δ Hr(298 K), of these reactions, even though — for reactions involving molecules containing strained double bonds — the agreement between the theoretical estimates and the experimental values of Δ Hr seems to be improved by the self-consistent solution of the Kohn—Sham equations. The remaining discrepancies are attributed to intramolecular dispersion effects, that are not described by ordinary exchange—correlation functionals, and are eliminated by introducing corrections based on a simple semi-empirical model.

  1. 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.

  2. Miscellaneous hydrocarbon solvents.

    Science.gov (United States)

    Bebarta, Vikhyat; DeWitt, Christopher

    2004-08-01

    The solvents discussed in this article are common solvents not categorized as halogenated, aromatic, or botanical. The solvents discussed are categorized into two groups: hydrocarbon mixtures and single agents. The hydrocarbon mixtures discussed are Stoddard solvent, naphtha, and kerosene. The remaining solvents described are n-hexane, methyl n-butyl ketone, dimethylformamide, dimethyl sulfoxide, and butyl mercaptans. Effects common to this group of agents and their unique effects are characterized. Treatment of exposures and toxic effects of these solvents is described, and physiochemical properties and occupational exposure levels are listed.

  3. Heavier drinking American college students may self-select into study abroad programs: An examination of sex and ethnic differences within a high-risk group.

    Science.gov (United States)

    Pedersen, Eric R; LaBrie, Joseph W; Hummer, Justin F; Larimer, Mary E; Lee, Christine M

    2010-09-01

    As with other heavier drinking groups, heavier drinking American college students may self-select into study abroad programs with specific intentions to use alcohol in the foreign environment. This cross-sectional study used a sample of 2144 students (mean age=20.00, SD=1.47) to explore differences in alcohol use and related negative consequences among (1) students intending to study abroad while in college, (2) students not intending to study abroad, and (3) students reporting prior study abroad participation. Results revealed that participants with no intention to study abroad drank less and experienced fewer alcohol-related consequences than participants intending to study abroad. In addition, students reporting prior completion of study abroad programs drank more and reported more hazardous alcohol use than those not intending to study abroad. Ethnic and sex differences existed; with White students, males, and females intending to study abroad and non-White students who previously completed study abroad programs demonstrating the most risk. These findings provide empirical support that study abroad students may be a heavier drinking subgroup necessitating intervention prior to beginning programs abroad. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. Adsorption of polar aromatic hydrocarbons on synthetic calcite

    DEFF Research Database (Denmark)

    Madsen, Lene; Grahl-Madsen, Laila; Grøn, Christian

    1996-01-01

    The wettability of hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. A model system of synthetic call cite, cyclohexane and the three probe molecules: benzoic acid, benzyl alcohol and benzylamine, have been...

  5. Fundamental spectroscopic studies of carbenes and hydrocarbon radicals

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-03-12

    Determination of bond dissociation energies and heats of formation of hydrocarbon radicals and carbenes requires knowledge of their structures, but this is not provided by standard mass spectrometric studies; what is needed is high-resolution spectroscopy, often best achieved at centimeter and millimeter wavelengths. Nearly 60 reactive organic molecules were investigated in the period from 1988--1998.

  6. Formation of Prebiotic Molecules in Interstellar and Cometary Ices

    Science.gov (United States)

    Bernstein, Max P.; Sandford, Scott A.; Allamandola, Louis J.; Dworkin, Jason; Gilette, J. Seb; Zare, Richard N.; DeVincenzi, D. (Technical Monitor)

    2000-01-01

    We report here on our lab studies of ice photochemistry of large organic molecules under cometary conditions. We focus on polycyclic aromatic hydrocarbons (PAHs), their photoproducts, and their similarities to molecules seen in living systems today. We note that these kinds of compounds are seen in meteorites and we propose an explanation for both their formation and their observed deuterium enrichments.

  7. Apparatus and methods for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2016-04-26

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  8. Optrode for sensing hydrocarbons

    Science.gov (United States)

    Miller, Holly; Milanovich, Fred P.; Hirschfeld, Tomas B.; Miller, Fred S.

    1987-01-01

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons.

  9. Bacterial sources for phenylalkane hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, L.; Winans, R.E. [Argonne National Lab., IL (United States); Langworthy, T. [Univ. of South Dakota, Vermillion, SD (United States)

    1996-10-01

    The presence of phenylalkane hydrocarbons in geochemical samples has been the source of much controversy. Although an anthropogenic input from detergent sources always appears likely, the distribution of phenylalkane hydrocarbons in some cases far exceeding that attributed to detergent input has led to a reappraisal of this view. Indeed, recent work involving analysis of the lipid hydrocarbon extracts from extant Thermoplasma bacteria has revealed the presence of phenylalkane hydrocarbons. The presence of phenylalkane hydrocarbons in sedimentary organic matter may therefore represent potential biological markers for thermophilic bacteria.

  10. A Review on the Genetics of Aliphatic and Aromatic Hydrocarbon Degradation.

    Science.gov (United States)

    Abbasian, Firouz; Lockington, Robin; Megharaj, Mallavarapu; Naidu, Ravi

    2016-01-01

    Because of the high diversity of hydrocarbons, degradation of each class of these compounds is activated by a specific enzyme. However, most of other downstream enzymes necessary for complete degradation of hydrocarbons maybe common between different hydrocarbons. The genes encoding proteins for degradation of hydrocarbons, including the proteins required for the uptake of these molecules, the specific enzyme used for the initial activation of the molecules and other necessary degrading enzymes are usually arranged as an operon. Although the corresponding genes in many phylogenetic groups of microbial species show different levels of diversity in terms of the gene sequence, the organisation of the genes in the genome or on plasmids and the activation mode (inductive or constitutive), some organisms show identical hydrocarbon-degrading genes, probably as a result of horizontal gene transfer between microorganisms.

  11. Microbial degradation of petroleum hydrocarbons.

    Science.gov (United States)

    Varjani, Sunita J

    2017-01-01

    Petroleum hydrocarbon pollutants are recalcitrant compounds and are classified as priority pollutants. Cleaning up of these pollutants from environment is a real world problem. Bioremediation has become a major method employed in restoration of petroleum hydrocarbon polluted environments that makes use of natural microbial biodegradation activity. Petroleum hydrocarbons utilizing microorganisms are ubiquitously distributed in environment. They naturally biodegrade pollutants and thereby remove them from the environment. Removal of petroleum hydrocarbon pollutants from environment by applying oleophilic microorganisms (individual isolate/consortium of microorganisms) is ecofriendly and economic. Microbial biodegradation of petroleum hydrocarbon pollutants employs the enzyme catalytic activities of microorganisms to enhance the rate of pollutants degradation. This article provides an overview about bioremediation for petroleum hydrocarbon pollutants. It also includes explanation about hydrocarbon metabolism in microorganisms with a special focus on new insights obtained during past couple of years. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Membrane separation of hydrocarbons

    Science.gov (United States)

    Chang, Y. Alice; Kulkarni, Sudhir S.; Funk, Edward W.

    1986-01-01

    Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture through a polymeric membrane. The membrane which is utilized to effect the separation comprises a polymer which is capable of maintaining its integrity in the presence of hydrocarbon compounds and which has been modified by being subjected to the action of a sulfonating agent. Sulfonating agents which may be employed will include fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, etc., the surface or bulk modified polymer will contain a degree of sulfonation ranging from about 15 to about 50%. The separation process is effected at temperatures ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psig.

  13. Ballonet String Model of Molecules

    Directory of Open Access Journals (Sweden)

    Gavril NIAC

    2008-06-01

    Full Text Available Strings of ballonets, modelling rows of orbitals, are assembled to molecule models by crossing them properly. The ballonets at the ends of the strings of 2, 3, 4 or 5 spheres represent bonding orbitals of hydrogen with other elements like C, N or O (the proton being inside the sphere, as well as nonbonding orbitals. The ballonets between them are modelling bonding orbitals among elements other than hydrogen - except the double bond in diborane, the atomic cores laying at the junction of two or more spheres.Advantages of elastic sphere models range from self-adjusting bond angles to resistance when closing cycles like cyclopropane or modeling double bonds.Examples comprise alkanes, including platonic hydrocarbons, ethene, acetylene, and some inorganic molecules.

  14. 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.

  15. Structural Evolution of Interstellar Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Hammonds, Mark; Candian, Alessandra; Mori, Tamami; Usui, Fumihiko; Onaka, Takashi

    2015-08-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are an important reservoir for molecular carbon in the interstellar medium (ISM), and investigations into their chemistry and behaviour may be important to the understanding of how carbon is processed from simple forms into complex prebiotic molecules such as those detected in chondritic meteorites. In this study, infrared astronomical data from AKARI and other observatories are used together with laboratory and theoretical data to study variations in the structure of emitting PAHs in interstellar environments using spectroscopic decomposition techniques and bands arising from carbon-hydrogen bond vibrations at wavelengths from 3 - 14 microns. Results and inferences are discussed in terms of the processing of large carbonaceous molecules in astrophysical environments.

  16. Thermodiffusion of polycyclic aromatic hydrocarbons in binary mixtures

    Science.gov (United States)

    Hashmi, Sara M.; Senthilnathan, Sid; Firoozabadi, Abbas

    2016-11-01

    Thermodiffusion in liquid mixtures may explain some counter-intuitive but naturally occurring phenomena such as hydrocarbon reservoirs with heavier component(s) stratified on top of lighter ones. However, beyond benchmark systems, systematic measurements of thermodiffusion in binary organic mixtures are lacking. We use an optical beam deflection apparatus to simultaneously probe Fickian and thermal diffusion in binary solution mixtures of polycyclic aromatic hydrocarbons dissolved in alkanes, and measure both Fickian diffusion D and the Soret coefficient ST, and then obtain the thermodiffusion coefficient DT. In a series of nine binary mixtures, we vary both the size of the aromatic compound from two to four rings, as well as the length of the alkane chain from 6 to 16 carbons. To probe the effect of increasing ring size, we include a 6-ringed aromatic compound, coronene, and toluene as a solvent, due to the insolubility of coronene in alkanes. Our results suggest that Fickian diffusion increases with the inverse of solvent viscosity and also with decreasing molecular weight of the solute. While both of these trends match our intuition, the behavior of ST and DT is more complicated. We find that ST and DT increase with the solute molecular weight when the solvent is held fixed and that the impact of solute ring size is higher in shorter chain alkane solvents.

  17. Microbial Bioremediation of Fuel Oil Hydrocarbons in Marine Environment

    Directory of Open Access Journals (Sweden)

    Sapna Pavitran

    2006-04-01

    Full Text Available Pollution in marine environment due to heavier petroleum products such as high-speeddiesel is known to take from days to months for complete natural remediation owing to its lowvolatility. For the survival of marine flora and fauna, it is important to control pollution causedby such recalcitrant and xenobiotic substances. Several petroleum hydrocarbons found in natureare toxic and recalcitrant. Therefore, pollution due to high-speed diesel is a cause of concern.The natural dispersion of high-speed diesel, a slow process, is attributed to an overall combinedeffect of physico-chemical and biological processes which take months for complete dispersion.History of marine oil spill bioremediation indicates limited laboratory studies. But experiencesfrom various oil spill management and field trials indicate important role of bioremediation, where,biodegradation of hydrocarbons through microbial mediators plays a major role in pollutant oildispersion. These microbial mediators such as bioemulsifiers and fimbrae, help in emulsification,dispersion, allowing attachment of bacteria to oil layers, followed by substrate-specific enzymaticbiodegradation in water.

  18. Hadron Molecules

    CERN Document Server

    Gutsche, Thomas; Faessler, Amand; Lee, Ian Woo; Lyubovitskij, Valery E

    2010-01-01

    We discuss a possible interpretation of the open charm mesons $D_{s0}^*(2317)$, $D_{s1}(2460)$ and the hidden charm mesons X(3872), Y(3940) and Y(4140) as hadron molecules. Using a phenomenological Lagrangian approach we review the strong and radiative decays of the $D_{s0}^* (2317)$ and $D_{s1}(2460)$ states. The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration. Determing the radiative ($\\gamma J/\\psi$ and $\\gamma \\psi(2s)$) and strong ($J/\\psi 2\\pi $ and $ J/\\psi 3\\pi$) decay modes we show that present experimental observation is consistent with the molecular structure assumption of the X(3872). Finally we give evidence for molecular interpretations of the Y(3940) and Y(4140) related to the observed strong decay modes $J/\\psi + \\omega$ or $J/\\psi + \\phi$, respectively.

  19. Study on molecular modelling of the selectivity of catalysts for heavy petroleum fractions hydrocracking; Etude sur molecule modele des parametres regissant la selectivite des catalyseurs d'hydrocraquage des charges lourdes

    Energy Technology Data Exchange (ETDEWEB)

    Leite, L.

    2000-10-19

    Hydrocracking is a catalytic petroleum refining process that is commonly applied to upgrade the heavier fractions obtained from the distillation of crude oils. Nowadays the European demand for good quality middle distillates (kerosene and gas-oil) is high and one important goal for the refining is to transform selectively feedstocks into middle distillates. To understand how this transformation occurs, studies on model compounds have been investigated. Numerous studies have been devoted to paraffin hydrocracking. However theses molecules do not fully represent heavy petroleum fraction. Taking into account that the trend in the future will be to treat heavier feedstocks containing a large quantity of PNA (Polynuclear Aromatic hydrocarbons), the understanding of their transformation under hydrocracking conditions is a key point. In this study, we studied hydrocracking of phenanthrene over platinum on acid solids catalysts. Our main aim was to compare hydrocracking catalysts in term of catalytic activity and selectivity toward primary products thanks to our model reaction and to correlate these catalytic performances with acid solid properties and especially to rationalize the effects due to the acidity and the porosity of the acid solids. Catalytic experiments emphasised an effect of the porous structure on the selectivities. The acidity of the catalysts seemed to impose the catalytic activity but did not permit to explain the selectivities. This 'effect of the structure' has been clarified with the simulation of intermediate products adsorption and diffusion in the studied structures thanks to a molecular modelling study. Indeed, the selectivities obtained during phenanthrene hydrocracking have been linked up with the intermediate products adsorption energies in the structures. The results of this study permit to propose that the key-step for selectivities determination is the physical desorption of the primary products. (author)

  20. NMR characterization of hydrocarbon adsorption on calcite surfaces: A first principles study

    Energy Technology Data Exchange (ETDEWEB)

    Bevilaqua, Rochele C. A.; Miranda, Caetano R. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Rigo, Vagner A. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Universidade Tecnológica Federal do Paraná, UTFPR, Cornélio Procópio, PR (Brazil); Veríssimo-Alves, Marcos [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Departamento de Física, ICEx, Universidade Federal Fluminense, UFF, Volta Redonda, RJ (Brazil)

    2014-11-28

    The electronic and coordination environment of minerals surfaces, as calcite, are very difficult to characterize experimentally. This is mainly due to the fact that there are relatively few spectroscopic techniques able to detect Ca{sup 2+}. Since calcite is a major constituent of sedimentary rocks in oil reservoir, a more detailed characterization of the interaction between hydrocarbon molecules and mineral surfaces is highly desirable. Here we perform a first principles study on the adsorption of hydrocarbon molecules on calcite surface (CaCO{sub 3} (101{sup ¯}4)). The simulations were based on Density Functional Theory with Solid State Nuclear Magnetic Resonance (SS-NMR) calculations. The Gauge-Including Projector Augmented Wave method was used to compute mainly SS-NMR parameters for {sup 43}Ca, {sup 13}C, and {sup 17}O in calcite surface. It was possible to assign the peaks in the theoretical NMR spectra for all structures studied. Besides showing different chemical shifts for atoms located on different environments (bulk and surface) for calcite, the results also display changes on the chemical shift, mainly for Ca sites, when the hydrocarbon molecules are present. Even though the interaction of the benzene molecule with the calcite surface is weak, there is a clearly distinguishable displacement of the signal of the Ca sites over which the hydrocarbon molecule is located. A similar effect is also observed for hexane adsorption. Through NMR spectroscopy, we show that aromatic and alkane hydrocarbon molecules adsorbed on carbonate surfaces can be differentiated.

  1. Defining remediation targets and treatment options for hydrocarbon contamination in Quttinirpaaq National Park (Ellesmere Island) : a holistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Sanscartier, D.; Laing, T.; Zeeb, B.; Li, J.; Mohn, W.; Mouland, G.; Glenfield, R.; Reimer, K.; Prevost, J.C. [Royal Military Coll. of Canada, Kingston, ON (Canada)

    2007-07-01

    A combined field investigation and research program to determine remediation targets for the Quttinirpaaq National Park was described. The park is a polar desert located on the northeastern tip of Ellesmere Island. The aim of the program was to define an appropriate remediation strategy for the area, which contains petroleum hydrocarbon contamination at various locations. Generic evaluation criteria that are successfully used in other regions of Canada are not appropriate for investigating Arctic ecosystems. A risk assessment approach was used to evaluate hydrocarbon concentrations that may pose a risk to plants and invertebrates living within the soil. Soil invertebrates were collected from hydrocarbon-contaminated and non-contaminated soils to assess if there was a difference between invertebrate communities at the sites. Data from the study were then used to evaluate risk as well as to derive F3 eco-soil contact remediation criteria. Microcosms containing small amounts of soil were used to investigate mineralization rates under different amendment regimes over a period of 6 weeks. Bench-scale bioreactors were then used to mimic conditions in the field. Bioremediation treatment plots were then established at 2 sites in the park. Hydrocarbon absorbent polymer technology (HAPT) was also used to extract hydrocarbons from soils. Both the laboratory and the field research programs showed that bioremediation is a good treatment option for the heavier hydrocarbons found at the park. 10 refs., 3 figs.

  2. Interstellar molecules - Formation in solar nebulae

    Science.gov (United States)

    Anders, E.

    1973-01-01

    Herbig's (1970) hypothesis that solar nebulae might be the principal source of interstellar grains and molecules is investigated. The investigation includes the determination of physical and chemical conditions in the early solar system. The production of organic compounds in the solar nebula is studied, and the compounds in meteorites are compared with those obtained in Miller-Urey and Fischer-Tropsch-type (FTT) reactions, taking into consideration aliphatic hydrocarbons, aromatic hydrocarbons, purines, pyrimidines, amino acids, porphyrins, and aspects of carbon-isotope fractionation. It is found that FTT reactions account reasonably well for all well-established features of organic matter in meteorites investigated. The distribution of compounds produced by FTT reactions is compared with the distribution of interstellar molecules. Biological implications of the results are considered.

  3. Separation of C2 Hydrocarbons by Porous Materials: Metal Organic Frameworks as Platform

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Debasis; Liu, Jun; Thallapally, Praveen K.

    2014-12-22

    The effective separation of small hydrocarbon molecules (C1 – C4) is an important process for petroleum industry, determining the end price of many essential commodities in our daily lives. Current technologies for separation of these molecules rely on energy intensive fractional distillation processes at cryogenic temperature, which is particularly difficult because of their similar volatility. In retrospect, adsorptive separation using solid state adsorbents might be a cost effective alternative. Several types of solid state adsorbents (e.g. zeolite molecular sieves) were tested for separation of small hydrocarbon molecules as a function of pressure, temperature or vacuum. Among different types of plausible adsorbents, metal organic frameworks (MOFs), a class of porous, crystalline, inorganic-organic hybrid materials, is particularly promising. In this brief comment article, we discuss the separation properties of different types of solid state adsorbents, with a particular emphasis on MOF based adsorbents for separation of C2 hydrocarbon molecules.

  4. Simplified Modeling of Oxidation of Hydrocarbons

    Science.gov (United States)

    Bellan, Josette; Harstad, Kenneth

    2008-01-01

    A method of simplified computational modeling of oxidation of hydrocarbons is undergoing development. This is one of several developments needed to enable accurate computational simulation of turbulent, chemically reacting flows. At present, accurate computational simulation of such flows is difficult or impossible in most cases because (1) the numbers of grid points needed for adequate spatial resolution of turbulent flows in realistically complex geometries are beyond the capabilities of typical supercomputers now in use and (2) the combustion of typical hydrocarbons proceeds through decomposition into hundreds of molecular species interacting through thousands of reactions. Hence, the combination of detailed reaction- rate models with the fundamental flow equations yields flow models that are computationally prohibitive. Hence, further, a reduction of at least an order of magnitude in the dimension of reaction kinetics is one of the prerequisites for feasibility of computational simulation of turbulent, chemically reacting flows. In the present method of simplified modeling, all molecular species involved in the oxidation of hydrocarbons are classified as either light or heavy; heavy molecules are those having 3 or more carbon atoms. The light molecules are not subject to meaningful decomposition, and the heavy molecules are considered to decompose into only 13 specified constituent radicals, a few of which are listed in the table. One constructs a reduced-order model, suitable for use in estimating the release of heat and the evolution of temperature in combustion, from a base comprising the 13 constituent radicals plus a total of 26 other species that include the light molecules and related light free radicals. Then rather than following all possible species through their reaction coordinates, one follows only the reduced set of reaction coordinates of the base. The behavior of the base was examined in test computational simulations of the combustion of

  5. Recommended Liquid-Liquid Equilibrium Data. Hydrocarbons with Seawater Systems

    Science.gov (United States)

    Góral, Marian; Gierycz, Paweł; Oracz, Paweł; Shaw, David G.

    2011-12-01

    The solubilities of C5-C26 hydrocarbons in seawater, reviewed previously, were re-evaluated using a predictive model based on the Sechenov equation. It was found that, within the scope of investigated data, the Sechenov constant is proportional to a hydrocarbon-specific parameter representing the size of the cavity in water needed to accommodate the dissolved molecule of the hydrocarbon. The proportionality coefficient has one value for n-alkanes, cycloalkanes, and alkylbenzenes, whereas for higher aromatics (including those with fused rings), a second value of the coefficient is indicated. The proposed model provides a framework for comparison of the data for various systems and helps in the recognition of systematic error. Evaluation of experimental solubility data and analysis of error propagation is given.

  6. Hydrocarbon pollutants shape bacterial community assembly of harbor sediments

    KAUST Repository

    Barbato, Marta

    2016-02-02

    Petroleum pollution results in co-contamination by different classes of molecules, entailing the occurrence of marine sediments difficult to remediate, as in the case of the Ancona harbor (Mediterranean Sea, Italy). Autochthonous bioaugmentation (ABA), by exploiting the indigenous microbes of the environment to be treated, could represent a successful bioremediation strategy. In this perspective we aimed to i) identify the main drivers of the bacterial communities\\' richness in the sediments, ii) establish enrichment cultures with different hydrocarbon pollutants evaluating their effects on the bacterial communities\\' composition, and iii) obtain a collection of hydrocarbon degrading bacteria potentially exploitable in ABA. The correlation between the selection of different specialized bacterial populations and the type of pollutants was demonstrated by culture-independent analyses, and by establishing a collection of bacteria with different hydrocarbon degradation traits. Our observations indicate that pollution dictates the diversity of sediment bacterial communities and shapes the ABA potential in harbor sediments.

  7. Carbon isotopic characteristics of hydrocarbon gases from coal-measure source rocks--A thermal simulation experiment

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jianjing; HU Huifang; SUN Guoqiang; JI Limin

    2006-01-01

    Gaseous hydrocarbon geochemistry research through a thermal simulation experiment in combination with the natural evolution process in which natural gases were formed from coal-measure source rocks revealed that the δ13C1 values of methane vary from light to heavy along with the increase of thermal evolution degree of coal-measure source rocks, and the δ13C2 values of ethane range from -28.3‰ to -20‰ (PDB). δ13C2 value was -28‰± ( Ro= 0.45% - 0.65%) at the lower thermal evolution stage of coal-measure source rocks. After the rocks entered the main hydrocarbon-generating stage (Ro=0.65% - 1.50%), δ13C2 values generally varied within the range of -26‰ - -23‰±; with further thermal evolution of the rocks the carbon isotopes of ethane became heavier and heavier, but generally less than - 20‰.The partial carbon isotope sequence inversion of hydrogen gases is a characteristic feature of mixing of natural gases of different origins. Under the condition of specially designated type of organic matter, hydrogen source rocks may show this phenomenon via their own evolution.In the lower evolution stages of the rocks, it is mainly determined by organic precursors that gaseous hydrocarbons display partial inversion of the carbon isotope sequence and the carbon isotopic values of ethane are relatively low. These characteristic features also are related to the geochemical composition of primary soluble organic matter.

  8. Hydrocarbon conversion catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, A.; Huizinga, T.; Maxwell, I.E.

    1989-08-15

    This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting a hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.35A, a water absorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of at least 8% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; an alumina binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

  9. Hydrocarbons, PCBs and DDT in the NW Mediterranean deep-sea fish Mora moro

    Science.gov (United States)

    Solé, Montserrat; Porte, Cinta; Albaigés, Joan

    2001-02-01

    Data on aliphatic and polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and DDTs in the deep-sea fish Mora moro are reported in relation to the animal's weight/size and tissues (muscle, liver, digestive tube and gills). Fish samples were collected in the Gulf of Lions (NW Mediterranean) at an approximate depth of 1000 m. The concentrations of these organic pollutants followed the trend musclelipid content of the organs. No clear bioaccumulation dependence on fish weight/size was observed for gills, digestive tube and liver when the fat contents of these tissues were taken into account. However, the concentrations in muscle decreased with size, possibly implying a simple dilution effect by the increase of body weight. Hydrocarbons, and particularly PAHs, were strongly depleted in all tissues with respect to organochlorinated compounds if compared with the amounts present in bottom waters and sediment. Smaller specimens displayed for most pollutants qualitatively different patterns than larger fish, which could be attributed to their particular habitat/diet. The aliphatic hydrocarbon profiles suggested that Mora moro was exposed to a more predominant intake of biogenic rather than petrogenic hydrocarbons. The entrance and storage organs exhibited characteristic PAH and PCB distributions, reflecting different bioaccumulation and metabolic pathways. Compared with the profiles currently found in surface fish species, a relatively higher contribution of heavier components, namely hepta- and octochlorinated PCBs, and 4-6-ringed PAHs, was found in the deep-sea fish.

  10. Inelastic Transport through Molecules: Comparing First-Principles Calculations to Experiments

    DEFF Research Database (Denmark)

    Paulsson, Magnus; Frederiksen, Thomas; Brandbyge, Mads

    2006-01-01

    We present calculations of the elastic and inelastic conductance through three different hydrocarbon molecules connected to gold electrodes. Our method is based on a combination of the nonequilibrium Green's function method with density functional theory. Vibrational effects in these molecular...

  11. 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.

  12. 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.

    2013-01-01

    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 protein

  13. 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

  14. Large molecules in diffuse interstellar clouds

    Science.gov (United States)

    Lepp, S.; Dalgarno, A.; Van Dishoeck, E. F.; Black, J. H.

    1988-01-01

    The effects of the presence of a substantial component of large molecules on the chemistry of diffuse molecular clouds are explored, and detailed models of the zeta Persei and zeta Ophiuchi clouds are constructed. The major consequence is a reduction in the abundances of singly charged atomic species. The long-standing discrepancy between cloud densities inferred from rotational and fine-structure level populations and from the ionization balance can be resolved by postulating a fractional abundance of large molecules of 1 x 10 to the -7th for zeta Persei and 6 x 10 to the -7th for zeta Ophiuchi. If the large molecules are polycyclic aromatic hydrocarbons (PAH) containing about 50 carbon atoms, they contain 1 percent of the carbon in zeta Persei and 7 percent in zeta Ophiuchi. Other consequences of the possible presence of PAH molecules are discussed.

  15. Crossed beam reaction of cyano radicals with hydrocarbon molecules. I. Chemical dynamics of cyanobenzene (C6H5CN; X 1A1) and perdeutero cyanobenzene (C6D5CN; X 1A1) formation from reaction of CN(X 2Σ+) with benzene C6H6(X 1A1g), and d6-benzene C6D6(X 1A1g)

    Science.gov (United States)

    Balucani, N.; Asvany, O.; Chang, A. H. H.; Lin, S. H.; Lee, Y. T.; Kaiser, R. I.; Bettinger, H. F.; Schleyer, P. v. R.; Schaefer, H. F.

    1999-10-01

    The chemical reaction dynamics to form cyanobenzene C6H5CN(X 1A1), and perdeutero cyanobenzene C6D5CN(X 1A1) via the neutral-neutral reaction of the cyano radical CN(X 2Σ+), with benzene C6H6(X 1A1g) and perdeutero benzene C6D6(X 1A1g), were investigated in crossed molecular beam experiments at collision energies between 19.5 and 34.4 kJ mol-1. The laboratory angular distributions and time-of-flight spectra of the products were recorded at mass to charge ratios m/e=103-98 and 108-98, respectively. Forward-convolution fitting of our experimental data together with electronic structure calculations (B3LYP/6-311+G**) indicate that the reaction is without entrance barrier and governed by an initial attack of the CN radical on the carbon side to the aromatic π electron density of the benzene molecule to form a Cs symmetric C6H6CN(C6D6CN) complex. At all collision energies, the center-of-mass angular distributions are forward-backward symmetric and peak at π/2. This shape documents that the decomposing intermediate has a lifetime longer than its rotational period. The H/D atom is emitted almost perpendicular to the C6H5CN plane, giving preferentially sideways scattering. This experimental finding can be rationalized in light of the electronic structure calculations depicting a H-C-C angle of 101.2° in the exit transition state. The latter is found to be tight and located about 32.8 kJ mol-1 above the products. Our experimentally determined reaction exothermicity of 80-95 kJ mol-1 is in good agreement with the theoretically calculated one of 94.6 kJ mol-1. Neither the C6H6CN adduct nor the stable iso cyanobenzene isomer C6H5NC were found to contribute to the scattering signal. The experimental identification of cyanobenzene gives a strong background for the title reaction to be included with more confidence in reaction networks modeling the chemistry in dark, molecular clouds, outflow of dying carbon stars, hot molecular cores, as well as the atmosphere of hydrocarbon

  16. Phenotypic plasticity in the common garden snail: big guts and heavier mucus glands compete in snails faced with the dual challenge of poor diet and coarse substrate.

    Science.gov (United States)

    Munn, Adam J; Treloar, Marguerite

    2016-12-26

    Phenotypic plasticity allows animals to manage environmental challenges. Studies aimed at quantifying plasticity often focus on one challenge, such as diet, and one organ system, such the gastrointestinal tract, but this approach may not adequately reflect how plasticity could buffer multiple challenges. Thus, we investigated the outcomes of a dual challenge experiment that fed land snails either a high-fibre (low quality) or a low-fibre (high quality) diet, and simultaneously exercised them daily over 1.2 m on either a smooth surface of polyvinyl chloride (PVC) or a rough sandpaper. By the end of 20 days, snails fed the poor quality diet had a longer crop and oesophagus and a heavier intestine and rectum than those offered a low-fibre diet. Additionally, high-fibre fed snails had a smaller spermoviduct and oviduct. When also exercised on sandpaper, high-fibre fed snails had a smaller digestive gland, a main energy store, than those exercised on PVC. All snails exercised on sandpaper had a heavier pedal mucus gland, used a loping gait and used less mucus than those on PVC plastic, but there was no difference in the average speed of snails on either surface, supporting the conclusion that loping is a mucus conserving gait. Notably, snails faced with both a diet and substrate challenge had a smaller kidney, which could directly effect fecundity. This demonstrates that our dual challenge approach has potential for evaluating the costs and limits of the plasticity necessary to fully appreciate the evolutionary significance of plasticity in snails and other species.

  17. Thermochemistry of Hydrocarbons. Back to Extended Hückel Theory.

    Science.gov (United States)

    Voityuk, Alexander A

    2008-11-11

    A modified Extended Hückel method that provides accurate values of heats of formation and structural parameters of hydrocarbons is described. The results are reported for an extensive set of molecules and radicals belonging to different classes. The calculated heats of formation for 120 molecules and 26 radicals are close to the experimental data with the mean absolute error of 1.90 kcal/mol. The internal consistency of the calculated data allows reliable prediction of the reaction enthalpy for various hydrocarbon transformations. The proposed scheme is computationally very efficient, and the calculation of a large system requires only a few seconds on a PC. A computer program for the calculation is provided in the Supporting Information .

  18. Rate constants for the reaction of CF3O radicals with hydrocarbons at 298 K

    DEFF Research Database (Denmark)

    Kelly, C.; Treacy, J.; Sidebottom, H.W.;

    1993-01-01

    Rate constant ratios of the reactions of CF3O radicals with a number of hydrocarbons have been determined at 298 +/- 2 K and atmospheric pressure using a relative rate method. Using a previously determined value k(CF30 + C2H6) = 1.2 x 10(-12) cm3 molecule-1 s-1 these rate constant ratios provide......-1. The importance of the reactions of CF3O radicals with hydrocarbons under atmospheric conditions is discussed....

  19. Charge Transfer and Bonding Strength in Lithium-intercalated Polyaromatic Hydrocarbons Studied by Photoelectron Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    R.Friedlein

    2007-01-01

    1 Results The potential applications of small-, medium-and large-size polyaromatic hydrocarbons for charge and energy storage in lithium metal and lithium ion batteries are discussed. In order to find the best carbon-based electrode materials, the specific roles of the molecular and solid-state contributions have to be understood. For the molecular contributions, a semi-quantitative method is proposed to compare the charge storage capability of polyaromatic hydrocarbon molecules. A compilation of result...

  20. A structural bridge between alternant and non-alternant hydrocarbons

    Directory of Open Access Journals (Sweden)

    Richard Francis Langler

    2001-06-01

    Full Text Available A simple set of trimethylene-substituted even, fully-pi-bonded, non-alternant monocycles is shown to have several key features in common with acyclic, even alternant polyenes at the Hückel level. These non-alternant molecules provide a bridge between alternant and non-alternant hydrocarbons. This topic might serve as a useful addition to Hückel theory courses targeted at senior undergraduate students.

  1. Hydrocarbons on Saturn's satellites Iapetus and Phoebe

    Science.gov (United States)

    Cruikshank, D.P.; Wegryn, E.; Dalle, Ore C.M.; Brown, R.H.; Bibring, J.-P.; Buratti, B.J.; Clark, R.N.; McCord, T.B.; Nicholson, P.D.; Pendleton, Y.J.; Owen, T.C.; Filacchione, G.; Coradini, A.; Cerroni, P.; Capaccioni, F.; Jaumann, R.; Nelson, R.M.; Baines, K.H.; Sotin, C.; Bellucci, G.; Combes, M.; Langevin, Y.; Sicardy, B.; Matson, D.L.; Formisano, V.; Drossart, P.; Mennella, V.

    2008-01-01

    Material of low geometric albedo (pV ??? 0.1) is found on many objects in the outer Solar System, but its distribution in the saturnian satellite system is of special interest because of its juxtaposition with high-albedo ice. In the absence of clear, diagnostic spectral features, the composition of this low-albedo (or "dark") material is generally inferred to be carbon-rich, but the form(s) of the carbon is unknown. Near-infrared spectra of the low-albedo hemisphere of Saturn's satellite Iapetus were obtained with the Visible-Infrared Mapping Spectrometer (VIMS) on the Cassini spacecraft at the fly-by of that satellite of 31 December 2004, yielding a maximum spatial resolution on the satellite's surface of ???65 km. The spectral region 3-3.6 ??m reveals a broad absorption band, centered at 3.29 ??m, and concentrated in a region comprising about 15% of the low-albedo surface area. This is identified as the C{single bond}H stretching mode vibration in polycyclic aromatic hydrocarbon (PAH) molecules. Two weaker bands attributed to {single bond}CH2{single bond} stretching modes in aliphatic hydrocarbons are found in association with the aromatic band. The bands most likely arise from aromatic and aliphatic units in complex macromolecular carbonaceous material with a kerogen- or coal-like structure, similar to that in carbonaceous meteorites. VIMS spectra of Phoebe, encountered by Cassini on 11 June 2004, also show the aromatic hydrocarbon band, although somewhat weaker than on Iapetus. The origin of the PAH molecular material on these two satellites is unknown, but PAHs are found in carbonaceous meteorites, cometary dust particles, circumstellar dust, and interstellar dust. ?? 2007 Elsevier Inc. All rights reserved.

  2. Failure of hydrogenation in protecting polycyclic aromatic hydrocarbons from fragmentation

    CERN Document Server

    Gatchell, Michael; de Ruette, Nathalie; Chen, Tao; Giacomozzi, Linda; Nascimento, Rodrigo F; Wolf, Michael; Anderson, Emma K; Delaunay, Rudy; Viziano, Violaine; Rousseau, Patrick; Adoui, Lamri; Huber, Bernd A; Schmidt, Henning T; Zettergren, Henning; Cederquist, Henrik

    2015-01-01

    A recent study of soft X-ray absorption in native and hydrogenated coronene cations, C$_{24}$H$_{12+m}^+$ $m=0-7$, led to the conclusion that additional hydrogen atoms protect (interstellar) Polycyclic Aromatic Hydrocarbon (PAH) molecules from fragmentation [Reitsma et al., Phys. Rev. Lett. 113, 053002 (2014)]. The present experiment with collisions between fast (30-200 eV) He atoms and pyrene (C$_{16}$H$_{10+m}^+$, $m=0$, 6, and 16) and simulations without reference to the excitation method suggests the opposite. We find that the absolute carbon-backbone fragmentation cross section does not decrease but increases with the degree of hydrogenation for pyrene molecules.

  3. Molecular dynamics studies of aromatic hydrocarbon liquids

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, E.; Gupta, S.

    1990-01-01

    This project mainly involves a molecular dynamics and Monte Carlo study of the effect of molecular shape on thermophysical properties of bulk fluids with an emphasis on the aromatic hydrocarbon liquids. In this regard we have studied the modeling, simulation methodologies, and predictive and correlating methods for thermodynamic properties of fluids of nonspherical molecules. In connection with modeling we have studied the use of anisotropic site-site potentials, through a modification of the Gay-Berne Gaussian overlap potential, to successfully model the aromatic rings after adding the necessary electrostatic moments. We have also shown these interaction sites should be located at the geometric centers of the chemical groups. In connection with predictive methods, we have shown two perturbation type theories to work well for fluids modeled using one-center anisotropic potentials and the possibility exists for extending these to anisotropic site-site models. In connection with correlation methods, we have studied, through simulations, the effect of molecular shape on the attraction term in the generalized van der Waals equation of state for fluids of nonspherical molecules and proposed a possible form which is to be studied further. We have successfully studied the vector and parallel processing aspects of molecular simulations for fluids of nonspherical molecules.

  4. Heavier hydrocarbons removing method study for oilfield fuel gas into gas engine generator%温差发电技术及其在海洋石油平台上的应用

    Institute of Scientific and Technical Information of China (English)

    胡蓉; 余智; 严雪莲; 戴磊; 宗远航

    2015-01-01

    A thermoelectric generator converts heat directly into electricity. As heat moves from a gas burner through a thermoelectric module,it causes an electrical current to flow. The durable module in the thermoelectric generator provides a chemically stable environment for the thermoelectric material and ensures a long service life. A burner maintains a high temperature on the hot side while cooling fins keeps the other side cool. The temperature difference across the thermopile which is the heart of the thermoelectric generator creates steady DC electricity with no moving parts. This paper introduces the operating philosophy of thermoelectric generation and its applications on offshore oil and gas platforms.%温差发电技术是利用热电转换材料直接将热能转化为电能的发电技术,该技术是一种固态能量转换方式,能够直接将热能转化为电能,具有无运动部件、体积小、重量轻、移动方便和可靠性高等特点,是绿色环保的发电方式.本文介绍了温差发电技术的原理及其在海洋石油平台上的应用.

  5. Chain-like molecules confined in nanopores

    Science.gov (United States)

    Huber, Patrick; Soprunyuk, Viktor; Hofmann, Tommy; Knorr, Klaus

    2004-03-01

    We present an x-ray diffraction study on chain-like molecules, i.e. a selection of n-alkane molecules, embedded in the pores of nanoporous silica matrices. The lengths of the hydrocarbon chains are comparable to the mean diameter ( 7nm) of the tubular like nanopores which leads to drastic geometric restrictions. Diffraction patterns, recorded on heating and cooling between 200 K and 310 K, elucidate how the structure and phase behavior of the molecules is affected by the random substrate disorder and the confinement. The confined n-alkanes form close-packed structures by aligning parallel to the pore axis. In the case of the medium-length hydrocarbon chains one basic ordering principle known from the bulk crystalline state, i.e. the lamellar ordering of the molecules, is quenched[1], whereas for shorter n-alkanes this ordering principle survives[2]. The confined solids mimic the orientational order-disorder transitions known from the 3D unconfined crystals albeit in a modified fashion. 1. P. Huber, D. Wallacher, J. Albers, K. Knorr, Europhysics Letters, in press; 2. P. Huber, D. Wallacher, J. Albers, K. Knorr, Journal of Physics: Condensed Matter 15, 309 (2003).

  6. Methods of using structures including catalytic materials disposed within porous zeolite materials to synthesize hydrocarbons

    Science.gov (United States)

    Rollins, Harry W.; Petkovic, Lucia M.; Ginosar, Daniel M.

    2011-02-01

    Catalytic structures include a catalytic material disposed within a zeolite material. The catalytic material may be capable of catalyzing a formation of methanol from carbon monoxide and/or carbon dioxide, and the zeolite material may be capable of catalyzing a formation of hydrocarbon molecules from methanol. The catalytic material may include copper and zinc oxide. The zeolite material may include a first plurality of pores substantially defined by a crystal structure of the zeolite material and a second plurality of pores dispersed throughout the zeolite material. Systems for synthesizing hydrocarbon molecules also include catalytic structures. Methods for synthesizing hydrocarbon molecules include contacting hydrogen and at least one of carbon monoxide and carbon dioxide with such catalytic structures. Catalytic structures are fabricated by forming a zeolite material at least partially around a template structure, removing the template structure, and introducing a catalytic material into the zeolite material.

  7. Systems including catalysts in porous zeolite materials within a reactor for use in synthesizing hydrocarbons

    Science.gov (United States)

    Rolllins, Harry W [Idaho Falls, ID; Petkovic, Lucia M [Idaho Falls, ID; Ginosar, Daniel M [Idaho Falls, ID

    2012-07-24

    Catalytic structures include a catalytic material disposed within a zeolite material. The catalytic material may be capable of catalyzing a formation of methanol from carbon monoxide and/or carbon dioxide, and the zeolite material may be capable of catalyzing a formation of hydrocarbon molecules from methanol. The catalytic material may include copper and zinc oxide. The zeolite material may include a first plurality of pores substantially defined by a crystal structure of the zeolite material and a second plurality of pores dispersed throughout the zeolite material. Systems for synthesizing hydrocarbon molecules also include catalytic structures. Methods for synthesizing hydrocarbon molecules include contacting hydrogen and at least one of carbon monoxide and carbon dioxide with such catalytic structures. Catalytic structures are fabricated by forming a zeolite material at least partially around a template structure, removing the template structure, and introducing a catalytic material into the zeolite material.

  8. Hydrocarbon Leak Detection Sensor Project

    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...

  9. 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...

  10. Final Report, "Molecular Design of Hydrocarbon Oxidation Catalytic Processes"

    Energy Technology Data Exchange (ETDEWEB)

    Professor Francisco Zaera

    2007-08-09

    production of small amounts of ethylene and water, most likely via the concerted decomposition or disproportionation of the adsorbed molecular species. The bulk of the 2-iodoethanol decomposes at about 150 K via an initial carbon-iodine scission to form –O(H)CH2CH2– (~80%) and 2-hydroxyethyl (~20%) intermediates. Two competing reactions are involved with the subsequent conversion of the 2-hydroxyethyl species around 160 K, a reductive elimination with surface hydrogen to yield ethanol, and a β-H elimination to surface vinyl alcohol. The –O(H)CH2CH2–, on the other hand, dehydrogenates to a –OCH2CH2– oxametallacycle species about the same temperature. Both 2-hydroxyethyl and oxametallacycle species tautomerize to acetaldehyde, around 210 K and above 250 K, respectively, and some of that acetaldehyde desorbs while the rest decomposes to hydrogen and carbon monoxide. We contend that a better understanding of the surface chemistry of oxygen-containing surfaces can lead to better selectivities in catalysis. This is arguably the most important issue in the field of catalysis in the near future, and one that impacts several technologies of interest to DOE such as the manufacturing of speciality chemicals and the control and removal of pollutants. Additional work was performed on the characterization of the chemistry of methyl and methylene adsorbed species on oxygen-treated nickel surfaces. Complex chemistry was observed involving not only hydrogenation and dehydrogenation steps, but also C-C couplings and methylene insertions to produce heavier hydrocarbons, and oxygen insertion reactions that yield oxygenates. Finally, a dual titration technique employing xenon and a chemically sensitive probe was developed to identify minority catalytic sites on oxide surfaces. In the case of oxygen-treated Ni(110) single crystals, it was found that both hydrogen transfer with adsorbed water or ammonia and certain hydrocarbon hydrogenation reactions take place at the end of the

  11. 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.

  12. Electrochemical decomposition of chlorinated hydrocarbons

    OpenAIRE

    McGee, Gerard Anthony

    1993-01-01

    This work involves the characterisation of the electrochemical decomposition of chlorinated hydrocarbons. A variety of methods were employed involving the use of catalytic reagents to enhance the rate at which chlorinated organic compounds are reduced. The first reagent used was oxygen which was electrochemically reduced to superoxide in nonaqueous solvents. Superoxide is a reactive intermediate and decomposes chlorinated hydrocarbons. However it was found that since the rate of reaction betw...

  13. Aliphatic hydrocarbons of the fungi.

    Science.gov (United States)

    Weete, J. D.

    1972-01-01

    Review of studies of aliphatic hydrocarbons which have been recently detected in the spores of phytopathogenic fungi, and are found to be structurally very similar to the alkanes of higher plants. It appears that the hydrocarbon components of the few mycelial and yeast forms reported resemble the distribution found in bacteria. The occurence and distribution of these compounds in the fungi is discussed. Suggested functional roles of fungal spore alkanes are presented.

  14. 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

  15. 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)

  16. Evaluation of hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Cashman, P.H.; Trexler, J.H. Jr. [Univ. of Nevada, Reno, NV (United States)

    1992-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock.

  17. Using metal nanostructures to form hydrocarbons from carbon dioxide, water and sunlight

    Science.gov (United States)

    Wang, Cong; Shen, Mengyan; Huo, Haibin; Ren, Haizhou; Johnson, Michael

    2011-12-01

    Based on experimental results, we propose a mechanism that allows the use of metal nanostructures to synthesize hydrocarbons and carbohydrates from carbon dioxide, water and sunlight. When sunlight impinges on cobalt nanostructures in a glass chamber, its intensity is greatly enhanced around the tips of the nanostructures through surface plasmon excitations focusing effect, and it then photodissociates the water and carbon dioxide molecules through enhanced photon absorptions of ions around the tips of the nanostructures. The photodissociated molecules in excited states remain on the cobalt nanostructure surfaces and various hydrocarbons and carbohydrates then will be formed around the surfaces at temperatures much lower than 100 oC.

  18. Hydrocarbons on Phoebe, Iapetus, and Hyperion: Quantitative Analysis

    Science.gov (United States)

    Cruikshank, Dale P.; MoreauDalleOre, Cristina; Pendleton, Yvonne J.; Clark, Roger Nelson

    2012-01-01

    We present a quantitative analysis of the hydrocarbon spectral bands measured on three of Saturn's satellites, Phoebe, Iaperus, and Hyperion. These bands, measured with the Cassini Visible-Infrared Mapping Spectrometer on close fly-by's of these satellites, are the C-H stretching modes of aromatic hydrocarbons at approximately 3.28 micrometers (approximately 3050 per centimeter), and the are four blended bands of aliphatic -CH2- and -CH3 in the range approximately 3.36-3.52 micrometers (approximately 2980- 2840 per centimeter) bably indicating the presence of polycyclic aromatic hydrocarbons (PAH), is unusually strong in comparison to the aliphatic bands, resulting in a unique signarure among Solar System bodies measured so far, and as such offers a means of comparison among the three satellites. The ratio of the C-H bands in aromatic molecules to those in aliphatic molecules in the surface materials of Phoebe, NAro:NAliph approximately 24; for Hyperion the value is approximately 12, while laperus shows an intermediate value. In view of the trend of the evolution (dehydrogenation by heat and radiation) of aliphatic complexes toward more compact molecules and eventually to aromatics, the relative abundances of aliphatic -CH2- and -CH3- is an indication of the lengths of the molecular chain structures, hence the degree of modification of the original material. We derive CH2:CH3 approximately 2.2 in the spectrum of low-albedo material on laperus; this value is the same within measurement errors to the ratio in the diffuse interstellar medium. The similarity in the spectral signatures of the three satellites, plus the apparent weak trend of aromatic/aliphatic abundance from Phoebe to Hyperion, is consistent with, and effectively confirms that the source of the hydrocarbon-bearing material is Phoebe, and that the appearance of that material on the other two satellites arises from the deposition of the inward-spiraling dust that populates the Phoebe ring.

  19. Environmental forensics evaluation of sources of sediment hydrocarbon contamination in Milford Haven Waterway.

    Science.gov (United States)

    Little, David I; Galperin, Yakov; Bullimore, Blaise; Camplin, Mike

    2015-02-01

    Current and historic petroleum-related activities in Milford Haven Waterway (MHW; Wales, UK) contribute to hydrocarbon contamination of surficial sediments. Three main hydrocarbon components of sediments were analyzed: (1) aliphatic hydrocarbons of predominantly biogenic origin, representing about 5-15% of total hydrocarbons (THC); (2) polycyclic aromatic hydrocarbons (PAHs) from recent petrogenic and mainly older pyrogenic sources, representing about 2-6% of THC; (3) unresolved complex mixture from spill-related and heavily-weathered petrogenic sources, representing as much as 70-85% of THC. Environmental forensics evaluation of the data demonstrate that although 72,000 tonnes (t) crude oil spilled from the Sea Empress in 1996, the Forties blend cargo was not identified in 2010. However, using biomarkers, heavy fuel oil (HFO) from Sea Empress' bunkers (480 t spilled) was detected further upstream and more widely than previously. Iranian crude (100 t) spilled by the El Omar in 1988 and fuel (130,000 t) lost during bombing in 1940 also were tentatively identified. The PAH source ratios demonstrate that the historic pyrogenic PAHs come mainly from biomass and coal combustion. The distribution pattern of PAHs appeared more pyrogenic in 2012 than in 1996, as if recovering from the more petrogenic signature, in places, of the Sea Empress. The heavier PAH distributions were pyrogenic at most stations, and similar to those in sediments from oil terminal berths up to 2006, when dredging operations peaked. Partly as a result of this, in 2007 the concentrations of PAHs peaked throughout the waterway. Apart from effluent, atmospheric and runoff inputs, most of the identified inputs to the surficial sediments are historic. Therefore, likely processes include disturbance by construction (e.g. pile-driving) and dredging of contaminants sequestered in sediments, followed by their wide redistribution via suspended sediment transport.

  20. Pyrolytic Treatment and Fertility Enhancement of Soils Contaminated with Heavy Hydrocarbons.

    Science.gov (United States)

    Vidonish, Julia E; Zygourakis, Kyriacos; Masiello, Caroline A; Gao, Xiaodong; Mathieu, Jacques; Alvarez, Pedro J J

    2016-03-01

    Pyrolysis of contaminated soils at 420 °C converted recalcitrant heavy hydrocarbons into "char" (a carbonaceous material similar to petroleum coke) and enhanced soil fertility. Pyrolytic treatment reduced total petroleum hydrocarbons (TPH) to below regulatory standards (typically hydrocarbons (PAHs) was not observed, with post-pyrolysis levels well below applicable standards. Plant growth studies showed a higher biomass production of Arabidopsis thaliana and Lactuca sativa (Simpson black-seeded lettuce) (80-900% heavier) in pyrolyzed soils than in contaminated or incinerated soils. Elemental analysis showed that pyrolyzed soils contained more carbon than incinerated soils (1.4-3.2% versus 0.3-0.4%). The stark color differences between pyrolyzed and incinerated soils suggest that the carbonaceous material produced via pyrolysis was dispersed in the form of a layer coating the soil particles. Overall, these results suggest that soil pyrolysis could be a viable thermal treatment to quickly remediate soils impacted by weathered oil while improving soil fertility, potentially enhancing revegetation.

  1. Coarse grained model for calculating the ion mobility of hydrocarbons

    Science.gov (United States)

    Kuroboshi, Y.; Takemura, K.

    2016-12-01

    Hydrocarbons are widely used as insulating compounds. However, their fundamental characteristics in conduction phenomena are not completely understood. A great deal of effort is required to determine reasonable ionic behavior from experiments because of their complicated procedures and tight controls of the temperature and the purity of the liquids. In order to understand the conduction phenomena, we have theoretically calculated the ion mobilities of hydrocarbons and investigated their characteristics using the coarse grained model in molecular dynamics simulations. We assumed a molecule of hydrocarbons to be a bead and simulated its dependence on the viscosity, electric field, and temperature. Furthermore, we verified the suitability of the conformation, scale size, and long-range interactions for the ion mobility. The results of the simulations show that the ion mobility values agree reasonably well with the values from Walden's rule and depend on the viscosity but not on the electric field. The ion mobility and self-diffusion coefficient exponentially increase with increasing temperature, while the activation energy decreases with increasing molecular size. These values and characteristics of the ion mobility are in reasonable agreement with experimental results. In the future, we can understand not only the ion mobilies of hydrocarbons in conduction, but also we can predict general phenomena in electrochemistry with molecular dynamics simulations.

  2. Characterization of Interstellar Organic Molecules

    Science.gov (United States)

    Gençaǧa, Deniz; Carbon, Duane F.; Knuth, Kevin H.

    2008-11-01

    Understanding the origins of life has been one of the greatest dreams throughout history. It is now known that star-forming regions contain complex organic molecules, known as Polycyclic Aromatic Hydrocarbons (PAHs), each of which has particular infrared spectral characteristics. By understanding which PAH species are found in specific star-forming regions, we can better understand the biochemistry that takes place in interstellar clouds. Identifying and classifying PAHs is not an easy task: we can only observe a single superposition of PAH spectra at any given astrophysical site, with the PAH species perhaps numbering in the hundreds or even thousands. This is a challenging source separation problem since we have only one observation composed of numerous mixed sources. However, it is made easier with the help of a library of hundreds of PAH spectra. In order to separate PAH molecules from their mixture, we need to identify the specific species and their unique concentrations that would provide the given mixture. We develop a Bayesian approach for this problem where sources are separated from their mixture by Metropolis Hastings algorithm. Separated PAH concentrations are provided with their error bars, illustrating the uncertainties involved in the estimation process. The approach is demonstrated on synthetic spectral mixtures using spectral resolutions from the Infrared Space Observatory (ISO). Performance of the method is tested for different noise levels.

  3. Concerning the petroleum hydrocarbons migration in the permafrost zone

    Science.gov (United States)

    Goncharov, I. V.; Panova, E.; Grinko, A.; Dudarev, O.; Semiletov, I. P.

    2015-12-01

    In order to understand the mechanisms controlling methane emissions in the Laptev Sea it is extremely important to know the distribution patterns of subsea permafrost in the coastal zone. One possible solution to this problem is to analyze the hydrocarbon fluids in the bottom sediments. The object of our study was the core sample from Ivashkinskaya lagoon (Lena Delta, Sakha Republic). Pyrolytic studies were performed for this core sample (ROCK- EVAL 6 TURBO). According to the pyrolysis results there were 5 samples from the upper section in the range 0.36-5.58m selected for the further studies. The common feature of these samples is high content level of the pelitic component. They contain more than 1.0% of TOC and are composed of volatile organic compounds. Extracts obtained from the core sample were analyzed by GC-MS («Hewlett Packard» 6890/5973). Analyzed extracts demonstrated different classes of organic compounds in their composition with saturated and unsaturated hydrocarbons and acids dominating. Here are the histograms of n-alkanes in function of the carbon atoms number in the molecule (Figure). Considering our work experience with the Black Sea sediments we suggest that the samples with a high degree of even n-alkanes are confined to zones of petroleum hydrocarbons migration coming from the deep oil deposits. Figure. Typical n-alkanes distribution in the extracts (horizontal axis - the number of carbon atoms in the molecule, vertical axis - relative abundance)

  4. New Empirical Potential Energy Functions for the Heavier Homonuclear Rare Gas Pairs: {Ne}_2, {Ar}_2, {Kr}_2, and {Xe}_2

    Science.gov (United States)

    Myatt, Philip Thomas; Baker, Matthew T.; Kang, Ju-Hee; Escobar Moya, Andres; McCourt, Frederick R. W.; Le Roy, Robert J.

    2016-06-01

    The many decades of work on determining accurate analytic pair potentials for rare gas dimers from experimental data focussed largely on the use of bulk non-ideal gas and collisional properties, with the use of spectroscopic data being somewhat of an afterthought, for testing the resulting functions. This was a natural result of experimental challenges, as the very weak binding of ground-state rare gas pairs made high resolution spectroscopy a relatively late arrival as a practical tool in this area. However, we believe that it is now time for a comprehensive reassessment. Following up on a preliminary report at this meeting five years ago, this paper describes work to determine a new generation of empirical potential energy functions for the four heavier (i.e., not involving He) homonuclear rare gas pairs from direct fits to all available spectroscopic, pressure virial, and acoustic virial coefficient data, with the resulting functions being `tuned' by comparisons with available thermal transport property data: viscosity, mass diffusion and thermal diffusion, and thermal conductivity data, and tested against the best available ab initio potentials. The resulting functions are everywhere smooth and differentiable to all orders, incorporate the correct (damped) theoretical inverse-power long-range behaviour, and have sensible short-range extrapolation behaviour. R.J. Le Roy, C.J.W. Mackie, P. Chandrasekhar and K.M. Sentjens, ``Accurate New Potential Energy Functions From Spectroscopic and Virial Coefficient Data for the Ten Rare Gas Pairs formed from Ne, Ar, Kr and Xe, paper MF03 at the 66th Ohio State University International Symposium on Molecular Spectroscopy, Columbus, Ohio, June 13-17 (2011).

  5. EXPERIMENTAL EVIDENCE FOR THE FORMATION OF HIGHLY SUPERHYDROGENATED POLYCYCLIC AROMATIC HYDROCARBONS THROUGH H ATOM ADDITION AND THEIR CATALYTIC ROLE IN H2 FORMATION

    DEFF Research Database (Denmark)

    Thrower, John; Jørgensen, Bjarke; Friis, Emil Enderup;

    2012-01-01

    Mass spectrometry measurements show the formation of highly superhydrogenated derivatives of the polycyclic aromatic hydrocarbon molecule coronene through H atom addition reactions. The observed product mass distribution provides evidence also for abstraction reactions resulting in H2 formation...

  6. Enrichment of light hydrocarbon mixture

    Science.gov (United States)

    Yang; Dali; Devlin, David; Barbero, Robert S.; Carrera, Martin E.; Colling, Craig W.

    2010-08-10

    Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

  7. Investigation of hydrocarbon oil transformation by gliding arc discharge: comparison of batch and recirculated configurations

    Science.gov (United States)

    Whitehead, J. Christopher; Prantsidou, Maria

    2016-04-01

    The degradation of liquid dodecane was studied in a gliding arc discharge (GAD) of humid argon or nitrogen. A batch or recirculating configuration was used. The products in the gaseous and liquid phase were analysed by infrared and chromatography and optical emission spectroscopy was used to identify the excited species in the discharge. The best degradation performance comes from the use of humid N2 but a GAD of humid argon produces fewer gas-phase products but more liquid-phase end-products. A wide range of products such as heavier saturated or unsaturated hydrocarbons both aliphatic and aromatic, and oxidation products mainly alcohols, but also aldehydes, ketones and esters are produced in the liquid-phase. The recirculating treatment mode is more effective than the batch mode increasing the reactivity and changing the product selectivities. Overall, the study shows promising results for the organic liquid waste treatment, especially in the recirculating mode.

  8. Hydrocarbon stapled peptides as modulators of biological function.

    Science.gov (United States)

    Cromm, Philipp M; Spiegel, Jochen; Grossmann, Tom N

    2015-06-19

    Peptide-based drug discovery has experienced a significant upturn within the past decade since the introduction of chemical modifications and unnatural amino acids has allowed for overcoming some of the drawbacks associated with peptide therapeutics. Strengthened by such features, modified peptides become capable of occupying a niche that emerges between the two major classes of today's therapeutics-small molecules (5000 Da). Stabilized α-helices have proven particularly successful at impairing disease-relevant PPIs previously considered "undruggable." Among those, hydrocarbon stapled α-helical peptides have emerged as a novel class of potential peptide therapeutics. This review provides a comprehensive overview of the development and applications of hydrocarbon stapled peptides discussing the benefits and limitations of this technique.

  9. Selective transformation of syngas into gasoline-range hydrocarbons over mesoporous H-ZSM-5-supported cobalt nanoparticles.

    Science.gov (United States)

    Cheng, Kang; Zhang, Lei; Kang, Jincan; Peng, Xiaobo; Zhang, Qinghong; Wang, Ye

    2015-01-26

    Bifunctional Fischer-Tropsch (FT) catalysts that couple uniform-sized Co nanoparticles for CO hydrogenation and mesoporous zeolites for hydrocracking/isomerization reactions were found to be promising for the direct production of gasoline-range (C5-11 ) hydrocarbons from syngas. The Brønsted acidity results in hydrocracking/isomerization of the heavier hydrocarbons formed on Co nanoparticles, while the mesoporosity contributes to suppressing the formation of lighter (C1-4 ) hydrocarbons. The selectivity for C5-11 hydrocarbons could reach about 70 % with a ratio of isoparaffins to n-paraffins of approximately 2.3 over this catalyst, and the former is markedly higher than the maximum value (ca. 45 %) expected from the Anderson-Schulz-Flory distribution. By using n-hexadecane as a model compound, it was clarified that both the acidity and mesoporosity play key roles in controlling the hydrocracking reactions and thus contribute to the improved product selectivity in FT synthesis.

  10. High Pressure Preignition Chemistry of Hydrocarbons and Hydrocarbon Mixtures

    Science.gov (United States)

    2007-11-02

    and hydrocarbon blends in our various combustion systems, with emphasis on the effects of elevated pressure using our pressurized flow reactor ( PFR ...facility. Detailed experimental data were generated from the PFR for use in associated kinetic modeling work. We continued to develop and extend both

  11. Total Petroleum Hydrocarbons (TPH): ToxFAQs

    Science.gov (United States)

    ... a state: This map displays locations where Total Petroleum Hydrocarbons (TPH) is known to be present. On ... I get more information? ToxFAQs TM for Total Petroleum Hydrocarbons (TPH) ( Hidrocarburos Totales de Petróleo (TPH) ) August ...

  12. An equation of state for property prediction of alcohol-hydrocarbon and water-hydrocarbon systems

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Adolfo P. [Laboratory of Petroleum Engineering and Exploration, Universidade Estadual do Norte Fluminense-UENF, RJ Macae (Brazil); Mohamed, Rahoma S. [Process Engineering Laboratory, School of Chemical Engineering, Universidade Estadual de Campinas, Unicamp, Caixa Postal 6066, 13083-970 SP Campinas (Brazil); Ali Mansoori, G. [Department of Chemical Engineering, University of Illinois at Chicago, 810 S. Clinton Street, 60607-7000 Chicago, IL (United States)

    2001-12-29

    Equations of state have been widely used in the petroleum and chemical industries for thermodynamic property calculation. In the presence of polar substances that self-associate through hydrogen bonding (such as water or alcohol), equations of state are of very limited use. One way to account for the association is to consider the equation of state to be formed of two contributions: physical and chemical. In this work, we develop an equation of state consisting of two terms as proposed by Andreko [Fluid Phase Equilib. 65 (1991) 89], a chemical and a physical term, for correlation of thermodynamic properties of mixtures containing an associating species. This equation of state is used to correlate vapor pressure data for a number of associating molecules, such as alcohol and water, as well as bubble point pressure data for binary water-hydrocarbon and alcohol-hydrocarbon systems. The results obtained are in good agreement with the experimental data and requiring the use of only one adjustable parameter for each binary system.

  13. Experimentally Determined Binding Energies of Astrophysically Relevant Hydrocarbons in Pure and H2O-Layered Ices

    Science.gov (United States)

    Behmard, Aida; Graninger, Dawn; Fayolle, Edith; Oberg, Karin I.

    2017-01-01

    Small hydrocarbons represent an important organic reservoir in a variety of interstellar environments. Constraints on desorption temperatures and binding energies of hydrocarbons are thus necessary for accurate predictions of where and in which phase these molecules exist. Through a series of temperature programmed desorption experiments, we determined binding energies of 1, 2, and 3-carbon interstellar hydrocarbons (CH4, C2H2, C2H4, C2H6, C3H4, C3H6, and C3H8) in pure ices and in relation to water ice, the dominant ice constituent during star and planet formation. These empirically determined values can be used to inform observations and models of the molecular spatial distribution in protoplanetary disks, thus providing insight into planetesimal composition. In addition, knowledge of hydrocarbon binding energies will refine simulations of grain surface chemistry, allowing for better predictions of the chemical conditions that lead to the production of complex organic molecules vital for life.

  14. Molecular networks in Position, Momentum, and Phase Space: A Case Study on Simple Hydrocarbons

    DEFF Research Database (Denmark)

    Schmider, Hartmut; Ho, Minhhuy

    1996-01-01

    are identified in a series of nine small hydrocarbonic molecules, and the resulting "molecular graphs" are interpreted in terms of symmetry and topology. For the example of a symmetric SN2 reaction, it is shown that the topology of the Husimi function based graphs can be useful for the classification of chemical...

  15. The effects of polycyclic aromatic hydrocarbons on the chemistry of photodissociation regions

    NARCIS (Netherlands)

    Bakes, ELO; Tielens, AGGM

    1998-01-01

    We have investigated the effects of including polycylic aromatic hydrocarbons (PAHs) on the abundance of neutral atoms and molecules for two typical photodissociation regions (PDRs): a high-density case (the Orion complex) and a low-density case. PAHs provide a large surface area for chemistry betwe

  16. Gas phase adiabatic electron affinities of cyclopenta-fused polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Todorov, P.D.; Koper, C.; van Lenthe, J.H.; Jenneskens, L.W.

    2008-01-01

    The B3LYP/DZP++ adiabatic electron affinity (AEA) of nine (non)-alternant polycyclic aromatic hydrocarbons are reported and discussed. Calculations became feasible for molecules this size by projecting out the near-linearly dependent part of the one-electron basis. Non-alternant PAH consisting of an

  17. 33 CFR 157.166 - Hydrocarbon emissions.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hydrocarbon emissions. 157.166... Crude Oil Washing (COW) System on Tank Vessels Cow Operations § 157.166 Hydrocarbon emissions. If the... ballasted in that port the hydrocarbon vapors in each tank are contained by a means under § 157.132....

  18. Compositions and methods for hydrocarbon functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Gunnoe, Thomas Brent; Fortman, George; Boaz, Nicholas C.; Groves, John T.

    2017-03-28

    Embodiments of the present disclosure provide for methods of hydrocarbon functionalization, methods and systems for converting a hydrocarbon into a compound including at least one group ((e.g., hydroxyl group) (e.g., methane to methanol)), functionalized hydrocarbons, and the like.

  19. Theoretical study of hydrogen storage in a truncated tetrahedron hydrocarbon

    Science.gov (United States)

    Ishikawa, Shigeru; Yamabe, Tokio

    2017-02-01

    A hydrocarbon molecule, having a truncated tetrahedron shape with a suitable size for the storage of a hydrogen molecule, is designed using quantum chemical methods. The molecule consists of four benzene rings bridged by six vinylene groups at the 1, 3, and 5 carbon positions of each ring, and has a stoichiometry of C36H24. The molecular geometry optimized under T d symmetry by the B3LYP/cc-pVTZ method shows no imaginary frequencies. The size of the molecular cavity, measured by the distance between opposite vinylene groups, is 8.0 Å. The cavity has four openings along each tetrahedron face. The radius of the opening is approximately 2 Å. The system interacting with a hydrogen molecule is optimized by the MP2/cc-pVTZ method. The interaction energy is evaluated by an extrapolation method through increasing the basis set size of the hydrogen molecule from the cc-pVTZ to the cc-pV6Z with counterpoise corrections. The hydrogen molecule enters the opening by overcoming an energy barrier of +730 meV and locates at the center of the cavity with a binding energy of -140 meV. The high barrier arises from the small size of the opening. The binding energy is three times larger than that of a graphite surface and may allow hydrogen storage at milder temperatures and pressures than those required with graphite.

  20. 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...

  1. Fire-safe hydrocarbon fuels

    Energy Technology Data Exchange (ETDEWEB)

    Fodor, G.E.; Weatherford, W.D. Jr.; Wright, B.R.

    1979-11-06

    A stabilized, fire-safe, aqueous hydrocarbon fuel emulsion prepared by mixing: a diesel fuel; an emulsifier (consisting of oleyl diethanolamide, diethanolamine, and diethanolamine soap of oleic acid) which has been treated with about 0 to 7 1/2 of oleic acid. A modified version of this fuel also contains 0 to 0.5% of an antimisting agent, and water.

  2. Hydrophobic encapsulation of hydrocarbon gases.

    Science.gov (United States)

    Leontiev, Alexander V; Saleh, Anas W; Rudkevich, Dmitry M

    2007-04-26

    [reaction: see text] Encapsulation data for hydrophobic hydrocarbon gases within a water-soluble hemicarcerand in aqueous solution are reported. It is concluded that hydrophobic interactions serve as the primary driving force for the encapsulation, which can be used for the design of gas-separating polymers with intrinsic inner cavities.

  3. Conversion of natural gas to C2 hydrocarbons through dielectric-barrier discharge plasma catalysis

    Institute of Scientific and Technical Information of China (English)

    王保伟; 许根慧

    2002-01-01

    The experiments are carried out in the system of continuous flow reactors with dielectric-barrier discharge (DBD) for studies on the conversion of natural gas to C2 hydrocarbons through plasma catalysis under the atmosphere pressure and room temperature. The influence of discharge frequency, structure of electrode, discharge voltage, number of electrode, ratio of H2/CH4, flow rate and catalyst on conversion of methane and selectivity of C2 hydrocarbons are investigated. At the same time, the reaction process is investigated. Higher conversion of methane and selectivity of C2 hydrocarbons are achieved and deposited carbons are eliminated by proper choice of parameters. The appropriate operation parameters in dielectric-barrier discharge plasma field are that the supply voltage is 20-40 kV (8.4-40 W), the frequency of power supply is 20 kHz, the structure of (b) electrode is suitable, and the flow of methane is 20-60 mL@min?1. The conversion of methane can reach 45%, the selectivity of C2 hydrocarbons is 76%, and the total selectivity of C2 hydrocarbons and C3 hydrocarbons is nearly 100%. The conversion of methane increases with the increase of voltage and decreases with the flow of methane increase; the selectivity of C2 hydrocarbons decreases with the increase of voltage and increases with the flow of methane increase. The selectivity of C2 hydrocarbons is improved with catalyst for conversion of natural gas to C2 hydrocarbons in plasma field. Methane molecule collision with radicals is mainly responsible for product formation.

  4. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  5. 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.

  6. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Science.gov (United States)

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-01-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review. PMID:24031900

  7. Searching for line active molecules on biphasic lipid monolayers.

    Science.gov (United States)

    Bischof, Andrea Alejandra; Mangiarotti, Agustín; Wilke, Natalia

    2015-03-21

    In membranes with phase coexistence, line tension appears as an important parameter for the determination of the amount of domains, as well as their size and their shape, thus defining the membrane texture. Different molecules have been proposed as "linactants" (i.e. molecules that reduce the line tension, thereby modulating the membrane texture). In this work, we explore the efficiency of different molecules as linactants in monolayers with two coexisting phases of different thicknesses. We tested the linactant ability of a molecule with chains of different saturation degrees, another molecule with different chain lengths and a bulky molecule. In this way, we show in the same system the effect of molecules with chains of different rigidities, with an intrinsic thickness mismatch and with a bulky moiety, thereby analyzing different hypotheses of how a molecule may change the line tension in a monolayer system. Both lipids with different hydrocarbon chains did not act as linactants, while only one of the bulky molecules tested decreased the line tension in the monolayer studied. We conclude that there are no universal rules for the structure of a molecule that enable us to predict that it will behave as a linactant and thus, designing linactants appears to be a difficult task and a challenge for future studies. Furthermore, in regard to the membrane texture, there was no direct influence of the line tension in the distribution of domain sizes.

  8. Aqueous reactions of chlorine dioxide with hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Rav-Acha, C.; Choshen, E.

    1987-11-01

    In contrast to mechanisms proposed earlier in the literature, according to which chlorine dioxide (ClO/sub 2/) reacts with various hydrocarbons in aqueous media by abstracting allylic or benzylic hydrogens, it is shown that ClO/sub 2/ reacts with olefins through initial electron transfer. Hydrocarbons that can undergo facile oxidation, such as polycyclic aromatic hydrocarbons (PAH) and some olefins, react with ClO/sub 2/ quite rapidly, while saturated aliphatic hydrocarbons, some aromatic hydrocarbons, and olefins substituted with electron-withdrawing groups remain unreactive. This was substantiated by comparing the reactivities toward ClO/sub 2/ of a variety of hydrocarbons, including aliphatic and aromatic hydrocarbons, saturated and unsaturated acids, PAH, or cyclic and acyclic olefins. The results were supported by a detailed kinetic and product study of the reaction between ClO/sub 2/ and some model compounds.

  9. Poster 4: Investigating the first steps of hydrocarbon condensation in the laboratory and in Titan's atmosphere

    Science.gov (United States)

    Biennier, Ludovic; Bourgalais, Jeremy; Benidar, Abdessamad; Le Picard, Sebastien

    2016-06-01

    Hydrocarbons formed in Titan's cold atmosphere, starting with ethane C2H6, ethylene C2H4, acetylene C2H2, propane C3H8,... up to benzene C6H6, play some role in aerosol production, cloud processes, rain generation and Titan's lakes formation. We have started to study in the laboratory the kinetics of the first steps of condensation of these hydrocarbons. Rate coefficients are very sensitive to the description of the potential interaction surfaces of the molecules involved. Combined theoretical and experimental studies at the molecular level of the homogenous nucleation of various small molecules should improve greatly our fundamental understanding. This knowledge will serve as a model for studying more complex nucleation processes actually taking places in planetary atmospheres. Here we present the first experimental kinetic study of the dimerization of two small hydrocarbons: ethane C2H6 and propane C3H8. We have performed experiments to identify the temperature and partial densities ranges over which small hydrocarbon clusters form in saturated uniform supersonic flows. Using our unique reactor based on a Laval nozzle expansions, the kinetics of the formation has also been investigated down to 23 K. The chemical species present in the reactor are probed by a time of flight mass spectrometer equipped with an electron gun for soft ionization of the neutral reagents and products. This work aims at putting some constraints on the role of small hydrocarbon condensation in the formation of haze particles in the dense atmosphere of Titan.

  10. Monooxygenation of small hydrocarbons catalyzed by bacterial cytochrome p450s.

    Science.gov (United States)

    Shoji, Osami; Watanabe, Yoshihito

    2015-01-01

    Cytochrome P450s (P450s) catalyze the NAD(P)H/O2-dependent monooxygenation of less reactive organic molecules under mild conditions. The catalytic activity of bacterial P450s is very high compared with P450s isolated from animals and plants, and the substrate specificity of bacterial P450s is also very high. Accordingly, their catalytic activities toward nonnative substrates are generally low especially toward small hydrocarbons. However, mutagenesis approaches have been very successful for engineering bacterial P450s for the hydroxylation of small hydrocarbons. On the other hand, "decoy" molecules, whose structures are very similar to natural substrates, can be used to trick the substrate recognition of bacterial P450s, allowing the P450s to catalyze oxidation reactions of nonnative substrates without any substitution of amino acid residues in the presence of decoy molecules. Thus, the hydroxylation of small hydrocarbons such as ethane, propane, butane and benzene can be catalyzed by P450BM3, a long-alkyl-chain hydroxylase, using substrate misrecognition of P450s induced by decoy molecules. Furthermore, a number of H2O2-dependent bacterial P450s can catalyze the peroxygenation of a variety of nonnative substrates through a simple substrate-misrecognition trick, in which catalytic activities and enantioselectivity are dependent on the structure of decoy molecules.

  11. Microbial production of gaseous hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Hideo

    1987-10-20

    Microbial production of ethylene, isobutane and a saturated gaseous hydrocarbon mixture was described. Microbial ethylene production was studied with Penicillium digitatum IFO 9372 and a novel pathway of the ethylene biosynthesis through alpha-ketoglutarate was proposed. Rhodotorula minuta IFO 1102 was selected for the microbial production of isobutane and the interesting actions of L-leucine and L-phenylalanine for the isobutane production were found. It was finally presented about the microbial production of a saturated gaseous hydrocarbon mixture with Rhizopus japonicus IFO 4758 was described. A gas mixture was produced through a chemical reaction of SH compounds and some cellular component such as squalene under aerobic conditions. (4 figs, 7 tabs, 41 refs)

  12. 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

  13. Hydrocarbons Encapsulated in Diamonds From China and India

    Science.gov (United States)

    Leung, I.; Tsao, C.; Taj-Eddin, I.

    2005-05-01

    We examined a large number of diamonds from a kimberlite pipe located in Fuxian, China, and alluvial diamonds from Panna, India. We selected 6-10 diamonds from each locality based on certain characteristics: they are white, brilliant, mostly devoid of mineral inclusions, fracture-free, many contain microscopic bubbles, some display etched circular patterns. These diamonds were examined under ultraviolet (UV) light using a fluorescence microscope, then, investigated using a Nicolet 6700 FT-IR spectrometer. Several diamonds emit blue fluorescence when excited with UV light, while others appear dim because they are not fluorescent. It is the latter that render the included bubbles clearly visible, glowing as yellow and blue spherules within the dim diamond host. These fluorescent bubbles are probably filled with hydrocarbon fluids of variable compositions. FT-IR spectra of diamond typically show absorption due to intrinsic diamond lattice vibrations. We found in most of our diamonds used in this study an additional, outstanding group of absorption bands located just below the wavenumber 3000. Peak positions in this region correlate well with symmetric and asymmetric stretching of methylene and methyl groups, attributable to H bonded to C atoms. Comparing them with standard spectral shapes, we found a good match with an alkane molecule composed of saturated aliphatic hydrocarbons. Our observations provide evidence that hydrocarbons might be important components in the deep mantle, but, to transport them up to Earth's surface would require strong capsules which, perhaps, only diamond could provide.

  14. 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.

  15. PREBIOTIC HYDROCARBON SYNTHESIS IN IMPACTING REDUCED ASTROPHYSICAL ICY MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    Koziol, Lucas; Goldman, Nir, E-mail: lucas.koziol@exxonmobil.com, E-mail: ngoldman@llnl.gov [Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2015-04-20

    We present results of prebiotic organic synthesis in shock-compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium timescales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impacts on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon- and nitrogen-bonded extended structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Our results help provide a bottom-up understanding of hydrocarbon impact synthesis on the early Earth and its role in producing life-building molecules from simple starting materials.

  16. Prebiotic hydrocarbon synthesis in impacting reduced astrophysical icy mixtures

    Science.gov (United States)

    Goldman, Nir; Koziol, Lucas

    2015-06-01

    We present results of prebiotic organic synthesis in shock compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium time-scales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impact on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon and nitrogen bonded extended structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Our results help provide a bottom-up understanding for hydrocarbon impact synthesis on early Earth and its role in producing life building molecules from simple starting materials. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  17. 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.

  18. Optofluidic reactors for reverse combustion photocatalytic production of hydrocarbons (Conference Presentation)

    Science.gov (United States)

    Schein, Perry; Erickson, David

    2017-03-01

    In combustion, hydrocarbon fuels are burned with oxygen to release energy, carbon dioxide and water vapor. Here, we introduce a photocatalytic reactor for reversing this process, when carbon dioxide and water are combined and using optical and thermal energy from the sun hydrocarbons are produced and oxygen is released. This allows for the sustainable production of hydrocarbon products from non-fossil sources, allowing for the development of "green" hydrocarbon products. Our reactors take the form of modular cells of 10 x 10 x 10 cm scale where light is delivered to nanostructured catalysts through the evanescent field around dielectric slab waveguides. The light distribution is optimized through the use of engineered scattering sites to enhance field uniformity. This is combined with integrated fluidic architecture to deliver a stream rich in water and carbon dioxide (such as exhaust from a natural gas burning plant) to the nanostructured catalyst particles in a narrow channel. Exhaust streams rich in oxygen and hydrocarbon products are collected at the outlet of the reactor cell. The cell is heated using solar thermal energy and temperatures of up to 200°C are achieved, enhancing reaction efficiency. Hydrocarbon products produced include methanol as well as other potentially useful molecules for fuel production or precursors to the manufacture of plastics. These reactors can be coupled to solar collectors to take advantage of the sun as a free source of heat and light, and the modular nature of the cells enables scaling to larger deployments.

  19. Formation of Ultracold Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Robin [Univ. of Connecticut, Storrs, CT (United States)

    2016-01-28

    Advances in our ability to slow down and cool atoms and molecules to ultracold temperatures have paved the way to a revolution in basic research on molecules. Ultracold molecules are sensitive of very weak interactions, even when separated by large distances, which allow studies of the effect of those interactions on the behavior of molecules. In this program, we have explored ways to form ultracold molecules starting from pairs of atoms that have already reached the ultracold regime. We devised methods that enhance the efficiency of ultracold molecule production, for example by tuning external magnetic fields and using appropriate laser excitations. We also investigates the properties of those ultracold molecules, especially their de-excitation into stable molecules. We studied the possibility of creating new classes of ultra-long range molecules, named macrodimers, thousand times more extended than regular molecules. Again, such objects are possible because ultra low temperatures prevent their breakup by collision. Finally, we carried out calculations on how chemical reactions are affected and modified at ultracold temperatures. Normally, reactions become less effective as the temperature decreases, but at ultracold temperatures, they can become very effective. We studied this counter-intuitive behavior for benchmark chemical reactions involving molecular hydrogen.

  20. Hydrocarbon prospectivity in Western Greece

    Energy Technology Data Exchange (ETDEWEB)

    Maravelis, Angelos; Makrodimitras, George; Zelilidis, Avraam [Patras Univ. (Greece). Lab. of Sedimentology

    2012-06-15

    The geology of Western Greece is dominated by the most external zones of the Hellenide fold-and-thrust belt, namely the Pre-Apulian (or Paxoi) and Ionian zones. With Western Greece and Albania having undergone, in broad terms, similar geological histories, also the hydrocarbon potentials of both areas may be compared. Likewise, the hydrocarbon potential of Italy's Apulian Platform, adjoining in the westerly offshore, may serve as an analogue. Three basin types within Western Greece that deserve hydrocarbon exploration have been examined and are grouped, correlated to major tectonic features, namely foreland (Ionian thrusts' foreland basin), piggy-back (Ionian thrusts' back-arc basin) and strike-slip basins. Additionally, strike-slip basins are further subdivided into the basin north of the Borsh-Khardhiqit strike-slip fault and the Preveza basin, north of Cephalonia transfer fault. Their filling histories suggest the occurrence of Mesozoic carbonate plays and Oligocene/Miocene sandstone plays both for oil and gas.

  1. 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.

  2. Polycyclic Aromatic Hydrocarbons and Infrared Astrophysics with Spitzer

    Science.gov (United States)

    Hudgins, Douglas M.; Allamandola, L. J.

    2004-01-01

    Over the past fifteen years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role that carbon-rich plays in the interstellar medium (ISM). Twenty years ago, the possible existence of an abundant population of large, carbon-rich molecules in the ISM was unthinkable. Today, the unmistakable spectroscopic signatures of polycyclic aromatic hydrocarbons (PAHs) - shockingly large molecules by the standards of traditional interstellar chemistry -are recognized throughout the Universe. In this presentation, we will examine the current state of the interstellar PAH model and explore how this data, in conjunction with the unparalleled observational data provided by the Spitzer Space Telescope, can be used to draw ever-deeper insights into the physical and chemical natures of a wide range of astrophysical environments.

  3. Methane-the Promising Career of a Humble Molecule

    Institute of Scientific and Technical Information of China (English)

    Serge Kioes; Waldemar Liebner

    2004-01-01

    Methane, CH4, here represents natural gas (NG) of which it is the main constituent. Routes of chemical utilisation of NG - as opposed to energy usage - are discussed. A main step is the conversion of NG to synthesis gas, a mixture of CO and H2. Simple molecules derived from synthesis gas, like methanol,can be further reacted to longer-chained hydrocarbons like propylene and other olefins and even to gasoline and diesel.

  4. The Hydrocarbon Pool in Ethanol-to-Gasoline over HZSM-5 Catalysts

    DEFF Research Database (Denmark)

    Johansson, Roger; Hruby, S.L.; Hansen, Jeppe Rass

    2009-01-01

    It is shown that the conversion of ethanol-to-gasoline over an HZSM-5 catalyst yields essentially the same product distribution as for methanol-to-gasoline performed over the same catalyst. Interestingly, there is a significant difference between the identity of the hydrocarbon molecules trapped...... inside the HZSM-5 catalyst when ethanol is used as a feed instead of methanol. In particular, the hydrocarbon pool contains a significant amount of ethylsubstituted aromatics when ethanol is used as feedstock, but there remains only methyl-substituted aromatics in the product slate....

  5. Conversion of methanol to gasoline-range hydrocarbons in a ZSM-5 coated monolithic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Antia, J.E.; Govind, R. (Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering)

    1995-01-01

    Novel reactor configurations featuring catalysts supported on monolithic or honeycomb structures are being increasingly used for a number of applications. In this work, a zeolite-coated monolithic reactor is employed for the conversion of methanol to gasoline-range hydrocarbons. Experimental results show that the conversion and hydrocarbon product distribution compare favorably with data reported for fixed and fluid beds. Mathematical modeling shows that the conversion here is controlled by diffusion in the molecule-sized intracrystalline pores of the zeolite structure. This finding is of considerable important because it demonstrates that monolithic reactors are well-suited to zeolite-based catalytic processes.

  6. Steering proton migration in hydrocarbons using intense few-cycle laser fields

    CERN Document Server

    Kübel, M; Burger, C; Kling, Nora G; Li, H; Alnaser, A S; Bergues, B; Zherebtsov, S; Azzeer, A M; Ben-Itzhak, I; Moshammer, R; de Vivie-Riedle, R; Kling, M F

    2015-01-01

    Proton migration is a ubiquitous process in chemical reactions related to biology, combustion, and catalysis. Thus, the ability to control the movement of nuclei with tailored light, within a hydrocarbon molecule holds promise for far-reaching applications. Here, we demonstrate the steering of hydrogen migration in simple hydrocarbons, namely acetylene and allene, using waveform-controlled, few-cycle laser pulses. The rearrangement dynamics are monitored using coincident 3D momentum imaging spectroscopy, and described with a quantum-dynamical model. Our observations reveal that the underlying control mechanism is due to the manipulation of the phases in a vibrational wavepacket by the intense off-resonant laser field.

  7. 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

  8. Conversion of methanol to hydrocarbons over ZSM-5 zeolite: an examination of the role of aromatic hydrocarbons using /sup 13/carbon and deuterium-labeled feeds

    Energy Technology Data Exchange (ETDEWEB)

    Mole, T.; Bett, G.; Seddon, D.

    1983-12-01

    A mechanism is suggested for the acceleration by aromatic hydrocarbons of zeolite-catalyzed methanol conversion. According to this mechanism, the aromatic hydrocarbon undergoes successive ring methylation, prototropic conversion to an exo-methylene-cyclohexadiene, side-chain methylation, and ring de-ethylation. The overall result is that two methanol molecules give an ethylene molecule. The mechanism is supported by various reactions observed over ZSM-5 catalyst at methanol conversion temperatures: (I) deuteration of p-xylene by D/sub 2/O in the ring and methyl positions; (II) de-alkylation of p-ethyltoluene and n-propylbenzene; and (III) incorporation of the aromatic carbon of benzenes and alkylbenzenes into ethylene product, as revealed by /sup 13/C-labeling studies. 3 tables.

  9. [Endothelial cell adhesion molecules].

    Science.gov (United States)

    Ivanov, A N; Norkin, I A; Puchin'ian, D M; Shirokov, V Iu; Zhdanova, O Iu

    2014-01-01

    The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

  10. Trapping molecules on chips

    CERN Document Server

    Santambrogio, Gabriele

    2015-01-01

    In the last years, it was demonstrated that neutral molecules can be loaded on a microchip directly from a supersonic beam. The molecules are confined in microscopic traps that can be moved smoothly over the surface of the chip. Once the molecules are trapped, they can be decelerated to a standstill, for instance, or pumped into selected quantum states by laser light or microwaves. Molecules are detected on the chip by time-resolved spatial imaging, which allows for the study of the distribution in the phase space of the molecular ensemble.

  11. A review on carbon-rich molecules in space

    CERN Document Server

    Cataldo, F; Manchado, A

    2012-01-01

    We present and discuss carbon-rich compounds of astrochemical interest such as polyynes, acetylenic carbon chains and the related derivative known as monocyanopolyynes and dicyanopolyynes. Fullerenes are now known to be abundant in space, while fulleranes - the hydrogenated fullerenes - and other carbon-rich compounds such as very large polycyclic aromatic hydrocarbons (VLPAHs) and heavy petroleum fractions are suspected to be present in space. We review the synthesis, the infrared spectra as well as the electronic absorption spectra of these four classes of carbon-rich molecules. The existence or possible existence in space of the latter molecules is reported and discussed.

  12. Correlation between hydrocarbon distribution and water-hydrocarbon ratio in Fischer-Tropsch synthesis

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng Zhou; Qingling Chen; Yuewu Tao; Huixin Weng

    2011-01-01

    In order to shorten the evaluation cycle of cobalt catalyst before the optimized catalyst is fixed on,a mathematical method is proposed to calculate weight percentage of C5+ hydrocarbons.Based on the carbide polymerization mechanism and the main hydrocarbons being linear alkanes and α-olefins,the correlation between hydrocarbon distribution and the molecular mass ratio of water to hydrocarbons is discussed.The result shows the ratio was within the range of 1.125-1.286 and the lower the ratio,the more gaseous hydrocarbons were obtained.Moreover,a linear equation between the weight percentage of C5+ hydrocarbons and the weight ratio of C5+ hydrocarbons to the total water is established.These results are validated by corresponding experiments.The weight percentage of C5+ hydrocarbons could be immediately calculated by this linear equation without detailed gas chromatography (GC) analysis of them.

  13. HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Azad; Chris Holt; Todd Lesousky; Scott Swartz

    2003-11-01

    The following report summarizes work conducted during the Phase I program Hydrocarbon and Sulfur Sensors for SOFC Systems under contract No. DE-FC26-02NT41576. For the SOFC application, sensors are required to monitor hydrocarbons and sulfur in order to increase the operation life of SOFC components. This report discusses the development of two such sensors, one based on thick film approach for sulfur monitoring and the second galvanic based for hydrocarbon monitoring.

  14. 40 CFR 90.316 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 90... Equipment Provisions § 90.316 Hydrocarbon analyzer calibration. (a) Calibrate the FID and HFID hydrocarbon... thereafter, adjust the FID and HFID hydrocarbon analyzer for optimum hydrocarbon response as specified...

  15. 40 CFR 86.121-90 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86... Complete Heavy-Duty Vehicles; Test Procedures § 86.121-90 Hydrocarbon analyzer calibration. The hydrocarbon... FID and HFID hydrocarbon analyzers shall be adjusted for optimum hydrocarbon response....

  16. 40 CFR 91.316 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 91....316 Hydrocarbon analyzer calibration. (a) Calibrate the FID and HFID hydrocarbon analyzer as described... thereafter, adjust the FID and HFID hydrocarbon analyzer for optimum hydrocarbon response as specified...

  17. 40 CFR 89.319 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 89... Equipment Provisions § 89.319 Hydrocarbon analyzer calibration. (a) The FID hydrocarbon analyzer shall... and at least annually thereafter, adjust the FID hydrocarbon analyzer for optimum hydrocarbon...

  18. Reaction mechanism studies of unsaturated molecules using photofragment translational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Longfellow, C.A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley National Lab., CA (United States). Chemical Sciences Div.

    1996-05-01

    A number of molecules have been studied using the technique of photofragment translational spectroscopy. In Chapter One a brief introduction to the experimental technique is given. In Chapter Two the infrared multiphoton dissociation (IRMPD) of acetic acid is discussed. Carbon dioxide and methane were observed for the first time as products from dissociation under collisionless conditions. Chapter Three relates an IRMPD experiment of hexafluoropropene. The predominant channel produces CFCF{sub 3} or C{sub 2}F{sub 4} and CF{sub 2}, with the heavier species undergoing further dissociation to two CF{sub 2} fragments. In Chapter Four the ultraviolet (UV) dissociation of hexafluoropropene is investigated. Chapter Five explores the IRMPD of octafluoro-1-butene and octafluoro-2-butene.

  19. Phytoremediation of polyaromatic hydrocarbons, anilines and phenols.

    Science.gov (United States)

    Harvey, Patricia J; Campanella, Bruno F; Castro, Paula M L; Harms, Hans; Lichtfouse, Eric; Schäffner, Anton R; Smrcek, Stanislav; Werck-Reichhart, Daniele

    2002-01-01

    Phytoremediation technologies based on the combined action of plants and the microbial communities that they support within the rhizosphere hold promise in the remediation of land and waterways contaminated with hydrocarbons but they have not yet been adopted in large-scale remediation strategies. In this review plant and microbial degradative capacities, viewed as a continuum, have been dissected in order to identify where bottle-necks and limitations exist. Phenols, anilines and polyaromatic hydrocarbons (PAHs) were selected as the target classes of molecule for consideration, in part because of their common patterns of distribution, but also because of the urgent need to develop techniques to overcome their toxicity to human health. Depending on the chemical and physical properties of the pollutant, the emerging picture suggests that plants will draw pollutants including PAHs into the plant rhizosphere to varying extents via the transpiration stream. Mycorrhizosphere-bacteria and -fungi may play a crucial role in establishing plants in degraded ecosystems. Within the rhizosphere, microbial degradative activities prevail in order to extract energy and carbon skeletons from the pollutants for microbial cell growth. There has been little systematic analysis of the changing dynamics of pollutant degradation within the rhizosphere; however, the importance of plants in supplying oxygen and nutrients to the rhizosphere via fine roots, and of the beneficial effect of microorganisms on plant root growth is stressed. In addition to their role in supporting rhizospheric degradative activities, plants may possess a limited capacity to transport some of the more mobile pollutants into roots and shoots via fine roots. In those situations where uptake does occur (i.e. only limited microbial activity in the rhizosphere) there is good evidence that the pollutant may be metabolised. However, plant uptake is frequently associated with the inhibition of plant growth and an

  20. 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)

  1. Algebraic theory of molecules

    CERN Document Server

    Iachello, F

    1995-01-01

    1. The Wave Mechanics of Diatomic Molecules. 2. Summary of Elements of Algebraic Theory. 3. Mechanics of Molecules. 4. Three-Body Algebraic Theory. 5. Four-Body Algebraic Theory. 6. Classical Limit and Coordinate Representation. 8. Prologue to the Future. Appendices. Properties of Lie Algebras; Coupling of Algebras; Hamiltonian Parameters

  2. ISOLATED MOLECULES IN METALS

    NARCIS (Netherlands)

    1992-01-01

    In this paper, some results obtained on the formation of isolated molecules of composition SnOx in silver and SnFx in copper-are reviewed. Hyperfine interaction and ion beam interaction techniques were used for the identification of these molecules.

  3. ISOLATED MOLECULES IN METALS

    NARCIS (Netherlands)

    1992-01-01

    In this paper, some results obtained on the formation of isolated molecules of composition SnOx in silver and SnFx in copper-are reviewed. Hyperfine interaction and ion beam interaction techniques were used for the identification of these molecules.

  4. Molecules in galaxies

    CERN Document Server

    Omont, Alain

    2007-01-01

    The main achievements, current developments and prospects of molecular studies in external galaxies are reviewed. They are put in the context of the results of several decades of studies of molecules in local interstellar medium, their chemistry and their importance for star formation. CO observations have revealed the gross structure of molecular gas in galaxies. Together with other molecules, they are among the best tracers of star formation at galactic scales. Our knowledge about molecular abundances in various local galactic environments is progressing. They trace physical conditions and metallicity, and they are closely related to dust processes and large aromatic molecules. Major recent developments include mega-masers, and molecules in Active Galactic Nuclei; millimetre emission of molecules at very high redshift; and infrared H2 emission as tracer of warm molecular gas, shocks and photodissociation regions. The advent of sensitive giant interferometers from the centimetre to sub-millimetre range, espe...

  5. Applied bioremediation of petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Hinchee, R.E.; Kittel, J.A. [eds.] [Battelle Memorial Inst., Columbus, OH (United States); Reisinger, H.J. [ed.] [Integrated Science and Technology, Inc., Marietta, GA (United States)

    1995-12-31

    This volume is part of a ten volume set of papers derived from the Third International In Situ and On-Site Bioreclamation Symposium which was held in San Diego, California, in April 1995. The purpose of the conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on bioremediation. The papers in this volume focus on petroleum hydrocarbon bioremediation, with an emphasis on pilot-scale and field-scale applications. Individual papers have been processed separately for inclusion in the appropriate data bases.

  6. Raman spectra and DFT calculations for tetraterpene hydrocarbons from the L race of the green microalga Botryococcus braunii

    Science.gov (United States)

    Chun, Hye Jin; Waqued, Sergio; Thapa, Hem R.; Han, Arum; Yakovlev, Vladislav V.; Laane, Jaan; Devarenne, Timothy P.

    2017-02-01

    The green microalga Botryococcus braunii produces large amounts of liquid hydrocarbons that can be used as a renewable source for producing transportation fuels. In the L race of B. braunii the tetraterpene known as lycopadiene accumulates as the main hydrocarbon. Lycopadiene biosynthesis begins with the production of the eight carbon-carbon double bond (C=C) containing molecule lycopaoctaene, which is reduced to lycopadiene through four intermediates containing less C=C bonds. While the biosynthetic pathway for these hydrocarbons has recently been deciphered, a spectroscopic understanding of the molecular structure for these molecules remains to be reported. Here we describe the vibrational frequency assignments for all six L race hydrocarbons using density functional theory (DFT) calculations, showing that these molecules have between 312 and 348 vibrational frequencies. Experimental Raman spectroscopy analysis shows the regions for ν(C=C) stretch and CH2/CH3 bending vibrations offer unique spectral signatures allowing for the differentiation of several of the hydrocarbons from each other.

  7. 40 CFR 52.1877 - Control strategy: Photochemical oxidants (hydrocarbons).

    Science.gov (United States)

    2010-07-01

    ... oxidants (hydrocarbons). 52.1877 Section 52.1877 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....1877 Control strategy: Photochemical oxidants (hydrocarbons). (a) The requirements of Subpart G of this... national standard for photochemical oxidants (hydrocarbons) in the Metropolitan Cincinnati...

  8. Dynamics of Activated Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, Amy S. [Univ. of Maryland, College Park, MD (United States)

    2016-11-16

    Experimental studies have been performed to investigate the collisional energy transfer processes of gas-phase molecules that contain large amounts of internal energy. Such molecules are prototypes for molecules under high temperature conditions relevant in combustion and information about their energy transfer mechanisms is needed for a detailed understanding and modeling of the chemistry. We use high resolution transient IR absorption spectroscopy to measure the full, nascent product distributions for collisions of small bath molecules that relax highly vibrationally excited pyrazine molecules with E=38000 cm-1 of vibrational energy. To perform these studies, we developed new instrumentation based on modern IR light sources to expand our experimental capabilities to investigate new molecules as collision partners. This final report describes our research in four areas: the characterization of a new transient absorption spectrometer and the results of state-resolved collision studies of pyrazine(E) with HCl, methane and ammonia. Through this research we have gained fundamental new insights into the microscopic details of relatively large complex molecules at high energy as they undergo quenching collisions and redistribute their energy.

  9. Hydrocarbon conversion process and catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, A.; Huizinga, T.; Maxwell, I.E.

    1989-08-15

    This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.40 A, a water adsorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of between 10% and 15% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; am amorphous cracking component, a binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

  10. Hydrocarbon degradation by antarctic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cavanagh, J.A.E.; Nichols, P.D.; McMeekin, T.A.; Franzmann, P.D. [Univ. of Tasmania (Australia)] [and others

    1996-12-31

    Bacterial cultures obtained from sediment samples collected during a trial oil spill experiment conducted at Airport beach, Eastern Antarctica were selectively enriched for n-alkane-degrading and phenanthrenedegrading bacteria. Samples were collected from a control site and sites treated with different hydrocarbon mixtures - Special Antarctic blend (SAB), BP-Visco and orange roughy oils. One set of replicate sites was also treated with water from Organic Lake which had previously been shown to contain hydrocarbon-degrading bacteria. No viable bacteria were obtained from samples collected from sites treated with orange roughy oil. Extensive degradation of n-alkanes by enrichment cultures obtained from sites treated with SAB and BP-Visco occurred at both 25{degrees}C and 10{degrees}C. Extensive degradation of phenanthrene also occurred in enrichment cultures from these sites grown at 25{degrees}C. Concurrent increases of polar lipid in these cultures were also observed. The presence of 1,4-naphthaquinone and 1-naphthol during the growth of the cultures on phenanthrene is unusual and warrants further investigation of the mechanism of phenanthrene-degradation by these Antarctic bacteria.

  11. Cool Sooting Flames of Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    Z.A. MANSUROV

    2001-01-01

    This paper presents the study of polycyclic aromatic hydrocarbons (PAH) and paramagnetism of soot particles sampled from cool sooting flames of methane and propane in a separately-heated two-sectional reactor under atmospheric pressure at the reactor temperatures of 670-1170 K. The temperature profiles of the flames were studied. The sampling was carried out with a quartz sampler and the samples were frozen with liquid nitrogen. A number of polyaromatic hydrocarbons such as pyrene, fluoranthene, coronene, anthanthrene, 1,12-benzperylene,were identified by spectroscopic methods in the extract of soot. The processes of soot formation at methaneoxygen mixture combustion in the electric field with applied potential changed from 0 to 2,2 kV at different polarity of electrodes have been investigated. It has been stated that at the electrical field application, an increase in soot particle sizes and soot yield occurs; besides, at the application of the field, speeding up the positively charged particles, the interplanar distance decreases. On the basis of investigation of soot particles paramagnetism, it was shown that initially soot particles have high carcinogetic activity and pollute the environment owing to a rapid decrease of the number of these radical centers. The reduction of the radical concentration is connected with radical recombination on soot.

  12. Heavy Exotic Molecules

    CERN Document Server

    Liu, Yizhuang

    2016-01-01

    We briefly review the formation of pion-mediated heavy-light exotic molecules with both charm and bottom, under the general strictures of chiral and heavy quark symmetries. The charm isosinglet exotic molecules with $J^{PC}=1^{++}$ binds, which we identify as the reported neutral $X(3872)$. The bottom isotriplet exotic with $J^{PC}=1^{+-}$ binds, and is identified as a mixed state of the reported charged exotics $Z^+_b(10610)$ and $Z^+_b(10650)$. The bound bottom isosinglet molecule with $J^{PC}=1^{++}$ is a possible neutral $X_b(10532)$ to be observed.

  13. Heavy exotic molecules

    Science.gov (United States)

    Liu, Yizhuang; Zahed, Ismail

    We briefly review the formation of pion-mediated heavy-light exotic molecules with both charm and bottom, under the general structures of chiral and heavy quark symmetries. The charm isosinglet exotic molecules with JPC = 1++ binds, which we identify as the reported neutral X(3872). The bottom isotriplet exotic with JPC = 1+1 binds, and is identified as a mixed state of the reported charged exotics Zb+(10610) and Zb-(10650). The bound bottom isosinglet molecule with JPC = 1++ is a possible neutral Xb(10532) to be observed.

  14. Electron correlation in molecules

    CERN Document Server

    Wilson, S

    2007-01-01

    Electron correlation effects are of vital significance to the calculation of potential energy curves and surfaces, the study of molecular excitation processes, and in the theory of electron-molecule scattering. This text describes methods for addressing one of theoretical chemistry's central problems, the study of electron correlation effects in molecules.Although the energy associated with electron correlation is a small fraction of the total energy of an atom or molecule, it is of the same order of magnitude as most energies of chemical interest. If the solution of quantum mechanical equatio

  15. Combining HPLC-GCXGC, GCXGC/ToF-MS, and selected ecotoxicity assays for detailed monitoring of petroleum hydrocarbon degradation in soil and leaching water.

    Science.gov (United States)

    Mao, Debin; Lookman, Richard; Van De Weghe, Hendrik; Weltens, Reinhilde; Vanermen, Guido; De Brucker, Nicole; Diels, Ludo

    2009-10-15

    HPLC-GCXGC/FID (high-performance liquid chromatography followed by comprehensive two-dimensional gas chromatography with flame-ionization detection) and GCXGC/ToF-MS (comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry) were used to study the biodegradation of petroleum hydrocarbons in soil microcosms during 20 weeks. Two soils were studied: one spiked with fresh diesel and one field sample containing weathered diesel-like oil. Nutrient amended and unamended samples were included. Total petroleum hydrocarbon (TPH) levels in spiked soil decreased from 15,000 to 7,500 mg/kg d.m. and from 12,0O0 to 4,000 mg/kg d.m. in the field soil. Linear alkanes and aromatic hydrocarbons were better biodegradable (>60% degraded) than iso-alkanes; cycloalkanes were least degradable (water showed that initially various oxygenated hydrocarbons were produced. Compound peaks seemed to move up and rightward in the GCXGC chromatograms, indicating that more polar and heavier compounds were formed as biodegradation proceeded. Nutrient amendment can increase TPH removal rates, but had adverse effects on ecotoxicity and leaching potential in our experiment This was explained by observed shifts in the soil microbial community. Ecotoxicity assays showed that residual TPH still inhibited cress (Lepidium sativum) seed germination, but the leaching water was no longer toxic toward luminescent bacteria (Vibrio fischeri).

  16. Conversion of organic solids to hydrocarbons

    Science.gov (United States)

    Greenbaum, Elias

    1995-01-01

    A method of converting organic solids to liquid and gaseous hydrocarbons includes impregnating an organic solid with photosensitizing ions and exposing the impregnated solid to light in a non-oxidizing atmosphere for a time sufficient to photocatalytically reduce the solid to at least one of a liquid and a gaseous hydrocarbon.

  17. 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, H2O, and CO2 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.

  18. Primary biodegradation of petroleum hydrocarbons in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Comber, M.I.H.; Den Haan, K.H.; Djemel, N.; Eadsforth, C.V.; King, D.; Paumen, M.L.; Parkerton, T.; Dmytrasz, B.

    2012-12-15

    This report describes primary biodegradation experiments performed to determine the persistence of higher molecular weight petroleum hydrocarbons in seawater. Results from the biodegradation experiments show that the majority of tested petroleum hydrocarbons have half-lives in seawater less than 60 days.

  19. Plasma conversion of methane into higher hydrocarbons at surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sackinger, W.M.; Kamath, V.A. [Univ. of Alaska, Fairbanks, AK (United States)

    1995-12-31

    Natural gas is widely abundant, is easily withdrawn from reservoirs, is commonly produced as an associated gas along with crude oil production, and is found in many geologic settings as a resource separate from oil. A much larger fraction of the natural gas may be produced from a gas reservoir, as compared with a crude oil reservoir. However, natural gas is normally transported by pipeline, and the energy throughput of such a pipeline is perhaps only 20% to 30% of the throughput of an oil pipeline of the same size and cost. Gas is difficult to transport in moderate quantities at low cost, as it must either have a special pipeline or must be liquified into LNG, shipped in cryogenic LNG tankers, and regasified chemical stability of methane has made it difficult to convert it directly into conventional hydrocarbon fuel mixtures, and has also impeded its use as a feedstock for petrochemical production. Experiments are described in which a methane plasma is created, and the resulting methyl and hydrogen ions have been accelerated within a microchannel array so that they interact with neutral methane molecules on the inside surfaces of the microchannels. No catalysts are used, and the device operates at room temperature. Impact energies of the ions are in the range of 15 ev to greater than 100 ev, and the energy delivered in the interaction at the surfaces has caused the production of larger hydrocarbon molecules, such as C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 6}, along with C{sub 3}, C{sub 4}, C{sub 5}, C{sub 6}, C{sub 7}, and C{sub 8} molecules. Conversion effectiveness is greater at higher pressure, due to the increased ionic activity. The costs of production of the plasma conversion devices are projected to be quite low, and the technology appears to be commercially and economically feasible.

  20. Single molecules and nanotechnology

    CERN Document Server

    Vogel, Horst

    2007-01-01

    This book focuses on recent advances in the rapidly evolving field of single molecule research. These advances are of importance for the investigation of biopolymers and cellular biochemical reactions, and are essential to the development of quantitative biology. Written by leading experts in the field, the articles cover a broad range of topics, including: quantum photonics of organic dyes and inorganic nanoparticles their use in detecting properties of single molecules the monitoring of single molecule (enzymatic) reactions single protein (un)folding in nanometer-sized confined volumes the dynamics of molecular interactions in biological cells The book is written for advanced students and scientists who wish to survey the concepts, techniques and results of single molecule research and assess them for their own scientific activities.

  1. Electron-molecule collisions

    CERN Document Server

    Takayanagi, Kazuo

    1984-01-01

    Scattering phenomena play an important role in modern physics. Many significant discoveries have been made through collision experiments. Amongst diverse kinds of collision systems, this book sheds light on the collision of an electron with a molecule. The electron-molecule collision provides a basic scattering problem. It is scattering by a nonspherical, multicentered composite particle with its centers having degrees of freedom of motion. The molecule can even disintegrate, Le., dissociate or ionize into fragments, some or all of which may also be molecules. Although it is a difficult problem, the recent theoretical, experimental, and computational progress has been so significant as to warrant publication of a book that specializes in this field. The progress owes partly to technical develop­ ments in measurements and computations. No less important has been the great and continuing stimulus from such fields of application as astrophysics, the physics of the earth's upper atmosphere, laser physics, radiat...

  2. Quantum dot molecules

    CERN Document Server

    Wu, Jiang

    2014-01-01

    This book reviews recent advances in the exciting and rapidly growing field of quantum dot molecules (QDMs). It offers state-of-the-art coverage of novel techniques and connects fundamental physical properties with device design.

  3. Biodegradation, bioaccessibility, and genotoxicity of diffuse polycyclic aromatic hydrocarbon (PAH) pollution at a motorway site.

    Science.gov (United States)

    Johnsen, Anders R; De Lipthay, Julia R; Reichenberg, Fredrik; Sørensen, Søren J; Andersen, Ole; Christensen, Peter; Binderup, Mona-lise; Jacobsen, Carsten S

    2006-05-15

    Diffuse pollution of surface soil with polycyclic aromatic hydrocarbons (PAHs) is problematic in terms of the large areas and volumes of polluted soil. The levels and effects of diffuse PAH pollution at a motorway site were investigated. Surface soil was sampled with increasing distance from the asphalt pavement and tested for total amounts of PAHs, amounts of bioaccessible PAHs, total bacterial populations, PAH degrader populations, the potential for mineralization of 14C-PAHs, and mutagenicity. Elevated PAH concentrations were found in the samples taken 1-8 m from the pavement. Soil sampled at greater distances (12-24 m) contained only background levels of PAHs. The total bacterial populations (CFU and numbers of 16S rDNA genes) were similar for all soil samples, whereas the microbial degrader populations (culturable PAH degraders and numbers of PAH dioxygenase genes) were most abundant in the most polluted samples close to the pavement. Hydroxypropyl-beta-cyclodextrin extraction of soil PAHs, as a direct estimate of the bioaccessibility, indicated that only 1-5% of the PAHs were accessible to soil bacteria. This low bioaccessibility is suggested to be due to sorption to traffic soot particles. The increased PAH level close to the pavement was reflected in slightly increased mutagenic activity (1 m, 0.32 +/- 0.08 revertants g(-1) soil; background/ 24 m: 0.08 +/- 0.04), determined by the Salmonella/ microsome assay of total extractable PAHs activated by liver enzymes. The potential for lighter molecular weight PAH degradation in combination with low bioaccessibility of heavier PAHs is proposed to lead to a likely increase in concentration of heavier PAHs over time. These residues are, however, likely to be of low biological significance.

  4. Normal hydrocarbons as a source of resin formation in the process of obtaining isoprene from isopentane

    Energy Technology Data Exchange (ETDEWEB)

    Isagulyants, G.V.; Sire, Y.M.; Vasil' yeva, V.P.; Gitis, K.M.; Rozengart, M.I.

    1981-01-01

    A study was made on a catalyst of dehydrogenation of olefins of the conversion of isoamylenes and other C/sub 5/ hydrocarbons (isoprene, n-pentenes, piperylene), formed during dehydrogenation of isoamylenes to isoprene. It was found that the yield of heavy products increases on transition from hydrocarbons of iso-structure to normal hydrocarbons, which is due to the greater ease of polycondensation of cyclopentadiene formed from n-pentenes and particularly from piperylene under conditions of dehydrogenation. A study was made by chromato-mass-spectrometry of the composition of heavy products of conversion of piperylene and isoprene. In contrast with the catalysate of isoprene, the catalysate of piperylene contains a significant proportion of hydrocarbons containing a five-membered ring in the molecule (dicyclopentadiene, indane, indene, methylindenes, azilene), this being due to the participation of cyclopentadiene in the formation of heavy products. In the two-stage process of dehydrogenation of isopentane to isoprene 95% normal hydrocarbons are formed on dehydrogenation of isopentane to isoamylenes. (JMT)

  5. Low-energy ions interacting with anthracene molecules and clusters

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, P., E-mail: prousseau@ganil.fr [CEA, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); CNRS, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); ENSICAEN, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); Universite de Caen Basse-Normandie, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); Lawicki, A. [CEA, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); CNRS, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); ENSICAEN, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); Universite de Caen Basse-Normandie, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); Holm, A.I.S. [Department of Physics, Stockholm University, AlbaNova University Center, S-10691 Stockholm (Sweden); Capron, M.; Maisonny, R.; Maclot, S.; Lattouf, E. [CEA, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); CNRS, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); ENSICAEN, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); Universite de Caen Basse-Normandie, UMR 6252 CIMAP, Boulevard Henri Becquerel, BP 5133, F-14070 Caen cedex 5 (France); Johansson, H.A.B.; Seitz, F. [Department of Physics, Stockholm University, AlbaNova University Center, S-10691 Stockholm (Sweden); and others

    2012-05-15

    The interaction of slow ions (v{approx}0.4a.u.) with a small polycyclic aromatic hydrocarbon, namely anthracene (C{sub 14}H{sub 10}), is studied in the gas-phase either with the isolated molecule or with a pure cluster target. We discuss the ionization and fragmentation of the molecule with respect to the projectile charge state, i.e. for singly charged He{sup +} ions and for multiply charged Xe{sup 20+} ions. For the isolated C{sub 14}H{sub 10}, single or multiple ionization of the molecule occurs under ion impact. The (multi) cation relative yields are compared with those obtained by other ionization methods (electron and fs-laser). The molecular dissociation occurs by loss of hydrogen and small hydrocarbon molecules, leading to the formation of C{sub n}H{sub x} cations. The interaction of Xe{sup 20+} with C{sub 14}H{sub 10} clusters gives surprising results, i.e. the emission of hotter monomer compared to the interaction with He{sup +}.

  6. Method for producing diene hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Tsaylingol' d, A.L.; Abayev, G.N.; Mikhaylov, R.K.; Stepanov, G.A.; Troitskiy, A.P.

    1980-04-28

    A method is claimed for producing diene hydrocarbons by oxidational dehydration of paraffin or olefin hydrocarbons in a fluidized bed of a concentrate with circulation of the latter between the zones of the reaction of regeneration with the help of circulation stand pipes. To increase the efectiveness of the process, it is proposed to circulate the concentrate between the zones of reaction and regeneration, sequentially disposed in a common apparatus with a difference in the concentration of the concentrate in the circulation stand pipes disposed in the same apparatus and the zone of the reaction equal to 20-700 kg/m/sup 3/. For example, the process of oxidational dehydration of butane through the proposed system is conducted in an apparatus with a diameter of 1,000 mm, a circulation stand pipe diameter of 500 mm, a linear gas speed in the reaction zone of 0.6 m/s, and in the circulation stand pipe of 0.15 m/s. The concentration of the concentrate in the dehydration zone is 640 kg/m/sup 3/ and in the stand pipe, 970 kg/m/sup 3/. The volumetric ratio of the n-C/sub 4/H/sub 10/:air, air:vapor vapor in the form of a condensate is 1:7.2:4.5:5.5. The output of the butadiene is: in the passed butane, 32.9% and in the broken down butane, 52.5%. The butane conversion is 62.6%. The losses of the concentrate with the contact gas and with the regeneration gases is 1/3 as much for the supplied butane, than in a known method. The method makes it possible to reduce the air expenditure by 60%, to reduce the concentrate losses by 2-3 times and to simplify the industrial system.

  7. Early events following radiolytic and photogeneration of radical cations in hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Werst, D.W.; Trifunac, A.D.

    1992-11-01

    Real-time studies in hydrocarbons have revealed a richness of chemistry involving the initial ionic species produced in radiolysis and photoionization. A modified radical cation mechanism patterned after the core mechanism for alkane radiolysis-formation of radical cations and their disappearance via ion-molecule reactions - is capable of explaining a wide range of observations in high-energy photochemistry, and thus unifies two high-energy regimes. Fundamental studies of radical cations suggest strategies for mitigating radiation effects in materials.

  8. Early events following radiolytic and photogeneration of radical cations in hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Werst, D.W.; Trifunac, A.D.

    1992-01-01

    Real-time studies in hydrocarbons have revealed a richness of chemistry involving the initial ionic species produced in radiolysis and photoionization. A modified radical cation mechanism patterned after the core mechanism for alkane radiolysis-formation of radical cations and their disappearance via ion-molecule reactions - is capable of explaining a wide range of observations in high-energy photochemistry, and thus unifies two high-energy regimes. Fundamental studies of radical cations suggest strategies for mitigating radiation effects in materials.

  9. Natural gas conversion to higher hydrocarbons using plasma interactions with surfaces. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sackinger, W.M.; Kamath, V.A.; Morgan, B.L.; Airey, R.W.

    1993-12-01

    Experiments are reported in which a methane plasma is created, and the methyl ions and hydrogen ions are accelerated within a microchannel array so that they interact with neutral methane molecules on the inside surfaces of the microchannels. No catalysts are used, and the device operates at room temperature. Impact energies of the ions are in the range of 10 eV to greater than 100 eV, and the energy delivered in the interaction at the surfaces causes the production of larger hydrocarbon molecules, such as C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 6}, along with C{sub 3}, C{sub 4}, C{sub 5}m C{sub 6}, C{sub 7}m and C{sub 8} molecules. There is a decreasing percentage of larger molecules produced, in comparison with the C{sub 2} and C{sub 3} types. Conversion effectiveness is greater at higher pressure, due to the increased ionic activity. The yield of the higher hydrocarbons depends upon the external voltage used, and voltage can be used as a control parameter to adjust the output mixture proportions. A conversion energy of 2.59 kilowatt hours/killogram of output has been demonstrated, and a reduction of this by a factor of 10 is possible using known techniques. In batch experiments, the selectivity for C{sub 2} has varied from 47% to 88%, and selectivity for C{sub 6} has ranged from 0% to 12.8%. Other hydrocarbon selectivities also span a wide and useful range. The estimated costs for hydrocarbons produced with this technology are in the range of $200 per tonne, in production quantities, depending upon natural gas costs. Pilot production experiments are recommended to make these estimates more precise, and to address strategies for scaling the technology up to production levels. Applications are discussed.

  10. Influence of Parameters of a Reactive Interatomic Potential on the Properties of Saturated Hydrocarbons

    Science.gov (United States)

    2017-01-01

    reaction for select chemical reactions have also been explored, and it was found that MEAM gives reasonable predictions of the energies associated with...these 2 major chemical reactions in saturated hydrocarbons. The present work is associated with the initial development of the C–H MEAM potential.39 In...set of properties for these different molecules and configurations. Moreover, further analysis can shed light on the relationship between different

  11. Prediction of vapor-liquid equilibriafor hydrocarbon binary systems by regular solution model

    OpenAIRE

    下山, 裕介; 米澤, 節子; 小渕, 茂寿; 福地, 賢治; 荒井, 康彦; Shimoyama, Yusuke; Yonezawa, Setsuko; Kobuchi, Shigetoshi; Fukuchi, Kenii; Arai, Yasuhiko

    2007-01-01

    Vapor-liquid equilibria (VLE) of hydrocarbon binary systems : hexane + benzene (25 °C), toluene + octane (60°C) and cyclohexane + toluene (50°C) were predicted by using a regular solution model. In the present model, the mixing entropy term (Flory-Huggins equation) is included and an interaction parameter between unlike molecules is introduced. Solubility parameters and molar volumes at each temperature required in calculation are estimated by previously proposed methods. VLE of hexane + benz...

  12. Isolation of biosurfactant producing microorganisms and lipases from wastewaters from slaughterhouses and soils contaminated with hydrocarbons

    OpenAIRE

    Becerra, Lizzie; Horna, María

    2016-01-01

    Surfactants are amphipathic molecules which reduce stress at the interface, thereby increasing water solubility and availability of organic compounds are produced by bacteria, fungi, and yeasts. For the isolation of biosurfactant producing bacteria and lipases, was plant in inducing means 10% of sewage effluent from slaughterhouses and soils contaminated with hydrocarbons Province taps Trujillo - Peru. Isolates were seed in agar cultures lecithin and rhodamine agar for determination of lipase...

  13. How Do Heavier Halide Ligands Affect the Signs and Magnitudes of the Zero-Field Splittings in Halogenonickel(II) Scorpionate Complexes? A Theoretical Investigation Coupled to Ligand-Field Analysis.

    Science.gov (United States)

    Ye, Shengfa; Neese, Frank

    2012-07-10

    This work presents a detailed analysis of the physical origin of the zero-field splittings (ZFSs) in a series of high-spin (S = 1) nickel(II) scorpionate complexes Tp*NiX (Tp* = hydrotris(3,5-dimethylpyrazole)borate, X = Cl, Br, I) using quantum chemical approaches. High-frequency and -field electron paramagnetic resonance studies have shown that the complexes with heavier halide ligands (Br, I) have greater magnitudes but opposite signs of the ZFSs compared with the chloro congener (Desrochers, P. J.; Telser, J.; Zvyagin, S. A.; Ozarowski, A.; Krzystek, J.; Vicic, D. A. Inorg. Chem.2006, 45, 8930-8941). To rationalize the experimental findings, quantum chemical calculations of the ZFSs in this Ni(II) halide series have been conducted. The computed ZFS using wave-function-based ab initio methods (state-averaged CASSCF, NEVPT2, and SORCI) are in good agreement with the experiment. For comparison, density functional theory was only marginally successful. The ligand-field analysis demonstrates that the signs and magnitudes of the ZFSs are subtly determined by the trade-off between the negative contributions from the (1,3)A1(1e→2e) transitions relative to the positive contributions from the remaining d-d excited states. The term from (1,3)A1(1e→2e) stems from the structural feature that the metal center displaces out of the equatorial plane, and gains the importance when heavier halide ligand is involved.

  14. A modified microbial adhesion to hydrocarbons assay to account for the presence of hydrocarbon droplets.

    Science.gov (United States)

    Zoueki, Caroline Warne; Tufenkji, Nathalie; Ghoshal, Subhasis

    2010-04-15

    The microbial adhesion to hydrocarbons (MATH) assay has been used widely to characterize microbial cell hydrophobicity and/or the extent of cell adhesion to hydrophobic liquids. The classical MATH assay involves spectrophotometric absorbance measurements of the initial and final cell concentrations in an aqueous cell suspension that has been contacted with a hydrocarbon liquid. In this study, microscopic examination of the aqueous cell suspension after contact with hexadecane or a hexadecane/toluene mixture revealed the presence of hydrocarbon droplets. The hydrocarbon droplets contributed to the absorbance values during spectrophotometric measurements and caused erroneous estimates of cell concentrations and extents of microbial adhesion. A modified MATH assay that avoids such artefacts is proposed here. In this modified assay, microscopic examination of the aqueous suspension and direct cell counts provides cell concentrations that are free of interference from hydrocarbon droplets. The presence of hydrocarbon droplets was noted in MATH assays performed with three bacterial strains, and two different hydrocarbons, at ionic strengths of 0.2 mM and 20 mM and pH 6. In these experiments, the formation of quasi-stable hydrocarbon droplets cannot be attributed to the presence of biosurfactants, or stabilization by biocolloids. The presence of surface potential at the hydrocarbon-water interface that was characterized by electrophoretic mobility of up to -1 and -2 microm cm/Vs, likely caused the formation of the quasi-stable hydrocarbon droplets that provided erroneous results using the classical MATH assay.

  15. Earthworms (Eisenia fetida) demonstrate potential for use in soil bioremediation by increasing the degradation rates of heavy crude oil hydrocarbons.

    Science.gov (United States)

    Martinkosky, Luke; Barkley, Jaimie; Sabadell, Gabriel; Gough, Heidi; Davidson, Seana

    2017-02-15

    Crude oil contamination widely impacts soil as a result of release during oil and gas exploration and production activities. The success of bioremediation methods to meet remediation goals often depends on the composition of the crude oil, the soil, and microbial community. Earthworms may enhance bioremediation by mixing and aerating the soil, and exposing soil microorganisms to conditions in the earthworm gut that lead to increased activity. In this study, the common composting earthworm Eisenia fetida was tested for utility to improve remediation of oil-impacted soil. E. fetida survival in soil contaminated with two distinct crude oils was tested in an artificial (lab-mixed) sandy loam soil, and survival compared to that in the clean soil. Crude oil with a high fraction of light-weight hydrocarbons was more toxic to earthworms than the crude oil with a high proportion of heavy polyaromatic and aliphatic hydrocarbons. The heavier crude oil was added to soil to create a 30,000mg/kg crude oil impacted soil, and degradation in the presence of added earthworms and feed, feed alone, or no additions was monitored over time and compared. Earthworm feed was spread on top to test effectiveness of no mixing. TPH degradation rate for the earthworm treatments was ~90mg/day slowing by 200days to ~20mg/day, producing two phases of degradation. With feed alone, the rate was ~40mg/day, with signs of slowing after 500days. Both treatments reached the same end point concentrations, and exhibited faster degradation of aliphatic hydrocarbons C21, decreased. During these experiments, soils were moderately toxic during the first three months, then earthworms survived well, were active and reproduced with petroleum hydrocarbons present. This study demonstrated that earthworms accelerate bioremediation of crude oil in soils, including the degradation of the heaviest polyaromatic fractions.

  16. Hydrocarbon degradation abilities of psychrotolerant Bacillus strains

    Directory of Open Access Journals (Sweden)

    Fulya Kolsal

    2017-06-01

    Full Text Available Biodegradation requires identification of hydrocarbon degrading microbes and the investigation of psychrotolerant hydrocarbon degrading microbes is essential for successful biodegradation in cold seawater. In the present study, a total of 597 Bacillus isolates were screened to select psychrotolerant strains and 134 isolates were established as psychrotolerant on the basis of their ability to grow at 7 °C. Hydrocarbon degradation capacities of these 134 psychrotolerant isolate were initially investigated on agar medium containing different hydrocarbons (naphthalene, n-hexadecane, mineral oil and 47 positive isolates were grown in broth medium containing hydrocarbons at 20 °C under static culture. Bacterial growth was estimated in terms of viable cell count (cfu ml–1. Isolates showing the best growth in static culture were further grown in presence of crude oil under shaking culture and viable cell count was observed between 8.3 × 105–7.4 × 108 cfu ml–1. In the final step, polycyclic aromatic hydrocarbon (PAH (chrysene and naphthalene degradation yield of two most potent isolates was determined by GC-MS along with the measurement of pH, biomass and emulsification activities. Results showed that isolates Ege B.6.2i and Ege B.1.4Ka have shown 60% and 36% chrysene degradation yield, respectively, while 33% and 55% naphthalene degradation yield, respectively, with emulsification activities ranges between 33–50%. These isolates can be used to remove hydrocarbon contamination from different environments, particularly in cold regions.

  17. 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.

  18. 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.

  19. Molecules as Automata

    Science.gov (United States)

    Cardelli, Luca

    Molecular biology investigates the structure and function of biochemical systems starting from their basic building blocks: macromolecules. A macromolecule is a large, complex molecule (a protein or a nucleic acid) that usually has inner mutable state and external activity. Informal explanations of biochemical events trace individual macromolecules through their state changes and their interaction histories: a macromolecule is endowed with an identity that is retained through its transformations, even through changes in molecular energy and mass. A macromolecule, therefore, is qualitatively different from the small molecules of inorganic chemistry. Such molecules are stateless: in the standard notation for chemical reactions they are seemingly created and destroyed, and their atomic structure is used mainly for the bookkeeping required by the conservation of mass.

  20. Molecules in supernova ejecta

    CERN Document Server

    Cherchneff, Isabelle

    2011-01-01

    The first molecules detected at infrared wavelengths in the ejecta of a Type II supernova, namely SN1987A, consisted of CO and SiO. Since then, confirmation of the formation of these two species in several other supernovae a few hundred days after explosion has been obtained. However, supernova environments appear to hamper the synthesis of large, complex species due to the lack of microscopically-mixed hydrogen deep in supernova cores. Because these environments also form carbon and silicate dust, it is of importance to understand the role played by molecules in the depletion of elements and how chemical species get incorporated into dust grains. In the present paper, we review our current knowledge of the molecular component of supernova ejecta, and present new trends and results on the synthesis of molecules in these harsh, explosive events.

  1. MOLECULES IN {eta} CARINAE

    Energy Technology Data Exchange (ETDEWEB)

    Loinard, Laurent; Menten, Karl M.; Guesten, Rolf [Max-Planck Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Zapata, Luis A.; Rodriguez, Luis F. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 3-72, 58090 Morelia, Michoacan (Mexico)

    2012-04-10

    We report the detection toward {eta} Carinae of six new molecules, CO, CN, HCO{sup +}, HCN, HNC, and N{sub 2}H{sup +}, and of two of their less abundant isotopic counterparts, {sup 13}CO and H{sup 13}CN. The line profiles are moderately broad ({approx}100 km s{sup -1}), indicating that the emission originates in the dense, possibly clumpy, central arcsecond of the Homunculus Nebula. Contrary to previous claims, CO and HCO{sup +} do not appear to be underabundant in {eta} Carinae. On the other hand, molecules containing nitrogen or the {sup 13}C isotope of carbon are overabundant by about one order of magnitude. This demonstrates that, together with the dust responsible for the dimming of {eta} Carinae following the Great Eruption, the molecules detected here must have formed in situ out of CNO-processed stellar material.

  2. Molecules in \\eta\\ Carinae

    CERN Document Server

    Loinard, Laurent; Guesten, Rolf; Zapata, Luis A; Rodriguez, Luis F

    2012-01-01

    We report the detection toward \\eta\\ Carinae of six new molecules, CO, CN, HCO+, HCN, HNC, and N2H+, and of two of their less abundant isotopic counterparts, 13CO and H13CN. The line profiles are moderately broad (about 100 km /s) indicating that the emission originates in the dense, possibly clumpy, central arcsecond of the Homunculus Nebula. Contrary to previous claims, CO and HCO+ do not appear to be under-abundant in \\eta\\ Carinae. On the other hand, molecules containing nitrogen or the 13C isotope of carbon are overabundant by about one order of magnitude. This demonstrates that, together with the dust responsible for the dimming of eta Carinae following the Great Eruption, the molecules detected here must have formed in situ out of CNO-processed stellar material.

  3. Enzyme molecules as nanomotors.

    Science.gov (United States)

    Sengupta, Samudra; Dey, Krishna K; Muddana, Hari S; Tabouillot, Tristan; Ibele, Michael E; Butler, Peter J; Sen, Ayusman

    2013-01-30

    Using fluorescence correlation spectroscopy, we show that the diffusive movements of catalase enzyme molecules increase in the presence of the substrate, hydrogen peroxide, in a concentration-dependent manner. Employing a microfluidic device to generate a substrate concentration gradient, we show that both catalase and urease enzyme molecules spread toward areas of higher substrate concentration, a form of chemotaxis at the molecular scale. Using glucose oxidase and glucose to generate a hydrogen peroxide gradient, we induce the migration of catalase toward glucose oxidase, thereby showing that chemically interconnected enzymes can be drawn together.

  4. Multicolor Bound Soliton Molecule

    CERN Document Server

    Luo, Rui; Lin, Qiang

    2015-01-01

    We show a new class of bound soliton molecule that exists in a parametrically driven nonlinear optical cavity with appropriate dispersion characteristics. The composed solitons exhibit distinctive colors but coincide in time and share a common phase, bound together via strong inter-soliton four-wave mixing and Cherenkov radiation. The multicolor bound soliton molecule shows intriguing spectral locking characteristics and remarkable capability of spectrum management to tailor soliton frequencies, which may open up a great avenue towards versatile generation and manipulation of multi-octave spanning phase-locked Kerr frequency combs, with great potential for applications in frequency metrology, optical frequency synthesis, and spectroscopy.

  5. Gated container molecules

    Institute of Scientific and Technical Information of China (English)

    LIU Fang; WANG Hao; HOUK K. N.

    2011-01-01

    Donald J.Cram,the great UCLA chemist,received the Nobel Prize for his discoveries about host-guest complexes [1].Both theoretical and experimental studies have been conducted about the nature and strength of interactions between the host and guest molecules.The concepts of constrictive binding (the activation energy of the binding process) and intrinsic binding (the free energy difference between the complex and the free host and guest molecules) were introduced to characterize different binding properties (Figure 1)[2].

  6. 40 CFR 86.317-79 - Hydrocarbon analyzer specifications.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer specifications....317-79 Hydrocarbon analyzer specifications. (a) Hydrocarbon measurements are to be made with a heated... measures hydrocarbon emissions on a dry basis is permitted for gasoline-fueled testing; Provided,...

  7. 40 CFR 92.119 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 92... Hydrocarbon analyzer calibration. The HFID hydrocarbon analyzer shall receive the following initial and... into service and at least annually thereafter, the HFID hydrocarbon analyzer shall be adjusted...

  8. 40 CFR 86.1321-94 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86... Procedures § 86.1321-94 Hydrocarbon analyzer calibration. The FID hydrocarbon analyzer shall receive the... into service and at least annually thereafter, the FID hydrocarbon analyzer shall be adjusted...

  9. 21 CFR 178.3530 - Isoparaffinic petroleum hydrocarbons, synthetic.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Isoparaffinic petroleum hydrocarbons, synthetic... hydrocarbons, synthetic. Isoparaffinic petroleum hydrocarbons, synthetic, may be safely used in the production... isoparaffinic petroleum hydrocarbons, produced by synthesis from petroleum gases consist of a mixture of...

  10. 21 CFR 172.882 - Synthetic isoparaffinic petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Synthetic isoparaffinic petroleum hydrocarbons. 172... hydrocarbons. Synthetic isoparaffinic petroleum hydrocarbons may be safely used in food, in accordance with the... liquid hydrocarbons meeting the following specifications: Boiling point 93-260 °C as determined by...

  11. Polycyclic Aromatic Hydrocarbons and the Diffuse Interstellar Bands: a Survey

    Science.gov (United States)

    Salama, F.; Galazutdinov, G. A.; Krelowski, J.; Allamandola, L. J.; Musaev, F. A.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    We discuss the proposal relating the origin of some of the diffuse interstellar bands (DIBs) to neutral and ionized polycyclic aromatic hydrocarbons (PAHs) present in interstellar clouds. Laboratory spectra of several PAHs, isolated at low temperature in inert gas matrices, are compared with an extensive set of astronomical spectra of reddened, early type stars. From this comparison, it is concluded that PAN ions are good candidates to explain some of the DIBs. Unambiguous assignments are difficult, however, due to the shift in wavelengths and the band broadening induced in the laboratory spectra by the solid matrix. Definitive band assignments and, ultimately, the test of the of the proposal that PAH ions carry some of the DIB must await the availability of gas-phase measurements in the laboratory. The present assessment offers a guideline for future laboratory experiments by allowing the preselection of promising PAH molecules to be studied in jet expansions.

  12. Dehydrogenation of polycyclic aromatic hydrocarbons in the diffuse interstellar medium

    CERN Document Server

    Foing, B H

    2000-01-01

    We present a model for the hydrogenation states of Polycyclic Aromatic Hydrocarbons (PAHs) in the diffuse interstellar medium. First, we study the abundance of hydrogenation and charge states of PAHs due to photo-ionization, photo-dissociation in the interstellar UV field, electron recombination and chemical reactions between PAH cations and H or H_2. For PAH cations, we find that the dehydrogenation effects are dominant. The hydrogenation state of PAHs depends strongly on the H density, the size of the molecule and UV field. In diffuse clouds with low H density and normal UV radiation, PAHs containing less than 40 C are completely or strongly dehydrogenated whereas at high H density, they are normally hydrogenated. The partially dehydrogenated species dominate in intermediate density clouds. PAHs above 40 C are quite stable and are fully hydrogenated, which would favor their spectroscopic search in near IR surveys of Diffuse Interstellar Bands (DIBs).

  13. Biosurfactant-enhanced bioremediation of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cameotra, S.S.; Bollag, J.M. [Penn State University, University Park, PA (USA). Soil Biochemical Lab.

    2003-07-01

    Biosurfactants are surface-active compounds synthesized by it wide variety of micro-organisms. They are molecules that have both hydrophobic and hydrophilic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures - lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs) can be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released to the environment its a result of spillage of oil and byproducts of coal treatment processes. The low water solubility of PAHs limits their availability to microorganisms, which is a potential problem for bioremediation of PAH-contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of PAHs has potential applications in bioremediation.

  14. Transport of Polycyclic Aromatic Hydrocarbons in Unsaturated Porous Media

    Science.gov (United States)

    Chahal, Maninder; Flury, Markus

    2016-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are complex organic molecules containing 2 or more fused benzene rings. Being hydrophobic and non-polar, PAHs tend to partition to the organic matter in the soil from bulk aqueous phase. Though transport of these contaminants has been well studied in saturated environment, interactive mechanisms of these fluorescent compounds in unsaturated (identified by presence of air-water interface) porous media is still not well understood. We studied is the transport of fluoranthene in unsaturated porous media as facilitated by moving air-water interfaces. Confocal microscopy was used to visualize the interactions of fluoranthene particles in a glass channel packed with quartz glass beads. The packed glass channel was used to mimic a porous media and effects of an advancing and receding capillary fringe on the detachment of fluoranthene.

  15. 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 behal

  16. Quantitative Hydrocarbon Energies from the PMO Method.

    Science.gov (United States)

    Cooper, Charles F.

    1979-01-01

    Details a procedure for accurately calculating the quantum mechanical energies of hydrocarbons using the perturbational molecular orbital (PMO) method, which does not require the use of a computer. (BT)

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... Total petroleum hydrocarbons (TPH) was reduced by 17% in the .... Identification of bacterial isolates was done by biochemical tests. Atagana 1517 ..... control the prolonged thermophilic period in two-phase olive oil mill.

  18. Infrared Spectra of Polycyclic Aromatic Hydrocarbons (PAHs)

    Science.gov (United States)

    Bauschlicher, Charles W., Jr.; Bakes, E. L. O.

    2000-01-01

    We have computed the synthetic infrared spectra of some polycyclic aromatic hydrocarbons containing up to 54 carbon atoms. The species studied include ovalene, circumcoronene, dicoronylene, and hexabenzocoronene. We report spectra for anions, neutrals, cations, and multiply charged cations.

  19. Molecular characterization of autochthonous hydrocarbon utilizing ...

    African Journals Online (AJOL)

    Hydrocarbon utilizing bacteria in water, soil and sediment samples collected from ... of the genomic DNA extracted from each bacterial isolate was amplified with ... that16S rRNA-gene-based techniques be used when studying the bacterial ...

  20. 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

  1. Determination of some polycyclic aromatic hydrocarbons (PAHs ...

    African Journals Online (AJOL)

    cinthia

    2013-08-01

    Aug 1, 2013 ... In this study, polycyclic aromatic hydrocarbons (PAHs) associated with airborne particulate ... compounds from the heavily industrialized Vaal Triangle region. ... benzene ring as cluster, linear or angular (Maliszewska-.

  2. Biodegradation of polycyclic hydrocarbons by Phanerochaete chrysosporium

    Science.gov (United States)

    The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHs) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. Analysis by capillary gas chromatography and high-performance li...

  3. Volatilisation of aromatic hydrocarbons from soil

    DEFF Research Database (Denmark)

    Lindhardt, B.; Christensen, T.H.

    1996-01-01

    The non-steady-state fluxes of aromatic hydrocarbons were measured in the laboratory from the surface of soils contaminated with coal tar Four soil samples from a former gasworks site were used for the experiments. The fluxes were quantified for 11 selected compounds, 4 mono- and 7 polycyclic...... aromatic hydrocarbons, for a period of up to 8 or 16 days. The concentrations of the selected compounds in the soils were between 0.2 and 3,100 mu g/g. The study included the experimental determination of the distribution coefficient of the aromatic hydrocarbons between the sorbed phase and the water under...... saturated conditions. The determined distribution coefficients showed that the aromatic hydrocarbons were more strongly sorbed to the total organic carbon including the coal tar pitch - by a factor of 8 to 25 - than expected for natural organic matter. The fluxes were also estimated using an analytical...

  4. Biodegradation of polycyclic hydrocarbons by Phanerochaete chrysosporium

    Science.gov (United States)

    The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHs) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. Analysis by capillary gas chromatography and high-performance li...

  5. Nile Red Detection of Bacterial Hydrocarbons and Ketones in a High-Throughput Format

    Energy Technology Data Exchange (ETDEWEB)

    Pinzon, NM; Aukema, KG; Gralnick, JA; Wackett, LP

    2011-06-28

    -throughput evaluation of bacterial and algal hydrophobic molecule production via Nile red fluorescence from lipids and esters was extended in this study to include hydrocarbons and ketones. This work demonstrated accurate, high-throughput detection of high-level bacterial long-chain ketone and hydrocarbon production by screening for increased fluorescence of the hydrophobic dye Nile red.

  6. Synthesis beyond the molecule

    NARCIS (Netherlands)

    Reinhoudt, D.N.; Crego-Calama, M.

    2002-01-01

    Weak, noncovalent interactions between molecules control many biological functions. In chemistry, noncovalent interactions are now exploited for the synthesis in solution of large supramolecular aggregates. The aim of these syntheses is not only the creation of a particular structure, but also the i

  7. Disentangling DNA molecules.

    Science.gov (United States)

    Vologodskii, Alexander

    2016-09-01

    The widespread circular form of DNA molecules inside cells creates very serious topological problems during replication. Due to the helical structure of the double helix the parental strands of circular DNA form a link of very high order, and yet they have to be unlinked before the cell division. DNA topoisomerases, the enzymes that catalyze passing of one DNA segment through another, solve this problem in principle. However, it is very difficult to remove all entanglements between the replicated DNA molecules due to huge length of DNA comparing to the cell size. One strategy that nature uses to overcome this problem is to create the topoisomerases that can dramatically reduce the fraction of linked circular DNA molecules relative to the corresponding fraction at thermodynamic equilibrium. This striking property of the enzymes means that the enzymes that interact with DNA only locally can access their topology, a global property of circular DNA molecules. This review considers the experimental studies of the phenomenon and analyzes the theoretical models that have been suggested in attempts to explain it. We describe here how various models of enzyme action can be investigated computationally. There is no doubt at the moment that we understand basic principles governing enzyme action. Still, there are essential quantitative discrepancies between the experimental data and the theoretical predictions. We consider how these discrepancies can be overcome.

  8. Disentangling DNA molecules

    Science.gov (United States)

    Vologodskii, Alexander

    2016-09-01

    The widespread circular form of DNA molecules inside cells creates very serious topological problems during replication. Due to the helical structure of the double helix the parental strands of circular DNA form a link of very high order, and yet they have to be unlinked before the cell division. DNA topoisomerases, the enzymes that catalyze passing of one DNA segment through another, solve this problem in principle. However, it is very difficult to remove all entanglements between the replicated DNA molecules due to huge length of DNA comparing to the cell size. One strategy that nature uses to overcome this problem is to create the topoisomerases that can dramatically reduce the fraction of linked circular DNA molecules relative to the corresponding fraction at thermodynamic equilibrium. This striking property of the enzymes means that the enzymes that interact with DNA only locally can access their topology, a global property of circular DNA molecules. This review considers the experimental studies of the phenomenon and analyzes the theoretical models that have been suggested in attempts to explain it. We describe here how various models of enzyme action can be investigated computationally. There is no doubt at the moment that we understand basic principles governing enzyme action. Still, there are essential quantitative discrepancies between the experimental data and the theoretical predictions. We consider how these discrepancies can be overcome.

  9. Diversity in Biological Molecules

    Science.gov (United States)

    Newbury, H. John

    2010-01-01

    One of the striking characteristics of fundamental biological processes, such as genetic inheritance, development and primary metabolism, is the limited amount of variation in the molecules involved. Natural selective pressures act strongly on these core processes and individuals carrying mutations and producing slightly sub-optimal versions of…

  10. Diversity in Biological Molecules

    Science.gov (United States)

    Newbury, H. John

    2010-01-01

    One of the striking characteristics of fundamental biological processes, such as genetic inheritance, development and primary metabolism, is the limited amount of variation in the molecules involved. Natural selective pressures act strongly on these core processes and individuals carrying mutations and producing slightly sub-optimal versions of…

  11. Atoms, Molecules, and Compounds

    CERN Document Server

    Manning, Phillip

    2007-01-01

    Explores the atoms that govern chemical processes. This book shows how the interactions between simple substances such as salt and water are crucial to life on Earth and how those interactions are predestined by the atoms that make up the molecules.

  12. Properties of entanglement molecules

    Energy Technology Data Exchange (ETDEWEB)

    Huang Yanxia [Department of Physics, Hubei Normal University, Huangshi 435002 (China); Zhan Mingsheng [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

    2004-09-14

    We propose a scheme to prepare a certain kind of N-atom entangled state that allows us to construct some possible types of entanglement molecules via cavity QED. The entanglement properties of entanglement molecules vertical bar {psi}{sub N}){sub {alpha}} are studied with respect to bipartite entanglement that is robust against the disposal of particles and are compared with entanglement molecules {rho}{sub I} introduced in Dur (2001 Phys. Rev. A 63 020303). We also give the maximal amount of entanglement achievable for two particular situations in two possible configurations. Meanwhile, we investigate the entanglement properties of entanglement molecules vertical bar {psi}{sub N}){sub {alpha}} in terms of local measurement using the maximum connectedness and persistency and compare them with other kinds of N-atom entangled states such as |GHZ), vertical bar W{sub N}) and vertical bar {phi}{sub N}). We show that the maximal value N - 1 of the persistency of the state vertical bar {psi}{sub N}){sub {alpha}} corresponds to the case that all atoms are pairwise entangled. If any pair of atoms {rho}{sub ij} is disentangled, the entanglement of the state vertical bar {psi}{sub N}){sub {alpha}} is very easy to destroy by a single local measurement.

  13. Properties of entanglement molecules

    Science.gov (United States)

    Huang, Yan-Xia; Zhan, Ming-Sheng

    2004-09-01

    We propose a scheme to prepare a certain kind of N-atom entangled state that allows us to construct some possible types of entanglement molecules via cavity QED. The entanglement properties of entanglement molecules |psgrNrangagr are studied with respect to bipartite entanglement that is robust against the disposal of particles and are compared with entanglement molecules rgrI introduced in Dur (2001 Phys. Rev. A 63 020303). We also give the maximal amount of entanglement achievable for two particular situations in two possible configurations. Meanwhile, we investigate the entanglement properties of entanglement molecules |psgrNrangagr in terms of local measurement using the maximum connectedness and persistency and compare them with other kinds of N-atom entangled states such as |GHZrang, |WNrang and |phgrNrang. We show that the maximal value N - 1 of the persistency of the state |psgrNrangagr corresponds to the case that all atoms are pairwise entangled. If any pair of atoms rgrij is disentangled, the entanglement of the state |psgrNrangagr is very easy to destroy by a single local measurement.

  14. Macroporous polymer foams by hydrocarbon templating

    OpenAIRE

    Shastri, Venkatram Prasad; Martin, Ivan; Langer, Robert

    2000-01-01

    Porous polymeric media (polymer foams) are utilized in a wide range of applications, such as thermal and mechanical insulators, solid supports for catalysis, and medical devices. A process for the production of polymer foams has been developed. This process, which is applicable to a wide range of polymers, uses a hydrocarbon particulate phase as a template for the precipitation of the polymer phase and subsequent pore formation. The use of a hydrocarbon template allows for enhanced control ov...

  15. 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.

  16. Pyrolysis of hydrocarbons from lignite semicoking tar

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Ryl' tsova, S.V.; Proskuryakov, V.A.; Rozental, D.A.; Polovetskaya, O.S.

    2000-07-01

    Pyrolysis of hydrocarbons from lignite semicoking tar in the range 750-900{degree}C at a contact time within 0.5-6.0 s was studied. The yields of pyrocarbons, pyrolysis gas, and liquid products and the group and component compositions of the liquid and gaseous products were determined. The optimal pyrolysis parameters from the viewpoint of obtaining the maximal yield of particular 'secondary' hydrocarbons were recommended.

  17. 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....

  18. 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....

  19. 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)

  20. Electrokinetic Remediation of Petroleum Hydrocarbons Spiked Soils

    OpenAIRE

    , M. Bilgin; , G. Akıncı

    2011-01-01

    In the presented study, remediation studies were conducted to determine the effectiveness of electrokinetic method on the treatment of natural soil contaminated with petroleum hydrocarbons, in laboratory scale reactors. Electokinetic remediation of agricultural soil with an initial TPHs (Total Petroleum Hydrocarbons) concentration of 10000 ppm was investigated under 20 V or 40 V direct current by using NaOH and acetic acid as electrolyte solution, treatment efficiencies were observed accordin...

  1. 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...

  2. Carbon Nanotubes as a chemical sensor: Six membered ring molecules

    Science.gov (United States)

    Sumanasekera, G. U.; Adu, C. K. A.; Pradhan, B. K.; Romero, H. E.; Eklund, P. C.

    2002-03-01

    The thermoelectric response of a mat of a carbon nanotubes has been shown to be sensitive to the details of the molecule-SWNT interaction. In this presentation, we consider the effects of the adsorption of the six-membered-ring hydrocarbon molecules with varying π electron population (C_6H_n; n=6,8,10,12), heteroatoms (N), and adducts, etc. A wide variety of the thermoelectric response to these similar molecules is observed. For example, adsorption of Benzene (n=6) induces a giant increase of the thermopower, even reversing the sign. As the π electrons of the molecule are removed (i.e., increasing hydrogenation), the effect disapears. Thus, a selective chemical response is observed. The phenomenon is identied with scattering driven by the coupling of the π electrons in the molecule and the nanotube wall. Pyridine, on the otherhand, drives the thermopower more negative, and decreases the resistivity, suggesting charge transfer between nanotube and adsorbed molecule. Work supported by ONR # N00014-99-1-0619

  3. Asymmetric polycyclic aromatic hydrocarbon as a capable source of astronomically observed interstellar infrared spectrum

    CERN Document Server

    Ota, Norio

    2015-01-01

    In order to find out capable molecular source of astronomically well observed infrared (IR) spectrum, asymmetric molecular configuration polycyclic aromatic hydrocarbon (PAH) was analyzed by the density functional theory (DFT) analysis. Starting molecules were benzene C6H6, naphthalene C10H8 and 1H-phenalene C13H9. In interstellar space, those molecules will be attacked by high energy photon and proton, which may bring cationic molecules as like C6H6n+ (n=0~3 in calculation), C10H8n+, and C13H9n+, also CH lacked molecules C5H5n+, C9H7n+, and C12H8n+. IR spectra of those molecules were analyzed based on DFT based Gaussian program. Results suggested that symmetrical configuration molecules as like benzene, naphthalene , 1H-phenalene and those cation ( +, 2+, and 3+) show little resemblance with observed IR. Contrast to such symmetrical molecules, several cases among cationic and asymmetric configuration molecules show fairly good IR tendency. One typical example was C12H83+, of which calculated harmonic IR wave...

  4. Hydrocarbon degradation by Antarctic coastal bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cavanagh, J.E. [University of Tasmania, Hobart (Australia). Antarctic Cooperative Research Centre; CSIRO Div of Marine Research, Hobart (Australia); University of Tasmania, Hobart (Australia). Dept. of Agricultural Science; Nichols, P.D. [University of Tasmania, Hobart (Australia). Antarctic Cooperative Research Centre; CSIRO Div. of Marine Research, Hobart (Australia); Franzmann, P.D. [CSIRO Land and Water, Wembley (Australia); McMeekin, T.A. [University of Tasmania, Hobart (Australia). Antarctic Cooperative Research Centre

    1999-07-01

    Bacterial cultures obtained through selective enrichment of beach sand collected 60 days and one year after treatment of sites in a pilot oil spill trial conducted at Airport Beach, Vestfold Hills, East Antarctica, were examined for the ability to degrade n-alkanes and phenanthrene. The effects of different hydrocarbon mixtures (Special Antarctic Blend [SAB] and BP-Visco), (fish oil [orange roughy]) and inoculation of replicate sites with water from Organic Lake, (previously shown to contain hydrocarbon-degrading bacteria) on the indigenous microbial population, were examined. Of the cultures obtained, those from sites treated with SAB and BP-Visco degraded n-alkanes most consistently and typically to the greatest extent. Two mixed cultures obtained from samples collected at 60 days and two isolates obtained from these cultures extensively degraded phenanthrene. 1-Hydroxy-naphthoic acid formed the major phenanthrene metabolite. Lower levels of salicyclic acid, 1-naphthol, 1,4-naphthaquinone and phenanthrene 9-10 dihydrodiol were detected in extracts of phenanthrene grown cultures. This study shows that under laboratory conditions indigenous Antarctica bacteria can degrade n-alkanes and the more recalcitrant polycyclic aromatic hydrocarbon, phenanthrene. The enrichment of hydrocarbon degrading microorganisms in Antarctic ecosystems exposed to hydrocarbons, is relevant for the long term fate of hydrocarbon spills in this environment. (author)

  5. Deuterated polycyclic aromatic hydrocarbons: Revisited

    CERN Document Server

    Doney, Kirstin D; Mori, Tamami; Onaka, Takashi; Tielens, A G G M

    2016-01-01

    The amount of deuterium locked up in polycyclic aromatic hydrocarbons (PAHs) has to date been an uncertain value. We present a near-infrared (NIR) spectroscopic survey of HII regions in the Milky Way, Large Magellanic Cloud (LMC), and Small Magellanic Cloud (SMC) obtained with AKARI, which aims to search for features indicative of deuterated PAHs (PAD or Dn-PAH) to better constrain the D/H ratio of PAHs. Fifty-three HII regions were observed in the NIR (2.5-5 {\\mu}m), using the Infrared Camera (IRC) on board the AKARI satellite. Through comparison of the observed spectra with a theoretical model of deuterated PAH vibrational modes, the aromatic and (a)symmetric aliphatic C-D stretch modes were identified. We see emission features between 4.4-4.8 {\\mu}m, which could be unambiguously attributed to deuterated PAHs in only six of the observed sources, all of which are located in the Milky Way. In all cases, the aromatic C-D stretching feature is weaker than the aliphatic C-D stretching feature, and, in the case o...

  6. 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.

  7. Microbial biodegradation of polyaromatic hydrocarbons.

    Science.gov (United States)

    Peng, Ri-He; Xiong, Ai-Sheng; Xue, Yong; Fu, Xiao-Yan; Gao, Feng; Zhao, Wei; Tian, Yong-Sheng; Yao, Quan-Hong

    2008-11-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread in various ecosystems and are pollutants of great concern due to their potential toxicity, mutagenicity and carcinogenicity. Because of their hydrophobic nature, most PAHs bind to particulates in soil and sediments, rendering them less available for biological uptake. Microbial degradation represents the major mechanism responsible for the ecological recovery of PAH-contaminated sites. The goal of this review is to provide an outline of the current knowledge of microbial PAH catabolism. In the past decade, the genetic regulation of the pathway involved in naphthalene degradation by different gram-negative and gram-positive bacteria was studied in great detail. Based on both genomic and proteomic data, a deeper understanding of some high-molecular-weight PAH degradation pathways in bacteria was provided. The ability of nonligninolytic and ligninolytic fungi to transform or metabolize PAH pollutants has received considerable attention, and the biochemical principles underlying the degradation of PAHs were examined. In addition, this review summarizes the information known about the biochemical processes that determine the fate of the individual components of PAH mixtures in polluted ecosystems. A deeper understanding of the microorganism-mediated mechanisms of catalysis of PAHs will facilitate the development of new methods to enhance the bioremediation of PAH-contaminated sites.

  8. Conjugated Molecules Described by a One-Dimensional Dirac Equation.

    Science.gov (United States)

    Ernzerhof, Matthias; Goyer, Francois

    2010-06-08

    Starting from the Hückel Hamiltonian of conjugated hydrocarbon chains (ethylene, allyl radical, butadiene, pentadienyl radical, hexatriene, etc.), we perform a simple unitary transformation and obtain a Dirac matrix Hamiltonian. Thus already small molecules are described exactly in terms of a discrete Dirac equation, the continuum limit of which yields a one-dimensional Dirac Hamiltonian. Augmenting this Hamiltonian with specially adapted boundary conditions, we find that all the orbitals of the unsaturated hydrocarbon chains are reproduced by the continuous Dirac equation. However, only orbital energies close to the highest occupied molecular orbital/lowest unoccupied molecular orbital energy are accurately predicted by the Dirac equation. Since it is known that a continuous Dirac equation describes the electronic structure of graphene around the Fermi energy, our findings answer the question to what extent this peculiar electronic structure is already developed in small molecules containing a delocalized π-electron system. We illustrate how the electronic structure of small polyenes carries over to a certain class of rectangular graphene sheets and eventually to graphene itself. Thus the peculiar electronic structure of graphene extends to a large degree to the smallest unsaturated molecule (ethylene).

  9. Bacterial invasion reconstructed molecule by molecule

    Energy Technology Data Exchange (ETDEWEB)

    Werner, James H [Los Alamos National Laboratory

    2009-01-01

    We propose to visualize the initial stages of bacterial infection of a human host cell with unmatched spatial and temporal resolution. This work will develop a new capability for the laboratory (super-resolution optical imaging), will test unresolved scientific hypotheses regarding host-pathogen interaction dynamics, and leverages state of the art 3D molecular tracking instrumentation developed recently by our group. There is much to be gained by applying new single molecule tools to the important and familiar problem of pathogen entry into a host cell. For example, conventional fluorescence microscopy has identified key host receptors, such as CD44 and {alpha}5{beta}1 integrin, that aggregate near the site of Salmonella typhimurium infection of human cells. However, due to the small size of the bacteria ({approx} 2 {micro}m) and the diffraction of the emitted light, one just sees a fluorescent 'blob' of host receptors that aggregate at the site of attachment, making it difficult to determine the exact number of receptors present or whether there is any particular spatial arrangement of the receptors that facilitates bacterial adhesion/entry. Using newly developed single molecule based super-resolution imaging methods, we will visualize how host receptors are directed to the site of pathogen adhesion and whether host receptors adopt a specific spatial arrangement for successful infection. Furthermore, we will employ our 3D molecular tracking methods to follow the injection of virulence proteins, or effectors, into the host cell by the pathogen Type III secretion system (TTSS). We expect these studies to provide mechanistic insights into the early events of pathogen infection that have here-to-fore been technically beyond our reach. Our Research Goals are: Goal 1--Construct a super-resolution fluorescence microscope and use this new capability to image the spatial distribution of different host receptors (e.g. CD44, as {alpha}5{beta}1 integrin) at the

  10. Energetic effects of adsorption of C6-C8 hydrocarbons on hard coal samples of different metamorphism

    Directory of Open Access Journals (Sweden)

    Orzechowska-Zięba Agnieszka

    2017-01-01

    Full Text Available The analysis of sorption equilibrium of aliphatic saturated and unsaturated hydrocarbons on low and medium rank coals were performed. Isosteric sorption enthalpy correlation with the degree of fill of sorption capacity was presented for the low rank coal. There was found a crucial role of primary pore structure in the coal grains in the process of sorption, especially in case of temperature anomalies occurrence. Hexane differently than other hydrocarbons of longer chains, represent the property of micropore penetration. Due to literature the presence of double bound in other molecules causes difficulties with penetration into porous structure of coal.

  11. Influence of molecular clustering on the interpretation of diffractograms of hydrocarbon films from tokamak T-10

    Energy Technology Data Exchange (ETDEWEB)

    Neverov, V. S., E-mail: vs-never@hotmail.com [National Research Center Kurchatov Institute, Tokamak Physics Institute (Russian Federation); Voloshinov, V. V., E-mail: vladimir.voloshinov@gmail.com [Russian Academy of Science, Institute for Information Transmission Problems (Kharkevich Institute) (Russian Federation); Kukushkin, A. B., E-mail: kukushkin-ab@nrcki.ru [National Research Center Kurchatov Institute, Tokamak Physics Institute (Russian Federation); Tarasov, A. S., E-mail: tarasov.alexey@gmail.com [Russian Academy of Science, Institute for Information Transmission Problems (Kharkevich Institute) (Russian Federation)

    2015-12-15

    The influence of molecular clustering on the formerly suggested interpretation of diffraction patterns of hydrocarbon films formed in the vacuum vessel of the tokamak T-10 is analyzed numerically. The simulation of clustering of simple hydrocarbon molecules C(D, H){sub 4}, C{sub 2}(D, H){sub 4}, and C{sub 6}(D, H){sub 6} and molecules composed of curved graphene (fullerenes and toroidal nanotubes) is carried out with the rigid body molecular dynamics method. It is shown that formerly neglected atomic correlations C–C and C–D(H) in the amorphous hydrocarbon component decrease the calculated values of the scattered intensity in the range of scattering vector modulus 5 < q < 20 nm{sup –1} because of homogenization of scatters on the spatial scale of ∼1 nm. The allowance for these correlations does not change the diffraction patterns in the range q > 20 nm{sup –1}. The results suggest the necessity to introduce to the procedure of determining the structural content of the films, similar to those from the tokamak T-10, the clusters formed by the van der Waals adhesion of hydrocarbon molecules to “graphene” nanoparticles. This simplifies the mathematical optimization to the former level of complexity—but for an extended ensemble of objects—and makes it possible to calculate the diffraction patterns of these objects using the distributed computing resources. A modified algorithm of structural content identification on the basis of joint X-ray and neutron diffractometry is suggested.

  12. Migration of Molecules and Dust in the Universe. Limitations of Panspermia

    Science.gov (United States)

    Bochkarev, N. G.

    2014-10-01

    Types of astronomical objects that may contain molecules are listed. Possible forms of migration of molecules are briefly described. Also described are: properties of interstellar molecular clouds, structure of interstellar dust grains, observational manifestations of polycyclic aromatic hydrocarbons and fullerenes, evolution of cosmic dust grains, the dust component of interstellar wind, possible mechanisms of migration of molecules and dust on scale from planetary systems to galaxies, Hoyle and Wickramasinghe hypothesis about the biological nature of some dust grains and the limitations of the area of possible panspermia

  13. Searching the Hearts of Graphene-like Molecules for Simplicity, Sensitivity, and Logic.

    Science.gov (United States)

    Sangtarash, Sara; Huang, Cancan; Sadeghi, Hatef; Sorohhov, Gleb; Hauser, Jürg; Wandlowski, Thomas; Hong, Wenjing; Decurtins, Silvio; Liu, Shi-Xia; Lambert, Colin J

    2015-09-09

    If quantum interference patterns in the hearts of polycyclic aromatic hydrocarbons could be isolated and manipulated, then a significant step toward realizing the potential of single-molecule electronics would be achieved. Here we demonstrate experimentally and theoretically that a simple, parameter-free, analytic theory of interference patterns evaluated at the mid-point of the HOMO-LUMO gap (referred to as M-functions) correctly predicts conductance ratios of molecules with pyrene, naphthalene, anthracene, anthanthrene, or azulene hearts. M-functions provide new design strategies for identifying molecules with phase-coherent logic functions and enhancing the sensitivity of molecular-scale interferometers.

  14. Molecules in Magnetic Fields

    Science.gov (United States)

    Berdyugina, Svetlana

    2015-08-01

    Molecules probe cool matter in the Universe and various astrophysical objects. Their ability to sense magnetic fields provides new insights into magnetic properties of these objects. During the past fifteen years we have carried out a theoretical study of molecular magnetic effects such as the Zeeman, Paschen-Back and Hanle effects and their applications for inferring magnetic structures and spatial inhomogeneities on the Sun, cool stars, brown dwarfs, and exoplanets from molecular spectro-polarimetry (e.g., Berdyugina 2011). Here, we present an overview of this study and compare our theoretical predictions with recent laboratory measurements of magnetic properties of some molecules. We present also a new web-based tool to compute molecular magnetic effects and polarized spectra which is supported by the ERC Advanced Grant HotMol.

  15. Atoms, molecules & elements

    CERN Document Server

    Graybill, George

    2007-01-01

    Young scientists will be thrilled to explore the invisible world of atoms, molecules and elements. Our resource provides ready-to-use information and activities for remedial students using simplified language and vocabulary. Students will label each part of the atom, learn what compounds are, and explore the patterns in the periodic table of elements to find calcium (Ca), chlorine (Cl), and helium (He) through hands-on activities.

  16. Time-dependent models of dense PDRs with complex molecules

    OpenAIRE

    Morata, O.; Herbst, E.

    2008-01-01

    We present a study of the chemistry of a dense photon-dominated region (PDR) using a time-dependent chemical model. Our major interest is to study the spatial distribution of complex molecules such as hydrocarbons and cyanopolyynes in the cool dense material bordering regions where star formation has taken place. Our standard model uses a homogeneous cloud of density 2x10e4 cm-3 and temperature T=40 K, which is irradiated by a far-ultraviolet radiation field of intermediate intensity, given b...

  17. Model molecules mimicking asphaltenes.

    Science.gov (United States)

    Sjöblom, Johan; Simon, Sébastien; Xu, Zhenghe

    2015-04-01

    Asphalthenes are typically defined as the fraction of petroleum insoluble in n-alkanes (typically heptane, but also hexane or pentane) but soluble in toluene. This fraction causes problems of emulsion formation and deposition/precipitation during crude oil production, processing and transport. From the definition it follows that asphaltenes are not a homogeneous fraction but is composed of molecules polydisperse in molecular weight, structure and functionalities. Their complexity makes the understanding of their properties difficult. Proper model molecules with well-defined structures which can resemble the properties of real asphaltenes can help to improve this understanding. Over the last ten years different research groups have proposed different asphaltene model molecules and studied them to determine how well they can mimic the properties of asphaltenes and determine the mechanisms behind the properties of asphaltenes. This article reviews the properties of the different classes of model compounds proposed and present their properties by comparison with fractionated asphaltenes. After presenting the interest of developing model asphaltenes, the composition and properties of asphaltenes are presented, followed by the presentation of approaches and accomplishments of different schools working on asphaltene model compounds. The presentation of bulk and interfacial properties of perylene-based model asphaltene compounds developed by Sjöblom et al. is the subject of the next part. Finally the emulsion-stabilization properties of fractionated asphaltenes and model asphaltene compounds is presented and discussed.

  18. Hydrogen molecules in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Joerg [Technische Universitaet Dresden, 01062 Dresden (Germany)], E-mail: joerg.weber@tu-dresden.de; Hiller, Martin; Lavrov, Edward V. [Technische Universitaet Dresden, 01062 Dresden (Germany)

    2007-12-15

    Molecular hydrogen, the simplest of all molecules, allows a direct insight into the fundamental properties of quantum mechanics. In the case of H{sub 2}, the Pauli principle leads to two different species, para-H{sub 2} and ortho-H{sub 2}. A conversion between these species is prohibited. Vibrational mode spectra reflect the fundamental properties and allow an unambiguous identification of the H{sub 2} molecules. Today, we have experimental evidence for the trapping of hydrogen molecules in the semiconductors Si, Ge and GaAs at the interstitial sites, within hydrogen-induced platelets, in voids and at impurities (interstitial oxygen in Si). Interstitial H{sub 2} is a nearly free rotor with a surprisingly simple behavior. We review on interstitial H{sub 2} in semiconductors and report on the unexpected preferential disappearance of the para-H{sub 2} or ortho-D{sub 2} species. The origin of the detected ortho-para conversion will be discussed.

  19. Photonic Molecule Lasers Revisited

    Science.gov (United States)

    Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J.

    2014-05-01

    Photonic molecules (PMs) formed by coupling two or more optical resonators are ideal candidates for the fabrication of integrated microlasers, photonic molecule lasers. Whereas most calculations on PM lasers have been based on cold-cavity (passive) modes, i.e. quasi-bound states, a recently formulated steady-state ab initio laser theory (SALT) offers the possibility to take into account the spectral properties of the underlying gain transition, its position and linewidth, as well as incorporating an arbitrary pump profile. We will combine two theoretical approaches to characterize the lasing properties of PM lasers: for two-dimensional systems, the generalized Lorenz-Mie theory will obtain the resonant modes of the coupled molecules in an active medium described by SALT. Not only is then the theoretical description more complete, the use of an active medium provides additional parameters to control, engineer and harness the lasing properties of PM lasers for ultra-low threshold and directional single-mode emission. We will extend our recent study and present new results for a number of promising geometries. The authors acknowledge financial support from NSERC (Canada) and the CERC in Photonic Innovations of Y. Messaddeq.

  20. Determination of the aromatic hydrocarbon to total hydrocarbon ratio of mineral oil in commercial lubricants.

    Science.gov (United States)

    Uematsu, Yoko; Suzuki, Kumi; Ogimoto, Mami

    2016-01-01

    A method was developed to determine the aromatic hydrocarbon to total hydrocarbon ratio of mineral oil in commercial lubricants; a survey was also conducted of commercial lubricants. Hydrocarbons in lubricants were separated from the matrix components of lubricants using a silica gel solid phase extraction (SPE) column. Normal-phase liquid chromatography (NPLC) coupled with an evaporative light-scattering detector (ELSD) was used to determine the aromatic hydrocarbon to total hydrocarbon ratio. Size exclusion chromatography (SEC) coupled with a diode array detector (DAD) and a refractive index detector (RID) was used to estimate carbon numbers and the presence of aromatic hydrocarbons, which supplemented the results obtained by NPLC/ELSD. Aromatic hydrocarbons were not detected in 12 lubricants specified for use for incidental food contact, but were detected in 13 out of 22 lubricants non-specified for incidental food contact at a ratio up to 18%. They were also detected in 10 out of 12 lubricants collected at food factories at a ratio up to 13%. The centre carbon numbers of hydrocarbons in commercial lubricants were estimated to be between C16 and C50.

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

    Science.gov (United States)

    Navarro, Violeta; van Spronsen, Matthijs A.; Frenken, Joost W. M.

    2016-10-01

    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 (200-350 °C). To gain further insight into the fundamental mechanisms of this industrial process, we have used a purpose-built scanning tunnelling microscope to monitor a cobalt model catalyst under reaction conditions. We show that, after 30 minutes of reaction, the terraces of the cobalt catalyst are covered by parallel arrays of stripes. We propose that the stripes are formed by the self-assembly of linear hydrocarbon product molecules. Surprisingly, the width of the stripes corresponds to molecules that are 14 or 15 carbon atoms long. We introduce a simple model that explains the accumulation of such long molecules by describing their monomer-by-monomer synthesis and explicitly accounting for their thermal desorption.

  2. Assessment of atmospheric distribution of polychlorinated biphenyls and polycyclic aromatic hydrocarbons using polyparameter model

    Directory of Open Access Journals (Sweden)

    Turk-Sekulić Maja M.

    2011-01-01

    Full Text Available Results of partial or total destruction of industrial plants, military targets, infrastructure, uncontrolled fires and explosions during the conflict period from 1991 to 1999, at the area of Western Balkans, were large amounts of hazardous organic matter that have been generated and emitted in the environment. In order to assess gas/particle partition of seven EPA polychlorinated biphenyls and sixteen EPA polycyclic aromatic hydrocarbons, twenty air samples have been collected at six urban, industrial and highly contaminated localities in Vojvodina. Hi-Vol methodology has been used for collecting ambiental air samples, that simultaneously collects gaseous and particulate phase with polyurethane foam filters (PUF and glass fiber filters (GFF. PUF and GFF filters have been analyzed, and concentration levels of gaseous PCBs and PAHs molecules in gaseous and particulate phase were obtained, converted and expressed through fraction of individual compounds sorbed onto particulate phase of the sample, in total detected quantity. Experimentally gained gas/particle partitioning values of PCBs and PAHs molecules have been compared with PP-LFER model estimated values. Significant deviation has been noticed during comparative analysis of estimated polyparameter model values for complete set of seven PCBs congeners. Much better agreement of experimental and estimated values is for polycyclic aromatic hydrocarbons, especially for molecules with four rings. These results are in a good correlation with literature data where polyparameter model has been used for predicting gas/particle partition of studied group of organic molecules.

  3. Propane decomposition and conversion into other hydrocarbons using metal target assisted laser induced plasma

    Science.gov (United States)

    Moosakhani, A.; Parvin, P.; Reyhani, A.; Mortazavi, S. Z.

    2017-01-01

    It is shown that the propane molecules are strongly decomposed in the metal assisted laser induced plasma based on the nano-catalytic adsorption. A Q-Switched Nd:YAG laser is employed to irradiate the propane gas filled in the control chamber in the presence of the reactive metals such as Ni, Fe, Pd, and Cu in order to study the effect of catalysts during the decomposition. The catalytic targets simultaneously facilitate the plasma formation and the decomposition events leading to generate a wide distribution of the light and heavy hydrocarbon molecules, mainly due to the recombination processes. Fourier transform infrared spectroscopy and gas chromatography instruments support the findings by detecting the synthetic components. Furthermore, the optical emission spectroscopy of the laser induced plasma emissions realizes the real time monitoring of the reactions taking place during each laser shot. The subsequent recombination events give rise to the generation of a variety of the hydrocarbon molecules. The dissociation rate, conversion ratio, selectivity, and yield as well as the performance factor arise mainly from the catalytic effects of the metal species. Moreover, the ablation rate of the targets of interest is taken into account as a measure of the catalytic reactivity due to the abundance of the metal species ablated from the target. This leads to assess the better performance factor for Pd among four metal catalysts of interest during propane decomposition. Finally, the molecules such as ethane and ethylene are identified as the stable abundant species created during the successive molecular recombination processes.

  4. Final technical report for the Center for Catalytic Hydrocarbon Functionalization (an EFRC)

    Energy Technology Data Exchange (ETDEWEB)

    Gunnoe, Thomas Brent [Univ. of Virginia, Charlottesville, VA (United States)

    2016-11-11

    Greater than 95% of all materials produced by the chemical industry are derived from a small slate of simple hydrocarbons that are derived primarily from natural gas and petroleum, predominantly through oxygenation, C–C bond formation, halogenation or amination. Yet, current technologies for hydrocarbon conversion are typically high temperature, multi-step processes that are energy and capital intensive and result in excessive emissions (including carbon dioxide). The Center for Catalytic Hydrocarbon Functionalization (CCHF) brought together research teams with the broad coalition of skills and knowledge needed to make the fundamental advances in catalysis required for next-generation technologies to convert hydrocarbons (particularly light alkanes and methane) at high efficiency and low cost. Our new catalyst technologies offer many opportunities including enhanced utilization of natural gas in the transportation sector (via conversion to liquid fuels), more efficient generation of electricity from natural gas using direct methane fuel cells, reduced energy consumption and waste production for large petrochemical processes, and the preparation of high value molecules for use in biological/medical applications or the agricultural sector. The five year collaborative project accelerated fundamental understanding of catalyst design for the conversion of C–H bonds to functionalized products, essential to achieve the goals listed above, as evidenced by the publication of 134 manuscripts. Many of these fundamental advancements provide a foundation for potential commercialization, as evidenced by the submission of 11 patents from research support by the CCHF.

  5. Optimization of the OPLS-AA Force Field for Long Hydrocarbons.

    Science.gov (United States)

    Siu, Shirley W I; Pluhackova, Kristyna; Böckmann, Rainer A

    2012-04-10

    The all-atom optimized potentials for liquid simulations (OPLS-AA) force field is a popular force field for simulating biomolecules. However, the current OPLS parameters for hydrocarbons developed using short alkanes cannot reproduce the liquid properties of long alkanes in molecular dynamics simulations. Therefore, the extension of OPLS-AA to (phospho)lipid molecules required for the study of biological membranes was hampered in the past. Here, we optimized the OPLS-AA force field for both short and long hydrocarbons. Following the framework of the OPLS-AA parametrization, we refined the torsional parameters for hydrocarbons by fitting to the gas-phase ab initio energy profiles calculated at the accurate MP2/aug-cc-pVTZ theory level. Additionally, the depth of the Lennard-Jones potential for methylene hydrogen atoms was adjusted to reproduce the densities and the heats of vaporization of alkanes and alkenes of different lengths. Optimization of partial charges finally allowed to reproduce the gel-to-liquid-phase transition temperature for pentadecane and solvation free energies. It is shown that the optimized parameter set (L-OPLS) yields improved hydrocarbon diffusion coefficients, viscosities, and gauche-trans ratios. Moreover, its applicability for lipid bilayer simulations is shown for a GMO bilayer in its liquid-crystalline phase.

  6. Multimedia model for polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs in Lake Michigan.

    Science.gov (United States)

    Huang, Lei; Batterman, Stuart A

    2014-12-02

    Polycyclic aromatic hydrocarbon (PAH) contamination in the U.S. Great Lakes has long been of concern, but information regarding the current sources, distribution, and fate of PAH contamination is lacking, and very little information exists for the potentially more toxic nitro-derivatives of PAHs (NPAHs). This study uses fugacity, food web, and Monte Carlo models to examine 16 PAHs and five NPAHs in Lake Michigan, and to derive PAH and NPAH emission estimates. Good agreement was found between predicted and measured PAH concentrations in air, but concentrations in water and sediment were generally under-predicted, possibly due to incorrect parameter estimates for degradation rates, discharges to water, or inputs from tributaries. The food web model matched measurements of heavier PAHs (≥5 rings) in lake trout, but lighter PAHs (≤4 rings) were overpredicted, possibly due to overestimates of metabolic half-lives or gut/gill absorption efficiencies. Derived PAH emission rates peaked in the 1950s, and rates now approach those in the mid-19th century. The derived emission rates far exceed those in the source inventories, suggesting the need to reconcile differences and reduce uncertainties. Although additional measurements and physiochemical data are needed to reduce uncertainties and for validation purposes, the models illustrate the behavior of PAHs and NPAHs in Lake Michigan, and they provide useful and potentially diagnostic estimates of emission rates.

  7. Sedimentary records of polycyclic aromatic hydrocarbons (PAHs) in remote lakes across the Tibetan Plateau.

    Science.gov (United States)

    Yang, Ruiqiang; Xie, Ting; Li, An; Yang, Handong; Turner, Simon; Wu, Guangjian; Jing, Chuanyong

    2016-07-01

    Sediment cores from five lakes across the Tibetan Plateau were used as natural archives to study the time trends of polycyclic aromatic hydrocarbons (PAHs). The depositional flux of PAHs generally showed an increasing trend from the deeper layers towards the upper layer sediments. The fluxes of PAHs were low with little variability before the 1950s, and then gradually increased to the late 1980s, with a faster increasing rate after the 1990s. This temporal pattern is clearly different compared with those remote lakes across the European mountains when PAHs started to decrease during the period 1960s-1980s. The difference of the temporal trend was attributed to differences in the economic development stages and energy structure between these regions. PAHs are dominated by the lighter 2&3-ring homologues with the averaged percentage over 87%, while it is notable that the percentage of heavier 4-6 ring PAHs generally increased in recent years, which suggests the contribution of local high-temperature combustion sources becoming more predominant.

  8. Removal of polycyclic aromatic hydrocarbons (PAHs) from inorganic clay mineral: Bentonite.

    Science.gov (United States)

    Karaca, Gizem; Baskaya, Hüseyin S; Tasdemir, Yücel

    2016-01-01

    There has been limited study of the removal of polycyclic aromatic hydrocarbons (PAHs) from inorganic clay minerals. Determining the amount of PAH removal is important in predicting their environmental fate. This study was carried out to the degradation and evaporation of PAHs from bentonite, which is an inorganic clay mineral. UV apparatus was designed specifically for the experiments. The impacts of temperature, UV, titanium dioxide (TiO2), and diethylamine (DEA) on PAH removal were determined. After 24 h, 75 and 44 % of ∑12 PAH in the bentonite were removed with and without UV rays, respectively. DEA was more effective as a photocatalyst than TiO2 during UV application. The ∑12 PAH removal ratio reached 88 % with the addition of DEA to the bentonite. It was concluded that PAHs were photodegraded at high ratios when the bentonite samples were exposed to UV radiation in the presence of a photocatalyst. At the end of all the PAH removal applications, higher evaporation ratios were obtained for 3-ring compounds than for heavier ones. More than 60 % of the amount of ∑12 PAH evaporated consisted of 3-ring compounds.

  9. Polycyclic aromatic hydrocarbons in sediments and mussels of the western Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Baumard, P.; Budzinski, H.; Garrigues, P. [Univ. Bordeaux I, Talence (France)

    1998-05-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) has been investigated in superficial sediments and mussels (Mytilus galloprovincialis) of the western Mediterranean sea. The analyses were performed by gas chromatography coupled to mass spectrometry (GC-MS). The PAH concentrations ranged from 1 to 20,500 ng/g in the sediments. Different molecular indices allowed differentiation between the different pollutant sources. On the French coast, PAHs originated mainly from incomplete combustion of organic matter (pyrolytic origin), whereas for some sites in Corsica and Sardinia an overimposition of petrogenic PAHs occurred. The mussel PAH concentrations ranged from 25 to 390 ng/g. The total and individual PAH bioaccumulation factors were calculated. The correlation between sediment and mussel PAH content was discussed in terms of bioavailability. It was possible to distinguish different absorption routes for the xenobiotics according to their physicochemical properties. Because the mussel distribution of phenanthrene and anthracene seems to be governed by their water solubility, these compounds were probably mainly absorbed as the water-dissolved form, whereas the heavier molecular weight PAHs (more than four aromatic rings), whose sediment and mussel concentrations are correlated with higher correlation coefficients than for phenanthrene and anthracene, were probably mainly absorbed as adsorbed on particles. Furthermore, a possible preferential biotransformation of benzo[a]pyrene over benzo[e]pyrene is discussed.

  10. Exploring the Framework Hydrophobicity and Flexibility of ZIF-8: From Biofuel Recovery to Hydrocarbon Separations

    KAUST Repository

    Zhang, Ke

    2013-11-07

    The framework hydrophobicity and flexibility of ZIF-8 are investigated by a detailed adsorption and diffusion study of a series of probe molecules including ethanol, 1-butanol, water, hexane isomers, xylene isomers, and 1,2,4-trimethylbenzene. The prospects for using ZIF-8 in biofuel recovery and hydrocarbon separations are discussed in terms of adsorption or kinetic selectivities. ZIF-8 shows extremely low water vapor uptakes and is especially suitable for vapor phase butanol-based biofuel recovery. The extraordinary framework flexibility of ZIF-8 is demonstrated by the adsorption of hydrocarbon molecules that are much larger than its nominal pore size, such as m-xylene, o-xylene and 1,2,4-trimethylbenzene. The calculation of corrected diffusion coefficients reveals an interesting spectrum of promising kinetic hydrocarbon separations by ZIF-8. These findings confirm that a molecular sieving effect tends to occur in the sorbate molecular size range of 4-6 Å rather than around the nominal ZIF-8 pore size of 3.4 Å, due to its surprising framework flexibility. © 2013 American Chemical Society.

  11. 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.

  12. Foaming of mixtures of pure hydrocarbons

    Science.gov (United States)

    Robinson, J. V.; Woods, W. W.

    1950-01-01

    Mixtures of pure liquid hydrocarbons are capable of foaming. Nine hydrocarbons were mixed in pairs, in all possible combinations, and four proportions of each combination. These mixtures were sealed in glass tubes, and the foaming was tested by shaking. Mixtures of aliphatic with other aliphatic hydrocarbons, or of alkyl benzenes with other alkyl benzenes, did not foam. Mixtures of aliphatic hydrocarbons with alkyl benzenes did foam. The proportions of the mixtures greatly affected the foaming, the maximum foaming of 12 of 20 pairs being at the composition 20 percent aliphatic hydrocarbon, 80 percent alkyl benzene. Six seconds was the maximum foam lifetime of any of these mixtures. Aeroshell 120 lubricating oil was fractionated into 52 fractions and a residue by extraction with acetone in a fractionating extractor. The index of refraction, foam lifetime, color, and viscosity of these fractions were measured. Low viscosity and high index fractions were extracted first. The viscosity of the fractions extracted rose and the index decreased as fractionation proceeded. Foam lifetimes and color were lowest in the middle fractions. Significance is attached to the observation that none of the foam lifetimes of the fractions or residue is as high as the foam lifetime of the original Aeroshell, indicating that the foaming is not due to a particular foaming constituent, but rather to the entire mixture.

  13. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, Mary J.; Dutta, Abhijit; Jones, Susanne B.; Meyer, Pimphan A.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This pathway case investigates the upgrading of 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 risk adverse 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 blendstocks.

  14. Velocity Dependence of Friction of Confined Hydrocarbons

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

    2010-01-01

    We present molecular dynamics friction calculations for confined hydrocarbon “polymer” solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate and (b) polymer sliding on polymer. We discuss the velocity dependence of the f......We present molecular dynamics friction calculations for confined hydrocarbon “polymer” solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate and (b) polymer sliding on polymer. We discuss the velocity dependence...... in the polymer film is always close to the thermostat temperature. In the first setup (a), for hydrocarbons with molecular lengths from 60 to 1400 carbon atoms, the shear stresses are nearly independent of molecular length, but for the shortest hydrocarbon C20H42 the frictional shear stress is lower. In all...... cases the frictional shear stress increases monotonically with the sliding velocity. For polymer sliding on polymer (case b) the friction is much larger, and the velocity dependence is more complex. For hydrocarbons with molecular lengths from 60 to 140 C atoms, the number of monolayers of lubricant...

  15. Threshold Energies for Single Carbon Knockout from Polycyclic Aromatic Hydrocarbons

    CERN Document Server

    Stockett, M H; Chen, T; de Ruette, N; Giacomozzi, L; Wolf, M; Schmidt, H T; Zettergren, H; Cederquist, H

    2015-01-01

    We have measured absolute cross sections for ultrafast (fs) single-carbon knockout from Polycyclic Aromatic Hydrocarbon (PAH) cations as functions of He-PAH center-of-mass collision energy in the range 10-200 eV. Classical Molecular Dynamics (MD) simulations cover this range and extend up to 10$^5$ eV. The shapes of the knockout cross sections are well described by a simple analytical expression yielding experimental and MD threshold energies of $E_{th}^{Exp}=32.5\\pm 0.4$ eV and $E_{th}^{MD}=41.0\\pm 0.3$ eV, respectively. These are the first measurements of knockout threshold energies for molecules isolated \\emph{in vacuo}. We further deduce semi-empirical (SE) and MD displacement energies --- \\emph{i.e.} the energy transfers to the PAH molecules at the threshold energies for knockout --- of $T_{disp}^{SE}=23.3\\pm 0.3$ eV and $T_{disp}^{MD}=27.0\\pm 0.3$ eV. The semi-empirical results compare favorably with measured displacement energies for graphene $T_{disp}=23.6$ eV [Meyer \\emph{et al.} Phys. Rev Lett. \\tex...

  16. Breakdown of interference rules in azulene, a nonalternant hydrocarbon.

    Science.gov (United States)

    Xia, Jianlong; Capozzi, Brian; Wei, Sujun; Strange, Mikkel; Batra, Arunabh; Moreno, Jose R; Amir, Roey J; Amir, Elizabeth; Solomon, Gemma C; Venkataraman, Latha; Campos, Luis M

    2014-05-14

    We have designed and synthesized five azulene derivatives containing gold-binding groups at different points of connectivity within the azulene core to probe the effects of quantum interference through single-molecule conductance measurements. We compare conducting paths through the 5-membered ring, 7-membered ring, and across the long axis of azulene. We find that changing the points of connectivity in the azulene impacts the optical properties (as determined from UV-vis absorption spectra) and the conductivity. Importantly, we show here that simple models cannot be used to predict quantum interference characteristics of nonalternant hydrocarbons. As an exemplary case, we show that azulene derivatives that are predicted to exhibit destructive interference based on widely accepted atom-counting models show a significant conductance at low biases. Although simple models to predict the low-bias conductance do not hold with all azulene derivatives, we demonstrate that the measured conductance trend for all molecules studied actually agrees with predictions based on the more complete GW calculations for model systems.

  17. Molecules in crystals

    Science.gov (United States)

    Spackman, Mark A.

    2013-04-01

    Hirshfeld surface analysis has developed from the serendipitous discovery of a novel partitioning of the crystal electron density into discrete molecular fragments, to a suite of computational tools used widely for the identification, analysis and discussion of intermolecular interactions in molecular crystals. The relationship between the Hirshfeld surface and very early ideas on the internal structure of crystals is outlined, and applications of Hirshfeld surface analysis are presented for three molecules of historical importance in the development of modern x-ray crystallography: hexamethylbenzene, hexamethylenetetramine and diketopiperazine.

  18. Paleozoic Hydrocarbon-Seep Limestones

    Science.gov (United States)

    Peckmann, J.

    2007-12-01

    To date, five Paleozoic hydrocarbon-seep limestones have been recognized based on carbonate fabrics, associated fauna, and stable carbon isotopes. These are the Middle Devonian Hollard Mound from the Antiatlas of Morocco [1], Late Devonian limestone lenses with the dimerelloid brachiopod Dzieduszyckia from the Western Meseta of Morocco [2], Middle Mississippian limestones with the dimerelloid brachiopod Ibergirhynchia from the Harz Mountains of Germany [3], Early Pennsylvanian limestones from the Tantes Mound in the High Pyrenees of France [4], and Late Pennsylvanian limestone lenses from the Ganigobis Shale Member of southern Namibia [5]. Among these examples, the composition of seepage fluids varied substantially as inferred from delta C-13 values of early diagenetic carbonate phases. Delta C-13 values as low as -50 per mil from the Tantes Mound and -51 per mil from the Ganigobis limestones reveal seepage of biogenic methane, whereas values of -12 per mil from limestones with Dzieduszyckia associated with abundant pyrobitumen agree with oil seepage. Intermediate delta C-13 values of carbonate cements from the Hollard Mound and Ibergirhynchia deposits probably reflect seepage of thermogenic methane. It is presently very difficult to assess the faunal evolution at seeps in the Paleozoic based on the limited number of examples. Two of the known seeps were typified by extremely abundant rhynchonellide brachiopods of the superfamily Dimerelloidea. Bivalve mollusks and tubeworms were abundant at two of the known Paleozoic seep sites; one was dominated by bivalve mollusks (Hollard Mound, Middle Devonian), another was dominated by tubeworms (Ganigobis Shale Member, Late Pennsylvanian). The tubeworms from these two deposits are interpreted to represent vestimentiferan worms, based on studies of the taphonomy of modern vestimentiferans. However, this interpretation is in conflict with the estimated evolutionary age of vestimentiferans based on molecular clock methods

  19. An analytical method of predicting Lee-Kesler-Ploecker binary interaction coefficients: Part 1, For non-polar hydrocarbon mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sand, J.R.

    1994-12-31

    An analytical method is proposed for finding numerical values of binary interaction coefficients for non-polar hydrocarbon mixtures when the Lee-Kesler (LK) equation of state is applied. The method is based on solving simultaneous equations, which are Ploecker`s mixing rules for pseudocritical parameters of a mixture, and the Lee-Kesler equation for the saturation line. For a hydrocarbon mixture, the method allows prediction of {kappa}{sub ij} interaction coefficients (ICs) which are close to values obtained by processing experimental p-v-t data on the saturation line and subsequent averaging. For mixtures of hydrocarbon molecules containing from 2 to 9 carbon atoms, the divergence between calculated and experimentally based ICs is no more than {plus_minus}0.4%. The possibility of extending application of this method to other non-polar substances is discussed.

  20. Spatially Resolved 3 um Spectroscopy of IRAS 22272+5435 Formation and Evolution of Aliphatic Hydrocarbon Dust in Proto-Planetary Nebula

    CERN Document Server

    Goto, M; Hayano, Y; Iye, M; Kamata, Y; Kanzawa, T; Kobayashi, N; Minowa, Y; Saint-Jacques, D J; Takami, H; Takato, N; Terada, H

    2003-01-01

    We present medium-resolution 3 um spectroscopy of the carbon-rich proto-planetary nebula IRAS 22272+5435. Spectroscopy with the Subaru Telescope adaptive optics system revealed a spatial variation of hydrocarbon molecules and dust surrounding the star. The ro-vibrational bands of acetylene (C2H2) and hydrogen cyanide (HCN) at 3.0 um are evident in the central star spectra. The molecules are concentrated in the compact region near the center. The 3.3 and 3.4 um emission of aromatic and aliphatic hydrocarbons is detected at 600--1300 AU from the central star. The separation of spatial distribution between gas and dust suggests that the small hydrocarbon molecules are indeed the source of solid material, and that the gas leftover from the grain formation is being observed near the central star. The intensity of aliphatic hydrocarbon emission relative to the aromatic hydrocarbon emission decreases with distance from the central star. The spectral variation is well matched to that of a laboratory analog thermally ...

  1. Electrochemical Routes towards Sustainable Hydrocarbon Fuels

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg

    2012-01-01

    The potential of renewable energy and possible solution to the intermittency problem of renewable energy sources like sun and wind are explained. The densest storage of energy is in the form of hydrocarbons. The most suitable method of conversion and storage within a foreseeable future is electro......The potential of renewable energy and possible solution to the intermittency problem of renewable energy sources like sun and wind are explained. The densest storage of energy is in the form of hydrocarbons. The most suitable method of conversion and storage within a foreseeable future...... is electrolysis followed by conversion into synthetic hydrocarbons, alcohols or ethers. Several types of electrolysers exist. The various types are listed together with a short description of principle and status. It is argued that electrolysis will at least become part of large sustainable energy systems...

  2. 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.

    2015-05-01

    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 (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.

  3. 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.

  4. Hydrocarbon Degrading Bacteria: Isolation and Identification

    Directory of Open Access Journals (Sweden)

    Lies Indah Sutiknowati

    2007-11-01

    Full Text Available There is little information how to identify hydrocarbon degrading bacteria for bioremediation of marine oil spills. We have used gravel which contaminated oil mousse from Beach Simulator Tank, in Marine Biotechnology Institute, Kamaishi, Japan, and grown on enrichment culture. Biostimulation with nutrients (N and P was done to analyze biodegradation of hydrocarbon compounds: Naphthalene, Phenanthrene, Trichlorodibenzofuran and Benzo[a]pyrene. Community of bacteria from enrichment culture was determined by DGGE. Isolating and screening the bacteria on inorganic medium contain hydrocarbon compounds and determination of bacteria by DAPI (number of cells and CFU. DNA was extracted from colonies of bacteria and sequence determination of the 16S rDNA was amplified by primers U515f and U1492r. Twenty nine strains had been sequence and have similarity about 90-99% to their closest taxa by homology Blast search and few of them have suspected as new species.

  5. Using supercritical fluids to refine hydrocarbons

    Science.gov (United States)

    Yarbro, Stephen Lee

    2014-11-25

    This is a method to reactively refine hydrocarbons, such as heavy oils with API gravities of less than 20.degree. and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure using a selected fluid at supercritical conditions. The reaction portion of the method delivers lighter weight, more volatile hydrocarbons to an attached contacting device that operates in mixed subcritical or supercritical modes. This separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques. This method produces valuable products with fewer processing steps, lower costs, increased worker safety due to less processing and handling, allow greater opportunity for new oil field development and subsequent positive economic impact, reduce related carbon dioxide, and wastes typical with conventional refineries.

  6. Mixed Quantum/Classical Theory for Molecule-Molecule Inelastic Scattering: Derivations of Equations and Application to N2 + H2 System.

    Science.gov (United States)

    Semenov, Alexander; Babikov, Dmitri

    2015-12-17

    The mixed quantum classical theory, MQCT, for inelastic scattering of two molecules is developed, in which the internal (rotational, vibrational) motion of both collision partners is treated with quantum mechanics, and the molecule-molecule scattering (translational motion) is described by classical trajectories. The resultant MQCT formalism includes a system of coupled differential equations for quantum probability amplitudes, and the classical equations of motion in the mean-field potential. Numerical tests of this theory are carried out for several most important rotational state-to-state transitions in the N2 + H2 system, in a broad range of collision energies. Besides scattering resonances (at low collision energies) excellent agreement with full-quantum results is obtained, including the excitation thresholds, the maxima of cross sections, and even some smaller features, such as slight oscillations of energy dependencies. Most importantly, at higher energies the results of MQCT are nearly identical to the full quantum results, which makes this approach a good alternative to the full-quantum calculations that become computationally expensive at higher collision energies and for heavier collision partners. Extensions of this theory to include vibrational transitions or general asymmetric-top rotor (polyatomic) molecules are relatively straightforward.

  7. Knockout driven reactions in complex molecules and their clusters

    Science.gov (United States)

    Gatchell, Michael; Zettergren, Henning

    2016-08-01

    Energetic ions lose some of their kinetic energy when interacting with electrons or nuclei in matter. Here, we discuss combined experimental and theoretical studies on such impulse driven reactions in polycyclic aromatic hydrocarbons (PAHs), fullerenes, and pure or mixed clusters of these molecules. These studies show that the nature of excitation is important for how complex molecular systems respond to ion/atom impact. Rutherford-like nuclear scattering processes may lead to prompt atom knockout and formation of highly reactive fragments, while heating of the molecular electron clouds in general lead to formation of more stable and less reactive fragments. In this topical review, we focus on recent studies of knockout driven reactions, and present new calculations of the angular dependent threshold (displacement) energies for such processes in PAHs. The so-formed fragments may efficiently form covalent bonds with neighboring molecules in clusters. These unique molecular growth processes may be important in astrophysical environments such as low velocity shock waves.

  8. Ultra-cold molecule production.

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Serrano, Jamie; Chandler, David W.; Strecker, Kevin; Rahn, Larry A.

    2005-12-01

    The production of Ultra-cold molecules is a goal of many laboratories through out the world. Here we are pursuing a unique technique that utilizes the kinematics of atomic and molecular collisions to achieve the goal of producing substantial numbers of sub Kelvin molecules confined in a trap. Here a trap is defined as an apparatus that spatially localizes, in a known location in the laboratory, a sample of molecules whose temperature is below one degree absolute Kelvin. Further, the storage time for the molecules must be sufficient to measure and possibly further cool the molecules. We utilize a technique unique to Sandia to form cold molecules from near mass degenerate collisions between atoms and molecules. This report describes the progress we have made using this novel technique and the further progress towards trapping molecules we have cooled.

  9. High-temperature two-dimensional gas chromatography of hydrocarbons up to nC60 for analysis of vacuum gas oils.

    Science.gov (United States)

    Dutriez, Thomas; Courtiade, Marion; Thiébaut, Didier; Dulot, Hugues; Bertoncini, Fabrice; Vial, Jérôme; Hennion, Marie-Claire

    2009-04-03

    In a tense energetic context, the characterization of heavy petroleum fractions becomes essential. Conventional comprehensive two-dimensional gas chromatography (2D-GC or GCxGC) is widely used for middle distillates analysis, but only a few applications are devoted to these heavier fractions. In this paper, it is shown how the optimization of GCxGC separation allowed the determination of suitable high-temperature (HT) conditions, adjusting column properties and operating conditions. 2D separations were evaluated using 2D separation criteria and a new concept of 2D asymmetry (As(2D)). New HT conditions allowed the extension of GCxGC range of applications to heavier hydrocarbons, up to nC(60). A first application of high-temperature two-dimensional gas chromatography (HT-2D-GC) to a full vacuum gas oil (VGO) feed stock is described. Comparisons with other standardized methods illustrate the high potential of HT-2D-GC for heavy fractions analysis.

  10. Bioremediation of Petroleum Hydrocarbon Contaminated Sites

    Energy Technology Data Exchange (ETDEWEB)

    Fallgren, Paul

    2009-03-30

    Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop a biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for this site soil. Artificial sea water had little effect on biodegradation rates, but biodegradation rates decreased after increasing the concentrations of salts. Biotreatment cell (biocell) tests demonstrated hydrocarbon biodegradation can be enhanced substantially when utilizing a leachate recirculation design where a 72% reduction of hydrocarbon concentration was observed with a 72-h period at a treatment temperature of 50 C. Overall, this study demonstrates the investigation of the effects of

  11. Structural Effects of Small Molecules on Phospholipid Bilayers Investigated by Molecular Simulations

    CERN Document Server

    Lee, B W; Sum, A K; Vattulainen, I; Patra, M; Karttunen, M; Lee, Bryan W; Faller, Roland; Sum, Amadeu K; Vattulainen, Ilpo; Patra, Michael; Karttunen, Mikko

    2004-01-01

    We summarize and compare recent Molecular Dynamics simulations on the interactions of dipalmitoylphosphatidylcholine (DPPC) bilayers in the liquid crystalline phase with a number of small molecules including trehalose, a disaccharide of glucose, alcohols, and dimethylsulfoxide (DMSO). The sugar molecules tend to stabilize the structure of the bilayer as they bridge adjacent lipid headgroups. They do not strongly change the structure of the bilayer. Alcohols and DMSO destabilize the bilayer as they increase its area per molecule in the bilayer plane and decrease the order parameter. Alcohols have a stronger detrimental effect than DMSO. The observables which we compare are the area per molecule in the plane of the bilayer, the membrane thickness, and the NMR order parameter of DPPC hydrocarbon tails. The area per molecule and the order parameter are very well correlated whereas the bilayer thickness is not necessarily correlated with them.

  12. Coherent Coupling of a Single Molecule to a Scanning Fabry-Perot Microcavity

    Directory of Open Access Journals (Sweden)

    Daqing Wang

    2017-04-01

    Full Text Available Organic dye molecules have been used in a great number of scientific and technological applications, but their wider use in quantum optics has been hampered by transitions to short-lived vibrational levels, which limit their coherence properties. To remedy this, one can take advantage of optical resonators. Here, we present the first results on coherent molecule-resonator coupling, where a single polycyclic aromatic hydrocarbon molecule extinguishes 38% of the light entering a microcavity at liquid helium temperature. We also demonstrate fourfold improvement of single-molecule stimulated emission compared to free-space focusing and take first steps for coherent mechanical manipulation of the molecular transition. Our approach of coupling molecules to an open and tunable microcavity with a very low mode volume and moderately low quality factors of the order of 10^{3} paves the way for the realization of nonlinear and collective quantum optical effects.

  13. Light Hydrocarbons Adsorption Mechanisms in Two Calcium-based Microporous Metal Organic Frameworks

    KAUST Repository

    Plonka, Anna M.

    2016-01-25

    The adsorption mechanism of ethane, ethylene and acetylene (C2Hn; n=2, 4, 6) on two microporous metal organic frameworks (MOFs) is described here that is consistent with observations from single crystal and powder X-ray diffraction, calorimetric measurments and gas adsorption isotherm measurements. Two calcium-based MOFs, designated as SBMOF-1 and SBMOF-2 (SB: Stony Brook), form three-dimensional frameworks with one-dimensional open channels. As determined form single crystal diffraction experiments channel geometries of both SBMOF-1 and SBMOF-2 provide multiple adsorption sites for hydrocarbon molecules trough C-H…π and C-H…O interactions, similarly to interactions in the molecular and protein crystals. Both materials selectively adsorb C2 hydrocarbon gases over methane as determined with IAST and breakthrough calculations, with C2H6/CH4 selectivity as high as 74 in SBMOF-1.

  14. Biological remediation of petroleum hydrocarbons from a refinery's soil : comparison of different technologies

    Energy Technology Data Exchange (ETDEWEB)

    Nazare Couto, M.; Vasconcelos, T.S.D. [CIMAR/CIIMAR, Porto (Portugal)

    2007-07-01

    This presentation discussed bioremediation methods used at a refinery in Portugal with a high distillation capacity. The aim of the project was to develop a method for restoring contaminated sites using rhizoremediation and bio-augmentation. Hydrocarbon molecules were tightly sorbed to the soil particles at the refinery. Plants used in the bioremediation project included Scirpus maritimus and Juncus maritimus, as well as Cortoaderia selloana taken from an estuary near the refinery. Tests were conducted both with, and without the use of microorganisms. Commercial bio-augmentation products were used. Plant growth was evaluated for a period of 64 days. It was concluded that the technology is cheaper than many traditional methods of treating hydrocarbon-contaminated soils. tabs., figs.

  15. The presence of hydrocarbons in southeast Norway

    DEFF Research Database (Denmark)

    Hanken, Niels Martin; Hansen, Malene Dolberg; Kresten Nielsen, Jesper

    Hydrocarbons, mostly found as solid pyrobitumen, are known from more than 30 localities in southeast Norway. They occur as inclusions in a wide range of "reservoir rocks" spanning from Permo-Carboniferous breccias to veins (vein quartz and calcite veins) in Precambrian granites, gneisses and amph......Hydrocarbons, mostly found as solid pyrobitumen, are known from more than 30 localities in southeast Norway. They occur as inclusions in a wide range of "reservoir rocks" spanning from Permo-Carboniferous breccias to veins (vein quartz and calcite veins) in Precambrian granites, gneisses...

  16. Mathematics of Periodic Tables for Benzenoid Hydrocarbons.

    Science.gov (United States)

    Dias, Jerry Ray

    2007-01-01

    The upper and lower bounds for invariants of polyhex systems based on the Harary and Harborth inequalities are studied. It is shown that these invariants are uniquely correlated by the Periodic Table for Benzenoid Hydrocarbons. A modified periodic table for total resonant sextet (TRS) benzenoids based on the invariants of Ds and r(empty) is presented; Ds is the number of disconnections among the empty rings for fused TRS benzenoid hydrocarbons. This work represents a contribution toward deciphering the topological information content of benzenoid formulas.

  17. Electrochemical removal of NOx and hydrocarbons

    DEFF Research Database (Denmark)

    Friedberg, Anja Zarah

    on the electrodes during polarisation, probably because of strong adsorption of the hydrocarbon relative to NO. On LSF/CGO electrode the impregnation of ionic conducting material increased the oxidation of NO to NO2 which is an important step before nitrogen formation. The propene inhibited this reaction because....... This could only be done if the electrode was impregnated with BaO. The nitrate formation did not seem to be inhibited by the presence of the hydrocarbon. However, the oxidation of propene was inhibited by the BaO because the active sites for oxidations were partially covered by the BaO nanoparticles...

  18. Transferable Tight-Binding Potential for Hydrocarbons

    CERN Document Server

    Wang, Y; Wang, Yang

    1994-01-01

    A transferable tight-binding potential has been constructed for heteroatomic systems containing carbon and hydrogen. The electronic degree of freedom is treated explicitly in this potential using a small set of transferable parameters which has been fitted to small hydrocarbons and radicals. Transferability to other higher hydrocarbons were tested by comparison with ab initio calculations and experimental data. The potential can correctly reproduce changes in the electronic configuration as a function of the local bonding geometry around each carbon atom. This type of potential is well suited for computer simulations of covalently bonded systems in both gas-phase and condensed-phase systems.

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

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, Kristoffer

    2000-07-01

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

  20. Passing Current through Touching Molecules

    DEFF Research Database (Denmark)

    Schull, G.; Frederiksen, Thomas; Brandbyge, Mads

    2009-01-01

    The charge flow from a single C-60 molecule to another one has been probed. The conformation and electronic states of both molecules on the contacting electrodes have been characterized using a cryogenic scanning tunneling microscope. While the contact conductance of a single molecule between two...

  1. Molecules Best Paper Award 2013.

    Science.gov (United States)

    McPhee, Derek J

    2013-02-05

    Molecules has started to institute a "Best Paper" award to recognize the most outstanding papers in the area of natural products, medicinal chemistry and molecular diversity published in Molecules. We are pleased to announce the second "Molecules Best Paper Award" for 2013.

  2. The Calculation of Accurate Harmonic Frequencies of Large Molecules: The Polycyclic Aromatic Hydrocarbons, a Case Study

    Science.gov (United States)

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

    1996-01-01

    The vibrational frequencies and infrared intensities of naphthalene neutral and cation are studied at the self-consistent-field (SCF), second-order Moller-Plesset (MP2), and density functional theory (DFT) levels using a variety of one-particle basis sets. Very accurate frequencies can be obtained at the DFT level in conjunction with large basis sets if they are scaled with two factors, one for the C-H stretches and a second for all other modes. We also find remarkably good agreement at the B3LYP/4-31G level using only one scale factor. Unlike the neutral PAHs where all methods do reasonably well for the intensities, only the DFT results are accurate for the PAH cations. The failure of the SCF and MP2 methods is caused by symmetry breaking and an inability to describe charge delocalization. We present several interesting cases of symmetry breaking in this study. An assessment is made as to whether an ensemble of PAH neutrals or cations could account for the unidentified infrared bands observed in many astronomical sources.

  3. Polycyclic aromatic hydrocarbons as plausible prebiotic membrane components.

    Science.gov (United States)

    Groen, Joost; Deamer, David W; Kros, Alexander; Ehrenfreund, Pascale

    2012-08-01

    Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C(6)-C(10) fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane.

  4. Cuticular hydrocarbons and aggression in the termite Macrotermes subhyalinus.

    Science.gov (United States)

    Kaib, Manfred; Jmhasly, Patrick; Wilfert, Lena; Durka, Walter; Franke, Stephan; Francke, Wittko; Leuthold, Reinhard H; Brandl, Roland

    2004-02-01

    Cuticular hydrocarbons are among the prime candidates for nestmate recognition in social insects. We analyzed the variation of cuticular hydrocarbons in the termite species M. subhyalinus in West Africa (Comoë National Park) on a small spatial scale (recognition.

  5. Time-dependent models of dense PDRs with complex molecules

    CERN Document Server

    Morata, O

    2008-01-01

    We present a study of the chemistry of a dense photon-dominated region (PDR) using a time-dependent chemical model. Our major interest is to study the spatial distribution of complex molecules such as hydrocarbons and cyanopolyynes in the cool dense material bordering regions where star formation has taken place. Our standard model uses a homogeneous cloud of density 2x10e4 cm-3 and temperature T=40 K, which is irradiated by a far-ultraviolet radiation field of intermediate intensity, given by X=100. We find that over a range of times unsaturated hydrocarbons (e.g., C2H, C4H, C3H2) have relatively high fractional abundances in the more external layers of the PDR, whereas their abundances in the innermost layers are several orders of magnitudes lower. On the other hand, molecules that are typical of late-time chemistry are usually more abundant in the inner parts of the PDR. We also present results for models with different density, temperature, intensity of the radiation field and initial fractional abundance...

  6. The Paleobiosphere: a novel device for the in vivo testing of hydrocarbon producing-utilizing microorganisms.

    Science.gov (United States)

    Strobel, Gary; Booth, Eric; Schaible, George; Mends, Morgan Tess; Sears, Joe; Geary, Brad

    2013-04-01

    The construction and testing of a unique instrument, the Paleobiosphere, which mimics some of the conditions of the ancient earth, is described. The instrument provides an experimental testing system for determining if certain microbes, when provided an adequate environment, can degrade biological materials to produce fuel-like hydrocarbons in a relatively short time frame that become trapped by the shale. The conditions selected for testing included a particulate Montana shale (serving as the "Trap Shale"), plant materials (leaves and stems of three extant species whose origins are in the late Cretaceous), a water-circulating system, sterile air, and a specially designed Carbotrap through which all air was passed as exhaust and volatile were hydrocarbons trapped. The fungus for initial testing was Annulohypoxylon sp., isolated as an endophyte of Citrus aurantifolia. It produces, in solid and liquid media, a series of hydrocarbon-like molecules. Some of these including 1,8-cineole, 2-butanone, propanoic acid, 2-methyl-, methyl ester, benzene (1-methylethyl)-, phenylethyl alcohol, benzophenone and azulene, 1,2,3,5,6,7,8,8a-octahydro-1,4-dimethyl-7-(1-methylethenyl), [1S-(1α,7α,8aβ)]. These were the key signature compounds used in an initial Paleobiosphere test. After 3 weeks, incubation, the volatiles associated with the harvested "Trap Shale" included each of the signature substances as well as other fungal-associated products: some indanes, benzene derivatives, some cyclohexanes, 3-octanone, naphthalenes and others. The fungus thus produced a series of "Trap Shale" products that were representative of each of the major classes of hydrocarbons in diesel fuel (Mycodiesel). Initial tests with the Paleobiosphere offer some evidence for a possible origin of hydrocarbons trapped in bentonite shale. Thus, with modifications, numerous other tests can also be designed for utilization in the Paleobiosphere.

  7. Determination of Beeswax Hydrocarbons by Gas Chromatography with a Mass Detector (GC -MS Technique

    Directory of Open Access Journals (Sweden)

    Waś Ewa

    2014-06-01

    Full Text Available Here we describe a method of hydrocarbon (alkanes, alkenes, dienes identification and quantitative determination of linear saturated hydrocarbons (n-alkanes in beeswax using gas chromatography with a mass detector technique (GC -MS . Beeswax hydrocarbons were isolated using a solid-phase extraction (SPE technique with neutral aluminum oxide (Alumina - N, 1000 mg, 6 mL, then were separated on a non-polar gas chromatography column ZB-5HT INFERNO (20 m×0.18 mm×0.18 μm. Qquantitative analysis of n-alkanes was conducted by the method of internal standard with squalane used as the internal standard. The basic parameters of validation (linearity and working range, limit of determination, repeatability and reproducibility, recovery were determined. For all of the identified compounds, satisfactory (≥0.997 coefficients of correlation in the working ranges of the method (from 0.005 to 5.0 g/100 g were obtained. The elaborated method was characterized by satisfactory repeatability and within-laboratory reproducibility. The average coefficients of variation for the total n-alkanes did not exceed 2% under conditions of repeatability or 4% under conditions of reproducibility. The recovery for individual n-alkanes was above 94%; for their total content, it was 100.5%. In beeswax originating from Apis mellifera, n-alkanes containing from 20 to 35 carbon atoms in their molecules were determined. The total content of these alkanes was between 9.08 g and 10.86 g/100 g (on average, 9.81 g/100 g. Additionally, apart from the saturated hydrocarbons, unsaturated hydrocarbons and dienes were identified.

  8. Kinetic simulating experiment on the secondary hydrocarbon generation of kerogen

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The kinetic parameters of generation have been obtained for different hydrocarbon classes, including methane, C2-C5 gas hydrocarbons, C6-C13 light hydrocarbons and C13+ heavy hydrocarbons, and vitrinite reflectance (Ro) by the kinetic simulating experiment of kerogen cracking. Then, combined with the detailed geology of Sichuan Basin, the effective gas-generating intensity of the Lower Cambrian source rock is approximately estimated by applying these parameters.

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

    Science.gov (United States)

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

    2015-02-14

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

  10. Quantitative analysis of fuel-related hydrocarbons in surface water and wastewater samples by solid-phase microextraction.

    Science.gov (United States)

    Langenfeld, J J; Hawthorne, S B; Miller, D J

    1996-01-01

    Solid-phase microextraction (SPME) parameters were examined on water contaminated with hydrocarbons including benzene and alkylbenzenes, n-alkanes, and polycyclic aromatic hydrocarbons (PAHs). Absorption equilibration times ranged from several minutes for low molecular weight compounds such as benzene to 5 h for high molecular weight compounds such as benzo[a]pyrene. Under equilibrium conditions, SPME analysis with GC/FID was linear over 3-6 orders of magnitude, with linear correlation coefficients (r(2)) greater than 0.96. Experimentally determined FID detection limits ranged from ∼30 ppt (w/w hydrocarbon/sample water) for high molecular weight PAHs (e.g., MW > 202) to ∼1 ppb for low molecular weight aromatic hydrocarbons. Experimental distribution constants (K) were different with 100- and 7-μm poly(dimethylsiloxane) fibers, and poor correlations with previously published values suggest that K depends on the fiber coating thickness and the sorbent preparation method. The sensitivity of SPME analysis is not significantly enhanced by larger sample volumes, since increasing the water volume (e.g., from 1 to 100 mL) has little effect on the number of analyte molecules absorbed by the fiber, especially for compounds with K solids. Quantitative determinations of aromatic and aliphatic hydrocarbons (e.g., in gasoline-contaminated water) can be performed using GC/MS with deuterated internal standard or standard addition calibration as long as the target components or standards had unique ions for quantitation or sufficient chromatographic resolution from interferences. SPME analysis gave good quantitative performance with surface waters having high suspended sediment contents, as well as with coal gasification wastewater which contained matrix organics at 10(6)-fold higher concentrations than the target aromatic hydrocarbons. Good agreement was obtained between a 45-min SPME and methylene chloride extraction for the determination of PAH concentrations in creosote

  11. Modulation of fatty acids and hydrocarbons in Anabaena 7120 and its ntcA mutant under calcium.

    Science.gov (United States)

    Singh, Savita; Verma, Ekta; Tiwari, Balkrishna; Niveshika; Mishra, Arun Kumar

    2017-02-01

    Calcium being a signaling molecule and mediator of cell response, we examined the modulation in fatty acid and hydrocarbon profiles of wild type cyanobacterium Anabaena sp. PCC 7120 and its ntcA mutant under the influence of different calcium chloride concentrations (0-10 mM). Dynamic modifications in fatty acid and hydrocarbon profile were evident through GC-FID analysis of extracted lipids. In the wild type, increase in CaCl2 (10 mM) resulted in unsaturation of fatty acids (observed in terms of high MUFA/PUFA ratio) while hydrocarbon production was distinctly high in the mutant strain compared to wild type at all tested concentrations. The synthesis of short chain hydrocarbons (C5-C8) were dominated at inhibitory concentration (10 mM CaCl2) in mutant strain. Results suggest that the increase in MUFA/PUFA ratio at inhibitory concentration in wild type, and higher percentage of hydrocarbons in mutant strain, may be attributed to the survival and acclimation strategies under altered calcium environment. Our results also suggest the involvement of the ntcA gene (master regulator of N2 metabolism) in regulation of carbon metabolism; specifically fatty acid, hydrocarbon, and other metabolic compounds essential for maintenance and sustenance of growth under stress condition. Thus, our study outlines basic acclimation response along with possibilities of production of fatty acid and hydrocarbon derived biofuel and other bioactive compounds in Anabaena sp. PCC 7120 under altered calcium levels which could be of biotechnological interest.

  12. Lanthanide single molecule magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jinkui; Zhang, Peng [Chinese Academy of Sciences, Changchun (China). Changchun Inst. of Applied Chemistry

    2015-10-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures - an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and explore new directions.

  13. Astrochemistry and Interstellar Molecules

    Science.gov (United States)

    Minh, Y. C.

    2010-03-01

    Astrochemistry provides powerful tools to understand various cosmic phenomena, including those in our solar system to the large-scale structure of the universe. In addition, the chemical property of an astronomical body is a crucial factor which governs the evolution of the system. Recent progress in astrophysical theories, computational modelings, and observational techniques requires a detailed understanding of the interactions between the constituents of an astronomical system, which are atoms and molecules within the system. Especially the far-infrared/sub-millimeter wave range, which is called as the last frontier in astronomical observations, contains numerous molecular lines, which may provide a huge amount of new information. However, we need an astrochemical understanding to use this information fully. Although this review is very limited, I would like to stress the importance of astrochemical approach in this overview for the field, which is getting much more attention than ever before.

  14. Lanthanide single molecule magnets

    CERN Document Server

    Tang, Jinkui

    2015-01-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs, and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures – an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and...

  15. Forces in molecules.

    Science.gov (United States)

    Hernández-Trujillo, Jesús; Cortés-Guzmán, Fernando; Fang, De-Chai; Bader, Richard F W

    2007-01-01

    Chemistry is determined by the electrostatic forces acting within a collection of nuclei and electrons. The attraction of the nuclei for the electrons is the only attractive force in a molecule and is the force responsible for the bonding between atoms. This is the attractive force acting on the electrons in the Ehrenfest force and on the nuclei in the Feynman force, one that is countered by the repulsion between the electrons in the former and by the repulsion between the nuclei in the latter. The virial theorem relates these forces to the energy changes resulting from interactions between atoms. All bonding, as signified by the presence of a bond path, has a common origin in terms of the mechanics determined by the Ehrenfest, Feynman and virial theorems. This paper is concerned in particular with the mechanics of interaction encountered in what are classically described as 'nonbonded interactions'--are atoms that 'touch' bonded or repelling one another?

  16. Dicarboxylic acids with limited numbers of hydrocarbons stabilize cell membrane and increase osmotic resistance in rat erythrocytes.

    Science.gov (United States)

    Mineo, Hitoshi; Amita, Nozomi; Kawawake, Megumi; Higuchi, Ayaka

    2013-11-01

    We examined the effect of dicarboxylic acids having 0 to 6 hydrocarbons and their corresponding monocarboxylic or tricarboxylic acids in changing the osmotic fragility (OF) in rat red blood cells (RBCs). Malonic, succinic, glutaric and adipic acids, which are dicarboxylic acids with 1, 2, 3 and 4 straight hydrocarbons located between two carboxylic groups, decreased the OF in a concentration-dependent manner. Other long-chain dicarboxylic acids did not change the OF in rat RBCs. The benzoic acid derivatives, isophthalic and terephthalic acids, but not phthalic acid, decreased the OF in a concentration-dependent manner. Benzene-1,2,3-tricarboxylic acid, but not benzene-1,3,5-tricarboxylic acid, also decreased the OF in rat RBCs. On the other hand, monocarboxylic acids possessing 2 to 7 straight hydrocarbons and benzoic acid increased the OF in rat RBCs. In short-chain dicarboxylic acids, a limited number of hydrocarbons between the two carboxylic groups are thought to form a V- or U-shaped structure and interact with phospholipids in the RBC membrane. In benzene dicarboxylic and tricarboxylic acids, a part of benzene nucleus between the two carboxylic groups is thought to enter the plasma membrane and act on acyl-chain in phospholipids in the RBC membrane. For dicarboxylic and tricarboxylic acids, limited numbers of hydrocarbons in molecules are speculated to enter the RBC membrane with the hydrophilic carboxylic groups remaining outside, stabilizing the structure of the cell membrane and resulting in an increase in osmotic resistance in rat RBCs.

  17. Study of the interaction between water and hydrogen sulfide with polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cabaleiro-Lago, Enrique M; Carrazana-García, Jorge A; Rodríguez-Otero, Jesús

    2009-06-21

    A computational study has been carried out for determining the characteristics of the interaction between one water and hydrogen sulfide molecule with a series of polycyclic aromatic hydrocarbons of increasing size, namely, benzene, anthracene, triphenylene, coronene, circumcoronene, and dicircumcoronene. Potential energy curves were calculated for structures where H(2)X (X=O,S) molecule is located over the central six-membered ring with its hydrogen atoms pointing toward to (mode A) or away from (mode B) the hydrocarbon. The accuracy of different methods has been tested against the results of coupled cluster calculations extrapolated to basis set limit for the smaller hydrocarbons. The spin component scaled MP2 (SCS-MP2) method and a density functional theory method empirically corrected for dispersion (DFT-D) reproduce fairly well the results of high level calculations and therefore were employed for studying the larger systems, though DFT-D seems to underestimate the interaction in hydrogen sulfide clusters. Water complexes in mode A have interaction energies that hardly change with the size of the hydrocarbon due to compensation between the increase in the correlation contribution to the interaction energy and the increase in the repulsive character of the Hartree-Fock energy. For all the other clusters studied, there is a continuous increase in the intensity of the interaction as the size of the hydrocarbon increases, suggesting already converged values for circumcoronene. The interaction energy for water clusters extrapolated to an infinite number of carbon atoms amounts to -13.0 and -15.8 kJ/mol with SCS-MP2 and DFT-D, respectively. Hydrogen sulfide interacts more strongly than water with the hydrocarbons studied, leading to a limiting value of -21.7 kJ/mol with the SCS-MP2 method. Also, complexes in mode B are less stable than the corresponding A structures, with interaction energies amounting to -8.2 and -18.2 kJ/mol for water and hydrogen sulfide

  18. Study of the interaction between water and hydrogen sulfide with polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Cabaleiro-Lago, Enrique M.; Carrazana-García, Jorge A.; Rodríguez-Otero, Jesús

    2009-06-01

    A computational study has been carried out for determining the characteristics of the interaction between one water and hydrogen sulfide molecule with a series of polycyclic aromatic hydrocarbons of increasing size, namely, benzene, anthracene, triphenylene, coronene, circumcoronene, and dicircumcoronene. Potential energy curves were calculated for structures where H2X (X=O,S) molecule is located over the central six-membered ring with its hydrogen atoms pointing toward to (mode A) or away from (mode B) the hydrocarbon. The accuracy of different methods has been tested against the results of coupled cluster calculations extrapolated to basis set limit for the smaller hydrocarbons. The spin component scaled MP2 (SCS-MP2) method and a density functional theory method empirically corrected for dispersion (DFT-D) reproduce fairly well the results of high level calculations and therefore were employed for studying the larger systems, though DFT-D seems to underestimate the interaction in hydrogen sulfide clusters. Water complexes in mode A have interaction energies that hardly change with the size of the hydrocarbon due to compensation between the increase in the correlation contribution to the interaction energy and the increase in the repulsive character of the Hartree-Fock energy. For all the other clusters studied, there is a continuous increase in the intensity of the interaction as the size of the hydrocarbon increases, suggesting already converged values for circumcoronene. The interaction energy for water clusters extrapolated to an infinite number of carbon atoms amounts to -13.0 and -15.8 kJ/mol with SCS-MP2 and DFT-D, respectively. Hydrogen sulfide interacts more strongly than water with the hydrocarbons studied, leading to a limiting value of -21.7 kJ/mol with the SCS-MP2 method. Also, complexes in mode B are less stable than the corresponding A structures, with interaction energies amounting to -8.2 and -18.2 kJ/mol for water and hydrogen sulfide

  19. 40 CFR 86.1221-90 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86...-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1221-90 Hydrocarbon analyzer calibration. The FID hydrocarbon analyzer shall receive the following initial and periodic calibrations. (a) Initial and...

  20. 40 CFR 52.987 - Control of hydrocarbon emissions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of hydrocarbon emissions. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Louisiana § 52.987 Control of hydrocarbon... compliance date of January 1, 1980. This shall result in an estimated hydrocarbon emission reduction of...

  1. 30 CFR 250.1202 - Liquid hydrocarbon measurement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Liquid hydrocarbon measurement. 250.1202..., Surface Commingling, and Security § 250.1202 Liquid hydrocarbon measurement. (a) What are the requirements for measuring liquid hydrocarbons? You must: (1) Submit a written application to, and obtain...

  2. 40 CFR 86.331-79 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86....331-79 Hydrocarbon analyzer calibration. The following steps are followed in sequence to calibrate the hydrocarbon analyzer. It is suggested, but not required, that efforts be made to minimize relative...

  3. 40 CFR 721.4365 - Substituted ethoxylated hydrocarbon (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted ethoxylated hydrocarbon... Specific Chemical Substances § 721.4365 Substituted ethoxylated hydrocarbon (generic). (a) Chemical... as Substituted ethoxylated hydrocarbon (PMN P-99-0313) is subject to reporting under this section...

  4. 40 CFR 86.521-90 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 86... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.521-90 Hydrocarbon analyzer calibration. (a) The FID hydrocarbon analyzer shall receive the following initial and periodic calibration....

  5. Cuticular hydrocarbons from the bed bug Cimex lectularius L.

    Science.gov (United States)

    Pentane extracts of male and female bed bugs were analyzed by gas chromatography and mass spectrometry in an effort to identify cuticular hydrocarbons. Seventeen hydrocarbons accounting for nearly 99% of the compounds eluting in the cuticular hydrocarbon region were identified. The sample contained ...

  6. 21 CFR 573.740 - Odorless light petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Odorless light petroleum hydrocarbons. 573.740... ANIMALS Food Additive Listing § 573.740 Odorless light petroleum hydrocarbons. Odorless light petroleum hydrocarbons complying with § 172.884(a) and (b) of this chapter may be safely used in an amount not in...

  7. 21 CFR 172.884 - Odorless light petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Odorless light petroleum hydrocarbons. 172.884... HUMAN CONSUMPTION Multipurpose Additives § 172.884 Odorless light petroleum hydrocarbons. Odorless light petroleum hydrocarbons may be safely used in food, in accordance with the following prescribed...

  8. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Science.gov (United States)

    2010-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  9. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Science.gov (United States)

    2010-07-01

    ... hydrocarbons. 503.44 Section 503.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a sewage sludge incinerator shall be corrected for zero percent moisture by multiplying the measured total...

  10. 21 CFR 178.3650 - Odorless light petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Odorless light petroleum hydrocarbons. 178.3650... SANITIZERS Certain Adjuvants and Production Aids § 178.3650 Odorless light petroleum hydrocarbons. Odorless light petroleum hydrocarbons may be safely used, as a component of nonfood articles intended for use...

  11. 27 CFR 21.125 - Rubber hydrocarbon solvent.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rubber hydrocarbon solvent. 21.125 Section 21.125 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative....

  12. Taxation on mining and hydrocarbon investments

    Directory of Open Access Journals (Sweden)

    Beatriz De La Vega Rengifo

    2014-07-01

    Full Text Available This article comments the most important aspects of the tax treatment applicable to investments of mining and oil and gas industry. The document highlights the relevant tax topics of the general tax legislation(Income Tax Law and the special legislation of both industries (General Mining Law and Hydrocarbons Organic Law.

  13. Site characterization and petroleum hydrocarbon plume mapping

    Energy Technology Data Exchange (ETDEWEB)

    Ravishankar, K. [Harding Lawson Associates, Houston, TX (United States)

    1996-12-31

    This paper presents a case study of site characterization and hydrocarbon contamination plume mapping/delineation in a gas processing plant in southern Mexico. The paper describes innovative and cost-effective use of passive (non-intrusive) and active (intrusive) techniques, including the use of compound-specific analytical methods for site characterization. The techniques used, on a demonstrative basis, include geophysical, geochemical, and borehole drilling. Geochemical techniques used to delineate the horizontal extent of hydrocarbon contamination at the site include soil gas surveys. The borehole drilling technique used to assess the vertical extent of contamination and confirm geophysical and geochemical data combines conventional hollow-stem auguring with direct push-probe using Geoprobe. Compound-specific analytical methods, such as hydrocarbon fingerprinting and a modified method for gasoline range organics, demonstrate the inherent merit and need for such analyses to properly characterize a site, while revealing the limitations of noncompound-specific total petroleum hydrocarbon analysis. The results indicate that the techniques used in tandem can properly delineate the nature and extent of contamination at a site; often supplement or complement data, while reducing the risk of errors and omissions during the assessment phase; and provide data constructively to focus site-specific remediation efforts. 7 figs.

  14. Microbial degradation of petroleum hydrocarbons in soil

    Directory of Open Access Journals (Sweden)

    Kupka Daniel

    1997-09-01

    Full Text Available The abilities of microorganisms to mineralize a wide range of pollutants are well known. Biological processes for the removal of crude oil hydrocarbons from environment are attractive because they consume less energy than conventional physico-chemical processes and offer possibilities for recycling chemicals in the framework of integrated system.

  15. Air Pollution: Where Do Hydrocarbons Come From?

    Science.gov (United States)

    Maugh, Thomas H., II

    1975-01-01

    Describes the controversy surrounding a report which concluded that, in certain areas and under certain conditions, hydrocarbons released from trees and other vegetation may be more important in the initiation of smog than those released from automobiles. Discusses relevant research which has not been able to support or refute this conclusion.…

  16. Method of dispersing a hydrocarbon using bacteria

    Science.gov (United States)

    Tyndall, Richard L.

    1996-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  17. Radiation Chemistry of Organic Liquids: Saturated Hydrocarbons

    CERN Document Server

    Shkrob, Ilya A; Trifunac, A D

    2004-01-01

    In this review (124 refs), several problems in radiolysis of saturated hydrocarbons are examined. Special attention is paid to the chemistry of radical cations, high-mobility holes, excited state and spur dynamics, magnetic field and spin effects, and optically detected magnetic resonance spectroscopy.

  18. Dissolved petroleum hydrocarbons in the Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Topgi, R.S.; Noronha, R.J.; Fondekar, S.P.

    Mean dissolved petroleum hydrocarbons, measured using UV-spectrophotometry, at 0 and 10m were 51 plus or minus 1 and 55 plus or minus 1.2 mu g/litre respectively; range of variation being between 28 and 83 mu g/litre. Very little difference...

  19. Growth of fungi on volatile aromatic hydrocarbons

    NARCIS (Netherlands)

    Prenafeta Boldú, F.X.

    2002-01-01

    The present study aimed the better understanding of the catabolism of monoaromatic hydrocarbons by fungi. This knowledge can be used to enhance the biodegradation of BTEX pollutants. Fungi with the capacity of using toluene as the sole source of carbon and energy were isolated by enriching environme

  20. Antioxidant Functions of the Aryl Hydrocarbon Receptor

    Directory of Open Access Journals (Sweden)

    Cornelia Dietrich

    2016-01-01

    Full Text Available The aryl hydrocarbon receptor (AhR is a transcription factor belonging to the basic helix-loop-helix/PER-ARNT-SIM family. It is activated by a variety of ligands, such as environmental contaminants like polycyclic aromatic hydrocarbons or dioxins, but also by naturally occurring compounds and endogenous ligands. Binding of the ligand leads to dimerization of the AhR with aryl hydrocarbon receptor nuclear translocator (ARNT and transcriptional activation of several xenobiotic phase I and phase II metabolizing enzymes. It is generally accepted that the toxic responses of polycyclic aromatic hydrocarbons, dioxins, and structurally related compounds are mediated by activation of the AhR. A multitude of studies indicate that the AhR operates beyond xenobiotic metabolism and exerts pleiotropic functions. Increasing evidence points to a protective role of the AhR against carcinogenesis and oxidative stress. Herein, I will highlight data demonstrating a causal role of the AhR in the antioxidant response and present novel findings on potential AhR-mediated antioxidative mechanisms.

  1. Cuticle hydrocarbons in saline aquatic beetles

    Directory of Open Access Journals (Sweden)

    María Botella-Cruz

    2017-07-01

    Full Text Available Hydrocarbons are the principal component of insect cuticle and play an important role in maintaining water balance. Cuticular impermeability could be an adaptative response to salinity and desiccation in aquatic insects; however, cuticular hydrocarbons have been poorly explored in this group and there are no previous data on saline species. We characterized cuticular hydrocarbons of adults and larvae of two saline aquatic beetles, namely Nebrioporus baeticus (Dytiscidae and Enochrus jesusarribasi (Hydrophilidae, using a gas chromatograph coupled to a mass spectrometer. The CHC profile of adults of both species, characterized by a high abundance of branched alkanes and low of unsaturated alkenes, seems to be more similar to that of some terrestrial beetles (e.g., desert Tenebrionidae compared with other aquatic Coleoptera (freshwater Dytiscidae. Adults of E. jesusarribasi had longer chain compounds than N. baeticus, in agreement with their higher resistance to salinity and desiccation. The more permeable cuticle of larvae was characterized by a lower diversity in compounds, shorter carbon chain length and a higher proportion of unsaturated hydrocarbons compared with that of the adults. These results suggest that osmotic stress on aquatic insects could exert a selection pressure on CHC profile similar to aridity in terrestrial species.

  2. Volatile hydrocarbons and fuel oxygenates: Chapter 12

    Science.gov (United States)

    Cozzarelli, Isabelle M.

    2014-01-01

    Petroleum hydrocarbons and fuel oxygenates are among the most commonly occurring and widely distributed contaminants in the environment. This chapter presents a summary of the sources, transport, fate, and remediation of volatile fuel hydrocarbons and fuel additives in the environment. Much research has focused on the transport and transformation processes of petroleum hydrocarbons and fuel oxygenates, such as benzene, toluene, ethylbenzene, and xylenes and methyl tert‐butyl ether, in groundwater following release from underground storage tanks. Natural attenuation from biodegradation limits the movement of these contaminants and has received considerable attention as an environmental restoration option. This chapter summarizes approaches to environmental restoration, including those that rely on natural attenuation, and also engineered or enhanced remediation. Researchers are increasingly combining several microbial and molecular-based methods to give a complete picture of biodegradation potential and occurrence at contaminated field sites. New insights into the fate of petroleum hydrocarbons and fuel additives have been gained by recent advances in analytical tools and approaches, including stable isotope fractionation, analysis of metabolic intermediates, and direct microbial evidence. However, development of long-term detailed monitoring programs is required to further develop conceptual models of natural attenuation and increase our understanding of the behavior of contaminant mixtures in the subsurface.

  3. Molecular characterization of autochthonous hydrocarbon utilizing ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Hydrocarbon utilizing bacteria in water, soil and sediment samples collected from ... oil spills to both terrestrial and aquatic environments in the past 5 decades of crude ... One of the major reasons for prolonged negative impact of oil spill on the .... in Gulf of Mexico beach sands impacted by the Deepwater Horizon oil spill.

  4. Occurrence and growth potentials of hydrocarbon degrading ...

    African Journals Online (AJOL)

    Occurrence and growth potentials of hydrocarbon degrading bacteria on the phylloplane ... The surface of leaf samples from ten tropical plants, Anthocleista, Sarcophrynium, Canna, Colocassia, Musa, Cola, Citrus, Mangifera, Terminalia and Annona were cultured for the estimation of total heterotrophic and ... Article Metrics.

  5. 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 ad

  6. MECHANISMS OF MEMBRANE TOXICITY OF HYDROCARBONS

    NARCIS (Netherlands)

    Sikkema, Jan; Poolman, Bert; de Bont, J.A.M.

    1995-01-01

    Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this nl ea. The metaboli

  7. Task 8: Evaluation of hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Cashman, P.H.; Trexler, J.H. Jr.

    1994-12-31

    Our studies focus on the stratigraphy of Late Devonian to early Pennsylvanian rocks at the NTS, because these are the best potential hydrocarbon source rocks in the vicinity of Yucca Mountain. In the last year, our stratigraphic studies have broadened to include the regional context for both the Chainman and the Eleana formations. New age data based on biostratigraphy constrain the age ranges of both Chainman and Eleana; accurate and reliable ages are essential for regional correlation and for regional paleogeographic reconstructions. Source rock analyses throughout the Chainman establish whether these rocks contained adequate organic material to generate hydrocarbons. Maturation analyses of samples from the Chainman determine whether the temperature history has been suitable for the generation of liquid hydrocarbons. Structural studies are aimed at defining the deformation histories and present position of the different packages of Devonian - Pennsylvanian rocks. This report summarizes new results of our structural, stratigraphic and hydrocarbon source rock potential studies at the Nevada Test Site and vicinity. Stratigraphy is considered first, with the Chainman Shale and Eleana Formation discussed separately. New biostratigraphic results are included in this section. New results from our structural studies are summarized next, followed by source rock and maturation analyses of the Chainman Shale. Directions for future work are included where appropriate.

  8. Polynuclear Aromatic Hydrocarbons with Curved Surfaces: Buckyballs

    Energy Technology Data Exchange (ETDEWEB)

    Sygula, Andrzej [Mississippi State Univ., Mississippi State, MS (United States)

    2016-08-15

    The discovery of a new allotropic form of elemental carbon – the fullerenes – and subsequently other novel forms of elemental carbon with pyramidalized surfaces, most notably single-walled and multi-walled carbon nanotubes, introduced a novel structural motif to the polycyclic aromatic hydrocarbons (PAHs) with nonplanar surfaces. Our research program supported by BES DOE grant DE-FG02-04ER15514 has dealt with the synthesis, structural studies, and chemistry of the novel curved-surface PAHs with carbon frameworks structurally related to fullerenes. They are referred to as “buckybowls”. We prepared several new buckybowls and, even more importantly, developed the efficient, gram-scale synthetic methodologies for the preparation of small buckybowls, most notably corannulene (C20H10) and its derivatives. In addition, the employment of the corannulene-based synthons previously developed in our laboratory led to a number of highly nonplanar molecular architectures with two or more corannulene subunits with a potential for the applications as novel materials in separation sciences, nanoelectronics, photovoltaics and catalysis. In collaboration with Professor Angelici (Iowa State) we prepared and characterized several transition metal complexes of corannulene, providing the first structural characterization of η6 metal complexes of buckybowls by a single crystal X-ray diffraction. In addition to the definitive structural characterization of the complexes we demonstrated that the (η6-C6Me6)Ru2+ unit in some relatively stable complexes activate the corannulene ligand to react with proper nucleophiles suggesting that such complexex may be used in catalysis. (Section C). We have explored the efficiency of the dispersion-based interactions of curved-surface conjugated carbon networks by high-level computational models. We showed that the curvature of such networks does not reduce the van der Waals attractions as compared to the planar systems of similar size. We than

  9. Green Methodologies to Test Hydrocarbon Reservoirs

    Directory of Open Access Journals (Sweden)

    Francesca Verga

    2010-01-01

    Full Text Available Problem statement: The definition and the economic viability of the best development strategy of a hydrocarbon reservoir mainly depend on the quantity and type of fluids and on the well productivity. Well testing, consisting in producing hydrocarbon to the surface while measuring the pressure variations induced in the reservoir, has been used for decades to determine the fluid nature and well potential. In exploration and appraisal scenarios the hydrocarbons produced during a test are flared, contributing to the emissions of greenhouse gases. Approach: Due to more stringent environmental regulations and a general need for reduced operating expenses, the current industry drivers in today’s formation evaluation methodologies demand short, safe, cost-effective and environmentally friendly test procedures, especially when conventional tests are prohibitively expensive, logistically not feasible or no surface emissions are allowed. Different methods have been proposed or resuscitated in the last years, such as wireline formation tests, closed chamber tests, production/reinjection tests and injection tests, as viable alternatives to conventional well testing. Results: While various short-term tests, test procedures and interpretation methods are apparently available for conducting successful tests without hydrocarbon production at the surface, clarity is lacking for specific applications of these techniques. An attempt to clarify advantages and limitations of each methodology, particularly with respect to the main testing target is pursued in this study. Specific insight is provided on injection testing, which is one of the most promising methodology to replace traditional well testing in reservoir characterization, except for the possibility to sample the formation fluids. Conclusion/Recommendations: Not a single one method but a combination of more methodologies, in particular injection testing and wireline formation testing, is the most promising

  10. Analysis of hydrocarbons generated in coalbeds

    Science.gov (United States)

    Butala, Steven John M.

    This dissertation describes kinetic calculations using literature data to predict formation rates and product yields of oil and gas at typical low-temperature conditions in coalbeds. These data indicate that gas formation rates from hydrocarbon thermolysis are too low to have generated commercial quantities of natural gas, assuming bulk first-order kinetics. Acid-mineral-catalyzed cracking, transition-metal-catalyzed hydrogenolysis of liquid hydrocarbons, and catalyzed CO2 hydrogenation form gas at high rates. The gaseous product compositions for these reactions are nearly the same as those for typical natural coalbed gases, while those from thermal and catalytic cracking are more representative of atypical coalbed gases. Three Argonne Premium Coals (Upper-Freeport, Pittsburgh #8 and Lewiston-Stockton) were extracted with benzene in both Soxhlet and elevated pressure extraction (EPE) systems. The extracts were compared on the basis of dry mass yield and hydrocarbon profiles obtained by gas chromatography/mass spectrometry. The dry mass yields for the Upper-Freeport coal gave consistent results by both methods, while the yields from the Pittsburgh #8 and Lewiston-Stockton coals were greater by the EPE method. EPE required ˜90 vol. % less solvent compared to Soxhlet extraction. Single-ion-chromatograms of the Soxhlet extracts all exhibited bimodal distributions, while those of the EPE extracts did not. Hydrocarbons analyzed from Greater Green River Basin samples indicate that the natural oils in the basin originated from the coal seams. Analysis of artificially produced oil indicates that hydrous pyrolysis mimics generation of C15+ n-alkanes, but significant variations were found in the branched alkane, low-molecular-weight n-alkanes, and high-molecular-weight aromatic hydrocarbon distributions.

  11. Studies of Polycyclic Aromatic Hydrocarbons in Dungeness Crabs: Biomonitoring, Physiologically Based Toxicokinetic Model, and Human Health Risk Assessment

    OpenAIRE

    Eickhoff, Curtis

    2004-01-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants released into the environment from the incomplete combustion of organic material and petrochemical sources. PAH are persistent molecules that partition into sediments and biota in the aquatic environment. PAH such as benzo[a]pyrene, are of concern because they are metabolised into potentially carcinogenic chemicals that can cause tumours in fish and mammals. The purpose of this research was three-fold, (1) to explore the use of ...

  12. Hydrocarbon geochemistry of the Puget Sound region. II. Sedimentary diterpenoid, steroid and triterpenoid hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Barrick, R.C.; Hedges, J.I.

    1981-03-01

    Cyclic components of the aliphatic hydrocarbon mixtures extracted from Puget Sound sediment cores include a suite of C/sub 19/ and C/sub 20/ diterpenoid hydrocarbons of which fichtelite, sandaracopimaradiene, and isopimaradiene have been identified. Although apparently also derived from vascular plants, these diterpenoid hydrocarbons have relative abundances distinctly different from the co-existing plant wax n-alkane suite. Five C/sub 27/, C/sub 28/ and C/sub 29/ diasteranes and four C/sub 29/, C/sub 30/ and C/sub 31/ 17..cap alpha..(H), 21..beta..(H) hopanes occur in relatively constant proportion as components of a highly weathered fossil hydrocarbon assemblage. These chromatographically resolved cycloalkanes, along with the strongly covarying unresolved complex mixture, have been introduced to Puget Sound sediments from adjacent urban centres at increasing levels over the last 100 yr in the absence of any major oil spill. Naturally-occurring triterpenoid hydrocarbons, including hop-22(29)-ene (diploptene), are also present. A new group of C/sub 30/ polyenes has been detected which contains compounds apparently structurally related to a co-existing bicyclic C/sub 25/ diene and to C/sub 20/ and C/sub 25/ acyclic multibranched hydrocarbons described in a previous paper (Barrick et al., 1980).

  13. Hydrocarbon geochemistry of the Puget Sound region - II. Sedimentary diterpenoid, steroid and triterpenoid hydrocarbons

    Science.gov (United States)

    Barrick, Robert C.; Hedges, John I.

    1981-03-01

    Cyclic components of the 'aliphatic' hydrocarbon mixtures extracted from Puget Sound sediment cores include a suite of C 19 and C 20 diterpenoid hydrocarbons of which fichtelite. sandaracopimaradiene, and isopimaradiene have been identified. Although apparently also derived from vascular plants, these diterpenoid hydrocarbons have relative abundances distinctly different from the co-existing plant wax n-alkane suite. Five C 27, C 28 and C 29 diasteranes and four C 29, C 30 and C 31 17α(H), 21β(H) hopanes occur in relatively constant proportion as components of a highly weathered fossil hydrocarbon assemblage. These chromatographically resolved cycloalkanes. along with the strongly covarying unresolved complex mixture, have been introduced to Puget Sound sediments from adjacent urban centres at increasing levels over the last 100 yr in the absence of any major oil spill. Naturally-occurring triterpenoid hydrocarbons, including hop-22(29)-ene (diploptene), are also present. A new group of C 30 polyenes has been detected which contains compounds apparently structurally related to a co-existing bicyclic C 25 diene and to C 20 and C 25 acyclic multibranched hydrocarbons described in a previous paper ( BARRICK et al., 1980).

  14. Wetting and superhydrophobic properties of PECVD grown hydrocarbon and fluorinated-hydrocarbon coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, D.K., E-mail: dsarkar@uqac.ca [Canada Research Chair on Atmospheric Icing Engineering of Power Networks (INGIVRE) and Industrial Chair on Atmospheric Icing of Power Network Equipment (CIGELE), Universite du Quebec a Chicoutimi UQAC, 555 Boulevard de l' Universite, Chicoutimi, Quebec, G7H 2B1 (Canada); Farzaneh, M. [Canada Research Chair on Atmospheric Icing Engineering of Power Networks (INGIVRE) and Industrial Chair on Atmospheric Icing of Power Network Equipment (CIGELE), Universite du Quebec a Chicoutimi UQAC, 555 Boulevard de l' Universite, Chicoutimi, Quebec, G7H 2B1 (Canada); Paynter, R.W. [INRS-EMT, 1650 boul. Lionel-Boulet, Varennes, Quebec, J3X 1S2 (Canada)

    2010-03-15

    Wetting characteristics of micro-nanorough substrates of aluminum and smooth silicon substrates have been studied and compared by depositing hydrocarbon and fluorinated-hydrocarbon coatings via plasma enhanced chemical vapor deposition (PECVD) technique using a mixture of Ar, CH{sub 4} and C{sub 2}F{sub 6} gases. The water contact angles on the hydrocarbon and fluorinated-hydrocarbon coatings deposited on silicon substrates were found to be 72 deg. and 105 deg., respectively. However, the micro-nanorough aluminum substrates demonstrated superhydrophobic properties upon coatings with fluorinated-hydrocarbon providing a water contact angle of {approx}165 deg. and contact angle hysteresis below 2 deg. with water drops rolling off from those surfaces while the same substrates showed contact angle of 135 deg. with water drops sticking on those surfaces. The superhydrophobic properties is due to the high fluorine content in the fluorinated-hydrocarbon coatings of {approx}36 at.%, as investigated by X-ray photoelectron spectroscopy (XPS), by lowering the surface energy of the micro-nanorough aluminum substrates.

  15. Geranyl diphosphate synthase molecules, and nucleic acid molecules encoding same

    Science.gov (United States)

    Croteau, Rodney Bruce; Burke, Charles Cullen

    2008-06-24

    In one aspect, the present invention provides isolated nucleic acid molecules that each encode a geranyl diphosphate synthase protein, wherein each isolated nucleic acid molecule hybridizes to a nucleic acid molecule consisting of the sequence set forth in SEQ ID NO:1 under conditions of 5.times.SSC at 45.degree. C. for one hour. The present invention also provides isolated geranyl diphosphate synthase proteins, and methods for altering the level of expression of geranyl diphosphate synthase protein in a host cell.

  16. Comparison of hydrocarbon gases (C{sub 1}-C{sub 5}) production from Carboniferous Donets (Ukraine) and Cretaceous Sabinas (Mexico) coals

    Energy Technology Data Exchange (ETDEWEB)

    Alsaab, D.; Elie, M.; Izart, A.; Martinez, L. [G2R, Nancy - Universite, CNRS, CREGU, BP-239, 54506 Vandoeuvres-les-Nancy (France); Sachsenhofer, R.F. [Institut fuer Geowissenschaften, Montanuniversitaet Leoben, Peter-Tunner-Strasse 5, A-8700 Leoben (Austria); Privalov, V.A. [Donetsk National Technical University, Artem str., 58, UA-83000 Donetsk (Ukraine); Suarez-Ruiz, I. [Instituto Nacional del Carbon - (INCAR) - CSIC. Ap.Co., 73, 33080-Oviedo (Spain)

    2008-04-03

    The main purpose of this contribution is to compare the ability of Carboniferous coals from the Donets Basin of the Ukraine and Cretaceous coal from the Sabinas Basin of the Mexico to generate hydrocarbon gases (C{sub 1}-C{sub 5}). Two bituminous coals from the Donets Basin (2c10YD and 1l1Dim; 0.55 and 0.65%R{sub r} respectively) and one bituminous coal from the Sabinas Basin (Olmos, 0.92%R{sub r}) were studied using heating experiments in a confined-pyrolysis system. The highest rank reached during the heating experiments corresponds to the anthracite stage (2.78 and 2.57%R{sub r}) for the 2c10YD and 1l1Dim coals and (2.65%R{sub r}) for the Olmos coal. The composition of the generated (C{sub 1}-C{sub 5}) gases was evaluated using a thermodesorption-multidimensional gas chromatography. The results show that the Carboniferous Donets coals produced more wet gas and methane during pyrolysis than the Cretaceous Olmos coal. This is probably due to their higher liptinite (6-20%) and collodetrinite content and to the loss of a major part of the petroleum potential of the Olmos coal during natural coalification. C{sub 2}-C{sub 5} compounds are mainly derived from the cracking of liquid hydrocarbons. Ethane is the most stable compound and formed from the cracking of higher hydrocarbon component. Large amounts of methane (up to 81 mg/g coal for the Donets coals and 50 mg/g coal for the Sabinas coal) were formed at high temperatures by cracking of previously formed heavier hydrocarbons and by dealkylation of the coal matrix. A linear relationship was observed between methane generation and the maturity level of both coal types. (author)

  17. Mechanism of Silurian Hydrocarbon Pool Formation in the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    Liu Luofu; Guo Yongqiang; Zhao Yande; Li Yan; Chen Yuanzhuang; Chen Lixin; Pang Xiongqi; Xie Qilai; Huo Hong; Zhao Suping; Li Chao; Li Shuangwen

    2007-01-01

    There are three formation stages of Silurian hydrocarbon pools in the Tarim Basin. The widely distributed asphaltic sandstones in the Tazhong (central Tarim) and Tabei (northern Tarim) areas are the results of destruction of hydrocarbon pools formed in the first-stage, and the asphaltic sandstones around the Awati Sag were formed in the second-stage. The hydrocarbon migration characteristics reflected by the residual dry asphalts could represent the migration characteristics of hydrocarbons in the Silurian paleo-pools, while the present movable oil in the Silurian reservoirs is related to the later-stage (the third-stage) hydrocarbon accumulation.

  18. Current Situation and Application in Coal- Generated Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    YANG Guang; XU Hongdong

    2001-01-01

    The characteristics and research methods of terrigenous organic hydrocarbon - generated source rock in coal measures are studied in this thesis. After abundance of organic matters, pyrolysis parameter of rocks and hydrocarbon generated capacity of macerals are basically discussed in coal measures of the Cretaceous Muleng- Chengzihe formation in Suibin depression in Sanjang basin, the hydrocarbon generated grade in coal- generated source rock is ascertained in this depression. At last, we think that it is a main attack prospect in coal - generated hydrocarbons study in the future to research the macerals of coal measures organic source rock and to build a criterion to classify the coal- generated hydrocarbons in Northeast region.

  19. Molecule-based magnets

    Indian Academy of Sciences (India)

    J V Yakhmi

    2009-06-01

    The conventional magnetic materials used in current technology, such as, Fe, Fe2O3, Cr2O3, SmCo5, Nd2Fe14B etc are all atom-based, and their preparation/processing require high temperature routes. Employing self-assembly methods, it is possible to engineer a bulk molecular material with long-range magnetic order, mainly because one can play with the weak intermolecular interactions. Since the first successful synthesis of molecular magnets in 1986, a large variety of them have been synthesized, which can be categorized on the basis of the chemical nature of the magnetic units involved: organic-, metal-based systems, heterobimetallic assemblies, or mixed organic–inorganic systems. The design of molecule-based magnets has also been extended to the design of poly-functional molecular magnets, such as those exhibiting second-order optical nonlinearity, liquid crystallinity, or chirality simultaneously with long-range magnetic order. Solubility, low density and biocompatibility are attractive features of molecular magnets. Being weakly coloured, unlike their opaque classical magnet ‘cousins’ listed above, possibilities of photomagnetic switching exist. Persistent efforts also continue to design the ever-elusive polymer magnets towards applications in industry. While providing a brief overview of the field of molecular magnetism, this article highlights some recent developments in it, with emphasis on a few studies from the author’s own lab.

  20. Microbiology and geochemistry of hydrocarbon-rich sediments erupted from the deep geothermal Lusi site, Indonesia

    Science.gov (United States)

    Krüger, Martin; Straten, Nontje; Mazzini, Adriano; Scheeder, Georg; Blumenberg, Martin

    2016-04-01

    The Lusi eruption represents one of the largest ongoing sedimentary hosted geothermal systems, which started in 2006 following an earthquake on Java Island. Since then it has been producing hot and hydrocarbon rich mud from a central crater with peaks reaching 180.000 m3 per day. Numerous investigations focused on the study of offshore microbial colonies that commonly thrive at offshore methane and oil seeps and mud volcanoes, however very little has been done for onshore seeping structures. Lusi represents a unique opportunity to complete a comprehensive study of onshore microbial communities fed by the seepage of CH4 as well as of heavier liquid hydrocarbons originating from one or more km below the surface. While the source of the methane at Lusi is clear (Mazzini et al., 2012), the origin of the seeping oil, either form the deep mature Eocene Ngimbang (type II kerogen) or from the less mature Pleistocene Upper Kalibeng Fm. (type III kerogen), is still discussed. In the framework of the Lusi Lab project (ERC grant n° 308126) we analysed an oil film and found that carbon preference indices among n-alkanes, sterane and hopane isomers (C29-steranes: 20S/(20S+20R) and α,β-C32 Hopanes (S/(S+R), respectively) are indicative of a low thermal maturity of the oil source rock (~0.5 to 0.6 % vitrinite reflectance equivalents = early oil window maturity). Furthermore, sterane distributions, the pristane to phytane ratio and a relatively high oleanane index, which is an indication of an angiosperm input, demonstrate a strong terrestrial component in the organic matter. Together, hydrocarbons suggest that the source of the oil film is predominantly terrestrial organic matter. Both, source and maturity estimates from biomarkers, are in favor of a type III organic matter source and are therefore suggestive of a mostly Pleistocene Upper Kalibeng Fm. origin. We also conducted a sampling campaign at the Lusi site collecting samples of fresh mud close to the erupting crater

  1. Molecular networks in Position, Momentum, and Phase Space: A Case Study on Simple Hydrocarbons

    DEFF Research Database (Denmark)

    Schmider, Hartmut; Ho, Minhhuy

    1996-01-01

    The notion of a molecular network as a system of local density maxima, connected by gradient paths, is extended from position space and the underlying charge density to momentum and phase space, and the momentum density and Husimi distribution, respectively. Local maxima and gradient paths...... are identified in a series of nine small hydrocarbonic molecules, and the resulting "molecular graphs" are interpreted in terms of symmetry and topology. For the example of a symmetric SN2 reaction, it is shown that the topology of the Husimi function based graphs can be useful for the classification of chemical...

  2. Strongly interacting ultracold polar molecules

    CERN Document Server

    Gadway, Bryce

    2016-01-01

    This paper reviews recent advances in the study of strongly interacting systems of dipolar molecules. Heteronuclear molecules feature large and tunable electric dipole moments, which give rise to long-range and anisotropic dipole-dipole interactions. Ultracold samples of dipolar molecules with long-range interactions offer a unique platform for quantum simulations and the study of correlated many-body physics. We provide an introduction to the physics of dipolar quantum gases, both electric and magnetic, and summarize the multipronged efforts to bring dipolar molecules into the quantum regime. We discuss in detail the recent experimental progress in realizing and studying strongly interacting systems of polar molecules trapped in optical lattices, with particular emphasis on the study of interacting spin systems and non-equilibrium quantum magnetism. Finally, we conclude with a brief discussion of the future prospects for studies of strongly interacting dipolar molecules.

  3. 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.

  4. 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.

  5. Sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants.

    Science.gov (United States)

    Gerner, Nadine V; Cailleaud, Kevin; Bassères, Anne; Liess, Matthias; Beketov, Mikhail A

    2017-09-06

    Hydrocarbons have an utmost economical importance but may also cause substantial ecological impacts due to accidents or inadequate transportation and use. Currently, freshwater biomonitoring methods lack an indicator that can unequivocally reflect the impacts caused by hydrocarbons while being independent from effects of other stressors. The aim of the present study was to develop a sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants, which can be used in hydrocarbon-specific bioindicators. We employed the Relative Sensitivity method and developed the sensitivity ranking S hydrocarbons based on literature ecotoxicological data supplemented with rapid and mesocosm test results. A first validation of the sensitivity ranking based on an earlier field study has been conducted and revealed the S hydrocarbons ranking to be promising for application in sensitivity based indicators. Thus, the first results indicate that the ranking can serve as the core component of future hydrocarbon-specific and sensitivity trait based bioindicators.

  6. Hydrocarbon-degradation by Isolate Pseudomonas lundensis UTAR FPE2

    Directory of Open Access Journals (Sweden)

    Adeline, S. Y. Ting

    2009-01-01

    Full Text Available In this study, the potential of isolate Pseudomonas lundensis UTAR FPE2 as a hydrocarbon degrader was established. Their biodegradation activity was first detected with the formation of clearing zones on Bushnell-Hass agar plates, with the largest diameter observed on plates supplemented with paraffin, followed by mineral oil and petrol. Utilization of hydrocarbon sources were again detected in broth cultures supplemented with similar hydrocarbon substrates, where the mean viable cell count recovered from hydrocarbon-supplemented broth cultures were higher than the initial inoculum except for napthalene. In both tests, the isolate showed higher degradability towards aliphatic hydrocarbon sources, and the least activity towards the aromatic hydrocarbon naphthalene. The isolate P. lundensis UTAR FPE2 (8 log10 cfu/mL also degraded crude diesel sample, with 69% degradation during the first three days. To conclude, this study suggests the potential use of this isolate for bioremediation of hydrocarbon-contaminated environments.

  7. Production of hydrocarbons by Aspergillus carbonarius ITEM 5010.

    Science.gov (United States)

    Sinha, Malavika; Sørensen, Annette; Ahamed, Aftab; Ahring, Birgitte Kiær

    2015-04-01

    The filamentous fungus, Asperigillus carbonarius, is able to produce a series of hydrocarbons in liquid culture using lignocellulosic biomasses, such as corn stover and switch grass as carbon source. The hydrocarbons produced by the fungus show similarity to jet fuel composition and might have industrial application. The production of hydrocarbons was found to be dependent on type of media used. Therefore, ten different carbon sources (oat meal, wheat bran, glucose, carboxymethyl cellulose, avicel, xylan, corn stover, switch grass, pretreated corn stover, and pretreated switch grass) were tested to identify the maximum number and quantity of hydrocarbons produced. Several hydrocarbons were produced include undecane, dodecane, tetradecane, hexadecane 2,4-dimethylhexane, 4-methylheptane, 3-methyl-1-butanol, ethyl benzene, o-xylene. Oatmeal was found to be the carbon source resulting in the largest amounts of hydrocarbon products. The production of fungal hydrocarbons, especially from lignocellulosic biomasses, holds a great potential for future biofuel production whenever our knowledge on regulators and pathways increases.

  8. Theoretical Investigations Regarding Single Molecules

    DEFF Research Database (Denmark)

    Pedersen, Kim Georg Lind

    Neoclassical Valence Bond Theory, Quantum Transport, Quantum Interference, Kondo Effect, and Electron Pumping. Trap a single organic molecule between two electrodes and apply a bias voltage across this "molecular junction". When electrons pass through the molecule, the different electron paths can...... interfere destructively or constructively. Destructive interference effects in electron transport could potentially improve thermo-electrics, organic logic circuits and energy harvesting. We have investigated destructive interference in off-resonant transport through organic molecules, and have found a set...

  9. Pure and N-substituted Small Cyclic Hydrocarbon Cations and Anions Synthesis in The Ionosphere of Titan: An Ab-Initio Quantum Chemical Perspective

    Science.gov (United States)

    Bera, P. P.

    2015-12-01

    The instruments on board the CASSINI spacecraft observed large carbonaceous molecules in the upper atmosphere of Titan. How these large polyatomic molecules are synthesized in such exotic conditions is, thus far, unknown. Molecular ions, including positive and negative ions, especially large anions, are in abundance in the ionosphere of Titan. Barrier-less ion-molecule interactions may play a major role ­- ions provide electrostatic steering force - in guiding molecules towards each other and initiating reactions. We study these condensation pathways to determine whether they are a viable means of forming large pure hydrocarbon molecules, and nitrogen-containing carbonaceous chains, stacks, and even cyclic compounds. We employ accurate quantum chemical methods to investigate the processes of growth, structures, nature of bonding, mechanisms, and spectroscopic properties of the ensuing ionic products after pairing small carbon, hydrogen, and nitrogen-containing molecules with major ions observed in the upper atmosphere of Titan, e.g. C2H5+ and HCNH+, apart from a whole host of small hydrocarbons. We also studied the ion-neutral association pathways involving pure-carbon molecules e.g. acetylene, ethylene and other hydrocarbons, and their dissociation fragments in a plasma discharge. We found the molecular building blocks of polycyclic aromatic hydrocarbons such as phenyl cations can form very easily by the combination of smaller hydrocarbons followed by hydrogen loss. We have investigated how nitrogen atoms are incorporated into the carbon ring during growth. Specifically, we explored the mechanisms by which the synthesis of pyrimidine will be feasible in the atmosphere of Titan in conjunction with ion-mobility experiments. Futher, we study the formation process of anions, and study their potential energy surfaces. We have used accurate ab initio coupled cluster theory, Møller-Plesset perturbation theory, density functional theory (DFT), and coupled cluster theory

  10. STM investigation of surfactant molecules

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Adsorption and self-organization of sodium alkyl sulfonates (STS and SHS) have been studied on HOPG by using the in situ scanning tunneling microscopy (STM). Both SHS and STS molecules adsorb on the HOPG surface and form long-range well-ordered monolayers. The neighboring molecules in different rows form a "head to head" configuration. In the high-resolution images of STS and SHS molecules, one end of the molecules shows bright spots which are attributed to the SO3- groups.

  11. Biofuels: from microbes to molecules

    National Research Council Canada - National Science Library

    Lu, Xuefeng

    2014-01-01

    .... The production of different biofuel molecules including hydrogen, methane, ethanol, butanol, higher chain alcohols, isoprenoids and fatty acid derivatives, from genetically engineered microbes...

  12. Noble gas and hydrocarbon tracers in multiphase unconventional hydrocarbon systems: Toward integrated advanced reservoir simulators

    Science.gov (United States)

    Darrah, T.; Moortgat, J.; Poreda, R. J.; Muehlenbachs, K.; Whyte, C. J.

    2015-12-01

    Although hydrocarbon production from unconventional energy resources has increased dramatically in the last decade, total unconventional oil and gas recovery from black shales is still less than 25% and 9% of the totals in place, respectively. Further, the majority of increased hydrocarbon production results from increasing the lengths of laterals, the number of hydraulic fracturing stages, and the volume of consumptive water usage. These strategies all reduce the economic efficiency of hydrocarbon extraction. The poor recovery statistics result from an insufficient understanding of some of the key physical processes in complex, organic-rich, low porosity formations (e.g., phase behavior, fluid-rock interactions, and flow mechanisms at nano-scale confinement and the role of natural fractures and faults as conduits for flow). Noble gases and other hydrocarbon tracers are capably of recording subsurface fluid-rock interactions on a variety of geological scales (micro-, meso-, to macro-scale) and provide analogs for the movement of hydrocarbons in the subsurface. As such geochemical data enrich the input for the numerical modeling of multi-phase (e.g., oil, gas, and brine) fluid flow in highly heterogeneous, low permeability formations Herein we will present a combination of noble gas (He, Ne, Ar, Kr, and Xe abundances and isotope ratios) and molecular and isotopic hydrocarbon data from a geographically and geologically diverse set of unconventional hydrocarbon reservoirs in North America. Specifically, we will include data from the Marcellus, Utica, Barnett, Eagle Ford, formations and the Illinois basin. Our presentation will include geochemical and geological interpretation and our perspective on the first steps toward building an advanced reservoir simulator for tracer transport in multicomponent multiphase compositional flow (presented separately, in Moortgat et al., 2015).

  13. "The Burden of Pregnancy"; heavier for the heaviest? The changes in Health Related Quality of Life (HRQoL) assessed by the 15D instrument during pregnancy and postpartum in different body mass index groups: a longitudinal survey.

    Science.gov (United States)

    Sahrakorpi, Niina; Koivusalo, Saila B; Stach-Lempinen, Beata; Eriksson, Johan G; Kautiainen, Hannu; Roine, Risto P

    2017-03-01

    Only little information is available on health-related quality of life (HRQoL) and its changes during the course of a normal pregnancy. We studied changes in HRQoL in a pregnant population during pregnancy and until 1 year postpartum in different body mass index (BMI) groups. Seven hundred and fifty pregnant women attending the first ultrasound examination before gestational week 14 were invited to participate in a longitudinal, communal-based survey. The participants were divided into three groups according to their BMI; <25, 25-29.9, and ≥30 kg/m(2) . The women were asked to fill in questionnaires assessing HRQoL (15D), depressive symptoms (Edinburgh Depression Scale, EPDS), medical, obstetric and socioeconomic status at baseline. HRQoL and EPDS were re-assessed at 30 weeks of gestation, and 6 weeks, 3 and 12 months postpartum. Of the invited 750 mothers, 325 (43%) returned the questionnaires and at least one follow-up questionnaire. At baseline, mean 15D scores decreased with increasing BMI but the difference was not statistically significant when adjusted for age, educational attainment, parity or EPDS-scores (0.929, 0.921 and 0.916, p = 0.16). During the course of pregnancy, the HRQoL of all women decreased but this decrease was significantly greater in the obese group (-0.088; 95% CI -0.110 to -0.065) than in the other groups [-0.054 (95% CI -0.062 to -0.045) and -0.051 (95% CI -0.068 to -0.033), p = 0.019]. Within 3 months postpartum the mean HRQoL recovered in all BMI groups to baseline levels, irrespective of the mode of delivery or pregnancy-related complications. The burden of pregnancy is heavier for the heaviest. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  14. Growth and Destruction of PAH Molecules in Reactions with Carbon Atoms

    Science.gov (United States)

    Krasnokutski, Serge A.; Huisken, Friedrich; Jäger, Cornelia; Henning, Thomas

    2017-02-01

    A very high abundance of atomic carbon in the interstellar medium (ISM), and the high reactivity of these species toward different hydrocarbon molecules including benzene, raise questions regarding the stability of polycyclic aromatic hydrocarbon (PAH) molecules in space. To test the efficiency of destruction of PAH molecules via reactions with atomic carbon, we performed a set of laboratory and computational studies of the reactions of naphthalene, anthracene, and coronene molecules with carbon atoms in the ground state. The reactions were investigated in liquid helium droplets at T = 0.37 K and by quantum chemical computations. Our studies suggest that all small and all large catacondensed PAHs react barrierlessly with atomic carbon, and therefore should be efficiently destroyed by such reactions in a broad temperature range. At the same time, large compact pericondensed PAHs should be more inert toward such a reaction. In addition, taking into account their higher photostability, much higher abundances of pericondensed PAHs should be expected in various astrophysical environments. The barrierless reactions between carbon atoms and small PAHs also suggest that, in the ISM, these reactions could lead to the bottom-up formation of PAH molecules.

  15. Electron ionization of open/closed chain isocarbonic molecules relevant in plasma processing: Theoretical cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Umang R., E-mail: umangpatel193@yahoo.ca [Gandhinagar Institute of Technology, Moti Bhoyan, Gandhinagar-382721, Gujarat (India); Sardar Patel University, Vallabh Vidyanagar-388120, Gujarat (India); Joshipura, K. N.; Pandya, Siddharth H. [Sardar Patel University, Vallabh Vidyanagar-388120, Gujarat (India); Kothari, Harshit N. [Universal College of Engineering and Technology, Moti Bhoyan, Gandhinagar-382721, Gujarat (India)

    2014-01-28

    In this paper, we report theoretical electron impact ionization cross sections from threshold to 2000 eV for isocarbonic open chain molecules C{sub 4}H{sub 6}, C{sub 4}H{sub 8}, C{sub 4}F{sub 6} including their isomers, and closed chain molecules c-C{sub 4}H{sub 8} and c-C{sub 4}F{sub 8}. Theoretical formalism employed presently, viz., Complex Scattering Potential-ionization contribution method has been used successfully for a variety of polyatomic molecules. The present ionization calculations are very important since results available for the studied targets are either scarce or none. Our work affords comparison of C{sub 4} containing hydrocarbon versus fluorocarbon molecules. Comparisons of the present ionization cross sections are made wherever possible, and new ionization data are also presented.

  16. Hydrocarbon contamination in Cartagena Bay, Colombia.

    Science.gov (United States)

    Parga-Lozano, C H; Marrugo-González, A J; Fernández-Maestre, R

    2002-01-01

    This study deals with the levels of aromatic and aliphatic hydrocarbon quantification in sediments and organisms in Cartagena Bay (Colombia), 1996-1997. Sediments (14 stations) and bivalves (2 stations) were monitored at different times of the year. Areas with high values were in the north with concentrations above 100 microg/g with a maximum of 1415 microg/g. Areas with low values were located toward the south, near the outlet of the Canal del Dique and Barú Island, with values below 10 microg/g. In other areas concentrations were between 50 and 100 microg/g. A decrease in sediment concentrations of hydrocarbons has occurred since 1983, but levels in some sectors are still similar to those in polluted areas. Organisms have relatively low values (8-30 microg/g for bivalves, and 10-40 microg/g for fish).

  17. Biodegradation of Petroleum Hydrocarbons in Soil

    Directory of Open Access Journals (Sweden)

    MR Mehrasbi

    2003-09-01

    Full Text Available Biodegradation of petroleum hydrocarbons (20 g/kg dw soil was investigated in 3 media, differing in the kind of petroleum fractions. In the laboratory experiments, during 5 months, the activities of petroleum hydrocarbon-degrading microorganisms and dehydrogenase activity of soil was determined. Gas chromatographic analysis showed the biological decontaminations for gas oil, kerosene and synthetic mixture (gas oil, kerosene and furnace oil are 60 %, 36 % and 55 %, respectively. Dehydrogenase activity which was assessed by TTC technique, correlated significantly positive with the numbers of microorganisms. The Spearman rank correlation coefficients(r in contaminated soils with gas oil, kerosene and synthetic mixture were 0.79, 0.80 and 0.69, respectively.

  18. Hydrocarbon potential of the Trinidad area - 1977

    Energy Technology Data Exchange (ETDEWEB)

    Persad, K.M.

    1978-06-01

    It is recognized that deltaic and associated sands, together with porous marine limestones, form the vast majority of the reservoirs in the major accumulations of hydrocarbons throughout the world. The source of the hydrocarbons is now thought to be kerogen which is generated from the organic content of principally marine shales which are formed in or near the continental shelves. The Trinidad area contains several sedimentary subbasins, most of which consist largely of deltaic and associated sediments. These sediments, like most of the ancient deltas of the world, contain major reserves of oil and gas. Other less important reserves should occur in sporadic (time-wise) porous limestones. The total proven and probable reserves of the Trinidad area are around 5 billion bbl of oil, of which 1.6 billion bbl already have been produced, and over 47 TCF of gas.

  19. CHARACTERISTICS OF HYDROCARBON EXPLOITATION IN ARCTIC CIRCLE

    Directory of Open Access Journals (Sweden)

    Vanja Lež

    2013-12-01

    Full Text Available The existence of large quantities of hydrocarbons is supposed within the Arctic Circle. Assumed quantities are 25% of the total undiscovered hydrocarbon reserves on Earth, mostly natural gas. Over 500 major and minor gas accumulations within the Arctic Circle were discovered so far, but apart from Snøhvit gas field, there is no commercial exploitation of natural gas from these fields. Arctic gas projects are complicated, technically hard to accomplish, and pose a great threat to the return of investment, safety of people and equipment and for the ecosystem. Russia is a country that is closest to the realization of the Arctic gas projects that are based on the giant gas fields. The most extreme weather conditions in the seas around Greenland are the reason why this Arctic region is the least explored and furthest from the realization of any gas project (the paper is published in Croatian .

  20. Behavioral toxicology, risk assessment, and chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Evangelista de Duffard, A.M.; Duffard, R. [Laboratorio de Toxicologia Experimental, Santa Fe (Argentina)

    1996-04-01

    Behavioral end points are being used with greater frequency in neurotoxicology to detect and characterize the adverse effects of chemicals on the nervous system. Behavioral measures are particularly important for neurotoxicity risk assessment since many known neurotoxicants do not result in neuropathology. The chlorinated hydrocarbon class consists of a wide variety of chemicals including polychlorinated biphenyls, clioquinol, trichloroethylene, hexachlorophene, organochlorine insecticides (DDT, dicofol, chlordecone, dieldrin, and lindane), and phenoxyherbicides. Each of these chemicals has effects on motor, sensory, or cognitive function that are detectable using functional measures such as behavior. Furthermore, there is evidence that if exposure occurs during critical periods of development, many of the chlorinated hydrocarbons are developmental neurotoxicants. Developmental neurotoxicity is frequently expressed as alterations in motor function or cognitive abilities or charges in the ontogeny of sensorimotor reflexes. Neurotoxicity risk assessment should include assessments of the full range of possible neurotoxicological effects, including both structural and functional indicators of neurotoxicity. 121 refs., 1 tab.

  1. HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

    2006-08-15

    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  2. Field metabolomics and laboratory assessments of anaerobic intrinsic bioremediation of hydrocarbons at a petroleum-contaminated site.

    Science.gov (United States)

    Parisi, Victoria A; Brubaker, Gaylen R; Zenker, Matthew J; Prince, Roger C; Gieg, Lisa M; Da Silva, Marcio L B; Alvarez, Pedro J J; Suflita, Joseph M

    2009-03-01

    Field metabolomics and laboratory assays were used to assess the in situ anaerobic attenuation of hydrocarbons in a contaminated aquifer underlying a former refinery. Benzene, ethylbenzene, 2-methylnaphthalene, 1,2,4- and 1,3,5-trimethylbenzene were targeted as contaminants of greatest regulatory concern (COC) whose intrinsic remediation has been previously reported. Metabolite profiles associated with anaerobic hydrocarbon decay revealed the microbial utilization of alkylbenzenes, including the trimethylbenzene COC, PAHs and several n-alkanes in the contaminated portions of the aquifer. Anaerobic biodegradation experiments designed to mimic in situ conditions showed no loss of exogenously amended COC; however, a substantive rate of endogenous electron acceptor reduction was measured (55 ± 8 µM SO(4) day(-1)). An assessment of hydrocarbon loss in laboratory experiments relative to a conserved internal marker revealed that non-COC hydrocarbons were being metabolized. Purge and trap analysis of laboratory assays showed a substantial loss of toluene, m- and o-xylene, as well as several alkanes (C(6)-C(12)). Multiple lines of evidence suggest that benzene is persistent under the prevailing site anaerobic conditions. We could find no in situ benzene intermediates (phenol or benzoate), the parent molecule proved recalcitrant in laboratory assays and low copy numbers of Desulfobacterium were found, a genus previously implicated in anaerobic benzene biodegradation. This study also showed that there was a reasonable correlation between field and laboratory findings, although with notable exception. Thus, while the intrinsic anaerobic bioremediation was clearly evident at the site, non-COC hydrocarbons were preferentially metabolized, even though there was ample literature precedence for the biodegradation of the target molecules.

  3. Field metabolomics and laboratory assessments of anaerobic intrinsic bioremediation of hydrocarbons at a petroleum‐contaminated site

    Science.gov (United States)

    Parisi, Victoria A.; Brubaker, Gaylen R.; Zenker, Matthew J.; Prince, Roger C.; Gieg, Lisa M.; Da Silva, Marcio L.B.; Alvarez, Pedro J. J.; Suflita, Joseph M.

    2009-01-01

    Summary Field metabolomics and laboratory assays were used to assess the in situ anaerobic attenuation of hydrocarbons in a contaminated aquifer underlying a former refinery. Benzene, ethylbenzene, 2‐methylnaphthalene, 1,2,4‐ and 1,3,5‐trimethylbenzene were targeted as contaminants of greatest regulatory concern (COC) whose intrinsic remediation has been previously reported. Metabolite profiles associated with anaerobic hydrocarbon decay revealed the microbial utilization of alkylbenzenes, including the trimethylbenzene COC, PAHs and several n‐alkanes in the contaminated portions of the aquifer. Anaerobic biodegradation experiments designed to mimic in situ conditions showed no loss of exogenously amended COC; however, a substantive rate of endogenous electron acceptor reduction was measured (55 ± 8 µM SO4 day−1). An assessment of hydrocarbon loss in laboratory experiments relative to a conserved internal marker revealed that non‐COC hydrocarbons were being metabolized. Purge and trap analysis of laboratory assays showed a substantial loss of toluene, m‐ and o‐xylene, as well as several alkanes (C6–C12). Multiple lines of evidence suggest that benzene is persistent under the prevailing site anaerobic conditions. We could find no in situ benzene intermediates (phenol or benzoate), the parent molecule proved recalcitrant in laboratory assays and low copy numbers of Desulfobacterium were found, a genus previously implicated in anaerobic benzene biodegradation. This study also showed that there was a reasonable correlation between field and laboratory findings, although with notable exception. Thus, while the intrinsic anaerobic bioremediation was clearly evident at the site, non‐COC hydrocarbons were preferentially metabolized, even though there was ample literature precedence for the biodegradation of the target molecules. PMID:21261914

  4. Hydrocarbon adsorption in an aqueous environment: A computational study of alkyls on Cu(111)

    Science.gov (United States)

    Montemore, Matthew M.; Andreussi, Oliviero; Medlin, J. Will

    2016-08-01

    Hydrocarbon chains are important intermediates in various aqueous-phase surface processes, such as CO2 electroreduction, aqueous Fischer-Tropsch synthesis, and aqueous phase reforming of biomass-derived molecules. Further, the interaction between water and adsorbed hydrocarbons represents a difficult case for modern computational methods. Here, we explore various methods for calculating the energetics of this interaction within the framework of density functional theory and explore trade-offs between the use of low water coverages, molecular dynamics approaches, and minima hopping for identification of low energy structures. An effective methodology for simulating low temperature processes is provided by using a unit cell in which the vacuum space is filled with water, employing the minima hopping algorithm to search for low-lying minima, and including dispersion (van der Waals) interactions. Using this methodology, we show that a high coverage of adsorbed alkyls is destabilized by the presence of water, while a low coverage of alkyls is stabilized. Solvation has a small effect on the energetics of hydrocarbon chain growth, generally decreasing its favorability at low temperatures. We studied higher temperatures by running molecular dynamics simulations starting at the minima found by the minima hopping algorithm and found that increased temperatures facilitate chain growth. The self-consistent continuum solvation method effectively describes the alkyl-water interaction and is in general agreement with the explicit solvation results in most cases, but care should be taken at high alkyl coverage.

  5. Isolation and determination of absolute configurations of insect-produced methyl-branched hydrocarbons.

    Science.gov (United States)

    Bello, Jan E; McElfresh, J Steven; Millar, Jocelyn G

    2015-01-27

    Although the effects of stereochemistry have been studied extensively for volatile insect pheromones, little is known about the effects of chirality in the nonvolatile methyl-branched hydrocarbons (MBCHs) used by many insects as contact pheromones. MBCHs generally contain one or more chiral centers and so two or more stereoisomeric forms are possible for each structure. However, it is not known whether insects biosynthesize these molecules in high stereoisomeric purity, nor is it known whether insects can distinguish the different stereoisomeric forms of MBCHs. This knowledge gap is due in part to the lack of methods for isolating individual MBCHs from the complex cuticular hydrocarbon (CHC) blends of insects, as well as the difficulty in determining the absolute configurations of the isolated MBCHs. To address these deficiencies, we report a straightforward method for the isolation of individual cuticular hydrocarbons from the complex CHC blend. The method was used to isolate 36 pure MBCHs from 20 species in nine insect orders. The absolute stereochemistries of the purified MBCHs then were determined by digital polarimetry. The absolute configurations of all of the isolated MBCHs were determined to be (R) by comparison with a library of synthesized, enantiomerically pure standards, suggesting that the biosynthetic pathways used to construct MBCHs are highly conserved within the Insecta. The development of a straightforward method for isolation of specific CHCs will enable determination of their functional roles by providing pure compounds for bioassays.

  6. Length dependence of the thermal conductance of alkane-based single-molecule junctions: An ab initio study

    Science.gov (United States)

    Klöckner, J. C.; Bürkle, M.; Cuevas, J. C.; Pauly, F.

    2016-11-01

    Motivated by recent experiments, we present here a systematic ab initio study of the length dependence of the thermal conductance of single-molecule junctions. We make use of a combination of density functional theory with nonequilibrium Green's function techniques to investigate the length dependence of the phonon transport in single-alkane chains, contacted with gold electrodes via both thiol and amine anchoring groups. Additionally, we study the effect of the substitution of the hydrogen atoms in the alkane chains by heavier fluorine atoms to form polytetrafluoroethylenes. Our results demonstrate that (i) the room-temperature thermal conductance is fairly length independent for chains with more than 5 methylene units and (ii) the efficiency of the thermal transport is strongly influenced by the strength of the phononic metal-molecule coupling. Our study sheds light on the phonon transport in molecular junctions, and it provides clear guidelines for the design of molecular junctions for thermal management.

  7. National Gas Survey. Synthesized gaseous hydrocarbon fuels

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    The supply-Technical Advisory Task Force-Synthesized Gaseous Hydrocarbon Fuels considered coal, hydrocarbon liquids, oil shales, tar sands, and bioconvertible materials as potential feedstocks for gaseous fuels. Current status of process technology for each feedstock was reviewed, economic evaluations including sensitivity analysis were made, and constraints for establishment of a synthesized gaseous hydrocarbon fuels industry considered. Process technology is presently available to manufacture gaseous hydrocarbon fuels from each of the feedstocks. In 1975 there were eleven liquid feedstock SNG plants in the United States having a capacity of 1.1 billion SCFD. There can be no contribution of SNG before 1982 from plants using feedstocks other than liquids because there are no plants in operation or under construction as of 1977. Costs for SNG are higher than current regulated prices for U.S. natural gas. Because of large reserves, coal is a prime feedstock candidate although there are major constraints in the area of coal leases, mining and water permits, and others. Commercial technology is available and several new gasification processes are under development. Oil shale is also a feedstock in large supply and commercial process technology is available. There are siting and permit constraints, and water availability may limit the ultimate size of an oil shale processing industry. Under projected conditions, bioconvertible materials are not expected to support the production of large quantities of pipeline quality gas during the next decade. Production of low or medium Btu gas from municipal solid wastes can be expected to be developed in urban areas in conjunction with savings in disposal costs. In the economic evaluations presented, the most significant factor for liquid feedstock plants is the anticipated cost of feedstock and fuel. The economic viability of plants using other feedstocks is primarily dependent upon capital requirements.

  8. Hydrochloric acid recycling from chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Sowieja, D. [Sulzer Escher Wyss GmbH, Ravensburg (Germany); Schaub, M. [Sulzer Chemtech Ltd., Winterthur (Switzerland)

    1993-12-31

    Chlorinated hydrocarbons present a major ecological hazard since most of them are only poorly biodegradable. Incineration is an economical process for their destruction, however the usually recovered sodium or calcium chlorides do not present a value and their disposal may even be very costly. Recovery of hydrochloric acid may therefore present an economical solution, mainly were large quantities of highly chlorinated compounds can be processed (author) 6 refs., 4 figs., 1 tab.

  9. Methane conversion to hydrocarbons by double discharge

    Directory of Open Access Journals (Sweden)

    A. M. Ghorbanzadeh

    2004-12-01

    Full Text Available   Methane conversion to higher hydrocarbons by pulsed glow discharge at the atmospheric pressure was investigated. The energy efficiency up to 10 % was obtained which is higher than any value ever published for nonequilibrium plasma conversion of pure methame. This method has a potential for development and it is expected that the energy efficiency will be improved further if the plasma parameters are optimized.

  10. Geophysical monitoring in a hydrocarbon reservoir

    Science.gov (United States)

    Caffagni, Enrico; Bokelmann, Goetz

    2016-04-01

    Extraction of hydrocarbons from reservoirs demands ever-increasing technological effort, and there is need for geophysical monitoring to better understand phenomena occurring within the reservoir. Significant deformation processes happen when man-made stimulation is performed, in combination with effects deriving from the existing natural conditions such as stress regime in situ or pre-existing fracturing. Keeping track of such changes in the reservoir is important, on one hand for improving recovery of hydrocarbons, and on the other hand to assure a safe and proper mode of operation. Monitoring becomes particularly important when hydraulic-fracturing (HF) is used, especially in the form of the much-discussed "fracking". HF is a sophisticated technique that is widely applied in low-porosity geological formations to enhance the production of natural hydrocarbons. In principle, similar HF techniques have been applied in Europe for a long time in conventional reservoirs, and they will probably be intensified in the near future; this suggests an increasing demand in technological development, also for updating and adapting the existing monitoring techniques in applied geophysics. We review currently available geophysical techniques for reservoir monitoring, which appear in the different fields of analysis in reservoirs. First, the properties of the hydrocarbon reservoir are identified; here we consider geophysical monitoring exclusively. The second step is to define the quantities that can be monitored, associated to the properties. We then describe the geophysical monitoring techniques including the oldest ones, namely those in practical usage from 40-50 years ago, and the most recent developments in technology, within distinct groups, according to the application field of analysis in reservoir. This work is performed as part of the FracRisk consortium (www.fracrisk.eu); this project, funded by the Horizon2020 research programme, aims at helping minimize the

  11. Terpene hydrocarbons in Pimpinella anisum L.

    Science.gov (United States)

    Burkhardt, G; Reichling, J; Martin, R; Becker, H

    1986-06-20

    The essential oil of anise (fruits and shoots) was investigated focusing on the composition of the hydrocarbon fraction. Several sesquiterpenes were identified by GC-MS and the relative composition of the fractions was established by GC analysis. gamma-Himachalene and the diterpene neophytadiene were isolated by TLC and column chromatography at low temperatures. Their structures were determined by MS and NMR including 1H-1H correlated COSY and NOE experiments.

  12. Supercritical Hydrocarbon Impinging Injector Simulation Facility

    Science.gov (United States)

    2006-04-01

    PC Beowulf cluster that was purchased under a previous AFOSR Grant (F49620-01-1-0432) managed by Dr. Mitat Birkan. The cluster consists of 22 Intel...computing cluster allows simulations to be conducted in a sufficiently short time period to allow investigation of the effects of operating conditions...hydrocarbon propellants are of interest to the next generation of liquid propellant rocket engines. The procured high performance computing cluster allows

  13. Gaseous Hydrocarbon Separations Using Functionalized Ionic Liquids

    OpenAIRE

    2016-01-01

    The functionalization of the side chains on the cation or the anion of an ionic liquid is a common approach to tailor its properties for different processes including the separation of gases. In this paper, we present the current state of the art concerning the usage of ionic liquids for hydrocarbon separations. We also show how the functionalization of ionic liquids or the appropriate anion/cation combinations can contribute to the increase of the performance of the ionic liquids for the sep...

  14. NEW TRENDS IN ARYL HYDROCARBON RECEPTOR BIOLOGY

    OpenAIRE

    Fernández-Salguero, Pedro M.; Sonia eMulero-Navarro

    2016-01-01

    Traditionally considered as a critical intermediate in the toxic and carcinogenic response to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD), the Aryl hydrocarbon/Dioxin receptor (AhR) has proven to be also an important regulator of cell physiology and organ homeostasis. AhR has become an interesting and actual area of research mainly boosted by a significant number of recent studies analyzing its contribution to the proper functioning of the immune, hepatic, cardiovascular, vascular and ...

  15. New Trends in Aryl Hydrocarbon Receptor Biology

    OpenAIRE

    Mulero-navarro, Sonia; Fernandez-Salguero, Pedro M.

    2016-01-01

    Traditionally considered as a critical intermediate in the toxic and carcinogenic response to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD), the Aryl hydrocarbon/Dioxin receptor (AhR) has proven to be also an important regulator of cell physiology and organ homeostasis. AhR has become an interesting and actual area of research mainly boosted by a significant number of recent studies analyzing its contribution to the proper functioning of the immune, hepatic, cardiovascular, vascular and ...

  16. Dissociation of polycyclic aromatic hydrocarbons: molecular dynamics studies

    Science.gov (United States)

    Simon, A.; Rapacioli, M.; Rouaut, G.; Trinquier, G.; Gadéa, F. X.

    2017-03-01

    We present dynamical studies of the dissociation of polycyclic aromatic hydrocarbon (PAH) radical cations in their ground electronic states with significant internal energy. Molecular dynamics simulations are performed, the electronic structure being described on-the-fly at the self-consistent-charge density functional-based tight binding (SCC-DFTB) level of theory. The SCC-DFTB approach is first benchmarked against DFT results. Extensive simulations are achieved for naphthalene , pyrene and coronene at several energies. Such studies enable one to derive significant trends on branching ratios, kinetics, structures and hints on the formation mechanism of the ejected neutral fragments. In particular, dependence of branching ratios on PAH size and energy were retrieved. The losses of H and C2H2 (recognized as the ethyne molecule) were identified as major dissociation channels. The H/C2H2 ratio was found to increase with PAH size and to decrease with energy. For , which is the most interesting PAH from the astrophysical point of view, the loss of H was found as the quasi-only channel for an internal energy of 30 eV. Overall, in line with experimental trends, decreasing the internal energy or increasing the PAH size will favour the hydrogen loss channels with respect to carbonaceous fragments. This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.

  17. Molecular Spectroscopy in Astrophysics: The Case of Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid; DeVincent, Donald L. (Technical Monitor)

    2000-01-01

    The role of molecular spectroscopy in astrophysics and astrochemistry is discussed in the context of the study of large, complex, carbon-bearing molecules, namely, Polycyclic Aromatic Hydrocarbons or PAHs. These molecular species are now thought to be widespread in the interstellar medium in their neutral and ionized forms. Identifying the carriers responsible for unidentified interstellar spectral bands will allow to derive important information on cosmic elemental abundances as well as information on the physical conditions (density, temperature) reigning in specific interstellar environments. These, in turn, are key elements for a correct understanding of the energetic mechanisms that govern the origin and the evolution of the interstellar medium. A multidisciplinary approach - combining astronomical observations with laboratory simulations and theoretical modeling - is required to address these complex issues. Laboratory spectra of several PAHs, isolated at low temperature in inert gas matrices or seeded in a supersonic jet expansion, are discussed here and compared to the astronomical spectra of reddened, early type, stars. The electronic spectroscopy of PAHs in the ultraviolet, visible, and near-infrared domains is reviewed and an assessment of the potential contribution of PAHs to the interstellar extinction in the ultraviolet and in the visible is discussed.

  18. Phytoremediation mechanisms for polycyclic aromatic hydrocarbons removing from contaminated soils

    Directory of Open Access Journals (Sweden)

    Alagić Slađana Č.

    2015-01-01

    Full Text Available Phytoremediation of polycyclic aromatic hydrocarbons (PAHs from soil aims to degrade them into less toxic/non toxic compounds and limit their further movement by sequestration and accumulation into the vacuoles. Lipophilic organic compounds such as PAHs are bound strongly to the epidermis of the root tissue and are rarely translocated within plant. There are no reports in the literature data of PAHs being completely mineralized by plants. There is little evidence to suggest that PAHs accumulate to significant degree in plants, but there still is a lot of evidences on the ability of various plant species (most often grasses and legumes, to degrade and dissipate these dangerous contaminants. The primary mechanism controlling the dissipation of PAHs is rhizosphere microbial degradation where microbes use PAHs molecules as carbon substrates for growth, which in final, leads to the breakdown or total mineralization of the contaminants. The process is usually augmented by the excretion of root exudates (e.g., sugars, alcohols, acids, enzymes, and the build-up of organic carbon in the soil, so the proper selection of particular plant species represents a critical management decision for PAHs phytoremediation. These facts favor the rhyzoremediation as the best solution for sites contaminated with PAHs.

  19. Chemical reaction and dust formation studies in laboratory hydrocarbon plasmas.

    Science.gov (United States)

    Hippler, Rainer; Majumdar, Abhijit; Thejaswini, H. C.

    Plasma chemical reaction studies with relevance to, e.g., Titan's atmosphere have been per-formed in various laboratory plasmas [1,2]. Chemical reactions in a dielectric barrier discharge at medium pressure of 250-300 mbar have been studied in CH4 /N2 and CH4 /Ar gas mixtures by means of mass spectrometry. The main reaction scheme is production of H2 by fragmenta-tion of CH4 , but also production of larger hydrocarbons like Cn Hm with n up to 10 including formation of different functional CN groups is observed. [1] A. Majumdar and R. Hippler, Development of dielectric barrier discharge plasma processing apparatus for mass spectrometry and thin film deposition, Rev. Sci. Instrum. 78, 075103 (2007) [2] H.T. Do, G. Thieme, M. Frühlich, H. Kersten, and R. Hippler, Ion Molecule and Dust Particle Formation in Ar/CH4 , Ar/C2 H2 and Ar/C3 H6 Radio-frequency Plasmas, Contrib. Plasma Phys. 45, No. 5-6, 378-384 (2005)

  20. Modeling Carbon and Hydrocarbon Molecular Structures in EZTB

    Science.gov (United States)

    Lee, Seungwon; vonAllmen, Paul

    2007-01-01

    A software module that models the electronic and mechanical aspects of hydrocarbon molecules and carbon molecular structures on the basis of first principles has been written for incorporation into, and execution within, the Easy (Modular) Tight-Binding (EZTB) software infrastructure, which is summarized briefly in the immediately preceding article. Of particular interest, this module can model carbon crystals and nanotubes characterized by various coordinates and containing defects, without need to adjust parameters of the physical model. The module has been used to study the changes in electronic properties of carbon nanotubes, caused by bending of the nanotubes, for potential utility as the basis of a nonvolatile, electriccharge- free memory devices. For example, in one application of the module, it was found that an initially 50-nmlong carbon, (10,10)-chirality nanotube, which is a metallic conductor when straight, becomes a semiconductor with an energy gap of .3 meV when bent to a lateral displacement of 4 nm at the middle.

  1. Micro-Kelvin cold molecules.

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, Kevin E.; Chandler, David W.

    2009-10-01

    We have developed a novel experimental technique for direct production of cold molecules using a combination of techniques from atomic optical and molecular physics and physical chemistry. The ability to produce samples of cold molecules has application in a broad spectrum of technical fields high-resolution spectroscopy, remote sensing, quantum computing, materials simulation, and understanding fundamental chemical dynamics. Researchers around the world are currently exploring many techniques for producing samples of cold molecules, but to-date these attempts have offered only limited success achieving milli-Kelvin temperatures with low densities. This Laboratory Directed Research and Development project is to develops a new experimental technique for producing micro-Kelvin temperature molecules via collisions with laser cooled samples of trapped atoms. The technique relies on near mass degenerate collisions between the molecule of interest and a laser cooled (micro-Kelvin) atom. A subset of collisions will transfer all (nearly all) of the kinetic energy from the 'hot' molecule, cooling the molecule at the expense of heating the atom. Further collisions with the remaining laser cooled atoms will thermally equilibrate the molecules to the micro-Kelvin temperature of the laser-cooled atoms.

  2. Theoretical Investigations Regarding Single Molecules

    DEFF Research Database (Denmark)

    Pedersen, Kim Georg Lind

    Neoclassical Valence Bond Theory, Quantum Transport, Quantum Interference, Kondo Effect, and Electron Pumping. Trap a single organic molecule between two electrodes and apply a bias voltage across this "molecular junction". When electrons pass through the molecule, the different electron paths can...

  3. Triatomic molecules laser-cooled

    Science.gov (United States)

    2017-06-01

    Molecules containing three atoms have been laser-cooled to ultracold temperatures for the first time. John Doyle and colleagues at Harvard University in the US used a technique called Sisyphus cooling to chill an ensemble of about a million strontium-monohydroxide molecules to 750 μK.

  4. Statistical Method of Estimating Nigerian Hydrocarbon Reserves

    Directory of Open Access Journals (Sweden)

    Jeffrey O. Oseh

    2015-01-01

    Full Text Available Hydrocarbon reserves are basic to planning and investment decisions in Petroleum Industry. Therefore its proper estimation is of considerable importance in oil and gas production. The estimation of hydrocarbon reserves in the Niger Delta Region of Nigeria has been very popular, and very successful, in the Nigerian oil and gas industry for the past 50 years. In order to fully estimate the hydrocarbon potentials in Nigerian Niger Delta Region, a clear understanding of the reserve geology and production history should be acknowledged. Reserves estimation of most fields is often performed through Material Balance and Volumetric methods. Alternatively a simple Estimation Model and Least Squares Regression may be useful or appropriate. This model is based on extrapolation of additional reserve due to exploratory drilling trend and the additional reserve factor which is due to revision of the existing fields. This Estimation model used alongside with Linear Regression Analysis in this study gives improved estimates of the fields considered, hence can be used in other Nigerian Fields with recent production history

  5. 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.

  6. Bioremediation of Petroleum Hydrocarbons in Heterogeneous Soils

    Energy Technology Data Exchange (ETDEWEB)

    Song Jin; Paul Fallgren; Terry Brown

    2006-03-02

    Western Research Institute (WRI) in conjunction with the University of Wyoming, Department of Renewable Resources and the U.S. Department of Energy, under Task 35, conducted a laboratory-scale study of hydrocarbon biodegradation rates versus a variety of physical and chemical parameters to develop a base model. By using this model, biodegradation of Petroleum hydrocarbons in heterogeneous soils can be predicted. The base model, as developed in this study, have been tested by both field and laboratory data. Temperature, pH, and nutrients appear to be the key parameters that can be incorporate into the model to predict biodegradation rates. Results to date show the effect of soil texture and source on the role of each parameter in the rates of hydrocarbon biodegradation. Derived from the existing study, an alternative approach of using CO{sub 2} accumulation data has been attempted by our collaborators at the University of Wyoming. The model has been modified and fine tuned by incorporating these data to provide more information on biodegradation.

  7. Adsorption of hydrocarbons in chalk reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, L.

    1996-12-31

    The present work is a study on the wettability of hydrocarbon bearing chalk reservoirs. Wettability is a major factor that influences flow, location and distribution of oil and water in the reservoir. The wettability of the hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. Organic compounds such as carboxylic acids are found in formation waters from various hydrocarbon reservoirs and in crude oils. In the present investigation the wetting behaviour of chalk is studied by the adsorption of the carboxylic acids onto synthetic calcite, kaolinite, quartz, {alpha}-alumina, and chalk dispersed in an aqueous phase and an organic phase. In the aqueous phase the results clearly demonstrate the differences between the adsorption behaviour of benzoic acid and hexanoic acid onto the surfaces of oxide minerals and carbonates. With NaCl concentration of 0.1 M and with pH {approx_equal} 6 the maximum adsorption of benzoic acid decreases in the order: quartz, {alpha}-alumina, kaolinite. For synthetic calcite and chalk no detectable adsorption was obtaind. In the organic phase the order is reversed. The maximum adsorption of benzoic acid onto the different surfaces decreases in the order: synthetic calcite, chalk, kaolinite and quartz. Also a marked difference in adsorption behaviour between probes with different functional groups onto synthetic calcite from organic phase is observed. The maximum adsorption decreases in the order: benzoic acid, benzyl alcohol and benzylamine. (au) 54 refs.

  8. Biofiltration of gasoline and diesel aliphatic hydrocarbons.

    Science.gov (United States)

    Halecky, Martin; Rousova, Jana; Paca, Jan; Kozliak, Evguenii; Seames, Wayne; Jones, Kim

    2015-02-01

    The ability of a biofilm to switch between the mixtures of mostly aromatic and aliphatic hydrocarbons was investigated to assess biofiltration efficiency and potential substrate interactions. A switch from gasoline, which consisted of both aliphatic and aromatic hydrocarbons, to a mixture of volatile diesel n-alkanes resulted in a significant increase in biofiltration efficiency, despite the lack of readily biodegradable aromatic hydrocarbons in the diesel mixture. This improved biofilter performance was shown to be the result of the presence of larger size (C₉-C(12)) linear alkanes in diesel, which turned out to be more degradable than their shorter-chain (C₆-C₈) homologues in gasoline. The evidence obtained from both biofiltration-based and independent microbiological tests indicated that the rate was limited by biochemical reactions, with the inhibition of shorter chain alkane biodegradation by their larger size homologues as corroborated by a significant substrate specialization along the biofilter bed. These observations were explained by the lack of specific enzymes designed for the oxidation of short-chain alkanes as opposed to their longer carbon chain homologues.

  9. Initial microbial degradation of polycyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    Milić Jelena

    2016-01-01

    Full Text Available The group of polycyclic aromatic hydrocarbons (PAHs are very hazardous environmental pollutants because of their mutagenic, carcinogenic and toxic effects on living systems. The aim of this study was to examine and compare the ability and efficiency of selected bacterial isolates obtained from oil-contaminated areas to biodegrade PAHs. The potential of the bacteria to biodegrade various aromatic hydrocarbons was assessed using the 2,6-dichlorophenol-indophenol assay. Further biodegradation of PAHs was monitored by gravimetric and gas-chromatographic analysis. Among the eight bacterial isolates, identified on the basis of 16S rDNA sequences, two isolates, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, had the ability to grow on and utilize almost all examined hydrocarbons. Those isolates were further examined for biodegradation of phenanthrene and pyrene, as single substrates, and as a mixture, in vitro for ten days. After three days, both isolates degraded a significant amount phenanthrene, which has a simpler chemical structure than pyrene. Planomicrobium sp.RNP01 commenced biodegradation of pyrene in the PAH mixture only after it had almost completly degraded phenanthrene. The isolated and characterized bacteria, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, have shown high bioremediation potential and are likely candidates to be used for degradation of highly toxic PAHs in contaminated areas. [Projekat Ministarstva nauke Republike Srbije, br. III43004

  10. Light color, low softening point hydrocarbon resins

    Energy Technology Data Exchange (ETDEWEB)

    Evans, M.L.; Hentges, S.G.

    1990-06-12

    This patent describes a hydrocarbon resin having a softening point of from 0{degrees} C to about 40{degrees} C, a Gardner color of about 7 or less, a number average molecular weight (Mn) of from about 100 to about 600, and a M{sub {ital w}}/M{sub {ital n}} ratio of from about 1.1 to about 2.7, prepared by Friedel Crafts polymerization of a hydrocarbon feed. It comprises: from about 5% to about 75% by weight of a C{sub 8} to C{sub 10} vinyl aromatic hydrocarbon stream; up to about 35% by weight of a piperylene stream; and from about 25% to about 70% by weight of a stream containing C{sub 4} to C{sub 8} monoolefin chain transfer agent of the formula RR{prime}C {double bond} CR{double prime}R triple{prime} where R and R{prime} are C{sub 1} to C{sub 5} alkyl, R{double prime} and R triple{prime} are independently selected from H and a C{sub 1} to C{sub 4} alkyl group.

  11. Gaseous Hydrocarbon Separations Using Functionalized Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Moura Leila

    2016-03-01

    Full Text Available The functionalization of the side chains on the cation or the anion of an ionic liquid is a common approach to tailor its properties for different processes including the separation of gases. In this paper, we present the current state of the art concerning the usage of ionic liquids for hydrocarbon separations. We also show how the functionalization of ionic liquids or the appropriate anion/cation combinations can contribute to the increase of the performance of the ionic liquids for the separation of gaseous hydrocarbons – either by improving the capacity of the ionic liquid to absorb a given gas or by increasing the selectivity towards a particular hydrocarbon. Original results concerning the usage of olefin-complexing metal salts of lithium (I, nickel (II and copper (II dissolved in ionic liquids for selectively absorbing light olefins are presented. It is observed that the absorption capacity of an imidazolium-based ionic liquid is doubled by the addition of a copper (II salt. This result is compared with the effect of the functionalization of the ionic liquid and the advantages and difficulties of the two approaches are analyzed.

  12. Thermal Adsorption Processing Of Hydrocarbon Residues

    Directory of Open Access Journals (Sweden)

    Sudad H. Al.

    2015-08-01

    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.

  13. An apparatus for vapor conversion of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, K.; Matsumoto, I.

    1983-03-23

    The installation for vapor conversion of hydrocarbons (Uv) with the formation of a mixture of H2 and C02 is a catalyst chamber (KK) filled with longitudinally disposed thin pipes (with thin walls) or with pipe units made of dolomite, MgO or potassium aluminate. These pipes have a multilayered coating (Pk) on their internal and external surfaces (Pv), which contain catalytically active components. Such pipes or pipe units form a honeycombed structure with through longitudinal channels. The catalyst chamber itself is made of a ceramic material and has a heating winding outside for heating the catalyst. To save fuel and to increase the efficiency (KPD) of the heating device, the catalyst chamber is in turn enclosed by two additional shells filled with heat conducting packings which are easily penetrated by the gases being processed. The hydrocarbon vapors or gaseous fuel from the natural gas or methane and the steam are fed through the above cited heat exchange layers with packings into the facial part of the catalytic chamber, in which the conversion of the hydrocarbons occurs with the production of H2 and C02. From the catalyzer layer the mixture of gases and steam goes through a refrigerator into a trap for the steam excess and when it is necessary, into a C02 absorber and then, pure H2 is discharged from the latter. Such a catalytic installation is convenient to use for producing pure H2 from natural gas, methane, propane or kerosene.

  14. Contribution of cyanobacterial alkane production to the ocean hydrocarbon cycle.

    Science.gov (United States)

    Lea-Smith, David J; Biller, Steven J; Davey, Matthew P; Cotton, Charles A R; Perez Sepulveda, Blanca M; Turchyn, Alexandra V; Scanlan, David J; Smith, Alison G; Chisholm, Sallie W; Howe, Christopher J

    2015-11-03

    Hydrocarbons are ubiquitous in the ocean, where alkanes such as pentadecane and heptadecane can be found even in waters minimally polluted with crude oil. Populations of hydrocarbon-degrading bacteria, which are responsible for the turnover of these compounds, are also found throughout marine systems, including in unpolluted waters. These observations suggest the existence of an unknown and widespread source of hydrocarbons in the oceans. Here, we report that strains of the two most abundant marine cyanobacteria, Prochlorococcus and Synechococcus, produce and accumulate hydrocarbons, predominantly C15 and C17 alkanes, between 0.022 and 0.368% of dry cell weight. Based on global population sizes and turnover rates, we estimate that these species have the capacity to produce 2-540 pg alkanes per mL per day, which translates into a global ocean yield of ∼ 308-771 million tons of hydrocarbons annually. We also demonstrate that both obligate and facultative marine hydrocarbon-degrading bacteria can consume cyanobacterial alkanes, which likely prevents these hydrocarbons from accumulating in the environment. Our findings implicate cyanobacteria and hydrocarbon degraders as key players in a notable internal hydrocarbon cycle within the upper ocean, where alkanes are continually produced and subsequently consumed within days. Furthermore we show that cyanobacterial alkane production is likely sufficient to sustain populations of hydrocarbon-degrading bacteria, whose abundances can rapidly expand upon localized release of crude oil from natural seepage and human activities.

  15. Biodegradation and bioremediation of hydrocarbons in extreme environments.

    Science.gov (United States)

    Margesin, R; Schinner, F

    2001-09-01

    Many hydrocarbon-contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, high salt concentrations, or high pressure, Hydrocarbon-degrading microorganisms, adapted to grow and thrive in these environments, play an important role in the biological treatment of polluted extreme habitats. The biodegradation (transformation or mineralization) of a wide range of hydrocarbons, including aliphatic, aromatic, halogenated and nitrated compounds, has been shown to occur in various extreme habitats. The biodegradation of many components of petroleum hydrocarbons has been reported in a variety of terrestrial and marine cold ecosystems. Cold-adapted hydrocarbon degraders are also useful for wastewater treatment. The use of thermophiles for biodegradation of hydrocarbons with low water solubility is of interest, as solubility and thus bioavailability, are enhanced at elevated temperatures. Thermophiles, predominantly bacilli, possess a substantial potential for the degradation of environmental pollutants, including all major classes. Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-polluted desert soil. Some studies have investigated composting as a bioremediation process. Hydrocarbon biodegradation in the presence of high salt concentrations is of interest for the bioremediation of oil-polluted salt marshes and industrial wastewaters, contaminated with aromatic hydrocarbons or with chlorinated hydrocarbons. Our knowledge of the biodegradation potential of acidophilic, alkaliphilic, or barophilic microorganisms is limited.

  16. Assessing impediments to hydrocarbon biodegradation in weathered contaminated soils.

    Science.gov (United States)

    Adetutu, Eric; Weber, John; Aleer, Sam; Dandie, Catherine E; Aburto-Medina, Arturo; Ball, Andrew S; Juhasz, Albert L

    2013-10-15

    In this study, impediments to hydrocarbon biodegradation in contaminated soils were assessed using chemical and molecular methodologies. Two long-term hydrocarbon contaminated soils were utilised which were similar in physico-chemical properties but differed in the extent of hydrocarbon (C10-C40) contamination (S1: 16.5 g kg(-1); S2: 68.9 g kg(-1)). Under enhanced natural attenuation (ENA) conditions, hydrocarbon biodegradation was observed in S1 microcosms (26.4% reduction in C10-C40 hydrocarbons), however, ENA was unable to stimulate degradation in S2. Although eubacterial communities (PCR-DGGE analysis) were similar for both soils, the alkB bacterial community was less diverse in S2 presumably due to impacts associated with elevated hydrocarbons. When hydrocarbon bioaccessibility was assessed using HP-β-CD extraction, large residual concentrations remained in the soil following the extraction procedure. However, when linear regression models were used to predict the endpoints of hydrocarbon degradation, there was no significant difference (P>0.05) between HP-β-CD predicted and microcosm measured biodegradation endpoints. This data suggested that the lack of hydrocarbon degradation in S2 resulted primarily from limited hydrocarbon bioavailability. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Biodegradation and bioremediation of hydrocarbons in extreme environments

    Energy Technology Data Exchange (ETDEWEB)

    Margesin, R.; Schinner, F. [Innsbruck Univ. (Austria). Inst. fuer Mikrobiologie

    2001-07-01

    Many hydrocarbon-contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, high salt concentrations, or high pressure. Hydrocarbon-degrading microorganisms, adapted to grow and thrive in these environments, play an important role in the biological treatment of polluted extreme habitats. The biodegradation (transformation or mineralization) of a wide range of hydrocarbons, including aliphatic, aromatic, halogenated and nitrated compounds, has been shown to occur in various extreme habitats. The biodegradation of many components of petroleum hydrocarbons has been reported in a variety of terrestrial and marine cold ecosystems. Cold-adapted hydrocarbon degraders are also useful for wastewater treatment. The use of thermophiles for biodegradation of hydrocarbons with low water solubility is of interest, as solubility and thus bioavailability, are enhanced at elevated temperatures. Thermophiles, predominantly bacilli, possess a substantial potential for the degradation of environmental pollutants, including all major classes. Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-polluted desert soil. Some studies have investigated composting as a bioremediation process. Hydrocarbon biodegradation in the presence of high salt concentrations is of interest for the bioremediation of oil-polluted salt marshes and industrial wastewaters, contaminated with aromatic hydrocarbons or with chlorinated hydrocarbons. Our knowledge of the biodegradation potential of acidophilic, alkaliphilic, or barophilic microorganisms is limited. (orig.)

  18. Enzyme molecules in solitary confinement.

    Science.gov (United States)

    Liebherr, Raphaela B; Gorris, Hans H

    2014-09-12

    Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.

  19. Enzyme Molecules in Solitary Confinement

    Directory of Open Access Journals (Sweden)

    Raphaela B. Liebherr

    2014-09-01

    Full Text Available Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.

  20. High-resolution IR absorption spectroscopy of polycyclic aromatic hydrocarbons: the realm of anharmonicity

    CERN Document Server

    Maltseva, Elena; Candian, Alessandra; Mackie, Cameron J; Huang, Xinchuan; Lee, Timothy J; Tielens, Alexander G G M; Oomens, Jos; Buma, Wybren Jan

    2015-01-01

    We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3 micron CH stretching region of Polycyclic Aromatic Hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold (~4K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions enhanced with a Fermi-resonance treatment that utilises intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination ...